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lib/stacktrace: drop impossible WARN_ON for depot_init_pool 

depot_init_pool has two call sites:

1. In depot_alloc_stack with a potentially NULL prealloc.
2. In __stack_depot_save with a non-NULL prealloc.

At the same time depot_init_pool can only return false when prealloc is
NULL.

As the second call site makes sure that prealloc is not NULL, the WARN_ON
there can never trigger. Thus, drop the WARN_ON and also move the prealloc
check from depot_init_pool to its first call site.

Also change the return type of depot_init_pool to void as it now always
returns true.

Link: https://lkml.kernel.org/r/ce149f9bdcbc80a92549b54da67eafb27f846b7b.1676063693.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Andrey Konovalov 2023-02-10 22:16:00 +01:00 committed by Andrew Morton
parent cb788e84a4
commit 514d5c557b
1 changed files with 5 additions and 7 deletions
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12
lib/stackdepot.c
View File

@ -218,16 +218,14 @@ out_unlock:
}
EXPORT_SYMBOL_GPL(stack_depot_init);
static bool depot_init_pool(void **prealloc)
static void depot_init_pool(void **prealloc)
{
if (!*prealloc)
return false;
/*
* This smp_load_acquire() pairs with smp_store_release() to
* |next_pool_inited| below and in depot_alloc_stack().
*/
if (smp_load_acquire(&next_pool_inited))
return true;
return;
if (stack_pools[pool_index] == NULL) {
stack_pools[pool_index] = *prealloc;
*prealloc = NULL;
@ -243,7 +241,6 @@ static bool depot_init_pool(void **prealloc)
*/
smp_store_release(&next_pool_inited, 1);
}
return true;
}
/* Allocation of a new stack in raw storage */
@ -270,7 +267,8 @@ depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc)
if (pool_index + 1 < DEPOT_MAX_POOLS)
smp_store_release(&next_pool_inited, 0);
}
depot_init_pool(prealloc);
if (*prealloc)
depot_init_pool(prealloc);
if (stack_pools[pool_index] == NULL)
return NULL;
@ -435,7 +433,7 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries,
* We didn't need to store this stack trace, but let's keep
* the preallocated memory for the future.
*/
WARN_ON(!depot_init_pool(&prealloc));
depot_init_pool(&prealloc);
}
raw_spin_unlock_irqrestore(&pool_lock, flags);