Commit Graph

28 Commits

Author SHA1 Message Date
Marco Elver f3b3c964c3 Revert "[tsan] Fix GCC 8.3 build after D107911"
This reverts commit 797fe59e6b.

The use of "EventType type : 3" is replicated for all Event structs and
therefore was still present. As a result this still caused failures on
older GCCs (9.2 or 8.3 or earlier).

The particular bot that was failing due to buggy GCC was fixed by
fef39cc472.

Therefore, no reason to keep the workaround around; revert it.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D108192
2021-08-17 19:26:20 +02:00
Vitaly Buka 797fe59e6b [tsan] Fix GCC 8.3 build after D107911
gcc 8.3 reports:
__tsan::v3::Event::type’ is too small to hold all values of ‘enum class __tsan::v3::EventType’
2021-08-16 16:18:42 -07:00
Dmitry Vyukov c97318996f tsan: add new trace
Add structures for the new trace format,
functions that serialize and add events to the trace
and trace replaying logic.

Differential Revision: https://reviews.llvm.org/D107911
2021-08-16 10:24:11 +02:00
Dmitry Vyukov a82c7476a7 tsan: introduce RawShadow type
Currently we hardcode u64 type for shadow everywhere
and do lots of uptr<->u64* casts. It makes it hard to
change u64 to another type (e.g. u32) and makes it easy
to introduce bugs.
Introduce RawShadow type and use it in MemToShadow, ShadowToMem,
IsShadowMem and throughout the code base as u64 replacement.
This makes it possible to change u64 to something else in future
and generally improves static typing.

Depends on D107481.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D107482
2021-08-05 13:37:10 +02:00
Dmitry Vyukov 9e3e97aa81 tsan: refactor MetaMap::GetAndLock interface
Don't lock the sync object inside of MetaMap methods.
This has several advantages:
 - the new interface does not confuse thread-safety analysis
   so we can remove a bunch of NO_THREAD_SAFETY_ANALYSIS attributes
 - this allows use of scoped lock objects
 - this allows more flexibility, e.g. locking some other mutex
   between searching and locking the sync object
Also prefix the methods with GetSync to be consistent with GetBlock method.
Also make interface wrappers inlinable, otherwise we either end up with
2 copies of the method, or with an additional call.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D107256
2021-08-02 13:29:46 +02:00
Dmitry Vyukov 103d075b05 tsan: introduce Tid and StackID typedefs
Currently we inconsistently use u32 and int for thread ids,
there are also "unique tid" and "os tid" and just lots of other
things identified by integers.
Additionally new tsan runtime will introduce yet another
thread identifier that is very different from current tids.
Similarly for stack IDs, it's easy to confuse u32 with other
integer identifiers. And when a function accepts u32 or a struct
contains u32 field, it's not always clear what it is.

Add Tid and StackID typedefs to make it clear what is what.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D107152
2021-07-31 09:05:31 +02:00
Dmitry Vyukov 817f942a28 tsan: introduce New/Alloc/Free helpers
We frequenty allocate sizeof(T) memory and call T ctor on that memory
(C++ new keyword effectively). Currently it's quite verbose and
usually takes 2 lines of code.
Add New<T>() helper that does it much more concisely.

Rename internal_free to Free that also sets the pointer to nullptr.
Shorter and safer.

Rename internal_alloc to Alloc, just shorter.

Reviewed By: vitalybuka, melver

Differential Revision: https://reviews.llvm.org/D107085
2021-07-30 11:51:55 +02:00
Dmitry Vyukov 0d68cfc996 tsan: store ThreadRegistry in Context by value
It's unclear why we allocate ThreadRegistry separately,
I assume it's some historical leftover.
Embed ThreadRegistry into Context.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D107045
2021-07-29 12:44:44 +02:00
Dmitry Vyukov 9dad34423b tsan: strip __libc_start_main frame
We strip all frames below main but in some cases it may be not enough.
Namely, when main is instrumented but does not call any other instrumented code.
In this case __tsan_func_entry in main obtains PC pointing to __libc_start_main
(as we pass caller PC to __tsan_func_entry), but nothing obtains PC pointing
to main itself (as main does not call any instrumented code).
In such case we will not have main in the stack, and stripping everything
below main won't work.
So strip __libc_start_main explicitly as well.
But keep stripping of main because __libc_start_main is glibc/linux-specific,
so looking for main is more reliable (and usually main is present in stacks).

Depends on D106957.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D106958
2021-07-28 20:26:42 +02:00
Dmitry Vyukov 5237b14087 tsan: print alloc stack for Java objects
We maintain information about Java allocations,
but for some reason never printed it in reports.
Print it.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D106956
2021-07-28 20:25:11 +02:00
Dmitry Vyukov b5bc386ca1 tsan: remove mblock types
We used to count number of allocations/bytes based on the type
and maybe record them in heap block headers.
But that's all in the past, now it's not used for anything.
Remove the mblock type.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D106971
2021-07-28 20:09:25 +02:00
Dmitry Vyukov 0118a64934 tsan: switch to the new sanitizer_common mutex
Now that sanitizer_common mutex has feature-parity with tsan mutex,
switch tsan to the sanitizer_common mutex and remove tsan's custom mutex.

Reviewed By: vitalybuka, melver

Differential Revision: https://reviews.llvm.org/D106379
2021-07-23 09:13:26 +02:00
Dmitry Vyukov 8924d8e37e tsan: disable thread safety analysis in more functions
In preparation for replacing tsan Mutex with sanitizer_common Mutex,
which has thread-safety annotations. Thread safety analysis does not
understand MetaMap::GetAndLock which returns a locked sync object.

Reviewed By: vitalybuka, melver

Differential Revision: https://reviews.llvm.org/D106548
2021-07-23 09:12:59 +02:00
Nico Weber 557855e047 Revert "tsan: make obtaining current PC faster"
This reverts commit e33446ea58.
Doesn't build on mac, and causes other problems. See reports
on https://reviews.llvm.org/D106046 and https://reviews.llvm.org/D106081

Also revert follow-up "tsan: strip top inlined internal frames"
This reverts commit 7b302fc9b0.
2021-07-15 19:29:19 -04:00
Dmitry Vyukov 7b302fc9b0 tsan: strip top inlined internal frames
The new GET_CURRENT_PC() can lead to spurious top inlined internal frames.
Here are 2 examples from bots, in both cases the malloc is supposed to be
the top frame (#0):

  WARNING: ThreadSanitizer: signal-unsafe call inside of a signal
    #0 __sanitizer::StackTrace::GetNextInstructionPc(unsigned long)
    #1 malloc

  Location is heap block of size 99 at 0xbe3800003800 allocated by thread T1:
    #0 __sanitizer::StackTrace::GetNextInstructionPc(unsigned long)
    #1 malloc

Let's strip these internal top frames from reports.
With other code changes I also observed some top frames
from __tsan::ScopedInterceptor, proactively remove these as well.

Differential Revision: https://reviews.llvm.org/D106081
2021-07-15 19:37:44 +02:00
Dmitry Vyukov 2721e27c3a sanitizer_common: deduplicate CheckFailed
We have some significant amount of duplication around
CheckFailed functionality. Each sanitizer copy-pasted
a chunk of code. Some got random improvements like
dealing with recursive failures better. These improvements
could benefit all sanitizers, but they don't.

Deduplicate CheckFailed logic across sanitizers and let each
sanitizer only print the current stack trace.
I've tried to dedup stack printing as well,
but this got me into cmake hell. So let's keep this part
duplicated in each sanitizer for now.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D102221
2021-05-12 08:50:53 +02:00
Dmitry Vyukov ed7bf7d73f tsan: refactor fork handling
Commit efd254b636 ("tsan: fix deadlock in pthread_atfork callbacks")
fixed another deadlock related to atfork handling.
But builders with DCHECKs enabled reported failures of
pthread_atfork_deadlock2.c and pthread_atfork_deadlock3.c tests
related to the fact that we hold runtime locks on interceptor exit:
https://lab.llvm.org/buildbot/#/builders/70/builds/6727
This issue is somewhat inherent to the current approach,
we indeed execute user code (atfork callbacks) with runtime lock held.

Refactor fork handling to not run user code (atfork callbacks)
with runtime locks held. This change does this by installing
own atfork callbacks during runtime initialization.
Atfork callbacks run in LIFO order, so the expectation is that
our callbacks run last, right before the actual fork.
This way we lock runtime mutexes around fork, but not around
user callbacks.

Extend tests to also install after fork callbacks just to cover
more scenarios. Some tests also started reporting real races
that we previously suppressed.

Also extend tests to cover fork syscall support.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D101517
2021-04-30 08:48:20 +02:00
Tres Popp d1e08b124c Revert "tsan: refactor fork handling"
This reverts commit e1021dd1fd.
2021-04-28 14:08:33 +02:00
Dmitry Vyukov e1021dd1fd tsan: refactor fork handling
Commit efd254b636 ("tsan: fix deadlock in pthread_atfork callbacks")
fixed another deadlock related to atfork handling.
But builders with DCHECKs enabled reported failures of
pthread_atfork_deadlock2.c and pthread_atfork_deadlock3.c tests
related to the fact that we hold runtime locks on interceptor exit:
https://lab.llvm.org/buildbot/#/builders/70/builds/6727
This issue is somewhat inherent to the current approach,
we indeed execute user code (atfork callbacks) with runtime lock held.

Refactor fork handling to not run user code (atfork callbacks)
with runtime locks held. This change does this by installing
own atfork callbacks during runtime initialization.
Atfork callbacks run in LIFO order, so the expectation is that
our callbacks run last, right before the actual fork.
This way we lock runtime mutexes around fork, but not around
user callbacks.

Extend tests to also install after fork callbacks just to cover
more scenarios. Some tests also started reporting real races
that we previously suppressed.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D101385
2021-04-27 22:37:27 +02:00
Evgenii Stepanov 5275d772da Revert "tsan: fix deadlock in pthread_atfork callbacks"
Tests fail on debug builders. See the forward fix in
https://reviews.llvm.org/D101385.

This reverts commit efd254b636.
2021-04-27 12:36:31 -07:00
Dmitry Vyukov efd254b636 tsan: fix deadlock in pthread_atfork callbacks
We take report/thread_registry locks around fork.
This means we cannot report any bugs in atfork handlers.
We resolved this by enabling per-thread ignores around fork.
This resolved some of the cases, but not all.
The added test triggers a race report from a signal handler
called from atfork callback, we reset per-thread ignores
around signal handlers, so we tried to report it and deadlocked.
But there are more cases: a signal handler can be called
synchronously if it's sent to itself. Or any other report
types would cause deadlocks as well: mutex misuse,
signal handler spoiling errno, etc.
Disable all reports for the duration of fork with
thr->suppress_reports and don't re-enable them around
signal handlers.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D101154
2021-04-27 13:25:26 +02:00
Vitaly Buka 20e78eb304 [sanitizer][NFC] Fix few cpplint warnings 2020-10-13 20:39:37 -07:00
Joachim Protze 7358a1104a [TSan] Optimize handling of racy address
This patch splits the handling of racy address and racy stack into separate
functions. If a race was already reported for the address, we can avoid the
cost for collecting the involved stacks.

This patch also removes the race condition in storing the racy address / racy
stack. This race condition allowed all threads to report the race.

This patch changes the transitive suppression of reports. Previously
suppression could transitively chain memory location and racy stacks.
Now racy memory and racy stack are separate suppressions.

Commit again, now with fixed tests.

Reviewed by: dvyukov

Differential Revision: https://reviews.llvm.org/D83625
2020-07-16 16:22:57 +02:00
Joachim Protze d3849dddd2 Revert "[TSan] Optimize handling of racy address"
This reverts commit 00e3a1ddec.
The commit broke most build bots, investigating.
2020-07-15 17:40:28 +02:00
Joachim Protze 00e3a1ddec [TSan] Optimize handling of racy address
This patch splits the handling of racy address and racy stack into separate
functions. If a race was already reported for the address, we can avoid the
cost for collecting the involved stacks.

This patch also removes the race condition in storing the racy address / racy
stack. This race condition allowed all threads to report the race.

This patch changes the transitive suppression of reports. Previously
suppression could transitively chain memory location and racy stacks.
Now racy memory and racy stack are separate suppressions.

Reviewed by: dvyukov

Differential Revision: https://reviews.llvm.org/D83625
2020-07-15 16:50:08 +02:00
Vitaly Buka c0fa632236 Remove NOLINTs from compiler-rt
llvm-svn: 371687
2019-09-11 23:19:48 +00:00
Nico Weber bb7ad98a47 Follow-up for r367863 and r367656
llvm-svn: 367888
2019-08-05 16:50:56 +00:00
Nico Weber 5a3bb1a4d6 compiler-rt: Rename .cc file in lib/tsan/rtl to .cpp
Like r367463, but for tsan/rtl.

llvm-svn: 367564
2019-08-01 14:22:42 +00:00