Re: [PATCH] Mips: Enable asynchronous unwind tables with both ASAN and TSAN

[Dimitrije Milosevic <Dimitrije.Milosevic@Syrmia.com>]

Hi Xi.
Correct, I am using a simulator.
Here are my changes:

diff --git a/libsanitizer/configure.tgt b/libsanitizer/configure.tgt
index fb89df4935c..6855a6ca9e7 100644
--- a/libsanitizer/configure.tgt
+++ b/libsanitizer/configure.tgt
@@ -55,6 +55,10 @@ case "${target}" in
   arm*-*-linux*)
        ;;
   mips*-*-linux*)
+       if test x$ac_cv_sizeof_void_p = x8; then
+               TSAN_SUPPORTED=yes
+               TSAN_TARGET_DEPENDENT_OBJECTS=tsan_rtl_mips64.lo
+       fi
        ;;
   aarch64*-*-linux*)
        if test x$ac_cv_sizeof_void_p = x8; then

Nit: Updated the code in gcc/config/mips/mips.cc a little bit, but no functional
change compared to your version.

diff --git a/gcc/config/mips/mips.cc b/gcc/config/mips/mips.cc
index 8a55d2fb8f7..4ccc9e75482 100644
--- a/gcc/config/mips/mips.cc
+++ b/gcc/config/mips/mips.cc
@@ -20118,13 +20118,12 @@ mips_option_override (void)
   /* -fsanitize=address needs to turn on -fasynchronous-unwind-tables
      in order for tracebacks to be complete but not if any
      -fasynchronous-unwind-table were already specified.  */
-  /* FIXME: TSAN could also utilize -fasynchronous-unwind-tables, but
-      should be first enabled for MIPS64.
-     FIXME: HWSAN could also utilize -fasynchronous-unwind-tables, but,
+  /* FIXME: HWSAN could also utilize -fasynchronous-unwind-tables, but,
       currently, it is only available on AArch64.
      FIXME: We would also like to check if -ffreestanding is passed in.
       However, it is only available in C-ish frontends.  */
-  if ((flag_sanitize & SANITIZE_USER_ADDRESS)
+  if (((flag_sanitize & SANITIZE_USER_ADDRESS)
+       || (TARGET_64BIT && (flag_sanitize & SANITIZE_THREAD)))
       && !global_options_set.x_flag_asynchronous_unwind_tables)
     flag_asynchronous_unwind_tables = 1;



From: Xi Ruoyao <xry111@xry111.site>
Sent: Tuesday, July 5, 2022 3:54 AM
To: Dimitrije Milosevic <Dimitrije.Milosevic@Syrmia.com>; gcc-patches@gcc.gnu.org <gcc-patches@gcc.gnu.org>
Cc: Djordje Todorovic <Djordje.Todorovic@syrmia.com>
Subject: Re: [PATCH] Mips: Enable asynchronous unwind tables with both ASAN and TSAN 
 
On Mon, 2022-07-04 at 14:28 +0000, Dimitrije Milosevic wrote:
> On Saturday, June 11, 2022 2:03 PM, Xi wrote:
> > Just tried TSAN_SUPPORTED=yes with asynchronous unwind tables
> > enabled,
> > but I got some strange test failures for tls_race.c:
> > 
> > FAIL: c-c++-common/tsan/tls_race.c   -O0  output pattern test
> > Output was:
> > ThreadSanitizer: CHECK failed: tsan_platform_linux.cpp:452
> > "((thr_end)) <= ((tls_addr + tls_size))" (0xffec35f8c0,
> > 0xffec35f784) (tid=748216)
> >     #0 __tsan::CheckUnwind()
> > ../../../../gcc/libsanitizer/tsan/tsan_rtl.cpp:627
> > (libtsan.so.2+0xa30ec)
> >     #1 __sanitizer::CheckFailed(char const*, int, char const*,
> > unsigned long long, unsigned long long)
> > ../../../../gcc/libsanitizer/sanitizer_common/sanitizer_termination.
> > cpp:86 (libtsan.so.2+0xeb8cc)
> >     #2 __tsan::ImitateTlsWrite(__tsan::ThreadState*, unsigned long,
> > unsigned long)
> > ../../../../gcc/libsanitizer/tsan/tsan_platform_linux.cpp:452
> > (libtsan.so.2+0xa0cac)
> >     #3 __tsan::ThreadStart(__tsan::ThreadState*, unsigned int,
> > unsigned long long, __sanitizer::ThreadType)
> > ../../../../gcc/libsanitizer/tsan/tsan_rtl_thread.cpp:197
> > (libtsan.so.2+0xc0e88)
> >     #4 __tsan_thread_start_func
> > ../../../../gcc/libsanitizer/tsan/tsan_interceptors_posix.cpp:1009
> > (libtsan.so.2+0x3e5dc)
> >     #5 start_thread /sources/glibc-2.35/nptl/pthread_create.c:442
> > (libc.so.6+0xc75f4)
> > 
> > I've tried to diagnose the root cause but failed.
> 
> Hi Xi, thanks for looking into this. I've tried running the testsuite
> on a cross-toolchain (as I do not currently have access to a physical
> machine)
> for a MIPS64R6 and the test passes successfully. Could you please
> verify that the test fails solely based on this change?

I guess you mean you are running MIPS64R6 target code with qemu?  I'm
not 100% sure because maybe something is wrong in my system.  I'm now
retrying on gcc230.fsffrance.org (an EdgeRouter 4 in Cfarm) but building
GCC on it is really slow.

The changes I've tested:

diff --git a/gcc/config/mips/mips.cc b/gcc/config/mips/mips.cc
index 5eb845960e1..a7f0580e9ba 100644
--- a/gcc/config/mips/mips.cc
+++ b/gcc/config/mips/mips.cc
@@ -20115,10 +20115,11 @@ mips_option_override (void)
         target_flags |= MASK_64BIT;
     }
 
-  /* -fsanitize=address needs to turn on -fasynchronous-unwind-tables in
-     order for tracebacks to be complete but not if any
-     -fasynchronous-unwind-table were already specified.  */
-  if (flag_sanitize & SANITIZE_USER_ADDRESS
+  /* For -fsanitize=address or -fsanitize=thread, it's needed to turn
+     on -fasynchronous-unwind-tables in order for tracebacks
+     to be complete but not if any -fasynchronous-unwind-table
+     were already specified.  */
+  if (flag_sanitize & (SANITIZE_USER_ADDRESS | SANITIZE_THREAD)
       && !global_options_set.x_flag_asynchronous_unwind_tables)
     flag_asynchronous_unwind_tables = 1;
 
diff --git a/libsanitizer/configure.tgt b/libsanitizer/configure.tgt
index fb89df4935c..52546bbe4e3 100644
--- a/libsanitizer/configure.tgt
+++ b/libsanitizer/configure.tgt
@@ -55,6 +55,9 @@ case "${target}" in
   arm*-*-linux*)
         ;;
   mips*-*-linux*)
+       if test x$ac_cv_sizeof_void_p = x8; then
+               TSAN_SUPPORTED=yes
+       fi
         ;;
   aarch64*-*-linux*)
         if test x$ac_cv_sizeof_void_p = x8; then
-- 
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University