lkml.org 
[lkml]   [2022]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
Subject[PATCH 2/5] x86/uaccess: instrument copy_from_user_nmi()
From
Make sure usercopy hooks from linux/instrumented.h are invoked for
copy_from_user_nmi().
This fixes KMSAN false positives reported when dumping opcodes for a
stack trace.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: x86@kernel.org
Signed-off-by: Alexander Potapenko <glider@google.com>
---
arch/x86/lib/usercopy.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index f1bb186171562..24b48af274173 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -6,6 +6,7 @@

#include <linux/uaccess.h>
#include <linux/export.h>
+#include <linux/instrumented.h>

#include <asm/tlbflush.h>

@@ -44,7 +45,9 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
* called from other contexts.
*/
pagefault_disable();
+ instrument_copy_from_user_before(to, from, n);
ret = raw_copy_from_user(to, from, n);
+ instrument_copy_from_user_after(to, from, n, ret);
pagefault_enable();

return ret;
--
2.38.1.273.g43a17bfeac-goog
\
 
 \ /
  Last update: 2022-11-02 12:06    [W:0.481 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site