lkml.org 
[lkml]   [2022]   [Apr]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 6/8] stackleak: remove redundant check
Date
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
\
 
 \ /
  Last update: 2022-04-25 13:59    [W:0.155 / U:0.296 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site