[compiler-rt] r350101 - [asan] Support running without /proc.
Evgeniy Stepanov via llvm-commits
llvm-commits at lists.llvm.org
Thu Dec 27 13:31:53 PST 2018
Author: eugenis
Date: Thu Dec 27 13:31:52 2018
New Revision: 350101
URL: http://llvm.org/viewvc/llvm-project?rev=350101&view=rev
Log:
[asan] Support running without /proc.
Summary:
This patch lets ASan run when /proc is not accessible (ex. not mounted
yet). It includes a special test-only flag that emulates this condition
in an unpriviledged process.
This only matters on Linux, where /proc is necessary to enumerate
virtual memory mappings.
Reviewers: pcc, vitalybuka
Subscribers: kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D55874
Modified:
compiler-rt/trunk/lib/asan/asan_linux.cc
compiler-rt/trunk/lib/asan/asan_thread.cc
compiler-rt/trunk/lib/hwasan/hwasan_thread.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.inc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_bsd.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_common.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_linux.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_solaris.cc
compiler-rt/trunk/test/asan/TestCases/Posix/no-fd.cc
Modified: compiler-rt/trunk/lib/asan/asan_linux.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_linux.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_linux.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_linux.cc Thu Dec 27 13:31:52 2018
@@ -210,6 +210,8 @@ void AsanCheckIncompatibleRT() {
}
} else {
if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
+ if (!MemoryMappingLayout::IsAvailable())
+ return;
// Ensure that dynamic runtime is not present. We should detect it
// as early as possible, otherwise ASan interceptors could bind to
// the functions in dynamic ASan runtime instead of the functions in
Modified: compiler-rt/trunk/lib/asan/asan_thread.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_thread.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_thread.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_thread.cc Thu Dec 27 13:31:52 2018
@@ -18,6 +18,7 @@
#include "asan_thread.h"
#include "asan_mapping.h"
#include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_file.h"
#include "sanitizer_common/sanitizer_placement_new.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
#include "sanitizer_common/sanitizer_tls_get_addr.h"
@@ -223,9 +224,11 @@ void AsanThread::Init(const InitOptions
atomic_store(&stack_switching_, false, memory_order_release);
CHECK_EQ(this->stack_size(), 0U);
SetThreadStackAndTls(options);
- CHECK_GT(this->stack_size(), 0U);
- CHECK(AddrIsInMem(stack_bottom_));
- CHECK(AddrIsInMem(stack_top_ - 1));
+ if (stack_top_ != stack_bottom_) {
+ CHECK_GT(this->stack_size(), 0U);
+ CHECK(AddrIsInMem(stack_bottom_));
+ CHECK(AddrIsInMem(stack_top_ - 1));
+ }
ClearShadowForThreadStackAndTLS();
fake_stack_ = nullptr;
if (__asan_option_detect_stack_use_after_return)
@@ -287,22 +290,29 @@ AsanThread *CreateMainThread() {
// OS-specific implementations that need more information passed through.
void AsanThread::SetThreadStackAndTls(const InitOptions *options) {
DCHECK_EQ(options, nullptr);
- uptr tls_size = 0;
- uptr stack_size = 0;
- GetThreadStackAndTls(tid() == 0, &stack_bottom_, &stack_size, &tls_begin_,
- &tls_size);
- stack_top_ = stack_bottom_ + stack_size;
- tls_end_ = tls_begin_ + tls_size;
- dtls_ = DTLS_Get();
+ // If this process is "init" (pid 1), /proc may not be mounted yet.
+ if (!start_routine_ && !MemoryMappingLayout::IsAvailable()) {
+ stack_top_ = stack_bottom_ = 0;
+ tls_begin_ = tls_end_ = 0;
+ } else {
+ uptr tls_size = 0;
+ uptr stack_size = 0;
+ GetThreadStackAndTls(tid() == 0, &stack_bottom_, &stack_size, &tls_begin_,
+ &tls_size);
+ stack_top_ = stack_bottom_ + stack_size;
+ tls_end_ = tls_begin_ + tls_size;
+ dtls_ = DTLS_Get();
- int local;
- CHECK(AddrIsInStack((uptr)&local));
+ int local;
+ CHECK(AddrIsInStack((uptr)&local));
+ }
}
#endif // !SANITIZER_FUCHSIA && !SANITIZER_RTEMS
void AsanThread::ClearShadowForThreadStackAndTLS() {
- PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
+ if (stack_top_ != stack_bottom_)
+ PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
if (tls_begin_ != tls_end_) {
uptr tls_begin_aligned = RoundDownTo(tls_begin_, SHADOW_GRANULARITY);
uptr tls_end_aligned = RoundUpTo(tls_end_, SHADOW_GRANULARITY);
@@ -314,6 +324,9 @@ void AsanThread::ClearShadowForThreadSta
bool AsanThread::GetStackFrameAccessByAddr(uptr addr,
StackFrameAccess *access) {
+ if (stack_top_ == stack_bottom_)
+ return false;
+
uptr bottom = 0;
if (AddrIsInStack(addr)) {
bottom = stack_bottom();
Modified: compiler-rt/trunk/lib/hwasan/hwasan_thread.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/hwasan/hwasan_thread.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/hwasan/hwasan_thread.cc (original)
+++ compiler-rt/trunk/lib/hwasan/hwasan_thread.cc Thu Dec 27 13:31:52 2018
@@ -44,7 +44,7 @@ void Thread::Init(uptr stack_buffer_star
ScopedTaggingDisabler disabler;
// If this process is "init" (pid 1), /proc may not be mounted yet.
- if (IsMainThread() && !FileExists("/proc/self/maps")) {
+ if (IsMainThread() && !MemoryMappingLayout::IsAvailable()) {
stack_top_ = stack_bottom_ = 0;
tls_begin_ = tls_end_ = 0;
} else {
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.inc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.inc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.inc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_flags.inc Thu Dec 27 13:31:52 2018
@@ -243,3 +243,6 @@ COMMON_FLAG(bool, dump_registers, true,
COMMON_FLAG(bool, detect_write_exec, false,
"If true, triggers warning when writable-executable pages requests "
"are being made")
+COMMON_FLAG(bool, test_only_emulate_no_procfs, false,
+ "TEST ONLY fail to open any files under /proc to emulate sanitized "
+ "\"init\"")
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc Thu Dec 27 13:31:52 2018
@@ -453,6 +453,8 @@ uptr internal_execve(const char *filenam
// ----------------- sanitizer_common.h
bool FileExists(const char *filename) {
+ if (ShouldMockFailureToOpen(filename))
+ return false;
struct stat st;
#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0))
@@ -1003,6 +1005,8 @@ ThreadLister::~ThreadLister() {
// Take care of unusable kernel area in top gigabyte.
static uptr GetKernelAreaSize() {
#if SANITIZER_LINUX && !SANITIZER_X32
+ if (!MemoryMappingLayout::IsAvailable())
+ return 0;
const uptr gbyte = 1UL << 30;
// Firstly check if there are writable segments
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.h Thu Dec 27 13:31:52 2018
@@ -44,6 +44,7 @@ struct MemoryMappingLayoutData {
};
void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
+bool IsProcMapsAvailable();
// Syscall wrappers.
uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc Thu Dec 27 13:31:52 2018
@@ -282,6 +282,8 @@ uptr internal_waitpid(int pid, int *stat
// ----------------- sanitizer_common.h
bool FileExists(const char *filename) {
+ if (ShouldMockFailureToOpen(filename))
+ return false;
struct stat st;
if (stat(filename, &st))
return false;
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc Thu Dec 27 13:31:52 2018
@@ -18,6 +18,7 @@
#include "sanitizer_common.h"
#include "sanitizer_file.h"
+#include "sanitizer_flags.h"
#include "sanitizer_libc.h"
#include "sanitizer_posix.h"
#include "sanitizer_procmaps.h"
@@ -157,6 +158,8 @@ void MprotectMallocZones(void *addr, int
#endif
fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *errno_p) {
+ if (ShouldMockFailureToOpen(filename))
+ return kInvalidFd;
int flags;
switch (mode) {
case RdOnly: flags = O_RDONLY; break;
@@ -229,6 +232,8 @@ static inline bool IntervalsAreSeparate(
// several worker threads on Mac, which aren't expected to map big chunks of
// memory).
bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
+ if (!MemoryMappingLayout::IsAvailable())
+ return true; // hope for the best
MemoryMappingLayout proc_maps(/*cache_enabled*/true);
MemoryMappedSegment segment;
while (proc_maps.Next(&segment)) {
@@ -334,6 +339,11 @@ fd_t ReserveStandardFds(fd_t fd) {
return fd;
}
+bool ShouldMockFailureToOpen(const char *path) {
+ return common_flags()->test_only_emulate_no_procfs &&
+ internal_strncmp(path, "/proc/", 6) == 0;
+}
+
} // namespace __sanitizer
#endif // SANITIZER_POSIX
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.h?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.h Thu Dec 27 13:31:52 2018
@@ -103,6 +103,8 @@ bool IsStateDetached(int state);
// Move the fd out of {0, 1, 2} range.
fd_t ReserveStandardFds(fd_t fd);
+bool ShouldMockFailureToOpen(const char *path);
+
} // namespace __sanitizer
#endif // SANITIZER_POSIX_H
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps.h?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps.h Thu Dec 27 13:31:52 2018
@@ -75,6 +75,7 @@ class MemoryMappingLayout {
// to obtain the memory mappings. It should fall back to pre-cached data
// instead of aborting.
static void CacheMemoryMappings();
+ static bool IsAvailable();
// Adds all mapped objects into a vector.
void DumpListOfModules(InternalMmapVectorNoCtor<LoadedModule> *modules);
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_bsd.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_bsd.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_bsd.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_bsd.cc Thu Dec 27 13:31:52 2018
@@ -45,6 +45,10 @@
namespace __sanitizer {
+bool IsProcMapsAvailable() {
+ return true;
+}
+
void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
const int Mib[] = {
#if SANITIZER_FREEBSD
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_common.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_common.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_common.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_common.cc Thu Dec 27 13:31:52 2018
@@ -144,6 +144,12 @@ void MemoryMappingLayout::DumpListOfModu
}
}
+bool MemoryMappingLayout::IsAvailable() {
+ if (cached_proc_self_maps.data)
+ return true;
+ return IsProcMapsAvailable();
+}
+
void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) {
char *smaps = nullptr;
uptr smaps_cap = 0;
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_linux.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_linux.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_linux.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_linux.cc Thu Dec 27 13:31:52 2018
@@ -13,10 +13,15 @@
#include "sanitizer_platform.h"
#if SANITIZER_LINUX
#include "sanitizer_common.h"
+#include "sanitizer_file.h"
#include "sanitizer_procmaps.h"
namespace __sanitizer {
+bool IsProcMapsAvailable() {
+ return FileExists("/proc/self/maps");
+}
+
void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
if (!ReadFileToBuffer("/proc/self/maps", &proc_maps->data,
&proc_maps->mmaped_size, &proc_maps->len)) {
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_solaris.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_solaris.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_solaris.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_procmaps_solaris.cc Thu Dec 27 13:31:52 2018
@@ -20,6 +20,10 @@
namespace __sanitizer {
+bool IsProcMapsAvailable() {
+ return FileExists("/proc/self/xmap");
+}
+
void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
ReadFileToBuffer("/proc/self/xmap", &proc_maps->data, &proc_maps->mmaped_size,
&proc_maps->len);
Modified: compiler-rt/trunk/test/asan/TestCases/Posix/no-fd.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/Posix/no-fd.cc?rev=350101&r1=350100&r2=350101&view=diff
==============================================================================
--- compiler-rt/trunk/test/asan/TestCases/Posix/no-fd.cc (original)
+++ compiler-rt/trunk/test/asan/TestCases/Posix/no-fd.cc Thu Dec 27 13:31:52 2018
@@ -9,6 +9,10 @@
#include <stdlib.h>
#include <unistd.h>
+extern "C" const char *__asan_default_options() {
+ return "test_only_emulate_no_procfs=1";
+}
+
void parent(int argc, char **argv) {
fprintf(stderr, "hello\n");
// CHECK: hello
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