Summary:
vfork is not ASan-friendly because it modifies stack shadow in the
parent process address space. While it is possible to compensate for that with, for example,
__asan_handle_no_return before each call to _exit or execve and friends, simply replacing
vfork with fork looks like by far the easiest solution.
Posix compliant programs can not detect the difference between vfork and fork.
Fixes https://github.com/google/sanitizers/issues/925
Reviewers: kcc, vitalybuka
Subscribers: kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D44587
llvm-svn: 327752
This is a workarond for the fallout from D42644:
[asan] Intercept std::rethrow_exception indirectly.
Reported problem on NetBSD/amd64:
$ sh ./projects/compiler-rt/test/sanitizer_common/asan-i386-NetBSD/NetBSD/Output/ttyent.cc.script
/usr/lib/i386/libgcc.a(unwind-dw2.o): In function `_Unwind_RaiseException':
unwind-dw2.c:(.text+0x1b41): multiple definition of `_Unwind_RaiseException'
/public/llvm-build/lib/clang/7.0.0/lib/netbsd/libclang_rt.asan-i386.a(asan_interceptors.cc.o):/public/llvm/projects/compiler-rt/lib/asan/asan_interceptors.cc:337: first defined here
clang-7.0: error: linker command failed with exit code 1 (use -v to see invocation)
llvm-svn: 326216
Summary:
Fixes Bug 32434
See https://bugs.llvm.org/show_bug.cgi?id=32434
Short summary:
std::rethrow_exception does not use __cxa_throw to rethrow the exception, so if
it is called from uninstrumented code, it will leave the stack poisoned. This
can lead to false positives.
Long description:
For functions which don't return normally (e.g. via exceptions), asan needs to
unpoison the entire stack. It is not known before a call to such a function
where execution will continue, some function which don't contain cleanup code
like destructors might be skipped. After stack unwinding, execution might
continue in uninstrumented code.
If the stack has been poisoned before such a function is called, but the stack
is unwound during the unconventional return, then zombie redzones (entries) for
no longer existing stack variables can remain in the shadow memory. Normally,
this is avoided by asan generating a call to asan_handle_no_return before all
functions marked as [[noreturn]]. This asan_handle_no_return unpoisons the
entire stack. Since these [[noreturn]] functions can be called from
uninstrumented code, asan also introduces interceptor functions which call
asan_handle_no_return before running the original [[noreturn]] function;
for example, cxa_throw is intercepted.
If a [[noreturn]] function is called from uninstrumented code (so the stack is
left poisoned) and additionally, execution continues in uninstrumented code, new
stack variables might be introduced and overlap with the stack variables
which have been removed during stack unwinding. Since the redzones are not
cleared nor overwritten by uninstrumented code, they remain but now contain
invalid data.
Now, if the redzones are checked against the new stack variables, false
positive reports can occur. This can happen for example by the uninstrumented
code calling an intercepted function such as memcpy, or an instrumented
function.
Intercepting std::rethrow_exception directly is not easily possible since it
depends on the C++ standard library implementation (e.g. libcxx vs libstdc++)
and the mangled name it produces for this function. As a rather simple
workaround, we're intercepting _Unwind_RaiseException for libstdc++. For
libcxxabi, we can intercept the ABI function __cxa_rethrow_primary_exception.
Patch by Robert Schneider.
Reviewers: kcc, eugenis, alekseyshl, vitalybuka
Reviewed By: vitalybuka
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42644
llvm-svn: 326132
Summary:
This is the first mostly working version of the Sanitizer port to 32-bit Solaris/x86.
It is currently based on Solaris 11.4 Beta.
This part was initially developed inside libsanitizer in the GCC tree and should apply to
both. Subsequent parts will address changes to clang, the compiler-rt build system
and testsuite.
I'm not yet sure what the right patch granularity is: if it's profitable to split the patch
up, I'd like to get guidance on how to do so.
Most of the changes are probably straightforward with a few exceptions:
* The Solaris syscall interface isn't stable, undocumented and can change within an
OS release. The stable interface is the libc interface, which I'm using here, if possible
using the internal _-prefixed names.
* While the patch primarily target 32-bit x86, I've left a few sparc changes in. They
cannot currently be used with clang due to a backend limitation, but have worked
fine inside the gcc tree.
* Some functions (e.g. largefile versions of functions like open64) only exist in 32-bit
Solaris, so I've introduced a separate SANITIZER_SOLARIS32 to check for that.
The patch (with the subsequent ones to be submitted shortly) was tested
on i386-pc-solaris2.11. Only a few failures remain, some of them analyzed, some
still TBD:
AddressSanitizer-i386-sunos :: TestCases/Posix/concurrent_overflow.cc
AddressSanitizer-i386-sunos :: TestCases/init-order-atexit.cc
AddressSanitizer-i386-sunos :: TestCases/log-path_test.cc
AddressSanitizer-i386-sunos :: TestCases/malloc-no-intercept.c
AddressSanitizer-i386-sunos-dynamic :: TestCases/Posix/concurrent_overflow.cc
AddressSanitizer-i386-sunos-dynamic :: TestCases/Posix/start-deactivated.cc
AddressSanitizer-i386-sunos-dynamic :: TestCases/default_options.cc
AddressSanitizer-i386-sunos-dynamic :: TestCases/init-order-atexit.cc
AddressSanitizer-i386-sunos-dynamic :: TestCases/log-path_test.cc
AddressSanitizer-i386-sunos-dynamic :: TestCases/malloc-no-intercept.c
SanitizerCommon-Unit :: ./Sanitizer-i386-Test/MemoryMappingLayout.DumpListOfModules
SanitizerCommon-Unit :: ./Sanitizer-i386-Test/SanitizerCommon.PthreadDestructorIterations
Maybe this is good enough the get the ball rolling.
Reviewers: kcc, alekseyshl
Reviewed By: alekseyshl
Subscribers: srhines, jyknight, kubamracek, krytarowski, fedor.sergeev, llvm-commits, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D40898
llvm-svn: 320740
Summary:
Part of the code inspired by the original work on libsanitizer in GCC 5.4 by Christos Zoulas.
Sponsored by <The NetBSD Foundation>
Reviewers: joerg, filcab, kcc, fjricci, vitalybuka
Reviewed By: vitalybuka
Subscribers: kubamracek, llvm-commits, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D36375
llvm-svn: 310246
Summary:
Fuchsia uses the "memintrinsics" interceptors, though not via any
generalized interception mechanism. It doesn't use any other interceptors.
Submitted on behalf of Roland McGrath.
Reviewers: vitalybuka, alekseyshl, kcc
Reviewed By: vitalybuka
Subscribers: kubamracek, phosek, filcab, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D36189
llvm-svn: 309798
This is a pure refactoring change. It simply moves all the code and
macros related to defining the ASan interceptor versions of memcpy,
memmove, and memset into a separate file. This makes it cleaner to
disable all the other interceptor code while still using these three,
for a port that defines these but not the other common interceptors.
Reviewers: alekseyshl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35590
llvm-svn: 308575
Summary:
glibc on Linux calls __longjmp_chk instead of longjmp (or _longjmp) when
_FORTIFY_SOURCE is defined. Ensure that an ASAN-instrumented program
intercepts this function when a system library calls it, otherwise the
stack might remain poisoned and result in CHECK failures and false
positives.
Fixes https://github.com/google/sanitizers/issues/721
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D32408
llvm-svn: 302152
Summary:
Adds strnlen to the common interceptors, under the existing flag
intercept_strlen.
Removes the now-duplicate strnlen interceptor from asan and msan.
This adds strnlen to tsan, which previously did not intercept it.
Adds a new test of strnlen to the sanitizer_common test cases.
Reviewers: samsonov
Subscribers: zhaoqin, llvm-commits, kcc
Differential Revision: http://reviews.llvm.org/D18397
llvm-svn: 264195
Some unit tests were failing because we didn't intercept strdup. It
turns out it works just fine on 2013 and 2015 with a small patch to the
interception logic.
llvm-svn: 264013
This fixes a crash in pthread_create on linux/i386 due to abi
incompatibility between intercepted and non-intercepted functions.
See the test case for more details.
llvm-svn: 248325
MSanDR is a dynamic instrumentation tool that can instrument the code
(prebuilt libraries and such) that could not be instrumented at compile time.
This code is unused (to the best of our knowledge) and unmaintained, and
starting to bit-rot.
llvm-svn: 222232
Large part of this change is required due to
https://code.google.com/p/android/issues/detail?id=61799
dlsym() crashes when symbol resolution fails, which means
we have to limit the interceptor list instead of relying on
runtime detection.
There are minor differencies in system headers, too.
llvm-svn: 212273
Reset coverage data on fork().
For memory-mapped mode (coverage_direct=1) this helps avoid loss of data
(before this change two processes would write to the same file simultaneously).
For normal mode, this reduces coverage dump size, because PCs from the parent
process are no longer inherited by the child.
llvm-svn: 210180
If the callback is set, Report() and Printf() print the reports into a buffer (together with stderr), which is then passed to the client.
llvm-svn: 151528
Evgeniy Stepanov