Messages in this thread Patch in this message | | | From | Mark Rutland <> | Subject | [PATCH 6/8] stackleak: remove redundant check | Date | Mon, 25 Apr 2022 12:56:01 +0100 |
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In __stackleak_erase() we check that the `erase_low` value derived from `current->lowest_stack` is above the lowest legitimate stack pointer value, but this is already enforced by stackleak_track_stack() when recording the lowest stack value.
Remove the redundant check.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Popov <alex.popov@linux.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Kees Cook <keescook@chromium.org> --- kernel/stackleak.c | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/kernel/stackleak.c b/kernel/stackleak.c index f597d3323729d..ba346d46218f5 100644 --- a/kernel/stackleak.c +++ b/kernel/stackleak.c @@ -79,10 +79,6 @@ static __always_inline void __stackleak_erase(void) unsigned int poison_count = 0; const unsigned int depth = STACKLEAK_SEARCH_DEPTH / sizeof(unsigned long); - /* Check that 'lowest_stack' value is sane */ - if (unlikely(erase_low - task_stack_low >= THREAD_SIZE)) - erase_low = task_stack_low; - /* Search for the poison value in the kernel stack */ while (erase_low > task_stack_low && poison_count <= depth) { if (*(unsigned long *)erase_low == STACKLEAK_POISON) -- 2.30.2
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