The rest of the patch is gcc-specific. Jakub?
On Tue, May 7, 2013 at 12:12 PM, Christophe Lyon
<christophe.l...@linaro.org> wrote:
> Oops, you are correct, I read the code too quickly and didn't notice
> the #endif right after the Thumb bit cancellation (I thought the
> function didn't return any value when on ARM).
>
> A white line before #if defined(__powerpc__) would help readability :-)
>
> Forget that part.
>
> Thanks,
>
> Christophe.
>
>
>
>
> On 7 May 2013 09:44, Evgeniy Stepanov <euge...@google.com> wrote:
>> On Tue, May 7, 2013 at 9:33 AM, Konstantin Serebryany
>> <konstantin.s.serebry...@gmail.com> wrote:
>>> +euge...@google.com (our ARM expert)
>>>
>>> Christophe,
>>>
>>> The change in sanitizer_common/sanitizer_stacktrace.cc changes the
>>> logic which is known to work well for us on Android/ARM.
>>> I'd like Evgeniy to comment on it.
>>>
>>> --kcc
>>>
>>> On Mon, May 6, 2013 at 10:52 PM, Christophe Lyon
>>> <christophe.l...@linaro.org> wrote:
>>>> Hi,
>>>>
>>>> Here is a 2nd attempt at enabling libsanitizer on ARM.
>>>> Compared with the previous version, this patch is more intrusive to
>>>> workaround some limitations with qemu:
>>>>
>>>> * qemu does not work well with threads, so I chose to disable
>>>> clone-test-1.c and rlimit-mmap-test-1.c when running on a simulator.
>>>> This is a bit overkill since the limitation is caused by qemu, not by
>>>> the fact of running on a simulator. Would it cause problems on other
>>>> targets?
>>>>
>>>> * due to different connexion mathod between runtest and the target
>>>> program in native mode and in simulated mode, causing isatty(2) to
>>>> give a different answer, I modified a few regexps to accept possible
>>>> decorations. This can be removed once ASAN_OPTIONS=color=0 is
>>>> implemented.
>>>>
>>>> Tested on x86 with no regression, on ARM cortex-a9 hardware and
>>>> a15-qemu with the expected new tests.
>>>>
>>>> OK?
>>>>
>>>> Christophe.
>>>>
>>>> 2013-05-06 Christophe Lyon <christophe.l...@linaro.org>
>>>>
>>>> gcc/
>>>> * config/arm/arm.c (arm_asan_shadow_offset): New function.
>>>> (TARGET_ASAN_SHADOW_OFFSET): Define.
>>>> * config/arm/linux-eabi.h (ASAN_CC1_SPEC): Define.
>>>> (LINUX_OR_ANDROID_CC): Add ASAN_CC1_SPEC.
>>>>
>>>> libsanitizer/
>>>> * configure.tgt: Add ARM pattern.
>>>> * sanitizer_common/sanitizer_stacktrace.cc: Return the computed
>>>> value.
>>>>
>>>> testsuite/
>>>> * lib/target-supports.exp (check_effective_target_hw): New
>>>> function.
>>>> * c-c++-common/asan/clone-test-1.c: Call
>>>> check_effective_target_hw.
>>>> * c-c++-common/asan/rlimit-mmap-test-1.c: Likewise.
>>>> * c-c++-common/asan/heap-overflow-1.c: Update regexps to accept
>>>> possible decorations.
>>>> * c-c++-common/asan/null-deref-1.c: Likewise.
>>>> * c-c++-common/asan/stack-overflow-1.c: Likewise.
>>>> * c-c++-common/asan/strncpy-overflow-1.c: Likewise.
>>>> * c-c++-common/asan/use-after-free-1.c: Likewise.
>>>> * g++.dg/asan/deep-thread-stack-1.C: Likewise.
>>>> * g++.dg/asan/large-func-test-1.C: Likewise.
>>>>
>>>> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
>>>> index 0b97cf8..c036a21 100644
>>>> --- a/gcc/config/arm/arm.c
>>>> +++ b/gcc/config/arm/arm.c
>>>> @@ -281,6 +281,8 @@ static unsigned arm_add_stmt_cost (void *data, int
>>>> count,
>>>>
>>>> static void arm_canonicalize_comparison (int *code, rtx *op0, rtx *op1,
>>>> bool op0_preserve_value);
>>>> +static unsigned HOST_WIDE_INT arm_asan_shadow_offset (void);
>>>> +
>>>>
>>>> /* Table of machine attributes. */
>>>> static const struct attribute_spec arm_attribute_table[] =
>>>> @@ -657,6 +659,9 @@ static const struct attribute_spec
>>>> arm_attribute_table[] =
>>>> #define TARGET_CANONICALIZE_COMPARISON \
>>>> arm_canonicalize_comparison
>>>>
>>>> +#undef TARGET_ASAN_SHADOW_OFFSET
>>>> +#define TARGET_ASAN_SHADOW_OFFSET arm_asan_shadow_offset
>>>> +
>>>> struct gcc_target targetm = TARGET_INITIALIZER;
>>>>
>>>> /* Obstack for minipool constant handling. */
>>>> @@ -28062,4 +28067,12 @@ arm_validize_comparison (rtx *comparison, rtx
>>>> * op1, rtx * op2)
>>>>
>>>> }
>>>>
>>>> +/* Implement the TARGET_ASAN_SHADOW_OFFSET hook. */
>>>> +
>>>> +static unsigned HOST_WIDE_INT
>>>> +arm_asan_shadow_offset (void)
>>>> +{
>>>> + return (unsigned HOST_WIDE_INT) 1 << 29;
>>>> +}
>>>> +
>>>> #include "gt-arm.h"
>>>> diff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.h
>>>> index 23671a7..cb0aad1 100644
>>>> --- a/gcc/config/arm/linux-eabi.h
>>>> +++ b/gcc/config/arm/linux-eabi.h
>>>> @@ -84,10 +84,14 @@
>>>> LINUX_OR_ANDROID_LD (LINUX_TARGET_LINK_SPEC, \
>>>> LINUX_TARGET_LINK_SPEC " " ANDROID_LINK_SPEC)
>>>>
>>>> +#undef ASAN_CC1_SPEC
>>>> +#define ASAN_CC1_SPEC "%{fsanitize=*:-funwind-tables}"
>>>> +
>>>> #undef CC1_SPEC
>>>> #define CC1_SPEC \
>>>> - LINUX_OR_ANDROID_CC (GNU_USER_TARGET_CC1_SPEC, \
>>>> - GNU_USER_TARGET_CC1_SPEC " " ANDROID_CC1_SPEC)
>>>> + LINUX_OR_ANDROID_CC (GNU_USER_TARGET_CC1_SPEC " " ASAN_CC1_SPEC, \
>>>> + GNU_USER_TARGET_CC1_SPEC " " ASAN_CC1_SPEC " " \
>>>> + ANDROID_CC1_SPEC)
>>>>
>>>> #define CC1PLUS_SPEC \
>>>> LINUX_OR_ANDROID_CC ("", ANDROID_CC1PLUS_SPEC)
>>>> diff --git a/gcc/testsuite/c-c++-common/asan/clone-test-1.c
>>>> b/gcc/testsuite/c-c++-common/asan/clone-test-1.c
>>>> index d9acc0d..fd187aa 100644
>>>> --- a/gcc/testsuite/c-c++-common/asan/clone-test-1.c
>>>> +++ b/gcc/testsuite/c-c++-common/asan/clone-test-1.c
>>>> @@ -3,6 +3,7 @@
>>>>
>>>> /* { dg-do run { target { *-*-linux* } } } */
>>>> /* { dg-require-effective-target clone } */
>>>> +/* { dg-require-effective-target hw } */
>>>> /* { dg-options "-D_GNU_SOURCE" } */
>>>>
>>>> #include <stdio.h>
>>>> diff --git a/gcc/testsuite/c-c++-common/asan/heap-overflow-1.c
>>>> b/gcc/testsuite/c-c++-common/asan/heap-overflow-1.c
>>>> index 43d47a3..e0b9038 100644
>>>> --- a/gcc/testsuite/c-c++-common/asan/heap-overflow-1.c
>>>> +++ b/gcc/testsuite/c-c++-common/asan/heap-overflow-1.c
>>>> @@ -25,7 +25,7 @@ int main(int argc, char **argv) {
>>>>
>>>> /* { dg-output "READ of size 1 at 0x\[0-9a-f\]+ thread T0.*(\n|\r\n|\r)"
>>>> } */
>>>> /* { dg-output " #0 0x\[0-9a-f\]+ (in _*main
>>>> (\[^\n\r]*heap-overflow-1.c:21|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)" } */
>>>> -/* { dg-output "0x\[0-9a-f\]+ is located 0 bytes to the right of
>>>> 10-byte region\[^\n\r]*(\n|\r\n|\r)" } */
>>>> -/* { dg-output "allocated by thread T0 here:\[^\n\r]*(\n|\r\n|\r)" } */
>>>> +/* { dg-output ".*0x\[0-9a-f\]+ is located 0 bytes to the right of
>>>> 10-byte region\[^\n\r]*(\n|\r\n|\r)" } */
>>>> +/* { dg-output ".*allocated by thread T0 here:\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #0 0x\[0-9a-f\]+ (in
>>>> _*(interceptor_|)malloc|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #1 0x\[0-9a-f\]+ (in _*main
>>>> (\[^\n\r]*heap-overflow-1.c:19|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)"
>>>> } */
>>>> diff --git a/gcc/testsuite/c-c++-common/asan/null-deref-1.c
>>>> b/gcc/testsuite/c-c++-common/asan/null-deref-1.c
>>>> index 2eee986..95e5036 100644
>>>> --- a/gcc/testsuite/c-c++-common/asan/null-deref-1.c
>>>> +++ b/gcc/testsuite/c-c++-common/asan/null-deref-1.c
>>>> @@ -18,6 +18,6 @@ int main()
>>>>
>>>> /* { dg-output "ERROR: AddressSanitizer:? SEGV on unknown
>>>> address\[^\n\r]*" } */
>>>> /* { dg-output "0x\[0-9a-f\]+ \[^\n\r]*pc
>>>> 0x\[0-9a-f\]+\[^\n\r]*(\n|\r\n|\r)" } */
>>>> -/* { dg-output "AddressSanitizer can not provide additional
>>>> info.*(\n|\r\n|\r)" } */
>>>> +/* { dg-output ".*AddressSanitizer can not provide additional
>>>> info.*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #0 0x\[0-9a-f\]+ (in \[^\n\r]*NullDeref\[^\n\r]*
>>>> (\[^\n\r]*null-deref-1.c:10|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)"
>>>> } */
>>>> /* { dg-output " #1 0x\[0-9a-f\]+ (in _*main
>>>> (\[^\n\r]*null-deref-1.c:15|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)"
>>>> } */
>>>> diff --git a/gcc/testsuite/c-c++-common/asan/rlimit-mmap-test-1.c
>>>> b/gcc/testsuite/c-c++-common/asan/rlimit-mmap-test-1.c
>>>> index 0b3d2ae..9dbbc85 100644
>>>> --- a/gcc/testsuite/c-c++-common/asan/rlimit-mmap-test-1.c
>>>> +++ b/gcc/testsuite/c-c++-common/asan/rlimit-mmap-test-1.c
>>>> @@ -2,6 +2,7 @@
>>>>
>>>> /* { dg-do run { target setrlimit } } */
>>>> /* { dg-skip-if "" { *-*-* } { "*" } { "-O0" } } */
>>>> +/* { dg-require-effective-target hw } */
>>>> /* { dg-shouldfail "asan" } */
>>>>
>>>> #include <stdlib.h>
>>>> diff --git a/gcc/testsuite/c-c++-common/asan/stack-overflow-1.c
>>>> b/gcc/testsuite/c-c++-common/asan/stack-overflow-1.c
>>>> index 790aa5e..5788b10 100644
>>>> --- a/gcc/testsuite/c-c++-common/asan/stack-overflow-1.c
>>>> +++ b/gcc/testsuite/c-c++-common/asan/stack-overflow-1.c
>>>> @@ -19,4 +19,4 @@ int main() {
>>>>
>>>> /* { dg-output "READ of size 1 at 0x\[0-9a-f\]+ thread
>>>> T0\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #0 0x\[0-9a-f\]+ (in _*main
>>>> (\[^\n\r]*stack-overflow-1.c:16|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)" }
>>>> */
>>>> -/* { dg-output "Address 0x\[0-9a-f\]+ is\[^\n\r]*frame <main>" } */
>>>> +/* { dg-output ".*Address 0x\[0-9a-f\]+ is\[^\n\r]*frame <main>" } */
>>>> diff --git a/gcc/testsuite/c-c++-common/asan/strncpy-overflow-1.c
>>>> b/gcc/testsuite/c-c++-common/asan/strncpy-overflow-1.c
>>>> index 10b3ad7..5e8ce40 100644
>>>> --- a/gcc/testsuite/c-c++-common/asan/strncpy-overflow-1.c
>>>> +++ b/gcc/testsuite/c-c++-common/asan/strncpy-overflow-1.c
>>>> @@ -15,7 +15,7 @@ int main(int argc, char **argv) {
>>>> /* { dg-output "WRITE of size \[0-9\]* at 0x\[0-9a-f\]+ thread
>>>> T0\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #0 0x\[0-9a-f\]+ (in
>>>> _*(interceptor_|)strncpy|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #1 0x\[0-9a-f\]+ (in _*main
>>>> (\[^\n\r]*strncpy-overflow-1.c:11|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)" }
>>>> */
>>>> -/* { dg-output "0x\[0-9a-f\]+ is located 0 bytes to the right of
>>>> 9-byte region\[^\n\r]*(\n|\r\n|\r)" } */
>>>> -/* { dg-output "allocated by thread T0 here:\[^\n\r]*(\n|\r\n|\r)" } */
>>>> +/* { dg-output ".*0x\[0-9a-f\]+ is located 0 bytes to the right of
>>>> 9-byte region\[^\n\r]*(\n|\r\n|\r)" } */
>>>> +/* { dg-output ".*allocated by thread T0 here:\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #0 0x\[0-9a-f\]+ (in
>>>> _*(interceptor_|)malloc|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #1 0x\[0-9a-f\]+ (in _*main
>>>> (\[^\n\r]*strncpy-overflow-1.c:10|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)"
>>>> } */
>>>> diff --git a/gcc/testsuite/c-c++-common/asan/use-after-free-1.c
>>>> b/gcc/testsuite/c-c++-common/asan/use-after-free-1.c
>>>> index 939feeb..65318c8 100644
>>>> --- a/gcc/testsuite/c-c++-common/asan/use-after-free-1.c
>>>> +++ b/gcc/testsuite/c-c++-common/asan/use-after-free-1.c
>>>> @@ -11,12 +11,12 @@ int main() {
>>>>
>>>> /* { dg-output "ERROR: AddressSanitizer:? heap-use-after-free on
>>>> address\[^\n\r]*" } */
>>>> /* { dg-output "0x\[0-9a-f\]+ at pc 0x\[0-9a-f\]+ bp 0x\[0-9a-f\]+ sp
>>>> 0x\[0-9a-f\]+\[^\n\r]*(\n|\r\n|\r)" } */
>>>> -/* { dg-output "READ of size 1 at 0x\[0-9a-f\]+ thread
>>>> T0\[^\n\r]*(\n|\r\n|\r)" } */
>>>> +/* { dg-output ".*READ of size 1 at 0x\[0-9a-f\]+ thread
>>>> T0\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #0 0x\[0-9a-f\]+ (in _*main
>>>> (\[^\n\r]*use-after-free-1.c:9|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)" } */
>>>> -/* { dg-output "0x\[0-9a-f\]+ is located 5 bytes inside of 10-byte
>>>> region .0x\[0-9a-f\]+,0x\[0-9a-f\]+\[^\n\r]*(\n|\r\n|\r)" } */
>>>> -/* { dg-output "freed by thread T0 here:\[^\n\r]*(\n|\r\n|\r)" } */
>>>> +/* { dg-output ".*0x\[0-9a-f\]+ is located 5 bytes inside of 10-byte
>>>> region .0x\[0-9a-f\]+,0x\[0-9a-f\]+\[^\n\r]*(\n|\r\n|\r)" } */
>>>> +/* { dg-output ".*freed by thread T0 here:\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #0 0x\[0-9a-f\]+ (in
>>>> _*(interceptor_|)free|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #1 0x\[0-9a-f\]+ (in _*main
>>>> (\[^\n\r]*use-after-free-1.c:8|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)" } */
>>>> -/* { dg-output "previously allocated by thread T0
>>>> here:\[^\n\r]*(\n|\r\n|\r)" } */
>>>> +/* { dg-output ".*previously allocated by thread T0
>>>> here:\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #0 0x\[0-9a-f\]+ (in
>>>> _*(interceptor_|)malloc|\[(\])\[^\n\r]*(\n|\r\n|\r)" } */
>>>> /* { dg-output " #1 0x\[0-9a-f\]+ (in _*main
>>>> (\[^\n\r]*use-after-free-1.c:7|\[^\n\r]*:0)|\[(\])\[^\n\r]*(\n|\r\n|\r)"
>>>> } */
>>>> diff --git a/gcc/testsuite/g++.dg/asan/deep-thread-stack-1.C
>>>> b/gcc/testsuite/g++.dg/asan/deep-thread-stack-1.C
>>>> index 12d8a7a..d29fe31 100644
>>>> --- a/gcc/testsuite/g++.dg/asan/deep-thread-stack-1.C
>>>> +++ b/gcc/testsuite/g++.dg/asan/deep-thread-stack-1.C
>>>> @@ -45,9 +45,9 @@ int main(int argc, char *argv[]) {
>>>> }
>>>>
>>>> // { dg-output "ERROR: AddressSanitizer:
>>>> heap-use-after-free.*(\n|\r\n|\r)" }
>>>> -// { dg-output "WRITE of size 4 at 0x\[0-9a-f\]+ thread
>>>> T(\[0-9\]+).*(\n|\r\n|\r)" }
>>>> -// { dg-output "freed by thread T(\[0-9\]+) here:.*(\n|\r\n|\r)" }
>>>> -// { dg-output "previously allocated by thread T(\[0-9\]+)
>>>> here:.*(\n|\r\n|\r)" }
>>>> +// { dg-output ".*WRITE of size 4 at 0x\[0-9a-f\]+ thread
>>>> T(\[0-9\]+).*(\n|\r\n|\r)" }
>>>> +// { dg-output ".*freed by thread T(\[0-9\]+) here:.*(\n|\r\n|\r)" }
>>>> +// { dg-output ".*previously allocated by thread T(\[0-9\]+)
>>>> here:.*(\n|\r\n|\r)" }
>>>> // { dg-output "Thread T\\2 created by T(\[0-9\]+) here:.*(\n|\r\n|\r)" }
>>>> // { dg-output "Thread T\\8 created by T0 here:.*(\n|\r\n|\r)" }
>>>> // { dg-output "Thread T\\4 created by T(\[0-9\]+) here:.*(\n|\r\n|\r)" }
>>>> diff --git a/gcc/testsuite/g++.dg/asan/large-func-test-1.C
>>>> b/gcc/testsuite/g++.dg/asan/large-func-test-1.C
>>>> index 32808e7..0d5c383 100644
>>>> --- a/gcc/testsuite/g++.dg/asan/large-func-test-1.C
>>>> +++ b/gcc/testsuite/g++.dg/asan/large-func-test-1.C
>>>> @@ -37,9 +37,9 @@ int main() {
>>>>
>>>> // { dg-output "ERROR: AddressSanitizer:? heap-buffer-overflow on
>>>> address\[^\n\r]*" }
>>>> // { dg-output "0x\[0-9a-f\]+ at pc 0x\[0-9a-f\]+ bp 0x\[0-9a-f\]+ sp
>>>> 0x\[0-9a-f\]+\[^\n\r]*(\n|\r\n|\r)" }
>>>> -// { dg-output "READ of size 4 at 0x\[0-9a-f\]+ thread
>>>> T0\[^\n\r]*(\n|\r\n|\r)" }
>>>> +// { dg-output ".*READ of size 4 at 0x\[0-9a-f\]+ thread
>>>> T0\[^\n\r]*(\n|\r\n|\r)" }
>>>> // { dg-output " #0 0x\[0-9a-f\]+ (in
>>>> \[^\n\r]*LargeFunction\[^\n\r]*(large-func-test-1.C:18|\[^\n\r]*:0)|\[(\]).*(\n|\r\n|\r)"
>>>> }
>>>> -// { dg-output "0x\[0-9a-f\]+ is located 44 bytes to the right of
>>>> 400-byte region.*(\n|\r\n|\r)" }
>>>> -// { dg-output "allocated by thread T0 here:\[^\n\r]*(\n|\r\n|\r)" }
>>>> +// { dg-output ".*0x\[0-9a-f\]+ is located 44 bytes to the right of
>>>> 400-byte region.*(\n|\r\n|\r)" }
>>>> +// { dg-output ".*allocated by thread T0 here:\[^\n\r]*(\n|\r\n|\r)" }
>>>> // { dg-output " #0( 0x\[0-9a-f\]+ (in
>>>> _*(interceptor_|)malloc|\[(\])\[^\n\r]*(\n|\r\n|\r)" }
>>>> // { dg-output " #1|) 0x\[0-9a-f\]+ (in (operator
>>>> new|_*_Zn\[aw\]\[mj\])|\[(\])\[^\n\r]*(\n|\r\n|\r)" }
>>>> diff --git a/gcc/testsuite/lib/target-supports.exp
>>>> b/gcc/testsuite/lib/target-supports.exp
>>>> index 45c8b84..28b6b6d 100644
>>>> --- a/gcc/testsuite/lib/target-supports.exp
>>>> +++ b/gcc/testsuite/lib/target-supports.exp
>>>> @@ -4668,6 +4668,33 @@ proc check_effective_target_simulator { } {
>>>> return 0
>>>> }
>>>>
>>>> +# Return 1 if programs are intended to be run on hardware rather than
>>>> +# on a simulator
>>>> +
>>>> +proc check_effective_target_hw { } {
>>>> +
>>>> + # All "src/sim" simulators set this one.
>>>> + if [board_info target exists is_simulator] {
>>>> + if [board_info target is_simulator] {
>>>> + return 0
>>>> + } else {
>>>> + return 1
>>>> + }
>>>> + }
>>>> +
>>>> + # The "sid" simulators don't set that one, but at least they set
>>>> + # this one.
>>>> + if [board_info target exists slow_simulator] {
>>>> + if [board_info target slow_simulator] {
>>>> + return 0
>>>> + } else {
>>>> + return 1
>>>> + }
>>>> + }
>>>> +
>>>> + return 1
>>>> +}
>>>> +
>>>> # Return 1 if the target is a VxWorks kernel.
>>>>
>>>> proc check_effective_target_vxworks_kernel { } {
>>>> diff --git a/libsanitizer/configure.tgt b/libsanitizer/configure.tgt
>>>> index 265da01..bdfc22e 100644
>>>> --- a/libsanitizer/configure.tgt
>>>> +++ b/libsanitizer/configure.tgt
>>>> @@ -29,6 +29,8 @@ case "${target}" in
>>>> ;;
>>>> sparc*-*-linux*)
>>>> ;;
>>>> + arm*-*-linux*)
>>>> + ;;
>>>> x86_64-*-darwin[1]* | i?86-*-darwin[1]*)
>>>> TSAN_SUPPORTED=no
>>>> ;;
>>>> diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
>>>> b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
>>>> index e14ea44..7b3e4ca 100644
>>>> --- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
>>>> +++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
>>>> @@ -27,7 +27,7 @@ const char *StripPathPrefix(const char *filepath,
>>>> uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
>>>> #ifdef __arm__
>>>> // Cancel Thumb bit.
>>>> - pc = pc & (~1);
>>>> + return pc & (~1);
>>
>> Here you are cancelling "pc - 1" operation, why? It is needed for the
>> function to return the address of the _previous_ instruction. It
>> matters when the call instruction is the last one in a function
>> (because the callee is no-return), and return address is actually
>> outside the function.
>>
>>>> #endif
>>>> #if defined(__powerpc__) || defined(__powerpc64__)
>>>> // PCs are always 4 byte aligned.
