Retro68/gcc/libsanitizer/asan/asan_linux.cc
2017-04-10 13:32:00 +02:00

178 lines
4.9 KiB
C++

//===-- asan_linux.cc -----------------------------------------------------===//
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of AddressSanitizer, an address sanity checker.
//
// Linux-specific details.
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_platform.h"
#if SANITIZER_FREEBSD || SANITIZER_LINUX
#include "asan_interceptors.h"
#include "asan_internal.h"
#include "asan_thread.h"
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_freebsd.h"
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_procmaps.h"
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <dlfcn.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
#include <unwind.h>
#if SANITIZER_FREEBSD
#include <sys/link_elf.h>
#endif
#if SANITIZER_ANDROID || SANITIZER_FREEBSD
#include <ucontext.h>
extern "C" void* _DYNAMIC;
#else
#include <sys/ucontext.h>
#include <link.h>
#endif
// x86-64 FreeBSD 9.2 and older define 'ucontext_t' incorrectly in
// 32-bit mode.
#if SANITIZER_FREEBSD && (SANITIZER_WORDSIZE == 32) && \
__FreeBSD_version <= 902001 // v9.2
#define ucontext_t xucontext_t
#endif
typedef enum {
ASAN_RT_VERSION_UNDEFINED = 0,
ASAN_RT_VERSION_DYNAMIC,
ASAN_RT_VERSION_STATIC,
} asan_rt_version_t;
// FIXME: perhaps also store abi version here?
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE
asan_rt_version_t __asan_rt_version;
}
namespace __asan {
void InitializePlatformInterceptors() {}
void DisableReexec() {
// No need to re-exec on Linux.
}
void MaybeReexec() {
// No need to re-exec on Linux.
}
void *AsanDoesNotSupportStaticLinkage() {
// This will fail to link with -static.
return &_DYNAMIC; // defined in link.h
}
#if SANITIZER_ANDROID
// FIXME: should we do anything for Android?
void AsanCheckDynamicRTPrereqs() {}
void AsanCheckIncompatibleRT() {}
#else
static int FindFirstDSOCallback(struct dl_phdr_info *info, size_t size,
void *data) {
// Continue until the first dynamic library is found
if (!info->dlpi_name || info->dlpi_name[0] == 0)
return 0;
// Ignore vDSO
if (internal_strncmp(info->dlpi_name, "linux-", sizeof("linux-") - 1) == 0)
return 0;
*(const char **)data = info->dlpi_name;
return 1;
}
static bool IsDynamicRTName(const char *libname) {
return internal_strstr(libname, "libclang_rt.asan") ||
internal_strstr(libname, "libasan.so");
}
static void ReportIncompatibleRT() {
Report("Your application is linked against incompatible ASan runtimes.\n");
Die();
}
void AsanCheckDynamicRTPrereqs() {
if (!ASAN_DYNAMIC)
return;
// Ensure that dynamic RT is the first DSO in the list
const char *first_dso_name = nullptr;
dl_iterate_phdr(FindFirstDSOCallback, &first_dso_name);
if (first_dso_name && !IsDynamicRTName(first_dso_name)) {
Report("ASan runtime does not come first in initial library list; "
"you should either link runtime to your application or "
"manually preload it with LD_PRELOAD.\n");
Die();
}
}
void AsanCheckIncompatibleRT() {
if (ASAN_DYNAMIC) {
if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
__asan_rt_version = ASAN_RT_VERSION_DYNAMIC;
} else if (__asan_rt_version != ASAN_RT_VERSION_DYNAMIC) {
ReportIncompatibleRT();
}
} else {
if (__asan_rt_version == ASAN_RT_VERSION_UNDEFINED) {
// 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
// system libraries, causing crashes later in ASan initialization.
MemoryMappingLayout proc_maps(/*cache_enabled*/true);
char filename[128];
while (proc_maps.Next(nullptr, nullptr, nullptr, filename,
sizeof(filename), nullptr)) {
if (IsDynamicRTName(filename)) {
Report("Your application is linked against "
"incompatible ASan runtimes.\n");
Die();
}
}
__asan_rt_version = ASAN_RT_VERSION_STATIC;
} else if (__asan_rt_version != ASAN_RT_VERSION_STATIC) {
ReportIncompatibleRT();
}
}
}
#endif // SANITIZER_ANDROID
#if !SANITIZER_ANDROID
void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
ucontext_t *ucp = (ucontext_t*)context;
*stack = (uptr)ucp->uc_stack.ss_sp;
*ssize = ucp->uc_stack.ss_size;
}
#else
void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
UNIMPLEMENTED();
}
#endif
void *AsanDlSymNext(const char *sym) {
return dlsym(RTLD_NEXT, sym);
}
} // namespace __asan
#endif // SANITIZER_FREEBSD || SANITIZER_LINUX