Crash in cpuidle lp2 suspend on Ouya #2
Comments
|
Hello, @Decatf! That's an interesting observation. At quick glance your change matches more closely to what downstream kernel does, seems the exact match will be to invoke the firmware call after L2 cache disabling. I'll check how the change works on Nexus 7 and incorporate it into the patch if everything will be fine. BTW, this is a good timing to fix the last firmware itches as I was going to send out the latest version of TF-support patches to upstream around Monday. Hopefully we'll manage to upstream them this time with some help from @thierryreding. |
|
I thought it made sense to run the cache operations just before disabling it. I've tested the firmware op after Rather than creating another github issue. There is an bug with the cpufreq patches. cpufreq can work on Ouya but it needs to skip the regulator enable. The Ouya regulators are on at boot and always on. The cpufreq patch always calls regulator enable during probe which makes the device lock up. It works fine when |
|
Thanks for the testing! The TF firmware is quite finicky to HW state at the time of SMC invocation, it took me some time to figure out that it doesn't like when L2 is disabled with MMU off. Ideally firmware should be agnostic to the CPU state (especially if it's about security), but nothing is ideal in this world :) Regulator enabling shall be a NO-OP if regulator is always-on because regulator core enables regulator at the registration time. It's either regulator-core or regulator's driver bug. You could try to add some debug messages to the core and drivers to narrow down the offending code. |
|
@Decatf, the TF change you suggested works fine on Nexus7, the relevant patch was updated and pushed out already to grate's kernel. I'll send out patches to upstream ML shortly and will add you to the CC list, please try out the updated version of the patches and don't shy to reply with yours Tested-by if everything will work fine for the Ouya. Also, I noticed that Nexus 7 now hangs quite easily on suspend and seems changing the CPU's suspend-freq to a 1GHz (in device tree) helps by raising the suspend-resume voltage. I'm not sure whether anything changed in kernel or I changed something in the cpufreq driver and forgot already... just keep that in mind if you'll experience some odd hangs on suspend. |
digetx
pushed a commit
that referenced
this issue
Mar 6, 2019
Kmemleak throws endless warnings during boot due to in __alloc_alien_cache(), alc = kmalloc_node(memsize, gfp, node); init_arraycache(&alc->ac, entries, batch); kmemleak_no_scan(ac); Kmemleak does not track the array cache (alc->ac) but the alien cache (alc) instead, so let it track the later by lifting kmemleak_no_scan() out of init_arraycache(). There is another place that calls init_arraycache(), but alloc_kmem_cache_cpus() uses the percpu allocation where will never be considered as a leak. [ 32.258841] kmemleak: Found object by alias at 0xffff8007b9aa7e38 [ 32.258847] CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2 [ 32.258851] Call trace: [ 32.258858] dump_backtrace+0x0/0x168 [ 32.258863] show_stack+0x24/0x30 [ 32.258868] dump_stack+0x88/0xb0 [ 32.258873] lookup_object+0x84/0xac [ 32.258877] find_and_get_object+0x84/0xe4 [ 32.258882] kmemleak_no_scan+0x74/0xf4 [ 32.258887] setup_kmem_cache_node+0x2b4/0x35c [ 32.258892] __do_tune_cpucache+0x250/0x2d4 [ 32.258896] do_tune_cpucache+0x4c/0xe4 [ 32.258901] enable_cpucache+0xc8/0x110 [ 32.258905] setup_cpu_cache+0x40/0x1b8 [ 32.258909] __kmem_cache_create+0x240/0x358 [ 32.258913] create_cache+0xc0/0x198 [ 32.258918] kmem_cache_create_usercopy+0x158/0x20c [ 32.258922] kmem_cache_create+0x50/0x64 [ 32.258928] fsnotify_init+0x58/0x6c [ 32.258932] do_one_initcall+0x194/0x388 [ 32.258937] kernel_init_freeable+0x668/0x688 [ 32.258941] kernel_init+0x18/0x124 [ 32.258946] ret_from_fork+0x10/0x18 [ 32.258950] kmemleak: Object 0xffff8007b9aa7e00 (size 256): [ 32.258954] kmemleak: comm "swapper/0", pid 1, jiffies 4294697137 [ 32.258958] kmemleak: min_count = 1 [ 32.258962] kmemleak: count = 0 [ 32.258965] kmemleak: flags = 0x1 [ 32.258969] kmemleak: checksum = 0 [ 32.258972] kmemleak: backtrace: [ 32.258977] kmemleak_alloc+0x84/0xb8 [ 32.258982] kmem_cache_alloc_node_trace+0x31c/0x3a0 [ 32.258987] __kmalloc_node+0x58/0x78 [ 32.258991] setup_kmem_cache_node+0x26c/0x35c [ 32.258996] __do_tune_cpucache+0x250/0x2d4 [ 32.259001] do_tune_cpucache+0x4c/0xe4 [ 32.259005] enable_cpucache+0xc8/0x110 [ 32.259010] setup_cpu_cache+0x40/0x1b8 [ 32.259014] __kmem_cache_create+0x240/0x358 [ 32.259018] create_cache+0xc0/0x198 [ 32.259022] kmem_cache_create_usercopy+0x158/0x20c [ 32.259026] kmem_cache_create+0x50/0x64 [ 32.259031] fsnotify_init+0x58/0x6c [ 32.259035] do_one_initcall+0x194/0x388 [ 32.259039] kernel_init_freeable+0x668/0x688 [ 32.259043] kernel_init+0x18/0x124 [ 32.259048] kmemleak: Not scanning unknown object at 0xffff8007b9aa7e38 [ 32.259052] CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2 [ 32.259056] Call trace: [ 32.259060] dump_backtrace+0x0/0x168 [ 32.259065] show_stack+0x24/0x30 [ 32.259070] dump_stack+0x88/0xb0 [ 32.259074] kmemleak_no_scan+0x90/0xf4 [ 32.259078] setup_kmem_cache_node+0x2b4/0x35c [ 32.259083] __do_tune_cpucache+0x250/0x2d4 [ 32.259088] do_tune_cpucache+0x4c/0xe4 [ 32.259092] enable_cpucache+0xc8/0x110 [ 32.259096] setup_cpu_cache+0x40/0x1b8 [ 32.259100] __kmem_cache_create+0x240/0x358 [ 32.259104] create_cache+0xc0/0x198 [ 32.259108] kmem_cache_create_usercopy+0x158/0x20c [ 32.259112] kmem_cache_create+0x50/0x64 [ 32.259116] fsnotify_init+0x58/0x6c [ 32.259120] do_one_initcall+0x194/0x388 [ 32.259125] kernel_init_freeable+0x668/0x688 [ 32.259129] kernel_init+0x18/0x124 [ 32.259133] ret_from_fork+0x10/0x18 Link: http://lkml.kernel.org/r/[email protected] Fixes: 1fe00d5 ("slab: factor out initialization of array cache") Signed-off-by: Qian Cai <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Catalin Marinas <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
digetx
pushed a commit
that referenced
this issue
Mar 15, 2019
Kmemleak throws endless warnings during boot due to in __alloc_alien_cache(), alc = kmalloc_node(memsize, gfp, node); init_arraycache(&alc->ac, entries, batch); kmemleak_no_scan(ac); Kmemleak does not track the array cache (alc->ac) but the alien cache (alc) instead, so let it track the latter by lifting kmemleak_no_scan() out of init_arraycache(). There is another place that calls init_arraycache(), but alloc_kmem_cache_cpus() uses the percpu allocation where will never be considered as a leak. [ 32.258841] kmemleak: Found object by alias at 0xffff8007b9aa7e38 [ 32.258847] CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2 [ 32.258851] Call trace: [ 32.258858] dump_backtrace+0x0/0x168 [ 32.258863] show_stack+0x24/0x30 [ 32.258868] dump_stack+0x88/0xb0 [ 32.258873] lookup_object+0x84/0xac [ 32.258877] find_and_get_object+0x84/0xe4 [ 32.258882] kmemleak_no_scan+0x74/0xf4 [ 32.258887] setup_kmem_cache_node+0x2b4/0x35c [ 32.258892] __do_tune_cpucache+0x250/0x2d4 [ 32.258896] do_tune_cpucache+0x4c/0xe4 [ 32.258901] enable_cpucache+0xc8/0x110 [ 32.258905] setup_cpu_cache+0x40/0x1b8 [ 32.258909] __kmem_cache_create+0x240/0x358 [ 32.258913] create_cache+0xc0/0x198 [ 32.258918] kmem_cache_create_usercopy+0x158/0x20c [ 32.258922] kmem_cache_create+0x50/0x64 [ 32.258928] fsnotify_init+0x58/0x6c [ 32.258932] do_one_initcall+0x194/0x388 [ 32.258937] kernel_init_freeable+0x668/0x688 [ 32.258941] kernel_init+0x18/0x124 [ 32.258946] ret_from_fork+0x10/0x18 [ 32.258950] kmemleak: Object 0xffff8007b9aa7e00 (size 256): [ 32.258954] kmemleak: comm "swapper/0", pid 1, jiffies 4294697137 [ 32.258958] kmemleak: min_count = 1 [ 32.258962] kmemleak: count = 0 [ 32.258965] kmemleak: flags = 0x1 [ 32.258969] kmemleak: checksum = 0 [ 32.258972] kmemleak: backtrace: [ 32.258977] kmemleak_alloc+0x84/0xb8 [ 32.258982] kmem_cache_alloc_node_trace+0x31c/0x3a0 [ 32.258987] __kmalloc_node+0x58/0x78 [ 32.258991] setup_kmem_cache_node+0x26c/0x35c [ 32.258996] __do_tune_cpucache+0x250/0x2d4 [ 32.259001] do_tune_cpucache+0x4c/0xe4 [ 32.259005] enable_cpucache+0xc8/0x110 [ 32.259010] setup_cpu_cache+0x40/0x1b8 [ 32.259014] __kmem_cache_create+0x240/0x358 [ 32.259018] create_cache+0xc0/0x198 [ 32.259022] kmem_cache_create_usercopy+0x158/0x20c [ 32.259026] kmem_cache_create+0x50/0x64 [ 32.259031] fsnotify_init+0x58/0x6c [ 32.259035] do_one_initcall+0x194/0x388 [ 32.259039] kernel_init_freeable+0x668/0x688 [ 32.259043] kernel_init+0x18/0x124 [ 32.259048] kmemleak: Not scanning unknown object at 0xffff8007b9aa7e38 [ 32.259052] CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2 [ 32.259056] Call trace: [ 32.259060] dump_backtrace+0x0/0x168 [ 32.259065] show_stack+0x24/0x30 [ 32.259070] dump_stack+0x88/0xb0 [ 32.259074] kmemleak_no_scan+0x90/0xf4 [ 32.259078] setup_kmem_cache_node+0x2b4/0x35c [ 32.259083] __do_tune_cpucache+0x250/0x2d4 [ 32.259088] do_tune_cpucache+0x4c/0xe4 [ 32.259092] enable_cpucache+0xc8/0x110 [ 32.259096] setup_cpu_cache+0x40/0x1b8 [ 32.259100] __kmem_cache_create+0x240/0x358 [ 32.259104] create_cache+0xc0/0x198 [ 32.259108] kmem_cache_create_usercopy+0x158/0x20c [ 32.259112] kmem_cache_create+0x50/0x64 [ 32.259116] fsnotify_init+0x58/0x6c [ 32.259120] do_one_initcall+0x194/0x388 [ 32.259125] kernel_init_freeable+0x668/0x688 [ 32.259129] kernel_init+0x18/0x124 [ 32.259133] ret_from_fork+0x10/0x18 Link: http://lkml.kernel.org/r/[email protected] Fixes: 1fe00d5 ("slab: factor out initialization of array cache") Signed-off-by: Qian Cai <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Catalin Marinas <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
|
@Decatf have you resolved the regulator's bug? I removed the regulators enabling and made some other minor changes to the driver, let me know if it works for you. |
|
Turned out that the current kernel base has some bug in block subsystem and only works over NFS, I'll let you know once it is fixed. |
I think it might be stuck in a loop in the function https://github.com/grate-driver/linux/blob/bc6e8e4/drivers/regulator/core.c#L3606 The system locks up after that line. That was as far I have traced the bug. I have not tried to debug it much since. |
|
Oh, that's not good. Although I'm planning to extend the regulators API with a custom voltage balancer for Tegra soonish, hence bypassing that code. |
|
I was wrong. It isn't the regulator framework. The minimum core voltage has to be 1.1v otherwise the device hangs. The |
digetx
pushed a commit
that referenced
this issue
Apr 11, 2019
Extend test_btf with various positive and negative tests around BTF verification of kind Var and DataSec. All passing as well: # ./test_btf [...] BTF raw test[4] (global data test #1): OK BTF raw test[5] (global data test #2): OK BTF raw test[6] (global data test #3): OK BTF raw test[7] (global data test #4, unsupported linkage): OK BTF raw test[8] (global data test #5, invalid var type): OK BTF raw test[9] (global data test #6, invalid var type (fwd type)): OK BTF raw test[10] (global data test #7, invalid var type (fwd type)): OK BTF raw test[11] (global data test #8, invalid var size): OK BTF raw test[12] (global data test #9, invalid var size): OK BTF raw test[13] (global data test #10, invalid var size): OK BTF raw test[14] (global data test #11, multiple section members): OK BTF raw test[15] (global data test #12, invalid offset): OK BTF raw test[16] (global data test #13, invalid offset): OK BTF raw test[17] (global data test #14, invalid offset): OK BTF raw test[18] (global data test #15, not var kind): OK BTF raw test[19] (global data test #16, invalid var referencing sec): OK BTF raw test[20] (global data test #17, invalid var referencing var): OK BTF raw test[21] (global data test #18, invalid var loop): OK BTF raw test[22] (global data test #19, invalid var referencing var): OK BTF raw test[23] (global data test #20, invalid ptr referencing var): OK BTF raw test[24] (global data test #21, var included in struct): OK BTF raw test[25] (global data test #22, array of var): OK [...] PASS:167 SKIP:0 FAIL:0 Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]>
digetx
pushed a commit
that referenced
this issue
Apr 11, 2019
In some cases, ocfs2_iget() reads the data of inode, which has been deleted for some reason. That will make the system panic. So We should judge whether this inode has been deleted, and tell the caller that the inode is a bad inode. For example, the ocfs2 is used as the backed of nfs, and the client is nfsv3. This issue can be reproduced by the following steps. on the nfs server side, ..../patha/pathb Step 1: The process A was scheduled before calling the function fh_verify. Step 2: The process B is removing the 'pathb', and just completed the call to function dput. Then the dentry of 'pathb' has been deleted from the dcache, and all ancestors have been deleted also. The relationship of dentry and inode was deleted through the function hlist_del_init. The following is the call stack. dentry_iput->hlist_del_init(&dentry->d_u.d_alias) At this time, the inode is still in the dcache. Step 3: The process A call the function ocfs2_get_dentry, which get the inode from dcache. Then the refcount of inode is 1. The following is the call stack. nfsd3_proc_getacl->fh_verify->exportfs_decode_fh->fh_to_dentry(ocfs2_get_dentry) Step 4: Dirty pages are flushed by bdi threads. So the inode of 'patha' is evicted, and this directory was deleted. But the inode of 'pathb' can't be evicted, because the refcount of the inode was 1. Step 5: The process A keep running, and call the function reconnect_path(in exportfs_decode_fh), which call function ocfs2_get_parent of ocfs2. Get the block number of parent directory(patha) by the name of ... Then read the data from disk by the block number. But this inode has been deleted, so the system panic. Process A Process B 1. in nfsd3_proc_getacl | 2. | dput 3. fh_to_dentry(ocfs2_get_dentry) | 4. bdi flush dirty cache | 5. ocfs2_iget | [283465.542049] OCFS2: ERROR (device sdp): ocfs2_validate_inode_block: Invalid dinode #580640: OCFS2_VALID_FL not set [283465.545490] Kernel panic - not syncing: OCFS2: (device sdp): panic forced after error [283465.546889] CPU: 5 PID: 12416 Comm: nfsd Tainted: G W 4.1.12-124.18.6.el6uek.bug28762940v3.x86_64 #2 [283465.548382] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/21/2015 [283465.549657] 0000000000000000 ffff8800a56fb7b8 ffffffff816e839c ffffffffa0514758 [283465.550392] 000000000008dc20 ffff8800a56fb838 ffffffff816e62d3 0000000000000008 [283465.551056] ffff880000000010 ffff8800a56fb848 ffff8800a56fb7e8 ffff88005df9f000 [283465.551710] Call Trace: [283465.552516] [<ffffffff816e839c>] dump_stack+0x63/0x81 [283465.553291] [<ffffffff816e62d3>] panic+0xcb/0x21b [283465.554037] [<ffffffffa04e66b0>] ocfs2_handle_error+0xf0/0xf0 [ocfs2] [283465.554882] [<ffffffffa04e7737>] __ocfs2_error+0x67/0x70 [ocfs2] [283465.555768] [<ffffffffa049c0f9>] ocfs2_validate_inode_block+0x229/0x230 [ocfs2] [283465.556683] [<ffffffffa047bcbc>] ocfs2_read_blocks+0x46c/0x7b0 [ocfs2] [283465.557408] [<ffffffffa049bed0>] ? ocfs2_inode_cache_io_unlock+0x20/0x20 [ocfs2] [283465.557973] [<ffffffffa049f0eb>] ocfs2_read_inode_block_full+0x3b/0x60 [ocfs2] [283465.558525] [<ffffffffa049f5ba>] ocfs2_iget+0x4aa/0x880 [ocfs2] [283465.559082] [<ffffffffa049146e>] ocfs2_get_parent+0x9e/0x220 [ocfs2] [283465.559622] [<ffffffff81297c05>] reconnect_path+0xb5/0x300 [283465.560156] [<ffffffff81297f46>] exportfs_decode_fh+0xf6/0x2b0 [283465.560708] [<ffffffffa062faf0>] ? nfsd_proc_getattr+0xa0/0xa0 [nfsd] [283465.561262] [<ffffffff810a8196>] ? prepare_creds+0x26/0x110 [283465.561932] [<ffffffffa0630860>] fh_verify+0x350/0x660 [nfsd] [283465.562862] [<ffffffffa0637804>] ? nfsd_cache_lookup+0x44/0x630 [nfsd] [283465.563697] [<ffffffffa063a8b9>] nfsd3_proc_getattr+0x69/0xf0 [nfsd] [283465.564510] [<ffffffffa062cf60>] nfsd_dispatch+0xe0/0x290 [nfsd] [283465.565358] [<ffffffffa05eb892>] ? svc_tcp_adjust_wspace+0x12/0x30 [sunrpc] [283465.566272] [<ffffffffa05ea652>] svc_process_common+0x412/0x6a0 [sunrpc] [283465.567155] [<ffffffffa05eaa03>] svc_process+0x123/0x210 [sunrpc] [283465.568020] [<ffffffffa062c90f>] nfsd+0xff/0x170 [nfsd] [283465.568962] [<ffffffffa062c810>] ? nfsd_destroy+0x80/0x80 [nfsd] [283465.570112] [<ffffffff810a622b>] kthread+0xcb/0xf0 [283465.571099] [<ffffffff810a6160>] ? kthread_create_on_node+0x180/0x180 [283465.572114] [<ffffffff816f11b8>] ret_from_fork+0x58/0x90 [283465.573156] [<ffffffff810a6160>] ? kthread_create_on_node+0x180/0x180 Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Shuning Zhang <[email protected]> Reviewed-by: Joseph Qi <[email protected]> Cc: Mark Fasheh <[email protected]> Cc: Joel Becker <[email protected]> Cc: Junxiao Bi <[email protected]> Cc: Changwei Ge <[email protected]> Cc: piaojun <[email protected]> Cc: "Gang He" <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
digetx
pushed a commit
that referenced
this issue
Apr 11, 2019
Patch series "lib/sort & lib/list_sort: faster and smaller", v2. Because CONFIG_RETPOLINE has made indirect calls much more expensive, I thought I'd try to reduce the number made by the library sort functions. The first three patches apply to lib/sort.c. Patch #1 is a simple optimization. The built-in swap has special cases for aligned 4- and 8-byte objects. But those are almost never used; most calls to sort() work on larger structures, which fall back to the byte-at-a-time loop. This generalizes them to aligned *multiples* of 4 and 8 bytes. (If nothing else, it saves an awful lot of energy by not thrashing the store buffers as much.) Patch #2 grabs a juicy piece of low-hanging fruit. I agree that nice simple solid heapsort is preferable to more complex algorithms (sorry, Andrey), but it's possible to implement heapsort with far fewer comparisons (50% asymptotically, 25-40% reduction for realistic sizes) than the way it's been done up to now. And with some care, the code ends up smaller, as well. This is the "big win" patch. Patch #3 adds the same sort of indirect call bypass that has been added to the net code of late. The great majority of the callers use the builtin swap functions, so replace the indirect call to sort_func with a (highly preditable) series of if() statements. Rather surprisingly, this decreased code size, as the swap functions were inlined and their prologue & epilogue code eliminated. lib/list_sort.c is a bit trickier, as merge sort is already close to optimal, and we don't want to introduce triumphs of theory over practicality like the Ford-Johnson merge-insertion sort. Patch #4, without changing the algorithm, chops 32% off the code size and removes the part[MAX_LIST_LENGTH+1] pointer array (and the corresponding upper limit on efficiently sortable input size). Patch #5 improves the algorithm. The previous code is already optimal for power-of-two (or slightly smaller) size inputs, but when the input size is just over a power of 2, there's a very unbalanced final merge. There are, in the literature, several algorithms which solve this, but they all depend on the "breadth-first" merge order which was replaced by commit 835cc0c with a more cache-friendly "depth-first" order. Some hard thinking came up with a depth-first algorithm which defers merges as little as possible while avoiding bad merges. This saves 0.2*n compares, averaged over all sizes. The code size increase is minimal (64 bytes on x86-64, reducing the net savings to 26%), but the comments expanded significantly to document the clever algorithm. TESTING NOTES: I have some ugly user-space benchmarking code which I used for testing before moving this code into the kernel. Shout if you want a copy. I'm running this code right now, with CONFIG_TEST_SORT and CONFIG_TEST_LIST_SORT, but I confess I haven't rebooted since the last round of minor edits to quell checkpatch. I figure there will be at least one round of comments and final testing. This patch (of 5): Rather than having special-case swap functions for 4- and 8-byte objects, special-case aligned multiples of 4 or 8 bytes. This speeds up most users of sort() by avoiding fallback to the byte copy loop. Despite what ca96ab8 ("lib/sort: Add 64 bit swap function") claims, very few users of sort() sort pointers (or pointer-sized objects); most sort structures containing at least two words. (E.g. drivers/acpi/fan.c:acpi_fan_get_fps() sorts an array of 40-byte struct acpi_fan_fps.) The functions also got renamed to reflect the fact that they support multiple words. In the great tradition of bikeshedding, the names were by far the most contentious issue during review of this patch series. x86-64 code size 872 -> 886 bytes (+14) With feedback from Andy Shevchenko, Rasmus Villemoes and Geert Uytterhoeven. Link: http://lkml.kernel.org/r/f24f932df3a7fa1973c1084154f1cea596bcf341.1552704200.git.lkml@sdf.org Signed-off-by: George Spelvin <[email protected]> Acked-by: Andrey Abramov <[email protected]> Acked-by: Rasmus Villemoes <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Cc: Rasmus Villemoes <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Daniel Wagner <[email protected]> Cc: Don Mullis <[email protected]> Cc: Dave Chinner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
digetx
pushed a commit
that referenced
this issue
Apr 11, 2019
Ido Schimmel says: ==================== mlxsw: Various fixes This patchset contains various small fixes for mlxsw. Patch #1 fixes a warning generated by switchdev core when the driver fails to insert an MDB entry in the commit phase. Patches #2-#4 fix a warning in check_flush_dependency() that can be triggered when a work item in a WQ_MEM_RECLAIM workqueue tries to flush a non-WQ_MEM_RECLAIM workqueue. It seems that the semantics of the WQ_MEM_RECLAIM flag are not very clear [1] and that various patches have been sent to remove it from various workqueues throughout the kernel [2][3][4] in order to silence the warning. These patches do the same for the workqueues created by mlxsw that probably should not have been created with this flag in the first place. Patch #5 fixes a regression where an IP address cannot be assigned to a VRF upper due to erroneous MAC validation check. Patch #6 adds a test case. Patch #7 adjusts Spectrum-2 shared buffer configuration to be compatible with Spectrum-1. The problem and fix are described in detail in the commit message. Please consider patches #1-#5 for 5.0.y. I verified they apply cleanly. [1] https://patchwork.kernel.org/patch/10791315/ [2] Commit ce162bf ("mac80211_hwsim: don't use WQ_MEM_RECLAIM") [3] Commit 39baf10 ("IB/core: Fix use workqueue without WQ_MEM_RECLAIM") [4] Commit 75215e5 ("iwcm: Don't allocate iwcm workqueue with WQ_MEM_RECLAIM") ==================== Signed-off-by: David S. Miller <[email protected]>
|
I pushed a new version that uses custom voltage balancer. Please give it a try. |
|
Is there a constraint that the difference between cpu and core voltage should not be greater 170mV? On Galaxy Tab 10.1 this constraint does not hold. This is the regulator values at 216 Mhz cpu. |
|
The 170mV voltage max-spread constraint is for the CORE and RTC regulators. For CPU the constraint is that CORE and RTC regulators should be at least 120mV higher than the CPU. The summary looks good to me, thank you very much for the testing. I'll prepare patches for upstream, will see what maintainers will say about it all. |
digetx
pushed a commit
that referenced
this issue
Apr 15, 2019
Alan Maguire says: ==================== Extend bpf_skb_adjust_room growth to mark inner MAC header so that L2 encapsulation can be used for tc tunnels. Patch #1 extends the existing test_tc_tunnel to support UDP encapsulation; later we want to be able to test MPLS over UDP and MPLS over GRE encapsulation. Patch #2 adds the BPF_F_ADJ_ROOM_ENCAP_L2(len) macro, which allows specification of inner mac length. Other approaches were explored prior to taking this approach. Specifically, I tried automatically computing the inner mac length on the basis of the specified flags (so inner maclen for GRE/IPv4 encap is the len_diff specified to bpf_skb_adjust_room minus GRE + IPv4 header length for example). Problem with this is that we don't know for sure what form of GRE/UDP header we have; is it a full GRE header, or is it a FOU UDP header or generic UDP encap header? My fear here was we'd end up with an explosion of flags. The other approach tried was to support inner L2 header marking as a separate room adjustment, i.e. adjust for L3/L4 encap, then call bpf_skb_adjust_room for L2 encap. This can be made to work but because it imposed an order on operations, felt a bit clunky. Patch #3 syncs tools/ bpf.h. Patch #4 extends the tests again to support MPLSoverGRE, MPLSoverUDP, and transparent ethernet bridging (TEB) where the inner L2 header is an ethernet header. Testing of BPF encap against tunnels is done for cases where configuration of such tunnels is possible (MPLSoverGRE[6], MPLSoverUDP, gre[6]tap), and skipped otherwise. Testing of BPF encap/decap is always carried out. Changes since v2: - updated tools/testing/selftest/bpf/config with FOU/MPLS CONFIG variables (patches 1, 4) - reduced noise in patch 1 by avoiding unnecessary movement of code - eliminated inner_mac variable in bpf_skb_net_grow (patch 2) Changes since v1: - fixed formatting of commit references. - BPF_F_ADJ_ROOM_FIXED_GSO flag enabled on all variants (patch 1) - fixed fou6 options for UDP encap; checksum errors observed were due to the fact fou6 tunnel was not set up with correct ipproto options (41 -6). 0 checksums work fine (patch 1) - added definitions for mask and shift used in setting L2 length (patch 2) - allow udp encap with fixed GSO (patch 2) - changed "elen" to "l2_len" to be more descriptive (patch 4) ==================== Acked-by: Willem de Bruijn <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]>
digetx
pushed a commit
that referenced
this issue
Apr 15, 2019
Move ieee80211_tx_status_ext() outside of status_list lock section in order to avoid locking dependency and possible deadlock reposed by LOCKDEP in below warning. Also do mt76_tx_status_lock() just before it's needed. [ 440.224832] WARNING: possible circular locking dependency detected [ 440.224833] 5.1.0-rc2+ #22 Not tainted [ 440.224834] ------------------------------------------------------ [ 440.224835] kworker/u16:28/2362 is trying to acquire lock: [ 440.224836] 0000000089b8cacf (&(&q->lock)->rlock#2){+.-.}, at: mt76_wake_tx_queue+0x4c/0xb0 [mt76] [ 440.224842] but task is already holding lock: [ 440.224842] 000000002cfedc59 (&(&sta->lock)->rlock){+.-.}, at: ieee80211_stop_tx_ba_cb+0x32/0x1f0 [mac80211] [ 440.224863] which lock already depends on the new lock. [ 440.224863] the existing dependency chain (in reverse order) is: [ 440.224864] -> #3 (&(&sta->lock)->rlock){+.-.}: [ 440.224869] _raw_spin_lock_bh+0x34/0x40 [ 440.224880] ieee80211_start_tx_ba_session+0xe4/0x3d0 [mac80211] [ 440.224894] minstrel_ht_get_rate+0x45c/0x510 [mac80211] [ 440.224906] rate_control_get_rate+0xc1/0x140 [mac80211] [ 440.224918] ieee80211_tx_h_rate_ctrl+0x195/0x3c0 [mac80211] [ 440.224930] ieee80211_xmit_fast+0x26d/0xa50 [mac80211] [ 440.224942] __ieee80211_subif_start_xmit+0xfc/0x310 [mac80211] [ 440.224954] ieee80211_subif_start_xmit+0x38/0x390 [mac80211] [ 440.224956] dev_hard_start_xmit+0xb8/0x300 [ 440.224957] __dev_queue_xmit+0x7d4/0xbb0 [ 440.224968] ip6_finish_output2+0x246/0x860 [ipv6] [ 440.224978] mld_sendpack+0x1bd/0x360 [ipv6] [ 440.224987] mld_ifc_timer_expire+0x1a4/0x2f0 [ipv6] [ 440.224989] call_timer_fn+0x89/0x2a0 [ 440.224990] run_timer_softirq+0x1bd/0x4d0 [ 440.224992] __do_softirq+0xdb/0x47c [ 440.224994] irq_exit+0xfa/0x100 [ 440.224996] smp_apic_timer_interrupt+0x9a/0x220 [ 440.224997] apic_timer_interrupt+0xf/0x20 [ 440.224999] cpuidle_enter_state+0xc1/0x470 [ 440.225000] do_idle+0x21a/0x260 [ 440.225001] cpu_startup_entry+0x19/0x20 [ 440.225004] start_secondary+0x135/0x170 [ 440.225006] secondary_startup_64+0xa4/0xb0 [ 440.225007] -> #2 (&(&sta->rate_ctrl_lock)->rlock){+.-.}: [ 440.225009] _raw_spin_lock_bh+0x34/0x40 [ 440.225022] rate_control_tx_status+0x4f/0xb0 [mac80211] [ 440.225031] ieee80211_tx_status_ext+0x142/0x1a0 [mac80211] [ 440.225035] mt76x02_send_tx_status+0x2e4/0x340 [mt76x02_lib] [ 440.225037] mt76x02_tx_status_data+0x31/0x40 [mt76x02_lib] [ 440.225040] mt76u_tx_status_data+0x51/0xa0 [mt76_usb] [ 440.225042] process_one_work+0x237/0x5d0 [ 440.225043] worker_thread+0x3c/0x390 [ 440.225045] kthread+0x11d/0x140 [ 440.225046] ret_from_fork+0x3a/0x50 [ 440.225047] -> #1 (&(&list->lock)->rlock#8){+.-.}: [ 440.225049] _raw_spin_lock_bh+0x34/0x40 [ 440.225052] mt76_tx_status_skb_add+0x51/0x100 [mt76] [ 440.225054] mt76x02u_tx_prepare_skb+0xbd/0x116 [mt76x02_usb] [ 440.225056] mt76u_tx_queue_skb+0x5f/0x180 [mt76_usb] [ 440.225058] mt76_tx+0x93/0x190 [mt76] [ 440.225070] ieee80211_tx_frags+0x148/0x210 [mac80211] [ 440.225081] __ieee80211_tx+0x75/0x1b0 [mac80211] [ 440.225092] ieee80211_tx+0xde/0x110 [mac80211] [ 440.225105] __ieee80211_tx_skb_tid_band+0x72/0x90 [mac80211] [ 440.225122] ieee80211_send_auth+0x1f3/0x360 [mac80211] [ 440.225141] ieee80211_auth.cold.40+0x6c/0x100 [mac80211] [ 440.225156] ieee80211_mgd_auth.cold.50+0x132/0x15f [mac80211] [ 440.225171] cfg80211_mlme_auth+0x149/0x360 [cfg80211] [ 440.225181] nl80211_authenticate+0x273/0x2e0 [cfg80211] [ 440.225183] genl_family_rcv_msg+0x196/0x3a0 [ 440.225184] genl_rcv_msg+0x47/0x8e [ 440.225185] netlink_rcv_skb+0x3a/0xf0 [ 440.225187] genl_rcv+0x24/0x40 [ 440.225188] netlink_unicast+0x16d/0x210 [ 440.225189] netlink_sendmsg+0x204/0x3b0 [ 440.225191] sock_sendmsg+0x36/0x40 [ 440.225193] ___sys_sendmsg+0x259/0x2b0 [ 440.225194] __sys_sendmsg+0x47/0x80 [ 440.225196] do_syscall_64+0x60/0x1f0 [ 440.225197] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 440.225198] -> #0 (&(&q->lock)->rlock#2){+.-.}: [ 440.225200] lock_acquire+0xb9/0x1a0 [ 440.225202] _raw_spin_lock_bh+0x34/0x40 [ 440.225204] mt76_wake_tx_queue+0x4c/0xb0 [mt76] [ 440.225215] ieee80211_agg_start_txq+0xe8/0x2b0 [mac80211] [ 440.225225] ieee80211_stop_tx_ba_cb+0xb8/0x1f0 [mac80211] [ 440.225235] ieee80211_ba_session_work+0x1c1/0x2f0 [mac80211] [ 440.225236] process_one_work+0x237/0x5d0 [ 440.225237] worker_thread+0x3c/0x390 [ 440.225239] kthread+0x11d/0x140 [ 440.225240] ret_from_fork+0x3a/0x50 [ 440.225240] other info that might help us debug this: [ 440.225241] Chain exists of: &(&q->lock)->rlock#2 --> &(&sta->rate_ctrl_lock)->rlock --> &(&sta->lock)->rlock [ 440.225243] Possible unsafe locking scenario: [ 440.225244] CPU0 CPU1 [ 440.225244] ---- ---- [ 440.225245] lock(&(&sta->lock)->rlock); [ 440.225245] lock(&(&sta->rate_ctrl_lock)->rlock); [ 440.225246] lock(&(&sta->lock)->rlock); [ 440.225247] lock(&(&q->lock)->rlock#2); [ 440.225248] *** DEADLOCK *** [ 440.225249] 5 locks held by kworker/u16:28/2362: [ 440.225250] #0: 0000000048fcd291 ((wq_completion)phy0){+.+.}, at: process_one_work+0x1b5/0x5d0 [ 440.225252] #1: 00000000f1c6828f ((work_completion)(&sta->ampdu_mlme.work)){+.+.}, at: process_one_work+0x1b5/0x5d0 [ 440.225254] #2: 00000000433d2b2c (&sta->ampdu_mlme.mtx){+.+.}, at: ieee80211_ba_session_work+0x5c/0x2f0 [mac80211] [ 440.225265] #3: 000000002cfedc59 (&(&sta->lock)->rlock){+.-.}, at: ieee80211_stop_tx_ba_cb+0x32/0x1f0 [mac80211] [ 440.225276] #4: 000000009d7b9a44 (rcu_read_lock){....}, at: ieee80211_agg_start_txq+0x33/0x2b0 [mac80211] [ 440.225286] stack backtrace: [ 440.225288] CPU: 2 PID: 2362 Comm: kworker/u16:28 Not tainted 5.1.0-rc2+ #22 [ 440.225289] Hardware name: LENOVO 20KGS23S0P/20KGS23S0P, BIOS N23ET55W (1.30 ) 08/31/2018 [ 440.225300] Workqueue: phy0 ieee80211_ba_session_work [mac80211] [ 440.225301] Call Trace: [ 440.225304] dump_stack+0x85/0xc0 [ 440.225306] print_circular_bug.isra.38.cold.58+0x15c/0x195 [ 440.225307] check_prev_add.constprop.48+0x5f0/0xc00 [ 440.225309] ? check_prev_add.constprop.48+0x39d/0xc00 [ 440.225311] ? __lock_acquire+0x41d/0x1100 [ 440.225312] __lock_acquire+0xd98/0x1100 [ 440.225313] ? __lock_acquire+0x41d/0x1100 [ 440.225315] lock_acquire+0xb9/0x1a0 [ 440.225317] ? mt76_wake_tx_queue+0x4c/0xb0 [mt76] [ 440.225319] _raw_spin_lock_bh+0x34/0x40 [ 440.225321] ? mt76_wake_tx_queue+0x4c/0xb0 [mt76] [ 440.225323] mt76_wake_tx_queue+0x4c/0xb0 [mt76] [ 440.225334] ieee80211_agg_start_txq+0xe8/0x2b0 [mac80211] [ 440.225344] ieee80211_stop_tx_ba_cb+0xb8/0x1f0 [mac80211] [ 440.225354] ieee80211_ba_session_work+0x1c1/0x2f0 [mac80211] [ 440.225356] process_one_work+0x237/0x5d0 [ 440.225358] worker_thread+0x3c/0x390 [ 440.225359] ? wq_calc_node_cpumask+0x70/0x70 [ 440.225360] kthread+0x11d/0x140 [ 440.225362] ? kthread_create_on_node+0x40/0x40 [ 440.225363] ret_from_fork+0x3a/0x50 Cc: [email protected] Fixes: 88046b2 ("mt76: add support for reporting tx status with skb") Signed-off-by: Stanislaw Gruszka <[email protected]> Acked-by: Felix Fietkau <[email protected]> Signed-off-by: Kalle Valo <[email protected]>
|
Hello, @Decatf! I see that you have EMC timings table in the device-tree for the Galaxy Tab (although the definition misses the ram-code), will be great if you could try the new Tegra20 devfreq driver on yours device. You'll need to:
Thanks in advance! |
|
I've updated the Galaxy Tab 10.1 device tree emc timings table to use ram-code. It is in the following branch: This is how I tested it: https://github.com/raas/mbw Here are the results: |
|
@Decatf, thank you very much! The results are absolutely correct, very nice 👍 |
|
I like this memory benchmarking utility https://github.com/ssvb/tinymembench, just in case if you haven't heard about it before. BTW, could you please check that the freq stays at 600000000 while memory benchmark is running? (at least most of the time) |
|
The frequency stays at 600Mhz while most memory benchmarks are running. With tinymembench "Memory latency test" the frequency is at 50Mhz for smaller block sizes. For every other benchmark of mbw and tinymembench it is at 600Mhz. |
|
Awesome, thank you very much again! |
digetx
pushed a commit
that referenced
this issue
May 29, 2019
When receiving a deauthentication/disassociation frame from a TDLS peer, a station should not disconnect the current AP, but only disable the current TDLS link if it's enabled. Without this change, a TDLS issue can be reproduced by following the steps as below: 1. STA-1 and STA-2 are connected to AP, bidirection traffic is running between STA-1 and STA-2. 2. Set up TDLS link between STA-1 and STA-2, stay for a while, then teardown TDLS link. 3. Repeat step #2 and monitor the connection between STA and AP. During the test, one STA may send a deauthentication/disassociation frame to another, after TDLS teardown, with reason code 6/7, which means: Class 2/3 frame received from nonassociated STA. On receive this frame, the receiver STA will disconnect the current AP and then reconnect. It's not a expected behavior, purpose of this frame should be disabling the TDLS link, not the link with AP. Cc: [email protected] Signed-off-by: Yu Wang <[email protected]> Signed-off-by: Johannes Berg <[email protected]>
digetx
pushed a commit
that referenced
this issue
May 29, 2019
struct dfl_feature_platform_data (and it's mutex) is used by both fme and port devices, and when lockdep is enabled it complains about nesting between these locks. Tell lockdep about the difference so it can track each class separately. Here's the lockdep complaint: [ 409.680668] WARNING: possible recursive locking detected [ 409.685983] 5.1.0-rc3.fpga+ #1 Tainted: G E [ 409.691469] -------------------------------------------- [ 409.696779] fpgaconf/9348 is trying to acquire lock: [ 409.701746] 00000000a443fe2e (&pdata->lock){+.+.}, at: port_enable_set+0x24/0x60 [dfl_afu] [ 409.710006] [ 409.710006] but task is already holding lock: [ 409.715837] 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme] [ 409.724012] [ 409.724012] other info that might help us debug this: [ 409.730535] Possible unsafe locking scenario: [ 409.730535] [ 409.736457] CPU0 [ 409.738910] ---- [ 409.741360] lock(&pdata->lock); [ 409.744679] lock(&pdata->lock); [ 409.747999] [ 409.747999] *** DEADLOCK *** [ 409.747999] [ 409.753920] May be due to missing lock nesting notation [ 409.753920] [ 409.760704] 4 locks held by fpgaconf/9348: [ 409.764805] #0: 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme] [ 409.773408] #1: 00000000213c8a66 (®ion->mutex){+.+.}, at: fpga_region_program_fpga+0x24/0x200 [fpga_region] [ 409.783489] #2: 00000000fe63afb9 (&mgr->ref_mutex){+.+.}, at: fpga_mgr_lock+0x15/0x40 [fpga_mgr] [ 409.792354] #3: 000000000b2285c5 (&bridge->mutex){+.+.}, at: __fpga_bridge_get+0x26/0xa0 [fpga_bridge] [ 409.801740] [ 409.801740] stack backtrace: [ 409.806102] CPU: 45 PID: 9348 Comm: fpgaconf Kdump: loaded Tainted: G E 5.1.0-rc3.fpga+ #1 [ 409.815658] Hardware name: Intel Corporation S2600BT/S2600BT, BIOS SE5C620.86B.01.00.0763.022420181017 02/24/2018 [ 409.825911] Call Trace: [ 409.828369] dump_stack+0x5e/0x8b [ 409.831686] __lock_acquire+0xf3d/0x10e0 [ 409.835612] ? find_held_lock+0x3c/0xa0 [ 409.839451] lock_acquire+0xbc/0x1d0 [ 409.843030] ? port_enable_set+0x24/0x60 [dfl_afu] [ 409.847823] ? port_enable_set+0x24/0x60 [dfl_afu] [ 409.852616] __mutex_lock+0x86/0x970 [ 409.856195] ? port_enable_set+0x24/0x60 [dfl_afu] [ 409.860989] ? port_enable_set+0x24/0x60 [dfl_afu] [ 409.865777] ? __mutex_unlock_slowpath+0x4b/0x290 [ 409.870486] port_enable_set+0x24/0x60 [dfl_afu] [ 409.875106] fpga_bridges_disable+0x36/0x50 [fpga_bridge] [ 409.880502] fpga_region_program_fpga+0xea/0x200 [fpga_region] [ 409.886338] fme_pr_ioctl+0x13e/0x330 [dfl_fme] [ 409.890870] fme_ioctl+0x66/0xe0 [dfl_fme] [ 409.894973] do_vfs_ioctl+0xa9/0x720 [ 409.898548] ? lockdep_hardirqs_on+0xf0/0x1a0 [ 409.902907] ksys_ioctl+0x60/0x90 [ 409.906225] __x64_sys_ioctl+0x16/0x20 [ 409.909981] do_syscall_64+0x5a/0x220 [ 409.913644] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 409.918698] RIP: 0033:0x7f9d31b9b8d7 [ 409.922276] Code: 44 00 00 48 8b 05 b9 15 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 89 15 2d 00 f7 d8 64 89 01 48 [ 409.941020] RSP: 002b:00007ffe4cae0d68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 409.948588] RAX: ffffffffffffffda RBX: 00007f9d32ade6a0 RCX: 00007f9d31b9b8d7 [ 409.955719] RDX: 00007ffe4cae0df0 RSI: 000000000000b680 RDI: 0000000000000003 [ 409.962852] RBP: 0000000000000003 R08: 00007f9d2b70a177 R09: 00007ffe4cae0e40 [ 409.969984] R10: 00007ffe4cae0160 R11: 0000000000000202 R12: 00007ffe4cae0df0 [ 409.977115] R13: 000000000000b680 R14: 0000000000000000 R15: 00007ffe4cae0f60 Signed-off-by: Scott Wood <[email protected]> Acked-by: Wu Hao <[email protected]> Acked-by: Alan Tull <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
digetx
pushed a commit
that referenced
this issue
May 29, 2019
Andrii Nakryiko says: ==================== This patch set adds BTF-to-C dumping APIs to libbpf, allowing to output a subset of BTF types as a compilable C type definitions. This is useful by itself, as raw BTF output is not easy to inspect and comprehend. But it's also a big part of BPF CO-RE (compile once - run everywhere) initiative aimed at allowing to write relocatable BPF programs, that won't require on-the-host kernel headers (and would be able to inspect internal kernel structures, not exposed through kernel headers). This patch set consists of three groups of patches and one pre-patch, with the BTF-to-C dumper API depending on the first two groups. Pre-patch #1 fixes issue with libbpf_internal.h. btf__parse_elf() API patches: - patch #2 adds btf__parse_elf() API to libbpf, allowing to load BTF and/or BTF.ext from ELF file; - patch #3 utilizies btf__parse_elf() from bpftool for `btf dump file` command; - patch #4 switches test_btf.c to use btf__parse_elf() to check for presence of BTF data in object file. libbpf's internal hashmap patches: - patch #5 adds resizeable non-thread safe generic hashmap to libbpf; - patch #6 adds tests for that hashmap; - patch #7 migrates btf_dedup()'s dedup_table to use hashmap w/ APPEND. BTF-to-C dumper API patches: - patch #8 adds btf_dump APIs with all the logic for laying out type definitions in correct order and emitting C syntax for them; - patch #9 adds lots of tests for common and quirky parts of C type system; - patch #10 adds support for C-syntax btf dumping to bpftool; - patch #11 updates bpftool documentation to mention C-syntax dump option; - patch #12 update bash-completion for btf dump sub-command. v2->v3: - fix bpftool-btf.rst formatting (Quentin); - simplify bash autocompletion script (Quentin); - better error message in btf dump (Quentin); v1->v2: - removed unuseful file header (Jakub); - removed inlines in .c (Jakub); - added 'format {c|raw}' keyword/option (Jakub); - re-use i var for iteration in btf_dump_c() (Jakub); - bumped libbpf version to 0.0.4; v0->v1: - fix bug in hashmap__for_each_bucket_entry() not handling empty hashmap; - removed `btf dump`-specific libbpf logging hook up (Quentin has more generic patchset); - change btf__parse_elf() to always load .BTF and return it as a result, with .BTF.ext being optional and returned through struct btf_ext** arg (Alexei); - endianness check to use __BYTE_ORDER__ (Alexei); - bool:1 to __u8:1 in type_aux_state (Alexei); - added HASHMAP_APPEND strategy to hashmap, changed hashmap__for_each_key_entry() to also check for key equality during iteration (multimap iteration for key); - added new tests for empty hashmap and hashmap as a multimap; - tried to clarify weak/strong dependency ordering comments (Alexei) - btf dump test's expected output - support better commenting aproach (Alexei); - added bash-completion for a new "c" option (Alexei). ==================== Signed-off-by: Alexei Starovoitov <[email protected]>
digetx
pushed a commit
that referenced
this issue
May 29, 2019
Yonghong Song says: ==================== This patch tries to solve the following specific use case. Currently, bpf program can already collect stack traces through kernel function get_perf_callchain() when certain events happens (e.g., cache miss counter or cpu clock counter overflows). But such stack traces are not enough for jitted programs, e.g., hhvm (jited php). To get real stack trace, jit engine internal data structures need to be traversed in order to get the real user functions. bpf program itself may not be the best place to traverse the jit engine as the traversing logic could be complex and it is not a stable interface either. Instead, hhvm implements a signal handler, e.g. for SIGALARM, and a set of program locations which it can dump stack traces. When it receives a signal, it will dump the stack in next such program location. This patch implements bpf_send_signal() helper to send a signal to hhvm in real time, resulting in intended stack traces. Patch #1 implemented the bpf_send_helper() in the kernel. Patch #2 synced uapi header bpf.h to tools directory. Patch #3 added a self test which covers tracepoint and perf_event bpf programs. Changelogs: v4 => v5: . pass the "current" task struct to irq_work as well since the current task struct may change between nmi and subsequent irq_work_interrupt. Discovered by Daniel. v3 => v4: . fix one typo and declare "const char *id_path = ..." to avoid directly use the long string in the func body in Patch #3. v2 => v3: . change the standalone test to be part of prog_tests. RFC v1 => v2: . previous version allows to send signal to an arbitrary pid. This version just sends the signal to current task to avoid unstable pid and potential races between sending signals and task state changes for the pid. ==================== Signed-off-by: Daniel Borkmann <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 2, 2021
Hou Tao says:
====================
Hi,
Currently the test of BPF STRUCT_OPS depends on the specific bpf
implementation (e.g, tcp_congestion_ops), but it can not cover all
basic functionalities (e.g, return value handling), so introduce
a dummy BPF STRUCT_OPS for test purpose.
Instead of loading a userspace-implemeted bpf_dummy_ops map into
kernel and calling the specific function by writing to sysfs provided
by bpf_testmode.ko, only loading bpf_dummy_ops related prog into
kernel and calling these prog by bpf_prog_test_run(). The latter
is more flexible and has no dependency on extra kernel module.
Now the return value handling is supported by test_1(...) ops,
and passing multiple arguments is supported by test_2(...) ops.
If more is needed, test_x(...) ops can be added afterwards.
Comments are always welcome.
Regards,
Hou
Change Log:
v4:
* add Acked-by tags in patch 1~4
* patch 2: remove unncessary comments and update commit message
accordingly
* patch 4: remove unnecessary nr checking in dummy_ops_init_args()
v3: https://www.spinics.net/lists/bpf/msg48303.html
* rebase on bpf-next
* address comments for Martin, mainly include: merge patch 3 &
patch 4 in v2, fix names of btf ctx access check helpers,
handle CONFIG_NET, fix leak in dummy_ops_init_args(), and
simplify bpf_dummy_init()
* patch 4: use a loop to check args in test_dummy_multiple_args()
v2: https://www.spinics.net/lists/bpf/msg47948.html
* rebase on bpf-next
* add test_2(...) ops to test the passing of multiple arguments
* a new patch (patch #2) is added to factor out ctx access helpers
* address comments from Martin & Andrii
v1: https://www.spinics.net/lists/bpf/msg46787.html
RFC: https://www.spinics.net/lists/bpf/msg46117.html
====================
Signed-off-by: Alexei Starovoitov <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 9, 2021
It is generally unsafe to call put_device() with dpm_list_mtx held,
because the given device's release routine may carry out an action
depending on that lock which then may deadlock, so modify the
system-wide suspend and resume of devices to always drop dpm_list_mtx
before calling put_device() (and adjust white space somewhat while
at it).
For instance, this prevents the following splat from showing up in
the kernel log after a system resume in certain configurations:
[ 3290.969514] ======================================================
[ 3290.969517] WARNING: possible circular locking dependency detected
[ 3290.969519] 5.15.0+ #2420 Tainted: G S
[ 3290.969523] ------------------------------------------------------
[ 3290.969525] systemd-sleep/4553 is trying to acquire lock:
[ 3290.969529] ffff888117ab1138 ((wq_completion)hci0#2){+.+.}-{0:0}, at: flush_workqueue+0x87/0x4a0
[ 3290.969554]
but task is already holding lock:
[ 3290.969556] ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.969571]
which lock already depends on the new lock.
[ 3290.969573]
the existing dependency chain (in reverse order) is:
[ 3290.969575]
-> #3 (dpm_list_mtx){+.+.}-{3:3}:
[ 3290.969583] __mutex_lock+0x9d/0xa30
[ 3290.969591] device_pm_add+0x2e/0xe0
[ 3290.969597] device_add+0x4d5/0x8f0
[ 3290.969605] hci_conn_add_sysfs+0x43/0xb0 [bluetooth]
[ 3290.969689] hci_conn_complete_evt.isra.71+0x124/0x750 [bluetooth]
[ 3290.969747] hci_event_packet+0xd6c/0x28a0 [bluetooth]
[ 3290.969798] hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969842] process_one_work+0x2aa/0x650
[ 3290.969851] worker_thread+0x39/0x400
[ 3290.969859] kthread+0x142/0x170
[ 3290.969865] ret_from_fork+0x22/0x30
[ 3290.969872]
-> #2 (&hdev->lock){+.+.}-{3:3}:
[ 3290.969881] __mutex_lock+0x9d/0xa30
[ 3290.969887] hci_event_packet+0xba/0x28a0 [bluetooth]
[ 3290.969935] hci_rx_work+0x213/0x640 [bluetooth]
[ 3290.969978] process_one_work+0x2aa/0x650
[ 3290.969985] worker_thread+0x39/0x400
[ 3290.969993] kthread+0x142/0x170
[ 3290.969999] ret_from_fork+0x22/0x30
[ 3290.970004]
-> #1 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}:
[ 3290.970013] process_one_work+0x27d/0x650
[ 3290.970020] worker_thread+0x39/0x400
[ 3290.970028] kthread+0x142/0x170
[ 3290.970033] ret_from_fork+0x22/0x30
[ 3290.970038]
-> #0 ((wq_completion)hci0#2){+.+.}-{0:0}:
[ 3290.970047] __lock_acquire+0x15cb/0x1b50
[ 3290.970054] lock_acquire+0x26c/0x300
[ 3290.970059] flush_workqueue+0xae/0x4a0
[ 3290.970066] drain_workqueue+0xa1/0x130
[ 3290.970073] destroy_workqueue+0x34/0x1f0
[ 3290.970081] hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970130] bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970195] device_release+0x33/0x90
[ 3290.970201] kobject_release+0x63/0x160
[ 3290.970211] dpm_resume+0x164/0x3e0
[ 3290.970215] dpm_resume_end+0xd/0x20
[ 3290.970220] suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970229] pm_suspend+0x26b/0x310
[ 3290.970236] state_store+0x42/0x90
[ 3290.970243] kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970251] new_sync_write+0x125/0x1c0
[ 3290.970257] vfs_write+0x360/0x3c0
[ 3290.970263] ksys_write+0xa7/0xe0
[ 3290.970269] do_syscall_64+0x3a/0x80
[ 3290.970276] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970284]
other info that might help us debug this:
[ 3290.970285] Chain exists of:
(wq_completion)hci0#2 --> &hdev->lock --> dpm_list_mtx
[ 3290.970297] Possible unsafe locking scenario:
[ 3290.970299] CPU0 CPU1
[ 3290.970300] ---- ----
[ 3290.970302] lock(dpm_list_mtx);
[ 3290.970306] lock(&hdev->lock);
[ 3290.970310] lock(dpm_list_mtx);
[ 3290.970314] lock((wq_completion)hci0#2);
[ 3290.970319]
*** DEADLOCK ***
[ 3290.970321] 7 locks held by systemd-sleep/4553:
[ 3290.970325] #0: ffff888103bcd448 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0xa7/0xe0
[ 3290.970341] #1: ffff888115a14488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x103/0x1b0
[ 3290.970355] #2: ffff888100f719e0 (kn->active#233){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x10c/0x1b0
[ 3290.970369] #3: ffffffff82661048 (autosleep_lock){+.+.}-{3:3}, at: state_store+0x12/0x90
[ 3290.970384] #4: ffffffff82658ac8 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend+0x9f/0x310
[ 3290.970399] #5: ffffffff827f2a48 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_suspend_begin+0x4c/0x80
[ 3290.970416] #6: ffffffff8280fca8 (dpm_list_mtx){+.+.}-{3:3}, at: dpm_resume+0x12e/0x3e0
[ 3290.970428]
stack backtrace:
[ 3290.970431] CPU: 3 PID: 4553 Comm: systemd-sleep Tainted: G S 5.15.0+ #2420
[ 3290.970438] Hardware name: Dell Inc. XPS 13 9380/0RYJWW, BIOS 1.5.0 06/03/2019
[ 3290.970441] Call Trace:
[ 3290.970446] dump_stack_lvl+0x44/0x57
[ 3290.970454] check_noncircular+0x105/0x120
[ 3290.970468] ? __lock_acquire+0x15cb/0x1b50
[ 3290.970474] __lock_acquire+0x15cb/0x1b50
[ 3290.970487] lock_acquire+0x26c/0x300
[ 3290.970493] ? flush_workqueue+0x87/0x4a0
[ 3290.970503] ? __raw_spin_lock_init+0x3b/0x60
[ 3290.970510] ? lockdep_init_map_type+0x58/0x240
[ 3290.970519] flush_workqueue+0xae/0x4a0
[ 3290.970526] ? flush_workqueue+0x87/0x4a0
[ 3290.970544] ? drain_workqueue+0xa1/0x130
[ 3290.970552] drain_workqueue+0xa1/0x130
[ 3290.970561] destroy_workqueue+0x34/0x1f0
[ 3290.970572] hci_release_dev+0x49/0x180 [bluetooth]
[ 3290.970624] bt_host_release+0x1d/0x30 [bluetooth]
[ 3290.970687] device_release+0x33/0x90
[ 3290.970695] kobject_release+0x63/0x160
[ 3290.970705] dpm_resume+0x164/0x3e0
[ 3290.970710] ? dpm_resume_early+0x251/0x3b0
[ 3290.970718] dpm_resume_end+0xd/0x20
[ 3290.970723] suspend_devices_and_enter+0x1a4/0xba0
[ 3290.970737] pm_suspend+0x26b/0x310
[ 3290.970746] state_store+0x42/0x90
[ 3290.970755] kernfs_fop_write_iter+0x135/0x1b0
[ 3290.970764] new_sync_write+0x125/0x1c0
[ 3290.970777] vfs_write+0x360/0x3c0
[ 3290.970785] ksys_write+0xa7/0xe0
[ 3290.970794] do_syscall_64+0x3a/0x80
[ 3290.970803] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 3290.970811] RIP: 0033:0x7f41b1328164
[ 3290.970819] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 4a d2 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83
[ 3290.970824] RSP: 002b:00007ffe6ae21b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 3290.970831] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f41b1328164
[ 3290.970836] RDX: 0000000000000004 RSI: 000055965e651070 RDI: 0000000000000004
[ 3290.970839] RBP: 000055965e651070 R08: 000055965e64f390 R09: 00007f41b1e3d1c0
[ 3290.970843] R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000004
[ 3290.970846] R13: 0000000000000001 R14: 000055965e64f2b0 R15: 0000000000000004
Cc: All applicable <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 9, 2021
The variable mm->total_vm could be accessed concurrently during mmaping and system accounting as noticed by KCSAN, BUG: KCSAN: data-race in __acct_update_integrals / mmap_region read-write to 0xffffa40267bd14c8 of 8 bytes by task 15609 on cpu 3: mmap_region+0x6dc/0x1400 do_mmap+0x794/0xca0 vm_mmap_pgoff+0xdf/0x150 ksys_mmap_pgoff+0xe1/0x380 do_syscall_64+0x37/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffffa40267bd14c8 of 8 bytes by interrupt on cpu 2: __acct_update_integrals+0x187/0x1d0 acct_account_cputime+0x3c/0x40 update_process_times+0x5c/0x150 tick_sched_timer+0x184/0x210 __run_hrtimer+0x119/0x3b0 hrtimer_interrupt+0x350/0xaa0 __sysvec_apic_timer_interrupt+0x7b/0x220 asm_call_irq_on_stack+0x12/0x20 sysvec_apic_timer_interrupt+0x4d/0x80 asm_sysvec_apic_timer_interrupt+0x12/0x20 smp_call_function_single+0x192/0x2b0 perf_install_in_context+0x29b/0x4a0 __se_sys_perf_event_open+0x1a98/0x2550 __x64_sys_perf_event_open+0x63/0x70 do_syscall_64+0x37/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 2 PID: 15610 Comm: syz-executor.3 Not tainted 5.10.0+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 In vm_stat_account which called by mmap_region, increase total_vm, and __acct_update_integrals may read total_vm at the same time. This will cause a data race which lead to undefined behaviour. To avoid potential bad read/write, volatile property and barrier are both used to avoid undefined behaviour. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Peng Liu <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 9, 2021
Patch series "Solve silent data loss caused by poisoned page cache (shmem/tmpfs)", v5.
When discussing the patch that splits page cache THP in order to offline
the poisoned page, Noaya mentioned there is a bigger problem [1] that
prevents this from working since the page cache page will be truncated
if uncorrectable errors happen. By looking this deeper it turns out
this approach (truncating poisoned page) may incur silent data loss for
all non-readonly filesystems if the page is dirty. It may be worse for
in-memory filesystem, e.g. shmem/tmpfs since the data blocks are
actually gone.
To solve this problem we could keep the poisoned dirty page in page
cache then notify the users on any later access, e.g. page fault,
read/write, etc. The clean page could be truncated as is since they can
be reread from disk later on.
The consequence is the filesystems may find poisoned page and manipulate
it as healthy page since all the filesystems actually don't check if the
page is poisoned or not in all the relevant paths except page fault. In
general, we need make the filesystems be aware of poisoned page before
we could keep the poisoned page in page cache in order to solve the data
loss problem.
To make filesystems be aware of poisoned page we should consider:
- The page should be not written back: clearing dirty flag could
prevent from writeback.
- The page should not be dropped (it shows as a clean page) by drop
caches or other callers: the refcount pin from hwpoison could prevent
from invalidating (called by cache drop, inode cache shrinking, etc),
but it doesn't avoid invalidation in DIO path.
- The page should be able to get truncated/hole punched/unlinked: it
works as it is.
- Notify users when the page is accessed, e.g. read/write, page fault
and other paths (compression, encryption, etc).
The scope of the last one is huge since almost all filesystems need do
it once a page is returned from page cache lookup. There are a couple
of options to do it:
1. Check hwpoison flag for every path, the most straightforward way.
2. Return NULL for poisoned page from page cache lookup, the most
callsites check if NULL is returned, this should have least work I
think. But the error handling in filesystems just return -ENOMEM,
the error code will incur confusion to the users obviously.
3. To improve #2, we could return error pointer, e.g. ERR_PTR(-EIO),
but this will involve significant amount of code change as well
since all the paths need check if the pointer is ERR or not just
like option #1.
I did prototypes for both #1 and #3, but it seems #3 may require more
changes than #1. For #3 ERR_PTR will be returned so all the callers
need to check the return value otherwise invalid pointer may be
dereferenced, but not all callers really care about the content of the
page, for example, partial truncate which just sets the truncated range
in one page to 0. So for such paths it needs additional modification if
ERR_PTR is returned. And if the callers have their own way to handle
the problematic pages we need to add a new FGP flag to tell FGP
functions to return the pointer to the page.
It may happen very rarely, but once it happens the consequence (data
corruption) could be very bad and it is very hard to debug. It seems
this problem had been slightly discussed before, but seems no action was
taken at that time. [2]
As the aforementioned investigation, it needs huge amount of work to
solve the potential data loss for all filesystems. But it is much
easier for in-memory filesystems and such filesystems actually suffer
more than others since even the data blocks are gone due to truncating.
So this patchset starts from shmem/tmpfs by taking option #1.
TODO:
* The unpoison has been broken since commit 0ed950d ("mm,hwpoison: make
get_hwpoison_page() call get_any_page()"), and this patch series make
refcount check for unpoisoning shmem page fail.
* Expand to other filesystems. But I haven't heard feedback from filesystem
developers yet.
Patch breakdown:
Patch #1: cleanup, depended by patch #2
Patch #2: fix THP with hwpoisoned subpage(s) PMD map bug
Patch #3: coding style cleanup
Patch #4: refactor and preparation.
Patch #5: keep the poisoned page in page cache and handle such case for all
the paths.
Patch #6: the previous patches unblock page cache THP split, so this patch
add page cache THP split support.
This patch (of 4):
A minor cleanup to the indent.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yang Shi <[email protected]>
Reviewed-by: Naoya Horiguchi <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Peter Xu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 9, 2021
KCSAN reports a data-race on v5.10 which also exists on mainline: BUG: KCSAN: data-race in extfrag_for_order+0x33/0x2d0 race at unknown origin, with read to 0xffff9ee9bfffab48 of 8 bytes by task 34 on cpu 1: extfrag_for_order+0x33/0x2d0 kcompactd+0x5f0/0xce0 kthread+0x1f9/0x220 ret_from_fork+0x22/0x30 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 34 Comm: kcompactd0 Not tainted 5.10.0+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Access to zone->free_area[order].nr_free in extfrag_for_order() and frag_show_print() is lockless. That's intentional and the stats are a rough estimate anyway. Annotate them with data_race(). [[email protected]: add comments] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Liu Shixin <[email protected]> Cc: "Paul E . McKenney" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 9, 2021
Problem Description:
When running running ~128 parallel instances of "TZ=/etc/localtime ps -fe
>/dev/null" on a 128CPU machine, the %sys utilization reaches 97%, and
perf shows the following code path as being responsible for heavy
contention on the d_lockref spinlock:
walk_component()
lookup_fast()
d_revalidate()
pid_revalidate() // returns -ECHILD
unlazy_child()
lockref_get_not_dead(&nd->path.dentry->d_lockref) <-- contention
The reason is that pid_revalidate() is triggering a drop from RCU to ref
path walk mode. All concurrent path lookups thus try to grab a reference
to the dentry for /proc/, before re-executing pid_revalidate() and then
stepping into the /proc/$pid directory. Thus there is huge spinlock
contention. This patch allows pid_revalidate() to execute in RCU mode,
meaning that the path lookup can successfully enter the /proc/$pid
directory while still in RCU mode. Later on, the path lookup may still
drop into ref mode, but the contention will be much reduced at this point.
By applying this patch, %sys utilization falls to around 85% under the
same workload, and the number of ps processes executed per unit time
increases by 3x-4x. Although this particular workload is a bit contrived,
we have seen some large collections of eager monitoring scripts which
produced similarly high %sys time due to contention in the /proc
directory.
As a result this patch, Al noted that several procfs methods which were
only called in ref-walk mode could now be called from RCU mode. To ensure
that this patch is safe, I audited all the inode get_link and permission()
implementations, as well as dentry d_revalidate() implementations, in
fs/proc. The purpose here is to ensure that they either are safe to call
in RCU (i.e. don't sleep) or correctly bail out of RCU mode if they don't
support it. My analysis shows that all at-risk procfs methods are safe to
call under RCU, and thus this patch is safe.
Procfs RCU-walk Analysis:
This analysis is up-to-date with 5.15-rc3. When called under RCU mode,
these functions have arguments as follows:
* get_link() receives a NULL dentry pointer when called in RCU mode.
* permission() receives MAY_NOT_BLOCK in the mode parameter when called
from RCU.
* d_revalidate() receives LOOKUP_RCU in flags.
For the following functions, either they are trivially RCU safe, or they
explicitly bail at the beginning of the function when they run:
proc_ns_get_link (bails out)
proc_get_link (RCU safe)
proc_pid_get_link (bails out)
map_files_d_revalidate (bails out)
map_misc_d_revalidate (bails out)
proc_net_d_revalidate (RCU safe)
proc_sys_revalidate (bails out, also not under /proc/$pid)
tid_fd_revalidate (bails out)
proc_sys_permission (not under /proc/$pid)
The remainder of the functions require a bit more detail:
* proc_fd_permission: RCU safe. All of the body of this function is
under rcu_read_lock(), except generic_permission() which declares
itself RCU safe in its documentation string.
* proc_self_get_link uses GFP_ATOMIC in the RCU case, so it is RCU aware
and otherwise looks safe. The same is true of proc_thread_self_get_link.
* proc_map_files_get_link: calls ns_capable, which calls capable(), and
thus calls into the audit code (see note #1 below). The remainder is
just a call to the trivially safe proc_pid_get_link().
* proc_pid_permission: calls ptrace_may_access(), which appears RCU
safe, although it does call into the "security_ptrace_access_check()"
hook, which looks safe under smack and selinux. Just the audit code is
of concern. Also uses get_task_struct() and put_task_struct(), see
note #2 below.
* proc_tid_comm_permission: Appears safe, though calls put_task_struct
(see note #2 below).
Note #1:
Most of the concern of RCU safety has centered around the audit code.
However, since b17ec22 ("selinux: slow_avc_audit has become
non-blocking"), it's safe to call this code under RCU. So all of the
above are safe by my estimation.
Note #2: get_task_struct() and put_task_struct():
The majority of get_task_struct() is under RCU read lock, and in any
case it is a simple increment. But put_task_struct() is complex, given
that it could at some point free the task struct, and this process has
many steps which I couldn't manually verify. However, several other
places call put_task_struct() under RCU, so it appears safe to use
here too (see kernel/hung_task.c:165 or rcu/tree-stall.h:296)
Patch description:
pid_revalidate() drops from RCU into REF lookup mode. When many threads
are resolving paths within /proc in parallel, this can result in heavy
spinlock contention on d_lockref as each thread tries to grab a reference
to the /proc dentry (and drop it shortly thereafter).
Investigation indicates that it is not necessary to drop RCU in
pid_revalidate(), as no RCU data is modified and the function never
sleeps. So, remove the LOOKUP_RCU check.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Stephen Brennan <[email protected]>
Cc: Konrad Wilk <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 10, 2021
…ue initialztion We got UAF report on v5.10 as follows: [ 1446.674930] ================================================================== [ 1446.675970] BUG: KASAN: use-after-free in blk_mq_get_driver_tag+0x9a4/0xa90 [ 1446.676902] Read of size 8 at addr ffff8880185afd10 by task kworker/1:2/12348 [ 1446.677851] [ 1446.678073] CPU: 1 PID: 12348 Comm: kworker/1:2 Not tainted 5.10.0-10177-gc9c81b1e346a #2 [ 1446.679168] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 1446.680692] Workqueue: kthrotld blk_throtl_dispatch_work_fn [ 1446.681448] Call Trace: [ 1446.681800] dump_stack+0x9b/0xce [ 1446.682916] print_address_description.constprop.6+0x3e/0x60 [ 1446.685999] kasan_report.cold.9+0x22/0x3a [ 1446.687186] blk_mq_get_driver_tag+0x9a4/0xa90 [ 1446.687785] blk_mq_dispatch_rq_list+0x21a/0x1d40 [ 1446.692576] __blk_mq_do_dispatch_sched+0x394/0x830 [ 1446.695758] __blk_mq_sched_dispatch_requests+0x398/0x4f0 [ 1446.698279] blk_mq_sched_dispatch_requests+0xdf/0x140 [ 1446.698967] __blk_mq_run_hw_queue+0xc0/0x270 [ 1446.699561] __blk_mq_delay_run_hw_queue+0x4cc/0x550 [ 1446.701407] blk_mq_run_hw_queue+0x13b/0x2b0 [ 1446.702593] blk_mq_sched_insert_requests+0x1de/0x390 [ 1446.703309] blk_mq_flush_plug_list+0x4b4/0x760 [ 1446.705408] blk_flush_plug_list+0x2c5/0x480 [ 1446.708471] blk_finish_plug+0x55/0xa0 [ 1446.708980] blk_throtl_dispatch_work_fn+0x23b/0x2e0 [ 1446.711236] process_one_work+0x6d4/0xfe0 [ 1446.711778] worker_thread+0x91/0xc80 [ 1446.713400] kthread+0x32d/0x3f0 [ 1446.714362] ret_from_fork+0x1f/0x30 [ 1446.714846] [ 1446.715062] Allocated by task 1: [ 1446.715509] kasan_save_stack+0x19/0x40 [ 1446.716026] __kasan_kmalloc.constprop.1+0xc1/0xd0 [ 1446.716673] blk_mq_init_tags+0x6d/0x330 [ 1446.717207] blk_mq_alloc_rq_map+0x50/0x1c0 [ 1446.717769] __blk_mq_alloc_map_and_request+0xe5/0x320 [ 1446.718459] blk_mq_alloc_tag_set+0x679/0xdc0 [ 1446.719050] scsi_add_host_with_dma.cold.3+0xa0/0x5db [ 1446.719736] virtscsi_probe+0x7bf/0xbd0 [ 1446.720265] virtio_dev_probe+0x402/0x6c0 [ 1446.720808] really_probe+0x276/0xde0 [ 1446.721320] driver_probe_device+0x267/0x3d0 [ 1446.721892] device_driver_attach+0xfe/0x140 [ 1446.722491] __driver_attach+0x13a/0x2c0 [ 1446.723037] bus_for_each_dev+0x146/0x1c0 [ 1446.723603] bus_add_driver+0x3fc/0x680 [ 1446.724145] driver_register+0x1c0/0x400 [ 1446.724693] init+0xa2/0xe8 [ 1446.725091] do_one_initcall+0x9e/0x310 [ 1446.725626] kernel_init_freeable+0xc56/0xcb9 [ 1446.726231] kernel_init+0x11/0x198 [ 1446.726714] ret_from_fork+0x1f/0x30 [ 1446.727212] [ 1446.727433] Freed by task 26992: [ 1446.727882] kasan_save_stack+0x19/0x40 [ 1446.728420] kasan_set_track+0x1c/0x30 [ 1446.728943] kasan_set_free_info+0x1b/0x30 [ 1446.729517] __kasan_slab_free+0x111/0x160 [ 1446.730084] kfree+0xb8/0x520 [ 1446.730507] blk_mq_free_map_and_requests+0x10b/0x1b0 [ 1446.731206] blk_mq_realloc_hw_ctxs+0x8cb/0x15b0 [ 1446.731844] blk_mq_init_allocated_queue+0x374/0x1380 [ 1446.732540] blk_mq_init_queue_data+0x7f/0xd0 [ 1446.733155] scsi_mq_alloc_queue+0x45/0x170 [ 1446.733730] scsi_alloc_sdev+0x73c/0xb20 [ 1446.734281] scsi_probe_and_add_lun+0x9a6/0x2d90 [ 1446.734916] __scsi_scan_target+0x208/0xc50 [ 1446.735500] scsi_scan_channel.part.3+0x113/0x170 [ 1446.736149] scsi_scan_host_selected+0x25a/0x360 [ 1446.736783] store_scan+0x290/0x2d0 [ 1446.737275] dev_attr_store+0x55/0x80 [ 1446.737782] sysfs_kf_write+0x132/0x190 [ 1446.738313] kernfs_fop_write_iter+0x319/0x4b0 [ 1446.738921] new_sync_write+0x40e/0x5c0 [ 1446.739429] vfs_write+0x519/0x720 [ 1446.739877] ksys_write+0xf8/0x1f0 [ 1446.740332] do_syscall_64+0x2d/0x40 [ 1446.740802] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1446.741462] [ 1446.741670] The buggy address belongs to the object at ffff8880185afd00 [ 1446.741670] which belongs to the cache kmalloc-256 of size 256 [ 1446.743276] The buggy address is located 16 bytes inside of [ 1446.743276] 256-byte region [ffff8880185afd00, ffff8880185afe00) [ 1446.744765] The buggy address belongs to the page: [ 1446.745416] page:ffffea0000616b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x185ac [ 1446.746694] head:ffffea0000616b00 order:2 compound_mapcount:0 compound_pincount:0 [ 1446.747719] flags: 0x1fffff80010200(slab|head) [ 1446.748337] raw: 001fffff80010200 ffffea00006a3208 ffffea000061bf08 ffff88801004f240 [ 1446.749404] raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 [ 1446.750455] page dumped because: kasan: bad access detected [ 1446.751227] [ 1446.751445] Memory state around the buggy address: [ 1446.752102] ffff8880185afc00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1446.753090] ffff8880185afc80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1446.754079] >ffff8880185afd00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1446.755065] ^ [ 1446.755589] ffff8880185afd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1446.756574] ffff8880185afe00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 1446.757566] ================================================================== Flag 'BLK_MQ_F_TAG_QUEUE_SHARED' will be set if the second device on the same host initializes it's queue successfully. However, if the second device failed to allocate memory in blk_mq_alloc_and_init_hctx() from blk_mq_realloc_hw_ctxs() from blk_mq_init_allocated_queue(), __blk_mq_free_map_and_rqs() will be called on error path, and if 'BLK_MQ_TAG_HCTX_SHARED' is not set, 'tag_set->tags' will be freed while it's still used by the first device. To fix this issue we move release newly allocated hardware context from blk_mq_realloc_hw_ctxs to __blk_mq_update_nr_hw_queues. As there is needn't to release hardware context in blk_mq_init_allocated_queue. Fixes: 868f2f0 ("blk-mq: dynamic h/w context count") Signed-off-by: Ye Bin <[email protected]> Signed-off-by: Yu Kuai <[email protected]> Reviewed-by: Ming Lei <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 10, 2021
Problem Description:
When running running ~128 parallel instances of
TZ=/etc/localtime ps -fe >/dev/null
on a 128CPU machine, the %sys utilization reaches 97%, and perf shows
the following code path as being responsible for heavy contention on the
d_lockref spinlock:
walk_component()
lookup_fast()
d_revalidate()
pid_revalidate() // returns -ECHILD
unlazy_child()
lockref_get_not_dead(&nd->path.dentry->d_lockref) <-- contention
The reason is that pid_revalidate() is triggering a drop from RCU to ref
path walk mode. All concurrent path lookups thus try to grab a
reference to the dentry for /proc/, before re-executing pid_revalidate()
and then stepping into the /proc/$pid directory. Thus there is huge
spinlock contention.
This patch allows pid_revalidate() to execute in RCU mode, meaning that
the path lookup can successfully enter the /proc/$pid directory while
still in RCU mode. Later on, the path lookup may still drop into ref
mode, but the contention will be much reduced at this point.
By applying this patch, %sys utilization falls to around 85% under the
same workload, and the number of ps processes executed per unit time
increases by 3x-4x. Although this particular workload is a bit
contrived, we have seen some large collections of eager monitoring
scripts which produced similarly high %sys time due to contention in the
/proc directory.
As a result this patch, Al noted that several procfs methods which were
only called in ref-walk mode could now be called from RCU mode. To
ensure that this patch is safe, I audited all the inode get_link and
permission() implementations, as well as dentry d_revalidate()
implementations, in fs/proc. The purpose here is to ensure that they
either are safe to call in RCU (i.e. don't sleep) or correctly bail out
of RCU mode if they don't support it. My analysis shows that all
at-risk procfs methods are safe to call under RCU, and thus this patch
is safe.
Procfs RCU-walk Analysis:
This analysis is up-to-date with 5.15-rc3. When called under RCU mode,
these functions have arguments as follows:
* get_link() receives a NULL dentry pointer when called in RCU mode.
* permission() receives MAY_NOT_BLOCK in the mode parameter when called
from RCU.
* d_revalidate() receives LOOKUP_RCU in flags.
For the following functions, either they are trivially RCU safe, or they
explicitly bail at the beginning of the function when they run:
proc_ns_get_link (bails out)
proc_get_link (RCU safe)
proc_pid_get_link (bails out)
map_files_d_revalidate (bails out)
map_misc_d_revalidate (bails out)
proc_net_d_revalidate (RCU safe)
proc_sys_revalidate (bails out, also not under /proc/$pid)
tid_fd_revalidate (bails out)
proc_sys_permission (not under /proc/$pid)
The remainder of the functions require a bit more detail:
* proc_fd_permission: RCU safe. All of the body of this function is
under rcu_read_lock(), except generic_permission() which declares
itself RCU safe in its documentation string.
* proc_self_get_link uses GFP_ATOMIC in the RCU case, so it is RCU aware
and otherwise looks safe. The same is true of proc_thread_self_get_link.
* proc_map_files_get_link: calls ns_capable, which calls capable(), and
thus calls into the audit code (see note #1 below). The remainder is
just a call to the trivially safe proc_pid_get_link().
* proc_pid_permission: calls ptrace_may_access(), which appears RCU
safe, although it does call into the "security_ptrace_access_check()"
hook, which looks safe under smack and selinux. Just the audit code is
of concern. Also uses get_task_struct() and put_task_struct(), see
note #2 below.
* proc_tid_comm_permission: Appears safe, though calls put_task_struct
(see note #2 below).
Note #1:
Most of the concern of RCU safety has centered around the audit code.
However, since b17ec22 ("selinux: slow_avc_audit has become
non-blocking"), it's safe to call this code under RCU. So all of the
above are safe by my estimation.
Note #2: get_task_struct() and put_task_struct():
The majority of get_task_struct() is under RCU read lock, and in any
case it is a simple increment. But put_task_struct() is complex, given
that it could at some point free the task struct, and this process has
many steps which I couldn't manually verify. However, several other
places call put_task_struct() under RCU, so it appears safe to use
here too (see kernel/hung_task.c:165 or rcu/tree-stall.h:296)
Patch description:
pid_revalidate() drops from RCU into REF lookup mode. When many threads
are resolving paths within /proc in parallel, this can result in heavy
spinlock contention on d_lockref as each thread tries to grab a
reference to the /proc dentry (and drop it shortly thereafter).
Investigation indicates that it is not necessary to drop RCU in
pid_revalidate(), as no RCU data is modified and the function never
sleeps. So, remove the LOOKUP_RCU check.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Stephen Brennan <[email protected]>
Cc: Konrad Wilk <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 16, 2021
Add a convenience function, folio_inode() that will get the host inode from a folio's mapping. Changes: ver #3: - Fix mistake in function description[2]. ver #2: - Fix contradiction between doc and implementation by disallowing use with swap caches[1]. Signed-off-by: David Howells <[email protected]> Reviewed-by: Matthew Wilcox (Oracle) <[email protected]> Tested-by: Jeff Layton <[email protected]> Tested-by: Dominique Martinet <[email protected]> Tested-by: [email protected] Link: https://lore.kernel.org/r/[email protected]/ [1] Link: https://lore.kernel.org/r/[email protected]/ [2] Link: https://lore.kernel.org/r/162880453171.3369675.3704943108660112470.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/162981151155.1901565.7010079316994382707.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/163005744370.2472992.18324470937328925723.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163584184628.4023316.9386282630968981869.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/163649325519.309189.15072332908703129455.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/163657850401.834781.1031963517399283294.stgit@warthog.procyon.org.uk/ # v5
digetx
pushed a commit
that referenced
this issue
Nov 16, 2021
Convert the netfs helper library to use folios throughout, convert the 9p and afs filesystems to use folios in their file I/O paths and convert the ceph filesystem to use just enough folios to compile. With these changes, afs passes -g quick xfstests. Changes ======= ver #5: - Got rid of folio_end{io,_read,_write}() and inlined the stuff it does instead (Willy decided he didn't want this after all). ver #4: - Fixed a bug in afs_redirty_page() whereby it didn't set the next page index in the loop and returned too early. - Simplified a check in v9fs_vfs_write_folio_locked()[1]. - Undid a change to afs_symlink_readpage()[1]. - Used offset_in_folio() in afs_write_end()[1]. - Changed from using page_endio() to folio_end{io,_read,_write}()[1]. ver #2: - Add 9p foliation. Signed-off-by: David Howells <[email protected]> Reviewed-by: Jeff Layton <[email protected]> Tested-by: Jeff Layton <[email protected]> Tested-by: Dominique Martinet <[email protected]> Tested-by: [email protected] cc: Matthew Wilcox (Oracle) <[email protected]> cc: Marc Dionne <[email protected]> cc: Ilya Dryomov <[email protected]> cc: Dominique Martinet <[email protected]> cc: [email protected] cc: [email protected] cc: [email protected] cc: [email protected] Link: https://lore.kernel.org/r/YYKa3bfQZxK5/[email protected]/ [1] Link: https://lore.kernel.org/r/[email protected]/ # rfc Link: https://lore.kernel.org/r/162877311459.3085614.10601478228012245108.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/162981153551.1901565.3124454657133703341.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/163005745264.2472992.9852048135392188995.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163584187452.4023316.500389675405550116.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/163649328026.309189.1124218109373941936.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/163657852454.834781.9265101983152100556.stgit@warthog.procyon.org.uk/ # v5
digetx
pushed a commit
that referenced
this issue
Nov 16, 2021
The exit function fixes a memory leak with the src field as detected by
leak sanitizer. An example of which is:
Indirect leak of 25133184 byte(s) in 207 object(s) allocated from:
#0 0x7f199ecfe987 in __interceptor_calloc libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x55defe638224 in annotated_source__alloc_histograms util/annotate.c:803
#2 0x55defe6397e4 in symbol__hists util/annotate.c:952
#3 0x55defe639908 in symbol__inc_addr_samples util/annotate.c:968
#4 0x55defe63aa29 in hist_entry__inc_addr_samples util/annotate.c:1119
#5 0x55defe499a79 in hist_iter__report_callback tools/perf/builtin-report.c:182
#6 0x55defe7a859d in hist_entry_iter__add util/hist.c:1236
#7 0x55defe49aa63 in process_sample_event tools/perf/builtin-report.c:315
#8 0x55defe731bc8 in evlist__deliver_sample util/session.c:1473
#9 0x55defe731e38 in machines__deliver_event util/session.c:1510
#10 0x55defe732a23 in perf_session__deliver_event util/session.c:1590
#11 0x55defe72951e in ordered_events__deliver_event util/session.c:183
#12 0x55defe740082 in do_flush util/ordered-events.c:244
#13 0x55defe7407cb in __ordered_events__flush util/ordered-events.c:323
#14 0x55defe740a61 in ordered_events__flush util/ordered-events.c:341
#15 0x55defe73837f in __perf_session__process_events util/session.c:2390
#16 0x55defe7385ff in perf_session__process_events util/session.c:2420
...
Signed-off-by: Ian Rogers <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Martin Liška <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 18, 2021
Use __release_guc_id (lock held) rather than release_guc_id (acquires
lock), add lockdep annotations.
213.280129] i915: Running i915_perf_live_selftests/live_noa_gpr
[ 213.283459] ============================================
[ 213.283462] WARNING: possible recursive locking detected
{{[ 213.283466] 5.15.0-rc6+ #18 Tainted: G U W }}
[ 213.283470] --------------------------------------------
[ 213.283472] kworker/u24:0/8 is trying to acquire lock:
[ 213.283475] ffff8ffc4f6cc1e8 (&guc->submission_state.lock){....}-{2:2}, at: destroyed_worker_func+0x2df/0x350 [i915]
{{[ 213.283618] }}
{{ but task is already holding lock:}}
[ 213.283621] ffff8ffc4f6cc1e8 (&guc->submission_state.lock){....}-{2:2}, at: destroyed_worker_func+0x4f/0x350 [i915]
{{[ 213.283720] }}
{{ other info that might help us debug this:}}
[ 213.283724] Possible unsafe locking scenario:[ 213.283727] CPU0
[ 213.283728] ----
[ 213.283730] lock(&guc->submission_state.lock);
[ 213.283734] lock(&guc->submission_state.lock);
{{[ 213.283737] }}
{{ *** DEADLOCK ***}}[ 213.283740] May be due to missing lock nesting notation[ 213.283744] 3 locks held by kworker/u24:0/8:
[ 213.283747] #0: ffff8ffb80059d38 ((wq_completion)events_unbound){..}-{0:0}, at: process_one_work+0x1f3/0x550
[ 213.283757] #1: ffffb509000e3e78 ((work_completion)(&guc->submission_state.destroyed_worker)){..}-{0:0}, at: process_one_work+0x1f3/0x550
[ 213.283766] #2: ffff8ffc4f6cc1e8 (&guc->submission_state.lock){....}-{2:2}, at: destroyed_worker_func+0x4f/0x350 [i915]
{{[ 213.283860] }}
{{ stack backtrace:}}
[ 213.283863] CPU: 8 PID: 8 Comm: kworker/u24:0 Tainted: G U W 5.15.0-rc6+ #18
[ 213.283868] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 0403 01/26/2021
[ 213.283873] Workqueue: events_unbound destroyed_worker_func [i915]
[ 213.283957] Call Trace:
[ 213.283960] dump_stack_lvl+0x57/0x72
[ 213.283966] __lock_acquire.cold+0x191/0x2d3
[ 213.283972] lock_acquire+0xb5/0x2b0
[ 213.283978] ? destroyed_worker_func+0x2df/0x350 [i915]
[ 213.284059] ? destroyed_worker_func+0x2d7/0x350 [i915]
[ 213.284139] ? lock_release+0xb9/0x280
[ 213.284143] _raw_spin_lock_irqsave+0x48/0x60
[ 213.284148] ? destroyed_worker_func+0x2df/0x350 [i915]
[ 213.284226] destroyed_worker_func+0x2df/0x350 [i915]
[ 213.284310] process_one_work+0x270/0x550
[ 213.284315] worker_thread+0x52/0x3b0
[ 213.284319] ? process_one_work+0x550/0x550
[ 213.284322] kthread+0x135/0x160
[ 213.284326] ? set_kthread_struct+0x40/0x40
[ 213.284331] ret_from_fork+0x1f/0x30
and a bit later in the trace:
{{ 227.499864] do_raw_spin_lock+0x94/0xa0}}
[ 227.499868] _raw_spin_lock_irqsave+0x50/0x60
[ 227.499871] ? guc_flush_destroyed_contexts+0x4f/0xf0 [i915]
[ 227.499995] guc_flush_destroyed_contexts+0x4f/0xf0 [i915]
[ 227.500104] intel_guc_submission_reset_prepare+0x99/0x4b0 [i915]
[ 227.500209] ? mark_held_locks+0x49/0x70
[ 227.500212] intel_uc_reset_prepare+0x46/0x50 [i915]
[ 227.500320] reset_prepare+0x78/0x90 [i915]
[ 227.500412] __intel_gt_set_wedged.part.0+0x13/0xe0 [i915]
[ 227.500485] intel_gt_set_wedged.part.0+0x54/0x100 [i915]
[ 227.500556] intel_gt_set_wedged_on_fini+0x1a/0x30 [i915]
[ 227.500622] intel_gt_driver_unregister+0x1e/0x60 [i915]
[ 227.500694] i915_driver_remove+0x4a/0xf0 [i915]
[ 227.500767] i915_pci_probe+0x84/0x170 [i915]
[ 227.500838] local_pci_probe+0x42/0x80
[ 227.500842] pci_device_probe+0xd9/0x190
[ 227.500844] really_probe+0x1f2/0x3f0
[ 227.500847] __driver_probe_device+0xfe/0x180
[ 227.500848] driver_probe_device+0x1e/0x90
[ 227.500850] __driver_attach+0xc4/0x1d0
[ 227.500851] ? __device_attach_driver+0xe0/0xe0
[ 227.500853] ? __device_attach_driver+0xe0/0xe0
[ 227.500854] bus_for_each_dev+0x64/0x90
[ 227.500856] bus_add_driver+0x12e/0x1f0
[ 227.500857] driver_register+0x8f/0xe0
[ 227.500859] i915_init+0x1d/0x8f [i915]
[ 227.500934] ? 0xffffffffc144a000
[ 227.500936] do_one_initcall+0x58/0x2d0
[ 227.500938] ? rcu_read_lock_sched_held+0x3f/0x80
[ 227.500940] ? kmem_cache_alloc_trace+0x238/0x2d0
[ 227.500944] do_init_module+0x5c/0x270
[ 227.500946] __do_sys_finit_module+0x95/0xe0
[ 227.500949] do_syscall_64+0x38/0x90
[ 227.500951] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 227.500953] RIP: 0033:0x7ffa59d2ae0d
[ 227.500954] Code: c8 0c 00 0f 05 eb a9 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 3b 80 0c 00 f7 d8 64 89 01 48
[ 227.500955] RSP: 002b:00007fff320bbf48 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 227.500956] RAX: ffffffffffffffda RBX: 00000000022ea710 RCX: 00007ffa59d2ae0d
[ 227.500957] RDX: 0000000000000000 RSI: 00000000022e1d90 RDI: 0000000000000004
[ 227.500958] RBP: 0000000000000020 R08: 00007ffa59df3a60 R09: 0000000000000070
[ 227.500958] R10: 00000000022e1d90 R11: 0000000000000246 R12: 00000000022e1d90
[ 227.500959] R13: 00000000022e58e0 R14: 0000000000000043 R15: 00000000022e42c0
v2:
(CI build)
- Fix build error
Fixes: 1a52fae ("drm/i915/guc: Take GT PM ref when deregistering context")
Signed-off-by: Matthew Brost <[email protected]>
Cc: [email protected]
Reviewed-by: Thomas Hellström <[email protected]>
Signed-off-by: John Harrison <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
digetx
pushed a commit
that referenced
this issue
Nov 18, 2021
Often some test cases like btrfs/161 trigger lockdep splats that complain about possible unsafe lock scenario due to the fact that during mount, when reading the chunk tree we end up calling blkdev_get_by_path() while holding a read lock on a leaf of the chunk tree. That produces a lockdep splat like the following: [ 3653.683975] ====================================================== [ 3653.685148] WARNING: possible circular locking dependency detected [ 3653.686301] 5.15.0-rc7-btrfs-next-103 #1 Not tainted [ 3653.687239] ------------------------------------------------------ [ 3653.688400] mount/447465 is trying to acquire lock: [ 3653.689320] ffff8c6b0c76e528 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.691054] but task is already holding lock: [ 3653.692155] ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 3653.693978] which lock already depends on the new lock. [ 3653.695510] the existing dependency chain (in reverse order) is: [ 3653.696915] -> #3 (btrfs-chunk-00){++++}-{3:3}: [ 3653.698053] down_read_nested+0x4b/0x140 [ 3653.698893] __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 3653.699988] btrfs_read_lock_root_node+0x31/0x40 [btrfs] [ 3653.701205] btrfs_search_slot+0x537/0xc00 [btrfs] [ 3653.702234] btrfs_insert_empty_items+0x32/0x70 [btrfs] [ 3653.703332] btrfs_init_new_device+0x563/0x15b0 [btrfs] [ 3653.704439] btrfs_ioctl+0x2110/0x3530 [btrfs] [ 3653.705405] __x64_sys_ioctl+0x83/0xb0 [ 3653.706215] do_syscall_64+0x3b/0xc0 [ 3653.706990] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.708040] -> #2 (sb_internal#2){.+.+}-{0:0}: [ 3653.708994] lock_release+0x13d/0x4a0 [ 3653.709533] up_write+0x18/0x160 [ 3653.710017] btrfs_sync_file+0x3f3/0x5b0 [btrfs] [ 3653.710699] __loop_update_dio+0xbd/0x170 [loop] [ 3653.711360] lo_ioctl+0x3b1/0x8a0 [loop] [ 3653.711929] block_ioctl+0x48/0x50 [ 3653.712442] __x64_sys_ioctl+0x83/0xb0 [ 3653.712991] do_syscall_64+0x3b/0xc0 [ 3653.713519] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.714233] -> #1 (&lo->lo_mutex){+.+.}-{3:3}: [ 3653.715026] __mutex_lock+0x92/0x900 [ 3653.715648] lo_open+0x28/0x60 [loop] [ 3653.716275] blkdev_get_whole+0x28/0x90 [ 3653.716867] blkdev_get_by_dev.part.0+0x142/0x320 [ 3653.717537] blkdev_open+0x5e/0xa0 [ 3653.718043] do_dentry_open+0x163/0x390 [ 3653.718604] path_openat+0x3f0/0xa80 [ 3653.719128] do_filp_open+0xa9/0x150 [ 3653.719652] do_sys_openat2+0x97/0x160 [ 3653.720197] __x64_sys_openat+0x54/0x90 [ 3653.720766] do_syscall_64+0x3b/0xc0 [ 3653.721285] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.721986] -> #0 (&disk->open_mutex){+.+.}-{3:3}: [ 3653.722775] __lock_acquire+0x130e/0x2210 [ 3653.723348] lock_acquire+0xd7/0x310 [ 3653.723867] __mutex_lock+0x92/0x900 [ 3653.724394] blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.725041] blkdev_get_by_path+0xb8/0xd0 [ 3653.725614] btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs] [ 3653.726332] open_fs_devices+0xd7/0x2c0 [btrfs] [ 3653.726999] btrfs_read_chunk_tree+0x3ad/0x870 [btrfs] [ 3653.727739] open_ctree+0xb8e/0x17bf [btrfs] [ 3653.728384] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 3653.729130] legacy_get_tree+0x30/0x50 [ 3653.729676] vfs_get_tree+0x28/0xc0 [ 3653.730192] vfs_kern_mount.part.0+0x71/0xb0 [ 3653.730800] btrfs_mount+0x11d/0x3a0 [btrfs] [ 3653.731427] legacy_get_tree+0x30/0x50 [ 3653.731970] vfs_get_tree+0x28/0xc0 [ 3653.732486] path_mount+0x2d4/0xbe0 [ 3653.732997] __x64_sys_mount+0x103/0x140 [ 3653.733560] do_syscall_64+0x3b/0xc0 [ 3653.734080] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.734782] other info that might help us debug this: [ 3653.735784] Chain exists of: &disk->open_mutex --> sb_internal#2 --> btrfs-chunk-00 [ 3653.737123] Possible unsafe locking scenario: [ 3653.737865] CPU0 CPU1 [ 3653.738435] ---- ---- [ 3653.739007] lock(btrfs-chunk-00); [ 3653.739449] lock(sb_internal#2); [ 3653.740193] lock(btrfs-chunk-00); [ 3653.740955] lock(&disk->open_mutex); [ 3653.741431] *** DEADLOCK *** [ 3653.742176] 3 locks held by mount/447465: [ 3653.742739] #0: ffff8c6acf85c0e8 (&type->s_umount_key#44/1){+.+.}-{3:3}, at: alloc_super+0xd5/0x3b0 [ 3653.744114] #1: ffffffffc0b28f70 (uuid_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x59/0x870 [btrfs] [ 3653.745563] #2: ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 3653.747066] stack backtrace: [ 3653.747723] CPU: 4 PID: 447465 Comm: mount Not tainted 5.15.0-rc7-btrfs-next-103 #1 [ 3653.748873] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 3653.750592] Call Trace: [ 3653.750967] dump_stack_lvl+0x57/0x72 [ 3653.751526] check_noncircular+0xf3/0x110 [ 3653.752136] ? stack_trace_save+0x4b/0x70 [ 3653.752748] __lock_acquire+0x130e/0x2210 [ 3653.753356] lock_acquire+0xd7/0x310 [ 3653.753898] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.754596] ? lock_is_held_type+0xe8/0x140 [ 3653.755125] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.755729] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.756338] __mutex_lock+0x92/0x900 [ 3653.756794] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.757400] ? do_raw_spin_unlock+0x4b/0xa0 [ 3653.757930] ? _raw_spin_unlock+0x29/0x40 [ 3653.758437] ? bd_prepare_to_claim+0x129/0x150 [ 3653.758999] ? trace_module_get+0x2b/0xd0 [ 3653.759508] ? try_module_get.part.0+0x50/0x80 [ 3653.760072] blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.760661] ? devcgroup_check_permission+0xc1/0x1f0 [ 3653.761288] blkdev_get_by_path+0xb8/0xd0 [ 3653.761797] btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs] [ 3653.762454] open_fs_devices+0xd7/0x2c0 [btrfs] [ 3653.763055] ? clone_fs_devices+0x8f/0x170 [btrfs] [ 3653.763689] btrfs_read_chunk_tree+0x3ad/0x870 [btrfs] [ 3653.764370] ? kvm_sched_clock_read+0x14/0x40 [ 3653.764922] open_ctree+0xb8e/0x17bf [btrfs] [ 3653.765493] ? super_setup_bdi_name+0x79/0xd0 [ 3653.766043] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 3653.766780] ? rcu_read_lock_sched_held+0x3f/0x80 [ 3653.767488] ? kfree+0x1f2/0x3c0 [ 3653.767979] legacy_get_tree+0x30/0x50 [ 3653.768548] vfs_get_tree+0x28/0xc0 [ 3653.769076] vfs_kern_mount.part.0+0x71/0xb0 [ 3653.769718] btrfs_mount+0x11d/0x3a0 [btrfs] [ 3653.770381] ? rcu_read_lock_sched_held+0x3f/0x80 [ 3653.771086] ? kfree+0x1f2/0x3c0 [ 3653.771574] legacy_get_tree+0x30/0x50 [ 3653.772136] vfs_get_tree+0x28/0xc0 [ 3653.772673] path_mount+0x2d4/0xbe0 [ 3653.773201] __x64_sys_mount+0x103/0x140 [ 3653.773793] do_syscall_64+0x3b/0xc0 [ 3653.774333] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.775094] RIP: 0033:0x7f648bc45aaa This happens because through btrfs_read_chunk_tree(), which is called only during mount, ends up acquiring the mutex open_mutex of a block device while holding a read lock on a leaf of the chunk tree while other paths need to acquire other locks before locking extent buffers of the chunk tree. Since at mount time when we call btrfs_read_chunk_tree() we know that we don't have other tasks running in parallel and modifying the chunk tree, we can simply skip locking of chunk tree extent buffers. So do that and move the assertion that checks the fs is not yet mounted to the top block of btrfs_read_chunk_tree(), with a comment before doing it. Signed-off-by: Filipe Manana <[email protected]> Signed-off-by: David Sterba <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 18, 2021
Often some test cases like btrfs/161 trigger lockdep splats that complain about possible unsafe lock scenario due to the fact that during mount, when reading the chunk tree we end up calling blkdev_get_by_path() while holding a read lock on a leaf of the chunk tree. That produces a lockdep splat like the following: [ 3653.683975] ====================================================== [ 3653.685148] WARNING: possible circular locking dependency detected [ 3653.686301] 5.15.0-rc7-btrfs-next-103 #1 Not tainted [ 3653.687239] ------------------------------------------------------ [ 3653.688400] mount/447465 is trying to acquire lock: [ 3653.689320] ffff8c6b0c76e528 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.691054] but task is already holding lock: [ 3653.692155] ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 3653.693978] which lock already depends on the new lock. [ 3653.695510] the existing dependency chain (in reverse order) is: [ 3653.696915] -> #3 (btrfs-chunk-00){++++}-{3:3}: [ 3653.698053] down_read_nested+0x4b/0x140 [ 3653.698893] __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 3653.699988] btrfs_read_lock_root_node+0x31/0x40 [btrfs] [ 3653.701205] btrfs_search_slot+0x537/0xc00 [btrfs] [ 3653.702234] btrfs_insert_empty_items+0x32/0x70 [btrfs] [ 3653.703332] btrfs_init_new_device+0x563/0x15b0 [btrfs] [ 3653.704439] btrfs_ioctl+0x2110/0x3530 [btrfs] [ 3653.705405] __x64_sys_ioctl+0x83/0xb0 [ 3653.706215] do_syscall_64+0x3b/0xc0 [ 3653.706990] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.708040] -> #2 (sb_internal#2){.+.+}-{0:0}: [ 3653.708994] lock_release+0x13d/0x4a0 [ 3653.709533] up_write+0x18/0x160 [ 3653.710017] btrfs_sync_file+0x3f3/0x5b0 [btrfs] [ 3653.710699] __loop_update_dio+0xbd/0x170 [loop] [ 3653.711360] lo_ioctl+0x3b1/0x8a0 [loop] [ 3653.711929] block_ioctl+0x48/0x50 [ 3653.712442] __x64_sys_ioctl+0x83/0xb0 [ 3653.712991] do_syscall_64+0x3b/0xc0 [ 3653.713519] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.714233] -> #1 (&lo->lo_mutex){+.+.}-{3:3}: [ 3653.715026] __mutex_lock+0x92/0x900 [ 3653.715648] lo_open+0x28/0x60 [loop] [ 3653.716275] blkdev_get_whole+0x28/0x90 [ 3653.716867] blkdev_get_by_dev.part.0+0x142/0x320 [ 3653.717537] blkdev_open+0x5e/0xa0 [ 3653.718043] do_dentry_open+0x163/0x390 [ 3653.718604] path_openat+0x3f0/0xa80 [ 3653.719128] do_filp_open+0xa9/0x150 [ 3653.719652] do_sys_openat2+0x97/0x160 [ 3653.720197] __x64_sys_openat+0x54/0x90 [ 3653.720766] do_syscall_64+0x3b/0xc0 [ 3653.721285] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.721986] -> #0 (&disk->open_mutex){+.+.}-{3:3}: [ 3653.722775] __lock_acquire+0x130e/0x2210 [ 3653.723348] lock_acquire+0xd7/0x310 [ 3653.723867] __mutex_lock+0x92/0x900 [ 3653.724394] blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.725041] blkdev_get_by_path+0xb8/0xd0 [ 3653.725614] btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs] [ 3653.726332] open_fs_devices+0xd7/0x2c0 [btrfs] [ 3653.726999] btrfs_read_chunk_tree+0x3ad/0x870 [btrfs] [ 3653.727739] open_ctree+0xb8e/0x17bf [btrfs] [ 3653.728384] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 3653.729130] legacy_get_tree+0x30/0x50 [ 3653.729676] vfs_get_tree+0x28/0xc0 [ 3653.730192] vfs_kern_mount.part.0+0x71/0xb0 [ 3653.730800] btrfs_mount+0x11d/0x3a0 [btrfs] [ 3653.731427] legacy_get_tree+0x30/0x50 [ 3653.731970] vfs_get_tree+0x28/0xc0 [ 3653.732486] path_mount+0x2d4/0xbe0 [ 3653.732997] __x64_sys_mount+0x103/0x140 [ 3653.733560] do_syscall_64+0x3b/0xc0 [ 3653.734080] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.734782] other info that might help us debug this: [ 3653.735784] Chain exists of: &disk->open_mutex --> sb_internal#2 --> btrfs-chunk-00 [ 3653.737123] Possible unsafe locking scenario: [ 3653.737865] CPU0 CPU1 [ 3653.738435] ---- ---- [ 3653.739007] lock(btrfs-chunk-00); [ 3653.739449] lock(sb_internal#2); [ 3653.740193] lock(btrfs-chunk-00); [ 3653.740955] lock(&disk->open_mutex); [ 3653.741431] *** DEADLOCK *** [ 3653.742176] 3 locks held by mount/447465: [ 3653.742739] #0: ffff8c6acf85c0e8 (&type->s_umount_key#44/1){+.+.}-{3:3}, at: alloc_super+0xd5/0x3b0 [ 3653.744114] #1: ffffffffc0b28f70 (uuid_mutex){+.+.}-{3:3}, at: btrfs_read_chunk_tree+0x59/0x870 [btrfs] [ 3653.745563] #2: ffff8c6b0a9f39e0 (btrfs-chunk-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x24/0x110 [btrfs] [ 3653.747066] stack backtrace: [ 3653.747723] CPU: 4 PID: 447465 Comm: mount Not tainted 5.15.0-rc7-btrfs-next-103 #1 [ 3653.748873] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 3653.750592] Call Trace: [ 3653.750967] dump_stack_lvl+0x57/0x72 [ 3653.751526] check_noncircular+0xf3/0x110 [ 3653.752136] ? stack_trace_save+0x4b/0x70 [ 3653.752748] __lock_acquire+0x130e/0x2210 [ 3653.753356] lock_acquire+0xd7/0x310 [ 3653.753898] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.754596] ? lock_is_held_type+0xe8/0x140 [ 3653.755125] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.755729] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.756338] __mutex_lock+0x92/0x900 [ 3653.756794] ? blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.757400] ? do_raw_spin_unlock+0x4b/0xa0 [ 3653.757930] ? _raw_spin_unlock+0x29/0x40 [ 3653.758437] ? bd_prepare_to_claim+0x129/0x150 [ 3653.758999] ? trace_module_get+0x2b/0xd0 [ 3653.759508] ? try_module_get.part.0+0x50/0x80 [ 3653.760072] blkdev_get_by_dev.part.0+0xe7/0x320 [ 3653.760661] ? devcgroup_check_permission+0xc1/0x1f0 [ 3653.761288] blkdev_get_by_path+0xb8/0xd0 [ 3653.761797] btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs] [ 3653.762454] open_fs_devices+0xd7/0x2c0 [btrfs] [ 3653.763055] ? clone_fs_devices+0x8f/0x170 [btrfs] [ 3653.763689] btrfs_read_chunk_tree+0x3ad/0x870 [btrfs] [ 3653.764370] ? kvm_sched_clock_read+0x14/0x40 [ 3653.764922] open_ctree+0xb8e/0x17bf [btrfs] [ 3653.765493] ? super_setup_bdi_name+0x79/0xd0 [ 3653.766043] btrfs_mount_root.cold+0x12/0xde [btrfs] [ 3653.766780] ? rcu_read_lock_sched_held+0x3f/0x80 [ 3653.767488] ? kfree+0x1f2/0x3c0 [ 3653.767979] legacy_get_tree+0x30/0x50 [ 3653.768548] vfs_get_tree+0x28/0xc0 [ 3653.769076] vfs_kern_mount.part.0+0x71/0xb0 [ 3653.769718] btrfs_mount+0x11d/0x3a0 [btrfs] [ 3653.770381] ? rcu_read_lock_sched_held+0x3f/0x80 [ 3653.771086] ? kfree+0x1f2/0x3c0 [ 3653.771574] legacy_get_tree+0x30/0x50 [ 3653.772136] vfs_get_tree+0x28/0xc0 [ 3653.772673] path_mount+0x2d4/0xbe0 [ 3653.773201] __x64_sys_mount+0x103/0x140 [ 3653.773793] do_syscall_64+0x3b/0xc0 [ 3653.774333] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 3653.775094] RIP: 0033:0x7f648bc45aaa This happens because through btrfs_read_chunk_tree(), which is called only during mount, ends up acquiring the mutex open_mutex of a block device while holding a read lock on a leaf of the chunk tree while other paths need to acquire other locks before locking extent buffers of the chunk tree. Since at mount time when we call btrfs_read_chunk_tree() we know that we don't have other tasks running in parallel and modifying the chunk tree, we can simply skip locking of chunk tree extent buffers. So do that and move the assertion that checks the fs is not yet mounted to the top block of btrfs_read_chunk_tree(), with a comment before doing it. Signed-off-by: Filipe Manana <[email protected]> Signed-off-by: David Sterba <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 23, 2021
Each thread executing in an enclave is associated with a Thread Control Structure (TCS). The test enclave contains two hardcoded TCS. Each TCS contains meta-data used by the hardware to save and restore thread specific information when entering/exiting the enclave. The two TCS structures within the test enclave share their SSA (State Save Area) resulting in the threads clobbering each other's data. Fix this by providing each TCS their own SSA area. Additionally, there is an 8K stack space and its address is computed from the enclave entry point which is correctly done for TCS #1 that starts on the first address inside the enclave but results in out of bounds memory when entering as TCS #2. Split 8K stack space into two separate pages with offset symbol between to ensure the current enclave entry calculation can continue to be used for both threads. While using the enclave with multiple threads requires these fixes the impact is not apparent because every test up to this point enters the enclave from the first TCS. More detail about the stack fix: ------------------------------- Before this change the test enclave (test_encl) looks as follows: .tcs (2 pages): (page 1) TCS #1 (page 2) TCS #2 .text (1 page) One page of code .data (5 pages) (page 1) encl_buffer (page 2) encl_buffer (page 3) SSA (page 4 and 5) STACK encl_stack: As shown above there is a symbol, encl_stack, that points to the end of the .data segment (pointing to the end of page 5 in .data) which is also the end of the enclave. The enclave entry code computes the stack address by adding encl_stack to the pointer to the TCS that entered the enclave. When entering at TCS #1 the stack is computed correctly but when entering at TCS #2 the stack pointer would point to one page beyond the end of the enclave and a #PF would result when TCS #2 attempts to enter the enclave. The fix involves moving the encl_stack symbol between the two stack pages. Doing so enables the stack address computation in the entry code to compute the correct stack address for each TCS. Signed-off-by: Reinette Chatre <[email protected]> Signed-off-by: Dave Hansen <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Acked-by: Dave Hansen <[email protected]> Link: https://lkml.kernel.org/r/a49dc0d85401db788a0a3f0d795e848abf3b1f44.1636997631.git.reinette.chatre@intel.com
digetx
pushed a commit
that referenced
this issue
Nov 23, 2021
Protect perf_guest_cbs with RCU to fix multiple possible errors. Luckily, all paths that read perf_guest_cbs already require RCU protection, e.g. to protect the callback chains, so only the direct perf_guest_cbs touchpoints need to be modified. Bug #1 is a simple lack of WRITE_ONCE/READ_ONCE behavior to ensure perf_guest_cbs isn't reloaded between a !NULL check and a dereference. Fixed via the READ_ONCE() in rcu_dereference(). Bug #2 is that on weakly-ordered architectures, updates to the callbacks themselves are not guaranteed to be visible before the pointer is made visible to readers. Fixed by the smp_store_release() in rcu_assign_pointer() when the new pointer is non-NULL. Bug #3 is that, because the callbacks are global, it's possible for readers to run in parallel with an unregisters, and thus a module implementing the callbacks can be unloaded while readers are in flight, resulting in a use-after-free. Fixed by a synchronize_rcu() call when unregistering callbacks. Bug #1 escaped notice because it's extremely unlikely a compiler will reload perf_guest_cbs in this sequence. perf_guest_cbs does get reloaded for future derefs, e.g. for ->is_user_mode(), but the ->is_in_guest() guard all but guarantees the consumer will win the race, e.g. to nullify perf_guest_cbs, KVM has to completely exit the guest and teardown down all VMs before KVM start its module unload / unregister sequence. This also makes it all but impossible to encounter bug #3. Bug #2 has not been a problem because all architectures that register callbacks are strongly ordered and/or have a static set of callbacks. But with help, unloading kvm_intel can trigger bug #1 e.g. wrapping perf_guest_cbs with READ_ONCE in perf_misc_flags() while spamming kvm_intel module load/unload leads to: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 6 PID: 1825 Comm: stress Not tainted 5.14.0-rc2+ #459 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:perf_misc_flags+0x1c/0x70 Call Trace: perf_prepare_sample+0x53/0x6b0 perf_event_output_forward+0x67/0x160 __perf_event_overflow+0x52/0xf0 handle_pmi_common+0x207/0x300 intel_pmu_handle_irq+0xcf/0x410 perf_event_nmi_handler+0x28/0x50 nmi_handle+0xc7/0x260 default_do_nmi+0x6b/0x170 exc_nmi+0x103/0x130 asm_exc_nmi+0x76/0xbf Fixes: 39447b3 ("perf: Enhance perf to allow for guest statistic collection from host") Signed-off-by: Sean Christopherson <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Paolo Bonzini <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected]
digetx
pushed a commit
that referenced
this issue
Nov 24, 2021
Ido Schimmel says: ==================== mlxsw: Various updates Patch #1 removes deadcode reported by Coverity. Patch #2 adds a shutdown method in the PCI driver to ensure the kexeced kernel starts working with a device that is in a sane state. ==================== Signed-off-by: David S. Miller <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 24, 2021
Ido Schimmel says: ==================== mlxsw: Two small fixes Patch #1 fixes a recent regression that prevents the driver from loading with old firmware versions. Patch #2 protects the driver from a NULL pointer dereference when working on top of a buggy firmware. This was never observed in an actual system, only on top of an emulator during development. ==================== Signed-off-by: David S. Miller <[email protected]>
digetx
pushed a commit
that referenced
this issue
Nov 30, 2021
The capture code is typically run entirely in the fence signalling critical path. We're about to add lockdep annotation in an upcoming patch which reveals a lockdep splat similar to the below one. Fix the associated potential deadlocks using __GFP_KSWAPD_RECLAIM (which is the same as GFP_WAIT, but open-coded for clarity) rather than GFP_KERNEL for memory allocation in the capture path. This has the potential drawback that capture might fail in situations with memory pressure. [ 234.842048] WARNING: possible circular locking dependency detected [ 234.842050] 5.15.0-rc7+ #20 Tainted: G U W [ 234.842052] ------------------------------------------------------ [ 234.842054] gem_exec_captur/1180 is trying to acquire lock: [ 234.842056] ffffffffa3e51c00 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc+0x4d/0x330 [ 234.842063] but task is already holding lock: [ 234.842064] ffffffffa3f57620 (dma_fence_map){++++}-{0:0}, at: i915_vma_snapshot_resource_pin+0x27/0x30 [i915] [ 234.842138] which lock already depends on the new lock. [ 234.842140] the existing dependency chain (in reverse order) is: [ 234.842142] -> #2 (dma_fence_map){++++}-{0:0}: [ 234.842145] __dma_fence_might_wait+0x41/0xa0 [ 234.842149] dma_resv_lockdep+0x1dc/0x28f [ 234.842151] do_one_initcall+0x58/0x2d0 [ 234.842154] kernel_init_freeable+0x273/0x2bf [ 234.842157] kernel_init+0x16/0x120 [ 234.842160] ret_from_fork+0x1f/0x30 [ 234.842163] -> #1 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}: [ 234.842166] fs_reclaim_acquire+0x6d/0xd0 [ 234.842168] __kmalloc_node+0x51/0x3a0 [ 234.842171] alloc_cpumask_var_node+0x1b/0x30 [ 234.842174] native_smp_prepare_cpus+0xc7/0x292 [ 234.842177] kernel_init_freeable+0x160/0x2bf [ 234.842179] kernel_init+0x16/0x120 [ 234.842181] ret_from_fork+0x1f/0x30 [ 234.842184] -> #0 (fs_reclaim){+.+.}-{0:0}: [ 234.842186] __lock_acquire+0x1161/0x1dc0 [ 234.842189] lock_acquire+0xb5/0x2b0 [ 234.842192] fs_reclaim_acquire+0xa1/0xd0 [ 234.842193] __kmalloc+0x4d/0x330 [ 234.842196] i915_vma_coredump_create+0x78/0x5b0 [i915] [ 234.842253] intel_engine_coredump_add_vma+0x36/0xe0 [i915] [ 234.842307] __i915_gpu_coredump+0x290/0x5e0 [i915] [ 234.842365] i915_capture_error_state+0x57/0xa0 [i915] [ 234.842415] intel_gt_handle_error+0x348/0x3e0 [i915] [ 234.842462] intel_gt_debugfs_reset_store+0x3c/0x90 [i915] [ 234.842504] simple_attr_write+0xc1/0xe0 [ 234.842507] full_proxy_write+0x53/0x80 [ 234.842509] vfs_write+0xbc/0x350 [ 234.842513] ksys_write+0x58/0xd0 [ 234.842514] do_syscall_64+0x38/0x90 [ 234.842516] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 234.842519] other info that might help us debug this: [ 234.842521] Chain exists of: fs_reclaim --> mmu_notifier_invalidate_range_start --> dma_fence_map [ 234.842526] Possible unsafe locking scenario: [ 234.842528] CPU0 CPU1 [ 234.842529] ---- ---- [ 234.842531] lock(dma_fence_map); [ 234.842532] lock(mmu_notifier_invalidate_range_start); [ 234.842535] lock(dma_fence_map); [ 234.842537] lock(fs_reclaim); [ 234.842539] *** DEADLOCK *** [ 234.842540] 4 locks held by gem_exec_captur/1180: [ 234.842543] #0: ffff9007812d9460 (sb_writers#17){.+.+}-{0:0}, at: ksys_write+0x58/0xd0 [ 234.842547] #1: ffff900781d9ecb8 (&attr->mutex){+.+.}-{3:3}, at: simple_attr_write+0x3a/0xe0 [ 234.842552] #2: ffffffffc11913a8 (capture_mutex){+.+.}-{3:3}, at: i915_capture_error_state+0x1a/0xa0 [i915] [ 234.842602] #3: ffffffffa3f57620 (dma_fence_map){++++}-{0:0}, at: i915_vma_snapshot_resource_pin+0x27/0x30 [i915] [ 234.842656] stack backtrace: [ 234.842658] CPU: 0 PID: 1180 Comm: gem_exec_captur Tainted: G U W 5.15.0-rc7+ #20 [ 234.842661] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 0403 01/26/2021 [ 234.842664] Call Trace: [ 234.842666] dump_stack_lvl+0x57/0x72 [ 234.842669] check_noncircular+0xde/0x100 [ 234.842672] ? __lock_acquire+0x3bf/0x1dc0 [ 234.842675] __lock_acquire+0x1161/0x1dc0 [ 234.842678] lock_acquire+0xb5/0x2b0 [ 234.842680] ? __kmalloc+0x4d/0x330 [ 234.842683] ? finish_task_switch.isra.0+0xf2/0x360 [ 234.842686] ? i915_vma_coredump_create+0x78/0x5b0 [i915] [ 234.842734] fs_reclaim_acquire+0xa1/0xd0 [ 234.842737] ? __kmalloc+0x4d/0x330 [ 234.842739] __kmalloc+0x4d/0x330 [ 234.842742] i915_vma_coredump_create+0x78/0x5b0 [i915] [ 234.842793] ? capture_vma+0xbe/0x110 [i915] [ 234.842844] intel_engine_coredump_add_vma+0x36/0xe0 [i915] [ 234.842892] __i915_gpu_coredump+0x290/0x5e0 [i915] [ 234.842939] i915_capture_error_state+0x57/0xa0 [i915] [ 234.842985] intel_gt_handle_error+0x348/0x3e0 [i915] [ 234.843032] ? __mutex_lock+0x81/0x830 [ 234.843035] ? simple_attr_write+0x3a/0xe0 [ 234.843038] ? __lock_acquire+0x3bf/0x1dc0 [ 234.843041] intel_gt_debugfs_reset_store+0x3c/0x90 [i915] [ 234.843083] ? _copy_from_user+0x45/0x80 [ 234.843086] simple_attr_write+0xc1/0xe0 [ 234.843089] full_proxy_write+0x53/0x80 [ 234.843091] vfs_write+0xbc/0x350 [ 234.843094] ksys_write+0x58/0xd0 [ 234.843096] do_syscall_64+0x38/0x90 [ 234.843098] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 234.843101] RIP: 0033:0x7fa467480877 [ 234.843103] Code: 75 05 48 83 c4 58 c3 e8 37 4e ff ff 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 [ 234.843108] RSP: 002b:00007ffd14d79b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 234.843112] RAX: ffffffffffffffda RBX: 00007ffd14d79b60 RCX: 00007fa467480877 [ 234.843114] RDX: 0000000000000014 RSI: 00007ffd14d79b60 RDI: 0000000000000007 [ 234.843116] RBP: 0000000000000007 R08: 0000000000000000 R09: 00007ffd14d79ab0 [ 234.843119] R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000014 [ 234.843121] R13: 0000000000000000 R14: 00007ffd14d79b60 R15: 0000000000000005 v5: - Use __GFP_KSWAPD_RECLAIM rather than __GFP_NOWAIT for clarity. (Daniel Vetter) v6: - Include an instance in execlists_capture_work(). - Rework the commit message due to patch reordering. Signed-off-by: Thomas Hellström <[email protected]> Reviewed-by: Ramalingam C <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
digetx
pushed a commit
that referenced
this issue
Nov 30, 2021
…/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 5.16, take #2 - Fix constant sign extension affecting TCR_EL2 and preventing running on ARMv8.7 models due to spurious bits being set - Fix use of helpers using PSTATE early on exit by always sampling it as soon as the exit takes place - Move pkvm's 32bit handling into a common helper
digetx
pushed a commit
that referenced
this issue
Nov 30, 2021
Support static initialization of BPF_MAP_TYPE_PROG_ARRAY with a
syntax similar to map-in-map initialization ([0]):
SEC("socket")
int tailcall_1(void *ctx)
{
return 0;
}
struct {
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
__uint(max_entries, 2);
__uint(key_size, sizeof(__u32));
__array(values, int (void *));
} prog_array_init SEC(".maps") = {
.values = {
[1] = (void *)&tailcall_1,
},
};
Here's the relevant part of libbpf debug log showing what's
going on with prog-array initialization:
libbpf: sec '.relsocket': collecting relocation for section(3) 'socket'
libbpf: sec '.relsocket': relo #0: insn #2 against 'prog_array_init'
libbpf: prog 'entry': found map 0 (prog_array_init, sec 4, off 0) for insn #0
libbpf: .maps relo #0: for 3 value 0 rel->r_offset 32 name 53 ('tailcall_1')
libbpf: .maps relo #0: map 'prog_array_init' slot [1] points to prog 'tailcall_1'
libbpf: map 'prog_array_init': created successfully, fd=5
libbpf: map 'prog_array_init': slot [1] set to prog 'tailcall_1' fd=6
[0] Closes: libbpf/libbpf#354
Signed-off-by: Hengqi Chen <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
digetx
pushed a commit
that referenced
this issue
Nov 30, 2021
Provide a pair of functions to count the number of users of a cookie (open files, writeback, invalidation, resizing, reads, writes), to obtain and pin resources for the cookie and to prevent culling for the whilst there are users. The first function marks a cookie as being in use: void fscache_use_cookie(struct fscache_cookie *cookie, bool will_modify); The caller should indicate the cookie to use and whether or not the caller is in a context that may modify the cookie (e.g. a file open O_RDWR). If the cookie is not already resourced, fscache will ask the cache backend in the background to do whatever it needs to look up, create or otherwise obtain the resources necessary to access data. This is pinned to the cookie and may not be culled, though it may be withdrawn if the cache as a whole is withdrawn. The second function removes the in-use mark from a cookie and, optionally, updates the coherency data: void fscache_unuse_cookie(struct fscache_cookie *cookie, const void *aux_data, const loff_t *object_size); If non-NULL, the aux_data buffer and/or the object_size will be saved into the cookie and will be set on the backing store when the object is committed. If this removes the last usage on a cookie, the cookie is placed onto an LRU list from which it will be removed and closed after a couple of seconds if it doesn't get reused. This prevents resource overload in the cache - in particular it prevents it from holding too many files open. Changes ======= ver #2: - Fix fscache_unuse_cookie() to use atomic_dec_and_lock() to avoid a potential race if the cookie gets reused before it completes the unusement. Signed-off-by: David Howells <[email protected]> cc: [email protected]
digetx
pushed a commit
that referenced
this issue
Jan 16, 2022
Change the 9p filesystem to take account of the changes to fscache's
indexing rewrite and reenable caching in 9p.
The following changes have been made:
(1) The fscache_netfs struct is no more, and there's no need to register
the filesystem as a whole.
(2) The session cookie is now an fscache_volume cookie, allocated with
fscache_acquire_volume(). That takes three parameters: a string
representing the "volume" in the index, a string naming the cache to
use (or NULL) and a u64 that conveys coherency metadata for the
volume.
For 9p, I've made it render the volume name string as:
"9p,<devname>,<cachetag>"
where the cachetag is replaced by the aname if it wasn't supplied.
This probably needs rethinking a bit as the aname can have slashes in
it. It might be better to hash the cachetag and use the hash or I
could substitute commas for the slashes or something.
(3) The fscache_cookie_def is no more and needed information is passed
directly to fscache_acquire_cookie(). The cache no longer calls back
into the filesystem, but rather metadata changes are indicated at
other times.
fscache_acquire_cookie() is passed the same keying and coherency
information as before.
(4) The functions to set/reset/flush cookies are removed and
fscache_use_cookie() and fscache_unuse_cookie() are used instead.
fscache_use_cookie() is passed a flag to indicate if the cookie is
opened for writing. fscache_unuse_cookie() is passed updates for the
metadata if we changed it (ie. if the file was opened for writing).
These are called when the file is opened or closed.
(5) wait_on_page_bit[_killable]() is replaced with the specific wait
functions for the bits waited upon.
(6) I've got rid of some of the 9p-specific cache helper functions and
called things like fscache_relinquish_cookie() directly as they'll
optimise away if v9fs_inode_cookie() returns an unconditional NULL
(which will be the case if CONFIG_9P_FSCACHE=n).
(7) v9fs_vfs_setattr() is made to call fscache_resize() to change the size
of the cache object.
Notes:
(A) We should call fscache_invalidate() if we detect that the server's
copy of a file got changed by a third party, but I don't know where to
do that. We don't need to do that when allocating the cookie as we
get a check-and-invalidate when we initially bind to the cache object.
(B) The copy-to-cache-on-writeback side of things will be handled in
separate patch.
Changes
=======
ver #3:
- Canonicalise the cookie key and coherency data to make them
endianness-independent.
ver #2:
- Use gfpflags_allow_blocking() rather than using flag directly.
- fscache_acquire_volume() now returns errors.
Signed-off-by: David Howells <[email protected]>
Acked-by: Jeff Layton <[email protected]>
Tested-by: Dominique Martinet <[email protected]>
cc: Eric Van Hensbergen <[email protected]>
cc: Latchesar Ionkov <[email protected]>
cc: [email protected]
cc: [email protected]
Link: https://lore.kernel.org/r/163819664645.215744.1555314582005286846.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906975017.143852.3459573173204394039.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967178512.1823006.17377493641569138183.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021573143.640689.3977487095697717967.stgit@warthog.procyon.org.uk/ # v4
digetx
pushed a commit
that referenced
this issue
Jan 16, 2022
When writing to the server from v9fs_vfs_writepage(), copy the data to the cache object too. To make this possible, the cookie must have its active users count incremented when the page is dirtied and kept incremented until we manage to clean up all the pages. This allows the writeback to take place after the last file struct is released. This is done by taking a use on the cookie in v9fs_set_page_dirty() if we haven't already done so (controlled by the I_PINNING_FSCACHE_WB flag) and dropping the pin in v9fs_write_inode() if __writeback_single_inode() clears all the outstanding dirty pages (conveyed by the unpinned_fscache_wb flag in the writeback_control struct). Inode eviction must also clear the flag after truncating away all the outstanding pages. In the future this will be handled more gracefully by netfslib. Changes ======= ver #3: - Canonicalise the coherency data to make it endianness-independent. ver #2: - Fix an unused-var warning due to CONFIG_9P_FSCACHE=n[1]. Signed-off-by: David Howells <[email protected]> Acked-by: Jeff Layton <[email protected]> Tested-by: Dominique Martinet <[email protected]> cc: Eric Van Hensbergen <[email protected]> cc: Latchesar Ionkov <[email protected]> cc: [email protected] cc: [email protected] Link: https://lore.kernel.org/r/163819667027.215744.13815687931204222995.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906978015.143852.10646669694345706328.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967180760.1823006.5831751873616248910.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021574522.640689.13849966660182529125.stgit@warthog.procyon.org.uk/ # v4
digetx
pushed a commit
that referenced
this issue
Jan 16, 2022
Change the nfs filesystem to support fscache's indexing rewrite and
reenable caching in nfs.
The following changes have been made:
(1) The fscache_netfs struct is no more, and there's no need to register
the filesystem as a whole.
(2) The session cookie is now an fscache_volume cookie, allocated with
fscache_acquire_volume(). That takes three parameters: a string
representing the "volume" in the index, a string naming the cache to
use (or NULL) and a u64 that conveys coherency metadata for the
volume.
For nfs, I've made it render the volume name string as:
"nfs,<ver>,<family>,<address>,<port>,<fsidH>,<fsidL>*<,param>[,<uniq>]"
(3) The fscache_cookie_def is no more and needed information is passed
directly to fscache_acquire_cookie(). The cache no longer calls back
into the filesystem, but rather metadata changes are indicated at
other times.
fscache_acquire_cookie() is passed the same keying and coherency
information as before.
(4) fscache_enable/disable_cookie() have been removed.
Call fscache_use_cookie() and fscache_unuse_cookie() when a file is
opened or closed to prevent a cache file from being culled and to keep
resources to hand that are needed to do I/O.
If a file is opened for writing, we invalidate it with
FSCACHE_INVAL_DIO_WRITE in lieu of doing writeback to the cache,
thereby making it cease caching until all currently open files are
closed. This should give the same behaviour as the uptream code.
Making the cache store local modifications isn't straightforward for
NFS, so that's left for future patches.
(5) fscache_invalidate() now needs to be given uptodate auxiliary data and
a file size. It also takes a flag to indicate if this was due to a
DIO write.
(6) Call nfs_fscache_invalidate() with FSCACHE_INVAL_DIO_WRITE on a file
to which a DIO write is made.
(7) Call fscache_note_page_release() from nfs_release_page().
(8) Use a killable wait in nfs_vm_page_mkwrite() when waiting for
PG_fscache to be cleared.
(9) The functions to read and write data to/from the cache are stubbed out
pending a conversion to use netfslib.
Changes
=======
ver #3:
- Added missing =n fallback for nfs_fscache_release_file()[1][2].
ver #2:
- Use gfpflags_allow_blocking() rather than using flag directly.
- fscache_acquire_volume() now returns errors.
- Remove NFS_INO_FSCACHE as it's no longer used.
- Need to unuse a cookie on file-release, not inode-clear.
Signed-off-by: Dave Wysochanski <[email protected]>
Co-developed-by: David Howells <[email protected]>
Signed-off-by: David Howells <[email protected]>
Tested-by: Dave Wysochanski <[email protected]>
Acked-by: Jeff Layton <[email protected]>
cc: Trond Myklebust <[email protected]>
cc: Anna Schumaker <[email protected]>
cc: [email protected]
cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]/ [1]
Link: https://lore.kernel.org/r/[email protected]/ [2]
Link: https://lore.kernel.org/r/163819668938.215744.14448852181937731615.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906979003.143852.2601189243864854724.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967182112.1823006.7791504655391213379.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021575950.640689.12069642327533368467.stgit@warthog.procyon.org.uk/ # v4
digetx
pushed a commit
that referenced
this issue
Jan 16, 2022
Rewrite the fscache documentation. Changes ======= ver #3: - The volume coherency data is now an arbitrarily-sized blob, not a u64. ver #2: - Put quoting around some bits of C being referred to in the docs[1]. - Stripped the markup off the ref to the netfs lib doc[2]. Signed-off-by: David Howells <[email protected]> Reviewed-by: Jeff Layton <[email protected]> cc: [email protected] Link: https://lore.kernel.org/r/[email protected]/ [1] Link: https://lore.kernel.org/r/[email protected]/ [2] Link: https://lore.kernel.org/r/163819672252.215744.15454333549935901588.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906986754.143852.17703291789683936950.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967193834.1823006.15991526817786159772.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021585970.640689.3162537597817521032.stgit@warthog.procyon.org.uk/ # v4
digetx
pushed a commit
that referenced
this issue
Jan 16, 2022
…rors
Use down_read_nested() and down_write_nested() when taking the
ctrl->reset_lock rw-sem, passing the number of PCIe hotplug controllers in
the path to the PCI root bus as lock subclass parameter.
This fixes the following false-positive lockdep report when unplugging a
Lenovo X1C8 from a Lenovo 2nd gen TB3 dock:
pcieport 0000:06:01.0: pciehp: Slot(1): Link Down
pcieport 0000:06:01.0: pciehp: Slot(1): Card not present
============================================
WARNING: possible recursive locking detected
5.16.0-rc2+ #621 Not tainted
--------------------------------------------
irq/124-pciehp/86 is trying to acquire lock:
ffff8e5ac4299ef8 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_check_presence+0x23/0x80
but task is already holding lock:
ffff8e5ac4298af8 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_ist+0xf3/0x180
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&ctrl->reset_lock);
lock(&ctrl->reset_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by irq/124-pciehp/86:
#0: ffff8e5ac4298af8 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_ist+0xf3/0x180
#1: ffffffffa3b024e8 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pciehp_unconfigure_device+0x31/0x110
#2: ffff8e5ac1ee2248 (&dev->mutex){....}-{3:3}, at: device_release_driver+0x1c/0x40
stack backtrace:
CPU: 4 PID: 86 Comm: irq/124-pciehp Not tainted 5.16.0-rc2+ #621
Hardware name: LENOVO 20U90SIT19/20U90SIT19, BIOS N2WET30W (1.20 ) 08/26/2021
Call Trace:
<TASK>
dump_stack_lvl+0x59/0x73
__lock_acquire.cold+0xc5/0x2c6
lock_acquire+0xb5/0x2b0
down_read+0x3e/0x50
pciehp_check_presence+0x23/0x80
pciehp_runtime_resume+0x5c/0xa0
device_for_each_child+0x45/0x70
pcie_port_device_runtime_resume+0x20/0x30
pci_pm_runtime_resume+0xa7/0xc0
__rpm_callback+0x41/0x110
rpm_callback+0x59/0x70
rpm_resume+0x512/0x7b0
__pm_runtime_resume+0x4a/0x90
__device_release_driver+0x28/0x240
device_release_driver+0x26/0x40
pci_stop_bus_device+0x68/0x90
pci_stop_bus_device+0x2c/0x90
pci_stop_and_remove_bus_device+0xe/0x20
pciehp_unconfigure_device+0x6c/0x110
pciehp_disable_slot+0x5b/0xe0
pciehp_handle_presence_or_link_change+0xc3/0x2f0
pciehp_ist+0x179/0x180
This lockdep warning is triggered because with Thunderbolt, hotplug ports
are nested. When removing multiple devices in a daisy-chain, each hotplug
port's reset_lock may be acquired recursively. It's never the same lock, so
the lockdep splat is a false positive.
Because locks at the same hierarchy level are never acquired recursively, a
per-level lockdep class is sufficient to fix the lockdep warning.
The choice to use one lockdep subclass per pcie-hotplug controller in the
path to the root-bus was made to conserve class keys because their number
is limited and the complexity grows quadratically with number of keys
according to Documentation/locking/lockdep-design.rst.
Link: https://lore.kernel.org/linux-pci/[email protected]/
Link: https://lore.kernel.org/linux-pci/[email protected]/
Link: https://lore.kernel.org/r/[email protected]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208855
Reported-by: "Theodore Ts'o" <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Lukas Wunner <[email protected]>
Cc: [email protected]
digetx
pushed a commit
that referenced
this issue
Jan 16, 2022
If the key is already present then free the key used for lookup.
Found with:
$ perf stat -M IO_Read_BW /bin/true
==1749112==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 32 byte(s) in 4 object(s) allocated from:
#0 0x7f6f6fa7d7cf in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:145
#1 0x55acecd9d7a6 in check_per_pkg util/stat.c:343
#2 0x55acecd9d9c5 in process_counter_values util/stat.c:365
#3 0x55acecd9e0ab in process_counter_maps util/stat.c:421
#4 0x55acecd9e292 in perf_stat_process_counter util/stat.c:443
#5 0x55aceca8553e in read_counters ./tools/perf/builtin-stat.c:470
#6 0x55aceca88fe3 in __run_perf_stat ./tools/perf/builtin-stat.c:1023
#7 0x55aceca89146 in run_perf_stat ./tools/perf/builtin-stat.c:1048
#8 0x55aceca90858 in cmd_stat ./tools/perf/builtin-stat.c:2555
#9 0x55acecc05fa5 in run_builtin ./tools/perf/perf.c:313
#10 0x55acecc064fe in handle_internal_command ./tools/perf/perf.c:365
#11 0x55acecc068bb in run_argv ./tools/perf/perf.c:409
#12 0x55acecc070aa in main ./tools/perf/perf.c:539
Reviewed-by: James Clark <[email protected]>
Signed-off-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Clarke <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Riccardo Mancini <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Vineet Singh <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
digetx
pushed a commit
that referenced
this issue
Jan 16, 2022
Change the cifs filesystem to take account of the changes to fscache's
indexing rewrite and reenable caching in cifs.
The following changes have been made:
(1) The fscache_netfs struct is no more, and there's no need to register
the filesystem as a whole.
(2) The session cookie is now an fscache_volume cookie, allocated with
fscache_acquire_volume(). That takes three parameters: a string
representing the "volume" in the index, a string naming the cache to
use (or NULL) and a u64 that conveys coherency metadata for the
volume.
For cifs, I've made it render the volume name string as:
"cifs,<ipaddress>,<sharename>"
where the sharename has '/' characters replaced with ';'.
This probably needs rethinking a bit as the total name could exceed
the maximum filename component length.
Further, the coherency data is currently just set to 0. It needs
something else doing with it - I wonder if it would suffice simply to
sum the resource_id, vol_create_time and vol_serial_number or maybe
hash them.
(3) The fscache_cookie_def is no more and needed information is passed
directly to fscache_acquire_cookie(). The cache no longer calls back
into the filesystem, but rather metadata changes are indicated at
other times.
fscache_acquire_cookie() is passed the same keying and coherency
information as before.
(4) The functions to set/reset cookies are removed and
fscache_use_cookie() and fscache_unuse_cookie() are used instead.
fscache_use_cookie() is passed a flag to indicate if the cookie is
opened for writing. fscache_unuse_cookie() is passed updates for the
metadata if we changed it (ie. if the file was opened for writing).
These are called when the file is opened or closed.
(5) cifs_setattr_*() are made to call fscache_resize() to change the size
of the cache object.
(6) The functions to read and write data are stubbed out pending a
conversion to use netfslib.
Changes
=======
ver #7:
- Removed the accidentally added-back call to get the super cookie in
cifs_root_iget().
- Fixed the right call to cifs_fscache_get_super_cookie() to take account
of the "-o fsc" mount flag.
ver #6:
- Moved the change of gfpflags_allow_blocking() to current_is_kswapd() for
cifs here.
- Fixed one of the error paths in cifs_atomic_open() to jump around the
call to use the cookie.
- Fixed an additional successful return in the middle of cifs_open() to
use the cookie on the way out.
- Only get a volume cookie (and thus inode cookies) when "-o fsc" is
supplied to mount.
ver #5:
- Fixed a couple of bits of cookie handling[2]:
- The cookie should be released in cifs_evict_inode(), not
cifsFileInfo_put_final(). The cookie needs to persist beyond file
closure so that writepages will be able to write to it.
- fscache_use_cookie() needs to be called in cifs_atomic_open() as it is
for cifs_open().
ver #4:
- Fixed the use of sizeof with memset.
- tcon->vol_create_time is __le64 so doesn't need cpu_to_le64().
ver #3:
- Canonicalise the cifs coherency data to make the cache portable.
- Set volume coherency data.
ver #2:
- Use gfpflags_allow_blocking() rather than using flag directly.
- Upgraded to -rc4 to allow for upstream changes[1].
- fscache_acquire_volume() now returns errors.
Signed-off-by: David Howells <[email protected]>
Acked-by: Jeff Layton <[email protected]>
cc: Steve French <[email protected]>
cc: Shyam Prasad N <[email protected]>
cc: [email protected]
cc: [email protected]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23b55d673d7527b093cd97b7c217c82e70cd1af0 [1]
Link: https://lore.kernel.org/r/[email protected]/ [2]
Link: https://lore.kernel.org/r/163819671009.215744.11230627184193298714.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906982979.143852.10672081929614953210.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967187187.1823006.247415138444991444.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021579335.640689.2681324337038770579.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/[email protected]/ # v5
Link: https://lore.kernel.org/r/[email protected]/ # v6
digetx
pushed a commit
that referenced
this issue
Jan 16, 2022
…patch-fixes Cc: Davidlohr Bueso <[email protected]> WARNING: A patch subject line should describe the change not the tool that found it #2: Subject: kernel-sys-only-take-tasklist_lock-for-get-setpriorityprio_pgrp-checkpatch-fixes WARNING: Commit log lines starting with '#' are dropped by git as comments #5: #102: FILE: kernel/sys.c:321: WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line) #13: mechanically convert to the typical style using --fix or --fix-inplace. total: 0 errors, 3 warnings, 8 lines checked NOTE: For some of the reported defects, checkpatch may be able to mechanically convert to the typical style using --fix or --fix-inplace. ./patches/kernel-sys-only-take-tasklist_lock-for-get-setpriorityprio_pgrp-checkpatch-fixes.patch has style problems, please review. NOTE: If any of the errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Cc: Davidlohr Bueso <[email protected]> Cc: Davidlohr Bueso <[email protected]> Cc: Oleg Nesterov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Stephen Rothwell <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
I'm working on the Ouya Console using the current master (5.0-rc5) branch of this kernel. The device crashes in the cpuidle lp2 state.
I don't have a serial debugger set up. I am using the android ram console driver. It isn't very reliable way to get kernel logs. The ram console logs are usually corrupted for this crash.
I was able to resolve the crash by moving the
call_firmware_op(prepare_idle, TF_PM_MODE_LP2)farther down the suspend path.Decatf/linux@3fee4a5
The text was updated successfully, but these errors were encountered: