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Re: [PATCH][PR sanitizer/78887] Don't emit ODR indicators if -fsanitize=kernel-address is present.
- From: Maxim Ostapenko <m dot ostapenko at samsung dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Fri, 13 Jan 2017 12:01:54 +0300
- Subject: Re: [PATCH][PR sanitizer/78887] Don't emit ODR indicators if -fsanitize=kernel-address is present.
- Authentication-results: sourceware.org; auth=none
- Cms-type: 201P
- References: <CGME20170113081926eucas1p2182a7b44313074dab4efc7d75d2362e2@eucas1p2.samsung.com> <58788D87.7040104@samsung.com> <20170113082439.GH21933@tucnak>
On 13/01/17 11:24, Jakub Jelinek wrote:
On Fri, Jan 13, 2017 at 11:19:19AM +0300, Maxim Ostapenko wrote:
as mentioned in PR, Linux kernel 4.9 fails to build with ASan due to wrong
handling of emitted ODR indicator symbols. Although this might be a kernel
bug (relying on specific pattern in symbol name sounds questionable), kernel
doesn't need ODR indicators at all thus we can just disable them if
-fsanitize=kernel-address is present.
Tested on x86_64-unknown-linux-gnu, OK for trunk?
gcc/ChangeLog:
2017-01-13 Maxim Ostapenko <m.ostapenko@samsung.com>
PR sanitizer/78887
* asan.c (asan_needs_odr_indicator_p): Don't emit ODR indicators
if -fsanitize=kernel-address is present.
diff --git a/gcc/asan.c b/gcc/asan.c
index bc7ebc8..157d468 100644
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -2360,7 +2360,8 @@ create_odr_indicator (tree decl, tree type)
static bool
asan_needs_odr_indicator_p (tree decl)
{
- return !DECL_ARTIFICIAL (decl) && !DECL_WEAK (decl) && TREE_PUBLIC (decl);
+ return !(flag_sanitize & SANITIZE_KERNEL_ADDRESS) && !DECL_ARTIFICIAL (decl)
+ && !DECL_WEAK (decl) && TREE_PUBLIC (decl);
As the condition is longer than a line, please use
return (!(flag_sanitize & SANITIZE_KERNEL_ADDRESS)
&& !DECL_ARTIFICIAL (decl)
&& !DECL_WEAK (decl)
&& TREE_PUBLIC (decl));
instead (i.e. one sub-condition per line, and ()s around the whole
condition. Perhaps a short comment why we don't emit those for
-fsanitize=kernel-address would be useful too.
Ok for trunk with those changes.
OK, thanks, I'm going to apply following patch.
-Maxim
Jakub
gcc/ChangeLog:
2017-01-13 Maxim Ostapenko <m.ostapenko@samsung.com>
PR sanitizer/78887
* asan.c (asan_needs_odr_indicator_p): Don't emit ODR indicators
if -fsanitize=kernel-address is present.
diff --git a/gcc/asan.c b/gcc/asan.c
index bc7ebc8..e3bf16d 100644
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -2360,7 +2360,16 @@ create_odr_indicator (tree decl, tree type)
static bool
asan_needs_odr_indicator_p (tree decl)
{
- return !DECL_ARTIFICIAL (decl) && !DECL_WEAK (decl) && TREE_PUBLIC (decl);
+ /* Don't emit ODR indicators for kernel because:
+ a) Kernel is written in C thus doesn't need ODR indicators.
+ b) Some kernel code may have assumptions about symbols containing specific
+ patterns in their names. Since ODR indicators contain original names
+ of symbols they are emmitted for, these assumptions would be broken for
+ ODR indicator symbols. */
+ return (!(flag_sanitize & SANITIZE_KERNEL_ADDRESS)
+ && !DECL_ARTIFICIAL (decl)
+ && !DECL_WEAK (decl)
+ && TREE_PUBLIC (decl));
}
/* Append description of a single global DECL into vector V.