[compiler-rt] r271046 - [sanitizers] introduce __sanitizer_set_report_fd so that we can re-route the sanitizer logging to another fd from inside the process

Tue May 31 13:43:31 PDT 2016

On Tue, May 31, 2016 at 1:38 PM, Mehdi Amini <mehdi.amini at apple.com> wrote:

>
> On May 31, 2016, at 1:22 PM, Kostya Serebryany <kcc at google.com> wrote:
>
>
>
> On Tue, May 31, 2016 at 1:16 PM, Mehdi Amini <mehdi.amini at apple.com>
> wrote:
>
>> Committed in r271323.
>>
>> Thanks!
>
>> I wonder what is the rational for the discrepancy between Darwin and
>> Linux?
>>
>
> Don't get me started :)
>
>
> Sorry :)
>
> http://reviews.llvm.org/D7203
> https://groups.google.com/forum/#!topic/address-sanitizer/FGYgD_P_884
>
>
> I see some rational to abort, I don't see some strong rational to *not*
> abort on every platform.
>

Abort is slow and verbose, it often involves lots of extra stuff that you
don't need when you see an asan report.

--kcc

>
>
> --
> Mehdi
>
>
>
>
> --kcc
>
>
>>
>> --
>> Mehdi
>>
>> On May 31, 2016, at 1:11 PM, Kostya Serebryany <kcc at google.com> wrote:
>>
>> Ah, I think this is caused by different defaults.
>> On linux by default asan dies with _exit and on Mac it dies with abort()
>> This difference was introduced by Kuba after a long resistance from my
>> side :)
>> The fix should be pretty simple: add abort_on_error=0 to %tool_options in
>> the test.
>> Could you please check if this helps on Mac?
>> If so, feel free to submit.
>>
>> Thanks!
>> --kcc
>>
>>
>> On Tue, May 31, 2016 at 1:01 PM, Mehdi Amini <mehdi.amini at apple.com>
>> wrote:
>>
>>> Hi Kostya,
>>>
>>> We see a bot failure with the test case you added below:
>>> http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-globalisel_check/2068/console
>>>
>>> After investigating, it seems that they trigger an ASAN failure, which
>>> is returning a negative error code. The `not` command tool interprets it as
>>> a crash, and you need to pass the --crash option to it.
>>>
>>> Don't you observe this on your setup? I wonder why they are passing?
>>>
>>> --
>>> Mehdi
>>>
>>>
>>>
>>>
>>> > On May 27, 2016, at 2:23 PM, Kostya Serebryany via llvm-commits <
>>> llvm-commits at lists.llvm.org> wrote:
>>> >
>>> > Author: kcc
>>> > Date: Fri May 27 16:23:05 2016
>>> > New Revision: 271046
>>> >
>>> > URL: http://llvm.org/viewvc/llvm-project?rev=271046&view=rev
>>> > Log:
>>> > [sanitizers] introduce __sanitizer_set_report_fd so that we can
>>> re-route the sanitizer logging to another fd from inside the process
>>> >
>>> > Added:
>>> >
>>> compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/sanitizer_set_report_fd_test.cc
>>> > Modified:
>>> >    compiler-rt/trunk/include/sanitizer/common_interface_defs.h
>>> >    compiler-rt/trunk/lib/asan/asan_posix.cc
>>> >    compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.cc
>>> >
>>> > Modified: compiler-rt/trunk/include/sanitizer/common_interface_defs.h
>>> > URL:
>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/include/sanitizer/common_interface_defs.h?rev=271046&r1=271045&r2=271046&view=diff
>>> >
>>> ==============================================================================
>>> > --- compiler-rt/trunk/include/sanitizer/common_interface_defs.h
>>> (original)
>>> > +++ compiler-rt/trunk/include/sanitizer/common_interface_defs.h Fri
>>> May 27 16:23:05 2016
>>> > @@ -41,6 +41,9 @@ extern "C" {
>>> >
>>> >   // Tell the tools to write their reports to "path.<pid>" instead of
>>> stderr.
>>> >   void __sanitizer_set_report_path(const char *path);
>>> > +  // Tell the tools to write their reports to the provided file
>>> descriptor
>>> > +  // (casted to void *).
>>> > +  void __sanitizer_set_report_fd(void *fd);
>>> >
>>> >   // Notify the tools that the sandbox is going to be turned on. The
>>> reserved
>>> >   // parameter will be used in the future to hold a structure with
>>> functions
>>> >
>>> > Modified: compiler-rt/trunk/lib/asan/asan_posix.cc
>>> > URL:
>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_posix.cc?rev=271046&r1=271045&r2=271046&view=diff
>>> >
>>> ==============================================================================
>>> > --- compiler-rt/trunk/lib/asan/asan_posix.cc (original)
>>> > +++ compiler-rt/trunk/lib/asan/asan_posix.cc Fri May 27 16:23:05 2016
>>> > @@ -36,8 +36,9 @@ namespace __asan {
>>> > void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
>>> >   ScopedDeadlySignal signal_scope(GetCurrentThread());
>>> >   int code = (int)((siginfo_t*)siginfo)->si_code;
>>> > -  // Write the first message using the bullet-proof write.
>>> > -  if (18 != internal_write(2, "ASAN:DEADLYSIGNAL\n", 18)) Die();
>>> > +  // Write the first message using fd=2, just in case.
>>> > +  // It may actually fail to write in case stderr is closed.
>>> > +  internal_write(2, "ASAN:DEADLYSIGNAL\n", 18);
>>> >   SignalContext sig = SignalContext::Create(siginfo, context);
>>> >
>>> >   // Access at a reasonable offset above SP, or slightly below it (to
>>> account
>>> >
>>> > Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.cc
>>> > URL:
>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.cc?rev=271046&r1=271045&r2=271046&view=diff
>>> >
>>> ==============================================================================
>>> > --- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.cc
>>> (original)
>>> > +++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.cc Fri May
>>> 27 16:23:05 2016
>>> > @@ -496,6 +496,11 @@ void __sanitizer_set_report_path(const c
>>> >   report_file.SetReportPath(path);
>>> > }
>>> >
>>> > +void __sanitizer_set_report_fd(void *fd) {
>>> > +  report_file.fd = reinterpret_cast<uptr>(fd);
>>> > +  report_file.fd_pid = internal_getpid();
>>> > +}
>>> > +
>>> > void __sanitizer_report_error_summary(const char *error_summary) {
>>> >   Printf("%s\n", error_summary);
>>> > }
>>> >
>>> > Added:
>>> compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/sanitizer_set_report_fd_test.cc
>>> > URL:
>>> http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/sanitizer_set_report_fd_test.cc?rev=271046&view=auto
>>> >
>>> ==============================================================================
>>> > ---
>>> compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/sanitizer_set_report_fd_test.cc
>>> (added)
>>> > +++
>>> compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/sanitizer_set_report_fd_test.cc
>>> Fri May 27 16:23:05 2016
>>> > @@ -0,0 +1,37 @@
>>> > +// Test __sanitizer_set_report_fd:
>>> > +// RUN: %clangxx -O2 %s -o %t
>>> > +// RUN: not %run %t 2>&1   | FileCheck %s
>>> > +// RUN: not %run %t stdout | FileCheck %s
>>> > +// RUN: not %run %t %t-out && FileCheck < %t-out %s
>>> > +
>>> > +// REQUIRES: stable-runtime
>>> > +// FIXME: implement SEGV handler in other sanitizers, not just asan.
>>> > +// XFAIL: msan
>>> > +// XFAIL: lsan
>>> > +// XFAIL: tsan
>>> > +
>>> > +#include <sanitizer/common_interface_defs.h>
>>> > +#include <stdio.h>
>>> > +#include <string.h>
>>> > +#include <stdlib.h>
>>> > +#include <sys/types.h>
>>> > +#include <sys/stat.h>
>>> > +#include <fcntl.h>
>>> > +#include <assert.h>
>>> > +
>>> > +volatile int *null = 0;
>>> > +
>>> > +int main(int argc, char **argv) {
>>> > +  if (argc == 2) {
>>> > +    if (!strcmp(argv[1], "stdout")) {
>>> > +      __sanitizer_set_report_fd(reinterpret_cast<void*>(1));
>>> > +    } else {
>>> > +      int fd = open(argv[1], O_CREAT | O_WRONLY | O_TRUNC, S_IRWXU);
>>> > +      assert(fd > 0);
>>> > +      __sanitizer_set_report_fd(reinterpret_cast<void*>(fd));
>>> > +    }
>>> > +  }
>>> > +  *null = 0;
>>> > +}
>>> > +
>>> > +// CHECK: ERROR: {{.*}} SEGV on unknown address
>>> >
>>> >
>>> > _______________________________________________
>>> > llvm-commits mailing list
>>> > llvm-commits at lists.llvm.org
>>> > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>
>>>
>>
>>
>
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