This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [RFC PATCH] Merge libsanitizer from upstream

On 30/10/17 18:46, Christophe Lyon wrote:

On 30/10/2017 16:21, Maxim Ostapenko wrote:

On 30/10/17 17:08, Christophe Lyon wrote:

On 30/10/2017 11:12, Maxim Ostapenko wrote:

Hi,

sorry for the late response.

On 20/10/17 13:45, Christophe Lyon wrote:

Hi,

On 19 October 2017 at 13:17, Jakub Jelinek <jakub@redhat.com> wrote:

On Thu, Oct 19, 2017 at 02:07:24PM +0300, Maxim Ostapenko wrote:

Is the patch (the merge + this incremental) ok for trunk?

I think the patch is OK, just wondering about two things:
Richi just approved the patch on IRC, so I'll commit, then we can deal with 
follow-ups.


Does anyone else run these tests on arm?
Since you applied this patch, I'm seeing lots of new errors and timeouts. I have been ignoring regression reports for *san because of yyrandomness in the results, but the timeouts are a major inconvenience in testing because it increases latency a lot in getting results, or worse I get no 
result at all because the validation job is killed before completion.

Looking at some intermediate logs, I have noticed:
==24797==AddressSanitizer CHECK failed:
/libsanitizer/asan/asan_poisoning.cc:34
"((AddrIsAlignedByGranularity(addr))) != (0)" (0x0, 0x0)
#0 0x408d7d65 in AsanCheckFailed /libsanitizer/asan/asan_rtl.cc:67 
     #1 0x408ecd5d in __sanitizer::CheckFailed(char const*, int, char
const*, unsigned long long, unsigned long long)
/libsanitizer/sanitizer_common/sanitizer_termination.cc:77
     #2 0x408d22d5 in __asan::PoisonShadow(unsigned long, unsigned
long, unsigned char) /libsanitizer/asan/asan_poisoning.cc:34
     #3 0x4085409b in __asan_register_globals
/libsanitizer/asan/asan_globals.cc:368
     #4 0x109eb in _GLOBAL__sub_I_00099_1_ten
(/aci-gcc-fsf/builds/gcc-fsf-gccsrc-thumb/obj-arm-none-linux-gnueabi/gcc3/gcc/testsuite/gcc/alloca_big_alignment.exe+0x109eb) 

in MANY (193 in gcc) tests.

and many others (152 in gcc) just time out individually (eg
c-c++-common/asan/alloca_instruments_all_paddings.c) with no error in
the logs besides Dejagnu's
WARNING: program timed out.
Since I'm using an apparently unusual setup, maybe I have to update it 
to cope with the new version,
so I'd like to know if others are seeing the same problems on arm?

I'm using qemu -R 0 to execute the test programs, encapsulated by
proot (similar to chroot, but does not require root privileges).

Am I missing something obvious?
I've caught the same error on my Arndale board. The issue seems to be quite obvious: after merge, ASan requires globals array to be aligned by shadow granularity.
Thanks for confirming. I've spent a lot of time investigating the timeout issues, that led to zombie processes and servers needing reboot. I've finally identified that going back to qemu-2.7 avoid the timeout issues (I've reported a qemu bug).
This trivial patch seems to fix the issue. Could you check it on your setup?
I was just about to finally start looking at this sanity check problem, so thank you very much for sharing your patch. I manually tested it on the subset of my configs and it solves the assertion failure, thanks! 
However, I can notice many regressions compared to before the merge:
c-c++-common/asan/alloca_instruments_all_paddings.c
c-c++-common/asan/alloca_loop_unpoisoning.c
c-c++-common/asan/alloca_safe_access.c
c-c++-common/asan/asan-interface-1.c
c-c++-common/asan/halt_on_error-1.c
c-c++-common/asan/pr59063-1.c
c-c++-common/asan/pr59063-2.c
c-c++-common/asan/pr63316.c
c-c++-common/asan/pr63888.c
c-c++-common/asan/pr70712.c
c-c++-common/asan/pr71480.c
c-c++-common/asan/pr79944.c
c-c++-common/asan/pr80308.c
c-c++-common/asan/swapcontext-test-1.c
gcc.dg/asan/nosanitize-and-inline.c
gcc.dg/asan/pr79196.c
gcc.dg/asan/pr80166.c
gcc.dg/asan/pr81186.c
gcc.dg/asan/use-after-scope-11.c
gcc.dg/asan/use-after-scope-4.c
gcc.dg/asan/use-after-scope-6.c
gcc.dg/asan/use-after-scope-7.c
gcc.dg/asan/use-after-scope-goto-1.c
gcc.dg/asan/use-after-scope-goto-2.c
gcc.dg/asan/use-after-scope-switch-1.c
gcc.dg/asan/use-after-scope-switch-2.c
gcc.dg/asan/use-after-scope-switch-3.c
gcc.dg/asan/use-after-scope-switch-4.c

out of which only
c-c++-common/asan/swapcontext-test-1.c
c-c++-common/asan/halt_on_error-1.c
print something in gcc.log

Do they pass for you?
Ah, I see. The problem is that after this merge LSan was enabled for ARM. LSan sets atexit handler that calls internal_clone function that's not supported in QEMU. 
That's why these tests pass on board, but fail under QEMU.
Could you try set ASAN_OPTIONS=detect_leaks=0 in your environment?



Ha, thanks it works!
The remaining failure is on c-c++-common/asan/halt_on_error-1.c, which seems to dump the expected messages, but exits with return code=4.
Same here, halt_on_error-1.c just overwrites ASAN_OPTIONS via "halt_on_error=false" thus enabling LSan back. 
Something like this (attached) should work.

-Maxim



Any idea ?

Thanks,

Christophe


-Maxim



Thanks,

Christophe


Thanks,
-Maxim



Thanks,

Christophe
1) We have a bunch of GCC local patches, did you include them into a 
cumulative patch (I guess yes)?
I have done some verification today, diff from upstream r285547 to unpatched GCC (with the LLVM Compiler infrastructure two liners removed), attached P1, and diff from upstream r315899 to patched GCC (again, two liners removed), attached P2 and went through the changes in P1 and verified that except for the ubsan backwards compatibility we had that can't work anymore everything else was upstreamed, or remained in P2. So P2 is the current diff from upstream, with the sanitizer_common/sanitizer_symbolizer_libbacktrace.cc 
changes now filed upstream.
2) Upstream has enabled LSan for x86 and ARM, is it worth to enable them in 
GCC too?
Maybe, feel free to post patches. For LSan we need to split off lsan_preinit out of liblsan and link it into executables, will handle it next (there is a 
PR about it, just wanted to wait until the merge is in).

         Jakub












.









diff --git a/gcc/testsuite/c-c++-common/asan/halt_on_error-1.c b/gcc/testsuite/c-c++-common/asan/halt_on_error-1.c
index 52e705d..ae55dea 100644
--- a/gcc/testsuite/c-c++-common/asan/halt_on_error-1.c
+++ b/gcc/testsuite/c-c++-common/asan/halt_on_error-1.c
@@ -1,7 +1,7 @@
 /* Test recovery mode.  */
 /* { dg-do run } */
 /* { dg-options "-fsanitize-recover=address" } */
-/* { dg-set-target-env-var ASAN_OPTIONS "halt_on_error=false" } */
+/* { dg-set-target-env-var ASAN_OPTIONS "halt_on_error=false:detect_leaks=0" } */
 
 #include <string.h>
Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]