From 1132f86b83fc04e7aed1580b7f27b9f5ccaf69f1 Mon Sep 17 00:00:00 2001 From: Liu Shixin Date: Wed, 15 Nov 2023 16:21:37 +0800 Subject: [PATCH] Revert "mm/kmemleak: move the initialisation of object to __link_object" Patch series "Fix invalid wait context of set_track_prepare()". Geert reported an invalid wait context[1] which is resulted by moving set_track_prepare() inside kmemleak_lock. This is not allowed because in RT mode, the spinlocks can be preempted but raw_spinlocks can not, so it is not allowd to acquire spinlocks while holding raw_spinlocks. The second patch fix same problem in kmemleak_update_trace(). This patch (of 2): Move the initialisation of object back to__alloc_object() because set_track_prepare() attempt to acquire zone->lock(spinlocks) while __link_object is holding kmemleak_lock(raw_spinlocks). This is not right for RT mode. This reverts commit 245245c2fffd00 ("mm/kmemleak: move the initialisation of object to __link_object"). Link: https://lkml.kernel.org/r/20231115082138.2649870-1-liushixin2@huawei.com Link: https://lkml.kernel.org/r/20231115082138.2649870-2-liushixin2@huawei.com Fixes: 245245c2fffd ("mm/kmemleak: move the initialisation of object to __link_object") Signed-off-by: Liu Shixin Reported-by: Geert Uytterhoeven Closes: https://lore.kernel.org/linux-mm/CAMuHMdWj0UzwNaxUvcocTfh481qRJpOWwXxsJCTJfu1oCqvgdA@mail.gmail.com/ [1] Acked-by: Catalin Marinas Cc: Kefeng Wang Cc: Patrick Wang Signed-off-by: Andrew Morton --- mm/kmemleak.c | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-) diff --git a/mm/kmemleak.c b/mm/kmemleak.c index 1eacca03bedd20..22bab3738a9ef3 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -642,32 +642,16 @@ static struct kmemleak_object *__alloc_object(gfp_t gfp) if (!object) { pr_warn("Cannot allocate a kmemleak_object structure\n"); kmemleak_disable(); + return NULL; } - return object; -} - -static int __link_object(struct kmemleak_object *object, unsigned long ptr, - size_t size, int min_count, bool is_phys) -{ - - struct kmemleak_object *parent; - struct rb_node **link, *rb_parent; - unsigned long untagged_ptr; - unsigned long untagged_objp; - INIT_LIST_HEAD(&object->object_list); INIT_LIST_HEAD(&object->gray_list); INIT_HLIST_HEAD(&object->area_list); raw_spin_lock_init(&object->lock); atomic_set(&object->use_count, 1); - object->flags = OBJECT_ALLOCATED | (is_phys ? OBJECT_PHYS : 0); - object->pointer = ptr; - object->size = kfence_ksize((void *)ptr) ?: size; object->excess_ref = 0; - object->min_count = min_count; object->count = 0; /* white color initially */ - object->jiffies = jiffies; object->checksum = 0; object->del_state = 0; @@ -692,6 +676,24 @@ static int __link_object(struct kmemleak_object *object, unsigned long ptr, /* kernel backtrace */ object->trace_handle = set_track_prepare(); + return object; +} + +static int __link_object(struct kmemleak_object *object, unsigned long ptr, + size_t size, int min_count, bool is_phys) +{ + + struct kmemleak_object *parent; + struct rb_node **link, *rb_parent; + unsigned long untagged_ptr; + unsigned long untagged_objp; + + object->flags = OBJECT_ALLOCATED | (is_phys ? OBJECT_PHYS : 0); + object->pointer = ptr; + object->size = kfence_ksize((void *)ptr) ?: size; + object->min_count = min_count; + object->jiffies = jiffies; + untagged_ptr = (unsigned long)kasan_reset_tag((void *)ptr); /* * Only update min_addr and max_addr with object