Summary:
Fuchsia's gcc uses this, which in turn prevents us to compile successfully
due to a few `memset`'ing some non-trivial classes in some `init`.
Change those `memset` to members initialization.
Reviewers: pcc, hctim
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D77902
For targets where char is unsigned (like PowerPC), something like
char c = fgetc(...) will never produce a char that will compare
equal to EOF so this loop does not terminate.
Change the type to int (which appears to be the POSIX return type
for fgetc).
This allows the test case to terminate normally on PPC.
Buildbots say:
[126/127] Running lint check for sanitizer sources...
FAILED: projects/compiler-rt/lib/CMakeFiles/SanitizerLintCheck
cd /home/buildbots/ppc64be-clang-multistage-test/clang-ppc64be-multistage/stage1/projects/compiler-rt/lib && env LLVM_CHECKOUT=/home/buildbots/ppc64be-clang-multistage-test/clang-ppc64be-multistage/llvm/llvm SILENT=1 TMPDIR= PYTHON_EXECUTABLE=/usr/bin/python COMPILER_RT=/home/buildbots/ppc64be-clang-multistage-test/clang-ppc64be-multistage/llvm/compiler-rt /home/buildbots/ppc64be-clang-multistage-test/clang-ppc64be-multistage/llvm/compiler-rt/lib/sanitizer_common/scripts/check_lint.sh
/home/buildbots/ppc64be-clang-multistage-test/clang-ppc64be-multistage/llvm/compiler-rt/test/tsan/fiber_cleanup.cpp:71: Could not find a newline character at the end of the file. [whitespace/ending_newline] [5]
ninja: build stopped: subcommand failed.
Somehow this check is not part of 'ninja check-tsan'.
When creating and destroying fibers in tsan a thread state is created and destroyed. Currently, a memory mapping is leaked with each fiber (in __tsan_destroy_fiber). This causes applications with many short running fibers to crash or hang because of linux vm.max_map_count.
The root of this is that ThreadState holds a pointer to ThreadSignalContext for handling signals. The initialization and destruction of it is tied to platform specific events in tsan_interceptors_posix and missed when destroying a fiber (specifically, SigCtx is used to lazily create the ThreadSignalContext in tsan_interceptors_posix). This patch cleans up the memory by makinh the ThreadState create and destroy the ThreadSignalContext.
The relevant code causing the leak with fibers is the fiber destruction:
void FiberDestroy(ThreadState *thr, uptr pc, ThreadState *fiber) {
FiberSwitchImpl(thr, fiber);
ThreadFinish(fiber);
FiberSwitchImpl(fiber, thr);
internal_free(fiber);
}
Author: Florian
Reviewed-in: https://reviews.llvm.org/D76073
Summary:
This commit adds two command-line options to clang.
These options let the user decide which functions will receive SanitizerCoverage instrumentation.
This is most useful in the libFuzzer use case, where it enables targeted coverage-guided fuzzing.
Patch by Yannis Juglaret of DGA-MI, Rennes, France
libFuzzer tests its target against an evolving corpus, and relies on SanitizerCoverage instrumentation to collect the code coverage information that drives corpus evolution. Currently, libFuzzer collects such information for all functions of the target under test, and adds to the corpus every mutated sample that finds a new code coverage path in any function of the target. We propose instead to let the user specify which functions' code coverage information is relevant for building the upcoming fuzzing campaign's corpus. To this end, we add two new command line options for clang, enabling targeted coverage-guided fuzzing with libFuzzer. We see targeted coverage guided fuzzing as a simple way to leverage libFuzzer for big targets with thousands of functions or multiple dependencies. We publish this patch as work from DGA-MI of Rennes, France, with proper authorization from the hierarchy.
Targeted coverage-guided fuzzing can accelerate bug finding for two reasons. First, the compiler will avoid costly instrumentation for non-relevant functions, accelerating fuzzer execution for each call to any of these functions. Second, the built fuzzer will produce and use a more accurate corpus, because it will not keep the samples that find new coverage paths in non-relevant functions.
The two new command line options are `-fsanitize-coverage-whitelist` and `-fsanitize-coverage-blacklist`. They accept files in the same format as the existing `-fsanitize-blacklist` option <https://clang.llvm.org/docs/SanitizerSpecialCaseList.html#format>. The new options influence SanitizerCoverage so that it will only instrument a subset of the functions in the target. We explain these options in detail in `clang/docs/SanitizerCoverage.rst`.
Consider now the woff2 fuzzing example from the libFuzzer tutorial <https://github.com/google/fuzzer-test-suite/blob/master/tutorial/libFuzzerTutorial.md>. We are aware that we cannot conclude much from this example because mutating compressed data is generally a bad idea, but let us use it anyway as an illustration for its simplicity. Let us use an empty blacklist together with one of the three following whitelists:
```
# (a)
src:*
fun:*
# (b)
src:SRC/*
fun:*
# (c)
src:SRC/src/woff2_dec.cc
fun:*
```
Running the built fuzzers shows how many instrumentation points the compiler adds, the fuzzer will output //XXX PCs//. Whitelist (a) is the instrument-everything whitelist, it produces 11912 instrumentation points. Whitelist (b) focuses coverage to instrument woff2 source code only, ignoring the dependency code for brotli (de)compression; it produces 3984 instrumented instrumentation points. Whitelist (c) focuses coverage to only instrument functions in the main file that deals with WOFF2 to TTF conversion, resulting in 1056 instrumentation points.
For experimentation purposes, we ran each fuzzer approximately 100 times, single process, with the initial corpus provided in the tutorial. We let the fuzzer run until it either found the heap buffer overflow or went out of memory. On this simple example, whitelists (b) and (c) found the heap buffer overflow more reliably and 5x faster than whitelist (a). The average execution times when finding the heap buffer overflow were as follows: (a) 904 s, (b) 156 s, and (c) 176 s.
We explain these results by the fact that WOFF2 to TTF conversion calls the brotli decompression algorithm's functions, which are mostly irrelevant for finding bugs in WOFF2 font reconstruction but nevertheless instrumented and used by whitelist (a) to guide fuzzing. This results in longer execution time for these functions and a partially irrelevant corpus. Contrary to whitelist (a), whitelists (b) and (c) will execute brotli-related functions without instrumentation overhead, and ignore new code paths found in them. This results in faster bug finding for WOFF2 font reconstruction.
The results for whitelist (b) are similar to the ones for whitelist (c). Indeed, WOFF2 to TTF conversion calls functions that are mostly located in SRC/src/woff2_dec.cc. The 2892 extra instrumentation points allowed by whitelist (b) do not tamper with bug finding, even though they are mostly irrelevant, simply because most of these functions do not get called. We get a slightly faster average time for bug finding with whitelist (b), which might indicate that some of the extra instrumentation points are actually relevant, or might just be random noise.
Reviewers: kcc, morehouse, vitalybuka
Reviewed By: morehouse, vitalybuka
Subscribers: pratyai, vitalybuka, eternalsakura, xwlin222, dende, srhines, kubamracek, #sanitizers, lebedev.ri, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D63616
Looks like this test fails on Darwin x86_64 as well:
http://green.lab.llvm.org/green/job/clang-stage1-RA/8593/
Command Output (stderr):
--
fatal error: error in backend: Global variable '__sancov_gen_' has an invalid section specifier '__DATA,__sancov_bool_flag': mach-o section specifier requires a section whose length is between 1 and 16 characters.
Summary:
Commit b684c1a50f ("Add a `Symbolizer::GetEnvP()` method that allows
symbolizer implementations to customise the environment of the
symbolizer binary.") exposed a latent ARM issue, and that broke
http://lab.llvm.org:8011/builders/clang-cmake-thumbv7-full-sh
This coincided with breakage caused by my commit 5f5fb56c68
("[compiler-rt] Intercept the uname() function"), so I had to
investigate.
The issue is that GetArgsAndEnv does not work on ARM: there glibc's
_start overwrites argc value stored at __libc_start_end, breaking the
existing argv/envp parsing logic.
Fix by inferring argc from argv.
Reviewers: eugenis, vitalybuka
Reviewed By: eugenis
Subscribers: dberris, kristof.beyls, danielkiss, #sanitizers, delcypher
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D77400
Summary:
MSan not implementing COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED looks
like an omission - this macro makes it possible for those intercepted
functions, which libc needs very early, to work before interceptors are
initialized (i.e. before REAL() is usable).
While currently there are no observable practical problems in this
area, changes in libc or in MSan runtime may provoke them. Therefore,
change MSan to work like ASan and TSan already do - use internal
functions in certain interceptors when initialization is not complete.
Reviewers: eugenis, vitalybuka
Reviewed By: eugenis
Subscribers: #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76969
Fix similar to https://reviews.llvm.org/D77111 but fow Windows.
gotsan.cpp:14071:16: error: missing terminating ' character [-Werror]
case 0b10'010: // c.lwsp (rd != x0)
^
Reported-by: Keith Randall
The intent of the `llvm_gcda_start_file` function is that only
one process create the .gcda file and initialize it to be updated
by other processes later.
Before this change, if multiple processes are started simultaneously,
some of them may initialize the file because both the first and
second `open` calls may succeed in a race condition and `new_file`
becomes 1 in those processes. This leads incorrect coverage counter
values. This often happens in MPI (Message Passing Interface) programs.
The test program added in this change is a simple reproducer.
This change ensures only one process creates/initializes the file by
using the `O_EXCL` flag.
Differential Revision: https://reviews.llvm.org/D76206
Summary:
When doing cross-compilation from Linux to MacOS we don't have
access to have access to `xcodebuild` and therefore need a way
to set the SDK version from the outside.
Fixes https://reviews.llvm.org/D68292#1853594 for me.
Reviewers: delcypher, yln
Reviewed By: delcypher
Subscribers: #julialang, mgorny, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D77026
The above change used a binary literal that is not supported in c++11 mode when
using gcc. It was formalized into the c++14 standard and works when using that
mode to compile, so change the script to use c++14 instead.
Reviewed by: dvyukov
Differential Revision: https://reviews.llvm.org/D77111
Summary:
Commit 5f5fb56c68 ("[compiler-rt] Intercept the uname() function")
broke sanitizer-x86_64-linux and clang-cmake-thumbv7-full-sh (again)
builds:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/26313http://lab.llvm.org:8011/builders/clang-cmake-thumbv7-full-sh/builds/4324
The reason is that uname() can be called as early as
__pthread_initialize_minimal_internal(). When intercepted, this
triggers ASan initialization, which eventually calls dlerror(), which
in turn uses pthreads, causing all sorts of issues.
Fix by falling back to internal_uname() when interceptor runs before
ASan is initialized. This is only for Linux at the moment.
Reviewers: eugenis, vitalybuka
Reviewed By: eugenis
Subscribers: dberris, #sanitizers, pcc
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76919
Summary:
Follow up fix to 445b810fbd. The `log show` command only works for
privileged users so run a quick test of the command during lit config to
see if the command works and only add the `darwin_log_cmd` feature if
this is the case.
Unfortunately this means the `asan/TestCases/Darwin/duplicate_os_log_reports.cpp`
test and any other tests in the future that use this feature won't run
for unprivileged users which is likely the case in CI.
rdar://problem/55986279
Reviewers: kubamracek, yln, dcoughlin
Subscribers: Charusso, #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76899
This patch follows the approach also used for MIPS, where we decode the
offending instruction to determine if the fault was caused by a read or
write operation, as that seems to be the only relevant information we have
in the signal context structure to determine that.
Differential Revision: https://reviews.llvm.org/D75168
Summary:
When ASan reports an issue the contents of the system log buffer
(`error_message_buffer`) get flushed to the system log (via
`LogFullErrorReport()`). After this happens the buffer is not cleared
but this is usually fine because the process usually exits soon after
reporting the issue.
However, when ASan runs in `halt_on_error=0` mode execution continues
without clearing the buffer. This leads to problems if more ASan
issues are found and reported.
1. Duplicate ASan reports in the system log. The Nth (start counting from 1)
ASan report will be duplicated (M - N) times in the system log if M is the
number of ASan issues reported.
2. Lost ASan reports. Given a sufficient
number of reports the buffer will fill up and consequently cannot be appended
to. This means reports can be lost.
The fix here is to reset `error_message_buffer_pos` to 0 which
effectively clears the system log buffer.
A test case is included but unfortunately it is Darwin specific because
querying the system log is an OS specific activity.
rdar://problem/55986279
Reviewers: kubamracek, yln, vitalybuka, kcc, filcab
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76749
Summary:
There's no unwinding functionality on Android that allows for line
numbers to be retrieved in-process. As a result, we can't have
this backtrace test run on Android.
Cleanup the test to use optnone functions instead, which is more stable
than line numbers anyway.
Reviewers: eugenis
Reviewed By: eugenis
Subscribers: #sanitizers, morehouse, cferris
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76807
Commit 5f5fb56c68 ("[compiler-rt] Intercept the uname() function")
broke clang-cmake-thumbv7-full-sh build:
http://lab.llvm.org:8011/builders/clang-cmake-thumbv7-full-sh/builds/4296
This also affects i386.
The reason is that intercepted uname() is called by GetKernelAreaSize()
during ASAN initialization on 32-bit platforms, but the respective
interceptor is not initialized yet at this point, leading to null
pointer dereference.
Introduce internal_uname() wrapper around uname syscall, and use it in
GetKernelAreaSize() and in FixedCVE_2016_2143().
Author: Ilya Leoshkevich
Reviewed By: Evgenii Stepanov
Differential Revision: https://reviews.llvm.org/D76776
Disable symbolization of results, since llvm-symbolizer cannot start
due to restricted readlink(), causing the test to die with SIGPIPE.
Author: Ilya Leoshkevich
Reviewed By: Evgenii Stepanov
Differential Revision: https://reviews.llvm.org/D76576
Temporarily revert "tsan: fix leak of ThreadSignalContext for fibers"
because it breaks the LLDB bot on GreenDragon.
This reverts commit 93f7743851.
This reverts commit d8a0f76de7.
When creating and destroying fibers in tsan a thread state
is created and destroyed. Currently, a memory mapping is
leaked with each fiber (in __tsan_destroy_fiber).
This causes applications with many short running fibers
to crash or hang because of linux vm.max_map_count.
The root of this is that ThreadState holds a pointer to
ThreadSignalContext for handling signals. The initialization
and destruction of it is tied to platform specific events
in tsan_interceptors_posix and missed when destroying a fiber
(specifically, SigCtx is used to lazily create the
ThreadSignalContext in tsan_interceptors_posix). This patch
cleans up the memory by inverting the control from the
platform specific code calling the generic ThreadFinish to
ThreadFinish calling a platform specific clean-up routine
after finishing a thread.
The relevant code causing the leak with fibers is the fiber destruction:
void FiberDestroy(ThreadState *thr, uptr pc, ThreadState *fiber) {
FiberSwitchImpl(thr, fiber);
ThreadFinish(fiber);
FiberSwitchImpl(fiber, thr);
internal_free(fiber);
}
I would appreciate feedback if this way of fixing the leak is ok.
Also, I think it would be worthwhile to more closely look at the
lifecycle of ThreadState (i.e. it uses no constructor/destructor,
thus requiring manual callbacks for cleanup) and how OS-Threads/user
level fibers are differentiated in the codebase. I would be happy to
contribute more if someone could point me at the right place to
discuss this issue.
Reviewed-in: https://reviews.llvm.org/D76073
Author: Florian (Florian)
tsan while used by golang's race detector was not working on alpine
linux, since it is using musl-c instead of glibc. Since alpine is very
popular distribution for container deployments, having working race
detector would be nice. This commits adds some ifdefs to get it working.
It fixes https://github.com/golang/go/issues/14481 on golang's issue tracker.
Reviewed-in: https://reviews.llvm.org/D75849
Author: graywolf-at-work (Tomas Volf)
Summary: Separate class definition and actual methods implementation. The main
goal is to keep the list of available methods in a concise readable form inside
the class definition.
Reviewers: hctim, metzman
Subscribers: dberris, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76651
This avoids the test failure that was introduced in rG32bddad where
this function pulls in the rest of InstrProfilingFile.c which is
undesirable in use cases when profile runtime is being used without
the rest of libc.
This also allows additional cleanup by eliminating another variable
from platforms that don't need it.
Differential Revision: https://reviews.llvm.org/D76750
On Fuchsia, we always use the continuous mode with runtime counter
relocation, so there's no need for atexit hook or support for dumping
the profile manually.
Differential Revision: https://reviews.llvm.org/D76556
Summary:
This change introduces the `Symbolizer::GetEnvP()` method that returns a
pointer to environment array used for spawning the symbolizer process.
The motivation is to allow implementations to customise the environment
if required. The default implementation just returns
`__sanitizer::GetEnviron()` which (provided it's implemented) should
preserve the existing behaviours of the various implementations.
This change has been plumbed through the `internal_spawn(...)` and
`StartSubprocess(...)` process spawning implementations.
For the `StartSubprocess()` implementation we need to call `execve()`
rather than `execv()` to pass the environment. However, it appears that
`internal_execve(...)` exists in sanitizer_common so this patch use that
which seems like a nice clean up.
Support in the Windows implementation of
`SymbolizerProcess:StartSymbolizerSubprocess()` has not been added
because the Windows sanitizer runtime doesn't implement `GetEnviron()`.
rdar://problem/58789439
Reviewers: kubamracek, yln, dvyukov, vitalybuka, eugenis, phosek, aizatsky, rnk
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76666
Summary:
Backtrace() returns the number of frames that are *available*, rather
than the number of frames stored. When we pack, we supply the number of
frames we have stored. The number of available frames can exceed the
number of stored frames, leading to stack OOB read.
Fix up this problem.
Reviewers: eugenis
Reviewed By: eugenis
Subscribers: #sanitizers, morehouse, cferris, pcc
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76722
realeaseAcquire() is a new function added to TSan in support of the Go data-race detector.
It's semantics is:
void ThreadClock::releaseAcquire(SyncClock *sc) const {
for (int i = 0; i < kMaxThreads; i++) {
tmp = clock[i];
clock[i] = max(clock[i], sc->clock[i]);
sc->clock[i] = tmp;
}
}
For context see: https://go-review.googlesource.com/c/go/+/220419
Reviewed-in: https://reviews.llvm.org/D76322
Author: dfava (Daniel Fava)
Matt Morehouse