Commit Graph

8 Commits

Author SHA1 Message Date
Francis Ricci 86e070f7e9 Implement tls scanning for darwin LSan
Summary:
This required for any users who call exit() after creating
thread-specific data, as tls destructors are only called when
pthread_exit() or pthread_cancel() are used. This should also
match tls behavior on linux.

Getting the base address of the tls section is straightforward,
as it's stored as a section offset in %gs. The size is a bit trickier
to work out, as there doesn't appear to be any official documentation
or source code referring to it. The size used in this patch was determined
by taking the difference between the base address and the address of the
subsequent memory region returned by vm_region_recurse_64, which was
1024 * sizeof(uptr) on all threads except the main thread, where it was
larger. Since the section must be the same size on all of the threads,
1024 * sizeof(uptr) seemed to be a reasonable size to use, barring
a more programtic way to get the size.

1024 seems like a reasonable number, given that PTHREAD_KEYS_MAX
is 512 on darwin, so pthread keys will fit inside the region while
leaving space for other tls data. A larger size would overflow the
memory region returned by vm_region_recurse_64, and a smaller size
wouldn't leave room for all the pthread keys. In addition, the
stress test added here passes, which means that we are scanning at
least the full set of possible pthread keys, and probably
the full tls section.

Reviewers: alekseyshl, kubamracek

Subscribers: krytarowski, llvm-commits

Differential Revision: https://reviews.llvm.org/D33215

llvm-svn: 303887
2017-05-25 17:41:13 +00:00
Francis Ricci 3b57da0c73 Revert "Implement tls scanning for darwin LSan"
This reverts r303262, due to TSan buildbot breakages.

llvm-svn: 303266
2017-05-17 15:25:41 +00:00
Francis Ricci eab89eb850 Implement tls scanning for darwin LSan
Summary:
This required for any users who call exit() after creating
thread-specific data, as tls destructors are only called when
pthread_exit() or pthread_cancel() are used. This should also
match tls behavior on linux.

Getting the base address of the tls section is straightforward,
as it's stored as a section offset in %gs. The size is a bit trickier
to work out, as there doesn't appear to be any official documentation
or source code referring to it. The size used in this patch was determined
by taking the difference between the base address and the address of the
subsequent memory region returned by vm_region_recurse_64, which was
1024 * sizeof(uptr) on all threads except the main thread, where it was
larger. Since the section must be the same size on all of the threads,
1024 * sizeof(uptr) seemed to be a reasonable size to use, barring
a more programtic way to get the size.

1024 seems like a reasonable number, given that PTHREAD_KEYS_MAX
is 512 on darwin, so pthread keys will fit inside the region while
leaving space for other tls data. A larger size would overflow the
memory region returned by vm_region_recurse_64, and a smaller size
wouldn't leave room for all the pthread keys. In addition, the
stress test added here passes, which means that we are scanning at
least the full set of possible pthread keys, and probably
the full tls section.

Reviewers: alekseyshl, kubamracek

Subscribers: krytarowski, llvm-commits

Differential Revision: https://reviews.llvm.org/D33215

llvm-svn: 303262
2017-05-17 14:35:17 +00:00
Francis Ricci 54ce07d093 Disable use of tls scanning on darwin leak sanitizer
Summary:
These checks appear linux-specific, disable them on darwin, at
least for now.

Reviewers: kubamracek, alekseyshl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32013

llvm-svn: 300248
2017-04-13 20:14:15 +00:00
Alexey Samsonov 1f242d6a77 [LSan] Add "use_ld_allocations" flag to disable old way of DTLS handling.
This flag allows to disable old way of determining dynamic TLS by
filtering out allocations from dynamic linker. This will be eventually
superseded by __tls_get_addr interceptor (see r257785), after we:
1) Test it in several supported environments
2) Deal with existing problems (currently we can't find a pointer to
  DTV which is calloc()-ed in pthread_create).

llvm-svn: 257789
2016-01-14 19:16:05 +00:00
Alexey Samsonov bb79b06f4e [Sanitizers] Unify the semantics and usage of "exitcode" runtime flag across all sanitizers.
Summary:
Merge "exitcode" flag from ASan, LSan, TSan and "exit_code" from MSan
into one entity. Additionally, make sure sanitizer_common now uses the
value of common_flags()->exitcode when dying on error, so that this
flag will automatically work for other sanitizers (UBSan and DFSan) as
well.

User-visible changes:
* "exit_code" MSan runtime flag is now deprecated. If explicitly
  specified, this flag will take precedence over "exitcode".
  The users are encouraged to migrate to the new version.
* __asan_set_error_exit_code() and __msan_set_exit_code() functions
  are removed. With few exceptions, we don't support changing runtime
  flags during program execution - we can't make them thread-safe.
  The users should use __sanitizer_set_death_callback()
  that would call _exit() with proper exit code instead.
* Plugin tools (LSan and UBSan) now inherit the exit code of the parent
  tool. In particular, this means that ASan would now crash the program
  with exit code "1" instead of "23" if it detects leaks.

Reviewers: kcc, eugenis

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12120

llvm-svn: 245734
2015-08-21 20:49:37 +00:00
Alexey Samsonov d1c318657b [Sanitizer] Refactor SuppressionContext class.
SuppressionContext is no longer a singleton, shared by all sanitizers,
but a regular class. Each of ASan, LSan, UBSan and TSan now have their
own SuppressionContext, which only parses suppressions specific to
that sanitizer.

"suppressions" flag is moved away from common flags into tool-specific
flags, so the user now may pass
  ASAN_OPTIONS=suppressions=asan_supp.txt LSAN_OPIONS=suppressions=lsan_supp.txt
in a single invocation.

llvm-svn: 230026
2015-02-20 17:41:59 +00:00
Alexey Samsonov 03499e920b [Sanitizer] Change the runtime flag representation.
This mirrors r225239 to all the rest sanitizers:
ASan, DFSan, LSan, MSan, TSan, UBSan.

Now the runtime flag type, name, default value and
description is located in the single place in the
.inc file.

llvm-svn: 225327
2015-01-07 00:38:00 +00:00