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add API routines to spill and restore xmm registers to our spill slots #412

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derekbruening opened this issue Nov 28, 2014 · 0 comments
Open

add API routines to spill and restore xmm registers to our spill slots #412

derekbruening opened this issue Nov 28, 2014 · 0 comments
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Component-API Migrated Priority-Medium Type-Feature

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@derekbruening
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From [email protected] on March 10, 2011 21:06:20

this was PR 315327

we should provide save and restore xmm register routines that use our dcontext spill slots. We don't use them much so there's little risk of collision and they are faster to access then the client could manage using the provided client tls (unless taking a ton of slots via calloc).

Original issue: http://code.google.com/p/dynamorio/issues/detail?id=412
abhinav92003 added a commit that referenced this issue Feb 1, 2024
@abhinav92003
i#6486 kernel tracing: Include BPF JIT code in kcore dump
5d0575a 
Fixes missing instruction encodings for some kernel code execution captured
using Intel-PT.

The root-cause seemed to be that JIT code executed by the kernel, eBPF code in
this case, does not have entries in /proc/kallsyms, so our kcore dump logic
did not include them. This fix looks for BPF related symbols in /proc/kallsyms
and includes them in the copied regions from /proc/kcore.

Note that BPF JIT symbols are not included in /proc/kallsyms by default. One
needs to set /proc/sys/net/core/bpf_jit_harden and
/proc/sys/net/core/bpf_jit_kallsyms appropriately (see
https://docs.kernel.org/admin-guide/sysctl/net.html#proc-sys-net-core-network-core-options
for more details). Added this suggestion to documentation.

Tested PT tracing related tests locally on a machine that supports Intel-PT:

$ ctest -R 'drpttracer|drcacheoff.kernel'
...
    Start 213: code_api|client.drpttracer_SUDO-test
[sudo] password for sharmaabhinav:
1/5 Test #213: code_api|client.drpttracer_SUDO-test .....................   Passed    4.29 sec
    Start 412: code_api|tool.drcacheoff.kernel.simple_SUDO
2/5 Test #412: code_api|tool.drcacheoff.kernel.simple_SUDO ..............   Passed    4.66 sec
    Start 413: code_api|tool.drcacheoff.kernel.opcode-mix_SUDO
3/5 Test #413: code_api|tool.drcacheoff.kernel.opcode-mix_SUDO ..........   Passed    4.71 sec
    Start 414: code_api|tool.drcacheoff.kernel.syscall-mix_SUDO
4/5 Test #414: code_api|tool.drcacheoff.kernel.syscall-mix_SUDO .........   Passed    4.59 sec
    Start 415: code_api|tool.drcacheoff.kernel.invariant-checker_SUDO
5/5 Test #415: code_api|tool.drcacheoff.kernel.invariant-checker_SUDO ...   Passed    5.75 sec

100% tests passed, 0 tests failed out of 5

Issue: #6486
abhinav92003 added a commit that referenced this issue Feb 5, 2024
@abhinav92003
i#6486 kernel tracing: Include BPF JIT code in kcore dump (#6619)
5cb0c61 
Fixes drmemtrace kernel trace libipt post-processing failures caused by
missing instruction encodings for some kernel code execution captured
using Intel-PT.

The root-cause seems to be that JIT code executed by the kernel, BPF
code in this case, does not have entries in `/proc/modules`. So, our
kcore dump logic did not include them. This fix looks for BPF related
symbols in `/proc/kallsyms` and includes them in the copied regions from
`/proc/kcore`.

Note that BPF JIT symbols are not included in `/proc/kallsyms` by
default. One needs to set `/proc/sys/net/core/bpf_jit_harden` and
`/proc/sys/net/core/bpf_jit_kallsyms` appropriately (see
https://docs.kernel.org/admin-guide/sysctl/net.html#proc-sys-net-core-network-core-options
for more details). Added this suggestion to documentation. It may be
better to not automatically make this possibly-too-intrusive change to
the user's machine in cmake. This is probably fine because the issue
is not widespread (not reproduced on public Linux distributions).

Tested PT tracing related tests locally on a machine that supports
Intel-PT:

```
$ ctest -R 'drpttracer|drcacheoff.kernel'
...
    Start 213: code_api|client.drpttracer_SUDO-test
[sudo] password for sharmaabhinav: 
1/5 Test #213: code_api|client.drpttracer_SUDO-test .....................   Passed    4.29 sec
    Start 412: code_api|tool.drcacheoff.kernel.simple_SUDO
2/5 Test #412: code_api|tool.drcacheoff.kernel.simple_SUDO ..............   Passed    4.66 sec
    Start 413: code_api|tool.drcacheoff.kernel.opcode-mix_SUDO
3/5 Test #413: code_api|tool.drcacheoff.kernel.opcode-mix_SUDO ..........   Passed    4.71 sec
    Start 414: code_api|tool.drcacheoff.kernel.syscall-mix_SUDO
4/5 Test #414: code_api|tool.drcacheoff.kernel.syscall-mix_SUDO .........   Passed    4.59 sec
    Start 415: code_api|tool.drcacheoff.kernel.invariant-checker_SUDO
5/5 Test #415: code_api|tool.drcacheoff.kernel.invariant-checker_SUDO ...   Passed    5.75 sec

100% tests passed, 0 tests failed out of 5
```

Unfortunately the decode errors do not go away completely even after
this fix, but they have become very less frequent now (tool.kernel.simple
in release build failed after 40 successful runs with this fix, which failed
every run before).

Issue: #6486
xdje42 pushed a commit that referenced this issue Feb 6, 2024
@abhinav92003 @xdje42
i#6486 kernel tracing: Include BPF JIT code in kcore dump (#6619)
0152f7a 
Fixes drmemtrace kernel trace libipt post-processing failures caused by
missing instruction encodings for some kernel code execution captured
using Intel-PT.

The root-cause seems to be that JIT code executed by the kernel, BPF
code in this case, does not have entries in `/proc/modules`. So, our
kcore dump logic did not include them. This fix looks for BPF related
symbols in `/proc/kallsyms` and includes them in the copied regions from
`/proc/kcore`.

Note that BPF JIT symbols are not included in `/proc/kallsyms` by
default. One needs to set `/proc/sys/net/core/bpf_jit_harden` and
`/proc/sys/net/core/bpf_jit_kallsyms` appropriately (see
https://docs.kernel.org/admin-guide/sysctl/net.html#proc-sys-net-core-network-core-options
for more details). Added this suggestion to documentation. It may be
better to not automatically make this possibly-too-intrusive change to
the user's machine in cmake. This is probably fine because the issue
is not widespread (not reproduced on public Linux distributions).

Tested PT tracing related tests locally on a machine that supports
Intel-PT:

```
$ ctest -R 'drpttracer|drcacheoff.kernel'
...
    Start 213: code_api|client.drpttracer_SUDO-test
[sudo] password for sharmaabhinav: 
1/5 Test #213: code_api|client.drpttracer_SUDO-test .....................   Passed    4.29 sec
    Start 412: code_api|tool.drcacheoff.kernel.simple_SUDO
2/5 Test #412: code_api|tool.drcacheoff.kernel.simple_SUDO ..............   Passed    4.66 sec
    Start 413: code_api|tool.drcacheoff.kernel.opcode-mix_SUDO
3/5 Test #413: code_api|tool.drcacheoff.kernel.opcode-mix_SUDO ..........   Passed    4.71 sec
    Start 414: code_api|tool.drcacheoff.kernel.syscall-mix_SUDO
4/5 Test #414: code_api|tool.drcacheoff.kernel.syscall-mix_SUDO .........   Passed    4.59 sec
    Start 415: code_api|tool.drcacheoff.kernel.invariant-checker_SUDO
5/5 Test #415: code_api|tool.drcacheoff.kernel.invariant-checker_SUDO ...   Passed    5.75 sec

100% tests passed, 0 tests failed out of 5
```

Unfortunately the decode errors do not go away completely even after
this fix, but they have become very less frequent now (tool.kernel.simple
in release build failed after 40 successful runs with this fix, which failed
every run before).

Issue: #6486
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