In short, CVE-2016-2143 will crash the machine if a process uses both >4TB
virtual addresses and fork(). ASan, TSan, and MSan will, by necessity, map
a sizable chunk of virtual address space, which is much larger than 4TB.
Even worse, sanitizers will always use fork() for llvm-symbolizer when a bug
is detected. Disable all three by aborting on process initialization if
the running kernel version is not known to contain a fix.
Unfortunately, there's no reliable way to detect the fix without crashing
the kernel. So, we rely on whitelisting - I've included a list of upstream
kernel versions that will work. In case someone uses a distribution kernel
or applied the fix themselves, an override switch is also included.
Differential Revision: http://reviews.llvm.org/D19576
llvm-svn: 267747
On OS X 10.11+, we have "automatic interceptors", so we don't need to use DYLD_INSERT_LIBRARIES when launching instrumented programs. However, non-instrumented programs that load TSan late (e.g. via dlopen) are currently broken, as TSan will still try to initialize, but the program will crash/hang at random places (because the interceptors don't work). This patch adds an explicit check that interceptors are working, and if not, it aborts and prints out an error message suggesting to explicitly use DYLD_INSERT_LIBRARIES.
TSan unit tests run with a statically linked runtime, where interceptors don't work. To avoid aborting the process in this case, the patch replaces `DisableReexec()` with a weak `ReexecDisabled()` function which is defined to return true in unit tests.
Differential Revision: http://reviews.llvm.org/D18212
llvm-svn: 263695
Summary:
This removes the hard limit on the number of loaded modules (used to be
16K), and makes it easier to use LoadedModules w/o causing a memory
leak: ListOfModules owns the modules, and makes sure to properly clean
them in destructor.
Remove filtering functionality that is only needed in one place (LSan).
Reviewers: aizatsky
Subscribers: llvm-commits, kcc
Differential Revision: http://reviews.llvm.org/D17470
llvm-svn: 261554
This is part of a new statistics gathering feature for the sanitizers.
See clang/docs/SanitizerStats.rst for further info and docs.
Differential Revision: http://reviews.llvm.org/D16176
llvm-svn: 257972
Log all of sanitizers' output (not just ASan bug reports) to CrashReport,
which simplifies diagnosing failed checks as well as other errors. This
also allows to strip the color sequences early from the printed buffer,
which is more efficient than what we had perviously.
Differential Revision: http://reviews.llvm.org/D15396
llvm-svn: 256988
System properties are not accessible through NDK (we've been using
hacks to get to them) and they are unavailable during ASan
initialization in .preinit_array. Use environment variables and
files instead (ex. ASAN_OPTIONS=include_if_exists=/path).
No test changes. This feature was not tested because the properties
are system-wide and would conflict with the parallel test runner. Yet
another reason to get rid of it.
llvm-svn: 254783
In AddressSanitizer, we have the MaybeReexec method to detect when we're running without DYLD_INSERT_LIBRARIES (in which case interceptors don't work) and re-execute with the environment variable set. On OS X 10.11+, this is no longer necessary, but to have ThreadSanitizer supported on older versions of OS X, let's use the same method as well. This patch moves the implementation from `asan/` into `sanitizer_common/`.
Differential Revision: http://reviews.llvm.org/D15123
llvm-svn: 254600
[asan] On OS X, log reports to syslog and os_trace, has been reverted in r252076 due to deadlocks on earlier versions of OS X. Alexey has also noticed deadlocks in some corner cases on Linux. This patch, if applied on top of the logging patch (http://reviews.llvm.org/D13452), addresses the known deadlock issues.
(This also proactively removes the color escape sequences from the error report buffer since we have to copy the buffer anyway.)
Differential Revision: http://reviews.llvm.org/D14470
llvm-svn: 253689
When ASan currently detects a bug, by default it will only print out the text
of the report to stderr. This patch changes this behavior and writes the full
text of the report to syslog before we terminate the process. It also calls
os_trace (Activity Tracing available on OS X and iOS) with a message saying
that the report is available in syslog. This is useful, because this message
will be shown in the crash log.
For this to work, the patch makes sure we store the full report into
error_message_buffer unconditionally, and it also strips out ANSI escape
sequences from the report (they are used when producing colored reports).
I've initially tried to log to syslog during printing, which is done on Android
right now. The advantage is that if we crash during error reporting or the
produced error does not go through ScopedInErrorReport, we would still get a
(partial) message in the syslog. However, that solution is very problematic on
OS X. One issue is that the logging routine uses GCD, which may spawn a new
thread on its behalf. In many cases, the reporting logic locks threadRegistry,
which leads to deadlocks.
Reviewed at http://reviews.llvm.org/D13452
(In addition, add sanitizer_common_libcdep.cc to buildgo.sh to avoid
build failures on Linux.)
llvm-svn: 253688
When ASan currently detects a bug, by default it will only print out the text
of the report to stderr. This patch changes this behavior and writes the full
text of the report to syslog before we terminate the process. It also calls
os_trace (Activity Tracing available on OS X and iOS) with a message saying
that the report is available in syslog. This is useful, because this message
will be shown in the crash log.
For this to work, the patch makes sure we store the full report into
error_message_buffer unconditionally, and it also strips out ANSI escape
sequences from the report (they are used when producing colored reports).
I've initially tried to log to syslog during printing, which is done on Android
right now. The advantage is that if we crash during error reporting or the
produced error does not go through ScopedInErrorReport, we would still get a
(partial) message in the syslog. However, that solution is very problematic on
OS X. One issue is that the logging routine uses GCD, which may spawn a new
thread on its behalf. In many cases, the reporting logic locks threadRegistry,
which leads to deadlocks.
Reviewed at http://reviews.llvm.org/D13452
(In addition, add sanitizer_common_libcdep.cc to buildgo.sh to avoid
build failures on Linux.)
llvm-svn: 251577
When ASan currently detects a bug, by default it will only print out the text
of the report to stderr. This patch changes this behavior and writes the full
text of the report to syslog before we terminate the process. It also calls
os_trace (Activity Tracing available on OS X and iOS) with a message saying
that the report is available in syslog. This is useful, because this message
will be shown in the crash log.
For this to work, the patch makes sure we store the full report into
error_message_buffer unconditionally, and it also strips out ANSI escape
sequences from the report (they are used when producing colored reports).
I've initially tried to log to syslog during printing, which is done on Android
right now. The advantage is that if we crash during error reporting or the
produced error does not go through ScopedInErrorReport, we would still get a
(partial) message in the syslog. However, that solution is very problematic on
OS X. One issue is that the logging routine uses GCD, which may spawn a new
thread on its behalf. In many cases, the reporting logic locks threadRegistry,
which leads to deadlocks.
Reviewed at http://reviews.llvm.org/D13452
llvm-svn: 251447
This patch adds a runtime check for asan, dfsan, msan, and tsan for
architectures that support multiple VMA size (like aarch64). Currently
the check only prints a warning indicating which is the VMA built and
expected against the one detected at runtime.
llvm-svn: 247413
This is required to properly re-apply r245770:
1) We should be able to dump coverage in __sanitizer::Die() if coverage
collection is turned on.
2) We don't want to explicitly do this in every single
sanitizer that supports it.
3) We don't want to link in coverage (and therefore symbolization) bits
into small sanitizers that don't support it (safestack).
The solution is to make InitializeCoverage() register its own Die()
callback that would call __sanitizer_cov_dump(). This callback should be
executed in addition to another tool-specific die callbacks (if there
are any).
llvm-svn: 245889
These changes break both autoconf Mac OS X buildbot (linker errors
due to wrong Makefiles) and CMake buildbot (safestack test failures).
llvm-svn: 245784
Previously we had to call __sanitizer_cov_dump() from tool-specific
callbacks - instead, let sanitizer_common library handle this in a single place.
llvm-svn: 245770
Summary:
Printing a stacktrace acquires a spinlock, and the sanitizer spinlocks
aren't re-entrant. Avoid the problem by reusing the logic we already
have on Posix.
This failure mode is already exercised by the existing mmap_limit_mb.cc
test case. It will be enabled in a forthcoming change, so I didn't add
standalone tests for this change.
Reviewers: samsonov
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11999
llvm-svn: 244840
Summary:
This is consistent with binutils and ASan behavior on other platforms,
and makes it easier to use llvm-symbolizer with WinASan. The
--relative-address flag to llvm-symbolizer is also no longer needed.
An RVA is a "relative virtual address", meaning it is the address of
something inside the image minus the base of the mapping at runtime.
A VA in this context is an RVA plus the "preferred base" of the module,
and not a real runtime address. The real runtime address of a symbol
will equal the VA iff the module is loaded at its preferred base at
runtime.
On Windows, the preferred base is stored in the ImageBase field of one
of the PE file header, and this change adds the necessary code to
extract it. On Linux, this offset is typically included in program and
section headers of executables.
ELF shared objects typically use a preferred base of zero, meaning the
smallest p_vaddr field in the program headers is zero. This makes it so
that PIC and PIE module offsets come out looking like RVAs, but they're
actually VAs. The difference between them simply happens to be zero.
Reviewers: samsonov, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11681
llvm-svn: 243895
It's implicated in a buildbot failure and while the failure looks unrelated,
this commit is the only probably candidate in the blamelist.
llvm-svn: 243740
Summary:
Using u64 as type for offset changes its value, changing starting address for map in file.
This patch solves Bug 24151, which raises issue while mapping file in mips32.
Patch by Mohit Bhakkad
Reviewers: dsanders, kcc
Subscribers: hans, llvm-commits, samsonov, nitesh.jain, sagar, bhushan, jaydeep
Differential Revision: http://reviews.llvm.org/D11588
llvm-svn: 243686
Rename getBinaryBasename() to getProcessName() and, on Linux,
read it from /proc/self/cmdline instead of /proc/self/exe. The former
can be modified by the process. The main motivation is Android, where
application processes re-write cmdline to a package name. This lets
us setup per-application ASAN_OPTIONS through include=/some/path/%b.
llvm-svn: 243473
Previously, Android target had a logic of duplicating all sanitizer
output to logcat. This change extends it to all posix platforms via
the use of syslog, controlled by log_to_syslog flag. Enabled by
default on Android, off everywhere else.
A bit of cmake magic is required to allow Printf() to call a libc
function. I'm adding a stub implementation to support no-libc builds
like dfsan and safestack.
This is a second attempt. I believe I've fixed all the issues that
prompted the revert: Mac build, and all kinds of non-CMake builds
(there are 3 of those).
llvm-svn: 243051
Previously, Android target had a logic of duplicating all sanitizer
output to logcat. This change extends it to all posix platforms via
the use of syslog, controlled by log_to_syslog flag. Enabled by
default on Android, off everywhere else.
A bit of cmake magic is required to allow Printf() to call a libc
function. I'm adding a stub implementation to support no-libc builds
like dfsan and safestack.
llvm-svn: 242975
Marcin Koscielnicki