lib/stackdepot.c: allow the stack trace hash to be zero

Do not bail out from depot_save_stack() if the stack trace has zero hash.
Initially depot_save_stack() silently dropped stack traces with zero
hashes, however there's actually no point in reserving this zero value.

Reported-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 654c9d87e83aac9da685d2626dc437f2be0ac95c..9e0b0315a724caf24ea195e275ed431639a262b4 100644 (file)
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -210,10 +210,6 @@ depot_stack_handle_t depot_save_stack(struct stack_trace *trace,
                goto fast_exit;
 
        hash = hash_stack(trace->entries, trace->nr_entries);
-       /* Bad luck, we won't store this stack. */
-       if (hash == 0)
-               goto exit;
-
        bucket = &stack_table[hash & STACK_HASH_MASK];
 
        /*