From ac7838b4e1c552d54e67f78a29bc1bd7701c13e8 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Wed, 27 Apr 2022 18:31:18 +0100 Subject: stackleak: remove redundant check 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 Cc: Alexander Popov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Kees Cook Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220427173128.2603085-4-mark.rutland@arm.com --- kernel/stackleak.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'kernel/stackleak.c') diff --git a/kernel/stackleak.c b/kernel/stackleak.c index 753eab797a04..f7a0f8cf73c3 100644 --- a/kernel/stackleak.c +++ b/kernel/stackleak.c @@ -78,10 +78,6 @@ 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(kstack_ptr - boundary >= THREAD_SIZE)) - kstack_ptr = boundary; - /* Search for the poison value in the kernel stack */ while (kstack_ptr > boundary && poison_count <= depth) { if (*(unsigned long *)kstack_ptr == STACKLEAK_POISON) -- cgit