Summary:
On platforms with `getrandom`, the system call defaults to blocking. This
becomes an issue in the very early stage of the boot for Scudo, when the RNG
source is not set-up yet: the syscall will block and we'll stall.
Introduce a parameter to specify that the function should not block, defaulting
to blocking as the underlying syscall does.
Update Scudo to use the non-blocking version.
Reviewers: alekseyshl
Reviewed By: alekseyshl
Subscribers: llvm-commits, kubamracek
Differential Revision: https://reviews.llvm.org/D36399
llvm-svn: 310839
Summary:
This is a pure refactoring change. It just moves code that is
related to filesystem operations from sanitizer_common.{cc,h} to
sanitizer_file.{cc,h}. This makes it cleaner to disable the
filesystem-related code for a new port that doesn't want it.
Submitted on behalf of Roland McGrath.
Reviewers: kcc, eugenis, alekseyshl
Reviewed By: alekseyshl
Subscribers: vitalybuka, llvm-commits, kubamracek, mgorny, phosek
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D35591
llvm-svn: 308819
On iOS/AArch64, the address space is very limited and has a dynamic maximum address based on the configuration of the device. We're already using a dynamic shadow, and we find a large-enough "gap" in the VM where we place the shadow memory. In some cases and some device configuration, we might not be able to find a large-enough gap: E.g. if the main executable is linked against a large number of libraries that are not part of the system, these libraries can fragment the address space, and this happens before ASan starts initializing.
This patch has a solution, where we have a "backup plan" when we cannot find a large-enough gap: We will restrict the address space (via MmapFixedNoAccess) to a limit, for which the shadow limit will fit.
Differential Revision: https://reviews.llvm.org/D35098
llvm-svn: 307865
We currently hardcode the maximum VM address on iOS/AArch64, which is not really correct and this value changes between device configurations. Let's use TASK_VM_INFO to retrieve the maximum VM address dynamically.
Differential Revision: https://reviews.llvm.org/D35032
llvm-svn: 307307
The logic in GetMaxVirtualAddress is already pretty complex, and I want to get rid of the hardcoded value for iOS/AArch64, which would need adding more Darwin-specific code, so let's split the implementation into sanitizer_linux.cc and sanitizer_mac.cc files. NFC.
Differential Revision: https://reviews.llvm.org/D35031
llvm-svn: 307281
On Darwin, sigprocmask changes the signal mask for the entire process. This has some unwanted consequences, because e.g. internal_start_thread wants to disable signals only in the current thread (to make the new thread inherit the signal mask), which is currently broken on Darwin. This patch switches to pthread_sigmask.
Differential Revision: https://reviews.llvm.org/D35016
llvm-svn: 307212
Summary:
AFAICT compiler-rt doesn't have a function that would return 'good' random
bytes to seed a PRNG. Currently, the `SizeClassAllocator64` uses addresses
returned by `mmap` to seed its PRNG, which is not ideal, and
`SizeClassAllocator32` doesn't benefit from the entropy offered by its 64-bit
counterpart address space, so right now it has nothing. This function aims at
solving this, allowing to implement good 32-bit chunk randomization. Scudo also
has a function that does this for Cookie purposes, which would go away in a
later CL once this lands.
This function will try the `getrandom` syscall if available, and fallback to
`/dev/urandom` if not.
Unfortunately, I do not have a way to implement and test a Mac and Windows
version, so those are unimplemented as of now. Note that `kRandomShuffleChunks`
is only used on Linux for now.
Reviewers: alekseyshl
Reviewed By: alekseyshl
Subscribers: zturner, rnk, llvm-commits, kubamracek
Differential Revision: https://reviews.llvm.org/D34412
llvm-svn: 305922
Summary:
After r303941 it was not possible to setup ASAN_OPTIONS to have the same
behavior for pre r303941 and post r303941 builds.
Pre r303941 Asan does not accept handle_sigbus=2.
Post r303941 Asan does not accept allow_user_segv_handler.
This fix ignores allow_user_segv_handler=1, but for allow_user_segv_handler=0
it will upgrade flags like handle_sigbus=1 to handle_sigbus=2. So user can set
ASAN_OPTIONS=allow_user_segv_handler=0 and have same behavior on old and new
clang builds (except range from r303941 to this revision).
In future users which need to prevent third party handlers should switch to
handle_sigbus=2 and remove allow_user_segv_handler as soon as suport of older
builds is not needed.
Related bugs:
https://github.com/google/oss-fuzz/issues/675https://bugs.chromium.org/p/chromium/issues/detail?id=731130
Reviewers: eugenis
Subscribers: llvm-commits, kubamracek
Differential Revision: https://reviews.llvm.org/D34227
llvm-svn: 305433
Summary:
allow_user_segv_handler had confusing name did not allow to control behavior for
signals separately.
Reviewers: eugenis, alekseyshl, kcc
Subscribers: llvm-commits, dberris, kubamracek
Differential Revision: https://reviews.llvm.org/D33371
llvm-svn: 303941
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
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
We seem to assume that OS-provided thread IDs are either uptr or int, neither of which is true on Darwin. This introduces a tid_t type, which holds a OS-provided thread ID (gettid on Linux, pthread_threadid_np on Darwin, pthread_self on FreeBSD).
Differential Revision: https://reviews.llvm.org/D31774
llvm-svn: 300473
Summary: This is useful in some platforms where one of these signals is special.
Reviewers: kubamracek, kcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30783
llvm-svn: 297665
People keep hitting on spurious failures in malloc/free routines when using sanitizers
with shared libraries dlopened with RTLD_DEEPBIND (see https://github.com/google/sanitizers/issues/611 for details).
Let's check for this flag and bail out with warning message instead of failing in random places.
Differential Revision: https://reviews.llvm.org/D30504
llvm-svn: 297370
Summary:
This patch unifies the behavior of BlockingMutex on linux and mac,
resolving problems that can arise when BlockingMutex is used in
code shared by the two platforms but has different behavior depending
on the platform.
No longer requires that the calling thread own the mutex for
CheckLocked calls to pass.
Reviewers: dvyukov, kubamracek
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29728
llvm-svn: 294614
This patch add a new sanitizer flag, print_module_map, which enables printing a module map when the process exits, or after each report (for TSan). The output format is very similar to what Crash Reporter produces on Darwin (e.g. the format of module UUIDs). This enables users to use the existing symbol servers to offline symbolicate and aggregate reports.
Differential Revision: https://reviews.llvm.org/D27400
llvm-svn: 291277
Handling SIGILL on Darwin works fine, so let's just make this feature work and re-enable the ill.cc testcase.
Differential Revision: https://reviews.llvm.org/D27141
llvm-svn: 287959
This patch prints out all CPU registers after a SIGSEGV. These are available in the signal handler context. Only implemented for Darwin. Can be turned off with the dump_registers flag.
Differential Revision: https://reviews.llvm.org/D11365
llvm-svn: 287957
Currently we either define SANITIZER_GO for Go or don't define it at all for C++.
This works fine with preprocessor (ifdef/ifndef/defined), but does not work
for C++ if statements (e.g. if (SANITIZER_GO) {...}). Also this is different
from majority of SANITIZER_FOO macros which are always defined to either 0 or 1.
Always define SANITIZER_GO to either 0 or 1.
This allows to use SANITIZER_GO in expressions and in flag default values.
Also remove kGoMode and kCppMode, which were meant to be used in expressions,
but they are not defined in sanitizer_common code, so SANITIZER_GO become prevalent.
Also convert some preprocessor checks to C++ if's or ternary expressions.
Majority of this change is done mechanically with:
sed "s#ifdef SANITIZER_GO#if SANITIZER_GO#g"
sed "s#ifndef SANITIZER_GO#if \!SANITIZER_GO#g"
sed "s#defined(SANITIZER_GO)#SANITIZER_GO#g"
llvm-svn: 285443
The VM layout is not stable between iOS version releases, so switch to dynamic shadow offset.
Differential Revision: https://reviews.llvm.org/D25218
llvm-svn: 283375
The VM layout is not stable between iOS version releases, so switch to dynamic shadow offset.
Differential Revision: https://reviews.llvm.org/D25218
llvm-svn: 283240
r280885 added a testcase for handle_abort, which is broken on macOS, let’s add this support into sanitizer_mac.cc.
Differential Revision: https://reviews.llvm.org/D24344
llvm-svn: 280945
We're using forkpty to spawn the atos symbolizer. In some cases, login_tty (part of forkpty) can fail due to security measures (sandboxing). In this case, we should exit with a status code instead of completely crashing the spawned process. Even processing a failed CHECK() is problematic here, because we're post-fork and pre-exec where a lot of things don't work (for multithreaded processes, for OS X GUI apps, etc.).
Differential Revision: http://reviews.llvm.org/D20048
llvm-svn: 269289
Recent TSan changes (r267678) which factor out parts of ThreadState into a Processor structure broke worker threads on OS X. This fixes it by properly calling ProcCreate for GCD worker threads and by replacing some CHECKs with RAW_CHECK in early process initialization. CHECK() in TSan calls the allocator, which requires a valid Processor.
llvm-svn: 267864
os_trace turns out to be a macro that creates static object.
Function-static objects use __cxa_atexit and __dso_handle
which are not present in Go runtime.
llvm-svn: 267720
Ifdef out global variables with destructors.
This requires runtime support that is not provided by Go runtime
(in particular _dso_handle symbol).
llvm-svn: 267709
This reverts commit r267477.
It broke our bots that enables the AArch64 backends, it seems that
this code is using a Darwin *X86 specific* field.
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267526
Let's use pthread_threadid_np which returns a more reasonable ID than pthread_self (which is actually a stack pointer). The numbers from pthread_threadid_np are already used in other tools, e.g. in LLDB, and often appear in logs, so it's much more useful than pthread_self.
Differential Revision: http://reviews.llvm.org/D18951
llvm-svn: 266991
This patch fixes https://github.com/google/sanitizers/issues/669. On older Darwin systems (in particular, Darwin 10),
dyld doesn't export '_dyldVersionNumber' symbol so we would have 'undefined reference' error in sanitzer library. Although
sanitizers support was added to LLVM on OS X 10.7+ where '_dyldVersionNumber' symbol is already exported, GCC users still
may want use them on older systems.
Differential Revision: http://reviews.llvm.org/D19218
llvm-svn: 266868
On OS X, internal_mmap just uses mmap, which can invoke callbacks into libmalloc (e.g. when MallocStackLogging is enabled). This can subsequently call other intercepted functions, and this breaks our Darwin-specific ThreadState initialization. Let's use direct syscalls in internal_mmap and internal_munmap. Added a testcase.
Differential Revision: http://reviews.llvm.org/D18431
llvm-svn: 264259
Kostya Kortchinsky