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Revert "mm/kmemleak: move the initialisation of object to __link_object"

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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 <liushixin2@huawei.com>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Closes: https://lore.kernel.org/linux-mm/CAMuHMdWj0UzwNaxUvcocTfh481qRJpOWwXxsJCTJfu1oCqvgdA@mail.gmail.com/ [1]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Patrick Wang <patrick.wang.shcn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Liu Shixin 2023-11-15 16:21:37 +08:00 committed by Andrew Morton
parent 727d16f199
commit 4eff7d62ab
1 changed files with 19 additions and 17 deletions
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36
mm/kmemleak.c
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@ -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