diff options
Diffstat (limited to 'lib/stackdepot.c')
| -rw-r--r-- | lib/stackdepot.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 8c6e4e9cb535..b625090890e1 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -278,8 +278,12 @@ depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc) return NULL; } - /* Move on to the next pool. */ - pool_index++; + /* + * Move on to the next pool. + * WRITE_ONCE pairs with potential concurrent read in + * stack_depot_fetch(). + */ + WRITE_ONCE(pool_index, pool_index + 1); pool_offset = 0; /* * If the maximum number of pools is not reached, take note @@ -502,6 +506,11 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries) { union handle_parts parts = { .handle = handle }; + /* + * READ_ONCE pairs with potential concurrent write in + * depot_alloc_stack. + */ + int pool_index_cached = READ_ONCE(pool_index); void *pool; size_t offset = parts.offset << DEPOT_STACK_ALIGN; struct stack_record *stack; @@ -510,9 +519,9 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle, if (!handle) return 0; - if (parts.pool_index > pool_index) { + if (parts.pool_index > pool_index_cached) { WARN(1, "pool index %d out of bounds (%d) for stack id %08x\n", - parts.pool_index, pool_index, handle); + parts.pool_index, pool_index_cached, handle); return 0; } pool = stack_pools[parts.pool_index]; |