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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-28 14:15:33 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-05-28 14:15:33 +0300 |
commit | d8f14b84fefd8669cbcbe4fee3f61a44be904993 (patch) | |
tree | f3ad219bf4bedc28ed88a2ee6736a36f0bb80eff /lib | |
parent | 9bd5386c653f64755dc33f77793273ef0763fe63 (diff) | |
parent | eb799279fb1f9c63c520fe8c1c41cb9154252db6 (diff) | |
download | linux-d8f14b84fefd8669cbcbe4fee3f61a44be904993.tar.xz |
Merge tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull debugobjects fixes from Thomas Gleixner:
"Two fixes for debugobjects:
- Prevent the allocation path from waking up kswapd.
That's a long standing issue due to the GFP_ATOMIC allocation flag.
As debug objects can be invoked from pretty much any context waking
kswapd can end up in arbitrary lock chains versus the waitqueue
lock
- Correct the explicit lockdep wait-type violation in
debug_object_fill_pool()"
* tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debugobjects: Don't wake up kswapd from fill_pool()
debugobjects,locking: Annotate debug_object_fill_pool() wait type violation
Diffstat (limited to 'lib')
-rw-r--r-- | lib/debugobjects.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 003edc5ebd67..984985c39c9b 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -126,7 +126,7 @@ static const char *obj_states[ODEBUG_STATE_MAX] = { static void fill_pool(void) { - gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN; + gfp_t gfp = __GFP_HIGH | __GFP_NOWARN; struct debug_obj *obj; unsigned long flags; @@ -591,10 +591,21 @@ static void debug_objects_fill_pool(void) { /* * On RT enabled kernels the pool refill must happen in preemptible - * context: + * context -- for !RT kernels we rely on the fact that spinlock_t and + * raw_spinlock_t are basically the same type and this lock-type + * inversion works just fine. */ - if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) + if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) { + /* + * Annotate away the spinlock_t inside raw_spinlock_t warning + * by temporarily raising the wait-type to WAIT_SLEEP, matching + * the preemptible() condition above. + */ + static DEFINE_WAIT_OVERRIDE_MAP(fill_pool_map, LD_WAIT_SLEEP); + lock_map_acquire_try(&fill_pool_map); fill_pool(); + lock_map_release(&fill_pool_map); + } } static void |