Google Git
Sign in
cobalt / cobalt / dc98e529721071ac658df8d497cd103ceb8762c1 / . / src / third_party / llvm-project / compiler-rt / lib / sanitizer_common / sanitizer_linux.cc
blob: 96d6c1eff42c3a9298a6fd31d71eece2c07d2712 [file] [log] [blame]
//===-- sanitizer_linux.cc ------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries and implements linux-specific functions from
// sanitizer_libc.h.
//===----------------------------------------------------------------------===//
#include "sanitizer_platform.h"
#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
SANITIZER_OPENBSD || SANITIZER_SOLARIS
#include "sanitizer_common.h"
#include "sanitizer_flags.h"
#include "sanitizer_getauxval.h"
#include "sanitizer_internal_defs.h"
#include "sanitizer_libc.h"
#include "sanitizer_linux.h"
#include "sanitizer_mutex.h"
#include "sanitizer_placement_new.h"
#include "sanitizer_procmaps.h"
#if SANITIZER_LINUX
#include <asm/param.h>
#endif
#if SANITIZER_NETBSD
#include <lwp.h>
#endif
// For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat'
// format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
// access stat from asm/stat.h, without conflicting with definition in
// sys/stat.h, we use this trick.
#if defined(__mips64)
#include <asm/unistd.h>
#include <sys/types.h>
#define stat kernel_stat
#include <asm/stat.h>
#undef stat
#endif
#include <dlfcn.h>
#include <errno.h>
#include <fcntl.h>
#include <link.h>
#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include <sys/mman.h>
#if !SANITIZER_SOLARIS
#include <sys/ptrace.h>
#endif
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#if !SANITIZER_OPENBSD
#include <ucontext.h>
#endif
#if SANITIZER_OPENBSD
#include <sys/futex.h>
#endif
#include <unistd.h>
#if SANITIZER_LINUX
#include <sys/utsname.h>
#endif
#if SANITIZER_LINUX && !SANITIZER_ANDROID
#include <sys/personality.h>
#endif
#if SANITIZER_FREEBSD
#include <sys/exec.h>
#include <sys/sysctl.h>
#include <machine/atomic.h>
extern "C" {
// <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
// FreeBSD 9.2 and 10.0.
#include <sys/umtx.h>
}
#include <sys/thr.h>
#endif // SANITIZER_FREEBSD
#if SANITIZER_NETBSD
#include <limits.h> // For NAME_MAX
#include <sys/sysctl.h>
#include <sys/exec.h>
extern struct ps_strings *__ps_strings;
#endif // SANITIZER_NETBSD
#if SANITIZER_SOLARIS
#include <stdlib.h>
#include <thread.h>
#define environ _environ
#endif
extern char **environ;
#if SANITIZER_LINUX
// <linux/time.h>
struct kernel_timeval {
long tv_sec;
long tv_usec;
};
// <linux/futex.h> is broken on some linux distributions.
const int FUTEX_WAIT = 0;
const int FUTEX_WAKE = 1;
#endif // SANITIZER_LINUX
// Are we using 32-bit or 64-bit Linux syscalls?
// x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
// but it still needs to use 64-bit syscalls.
#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
SANITIZER_WORDSIZE == 64)
# define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
#else
# define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
#endif
#if defined(__x86_64__) || SANITIZER_MIPS64
extern "C" {
extern void internal_sigreturn();
}
#endif
// Note : FreeBSD had implemented both
// Linux and OpenBSD apis, available from
// future 12.x version most likely
#if SANITIZER_LINUX && defined(__NR_getrandom)
# if !defined(GRND_NONBLOCK)
# define GRND_NONBLOCK 1
# endif
# define SANITIZER_USE_GETRANDOM 1
#else
# define SANITIZER_USE_GETRANDOM 0
#endif // SANITIZER_LINUX && defined(__NR_getrandom)
#if SANITIZER_OPENBSD
# define SANITIZER_USE_GETENTROPY 1
#else
# define SANITIZER_USE_GETENTROPY 0
#endif // SANITIZER_USE_GETENTROPY
namespace __sanitizer {
#if SANITIZER_LINUX && defined(__x86_64__)
#include "sanitizer_syscall_linux_x86_64.inc"
#elif SANITIZER_LINUX && defined(__aarch64__)
#include "sanitizer_syscall_linux_aarch64.inc"
#elif SANITIZER_LINUX && defined(__arm__)
#include "sanitizer_syscall_linux_arm.inc"
#else
#include "sanitizer_syscall_generic.inc"
#endif
// --------------- sanitizer_libc.h
#if !SANITIZER_SOLARIS
#if !SANITIZER_S390 && !SANITIZER_OPENBSD
uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
OFF_T offset) {
#if SANITIZER_NETBSD
return internal_syscall64(SYSCALL(mmap), addr, length, prot, flags, fd,
(long)0, offset);
#elif SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
offset);
#else
// mmap2 specifies file offset in 4096-byte units.
CHECK(IsAligned(offset, 4096));
return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
offset / 4096);
#endif
}
#endif // !SANITIZER_S390 && !SANITIZER_OPENBSD
#if !SANITIZER_OPENBSD
uptr internal_munmap(void *addr, uptr length) {
return internal_syscall_ptr(SYSCALL(munmap), (uptr)addr, length);
}
int internal_mprotect(void *addr, uptr length, int prot) {
return internal_syscall_ptr(SYSCALL(mprotect), (uptr)addr, length, prot);
}
#endif
uptr internal_close(fd_t fd) {
return internal_syscall(SYSCALL(close), fd);
}
uptr internal_open(const char *filename, int flags) {
#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags);
#else
return internal_syscall_ptr(SYSCALL(open), (uptr)filename, flags);
#endif
}
uptr internal_open(const char *filename, int flags, u32 mode) {
#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
return internal_syscall(SYSCALL(openat), AT_FDCWD, (uptr)filename, flags,
mode);
#else
return internal_syscall_ptr(SYSCALL(open), (uptr)filename, flags, mode);
#endif
}
uptr internal_read(fd_t fd, void *buf, uptr count) {
sptr res;
HANDLE_EINTR(res, (sptr)internal_syscall_ptr(SYSCALL(read), fd, (uptr)buf,
count));
return res;
}
uptr internal_write(fd_t fd, const void *buf, uptr count) {
sptr res;
HANDLE_EINTR(res, (sptr)internal_syscall_ptr(SYSCALL(write), fd, (uptr)buf,
count));
return res;
}
uptr internal_ftruncate(fd_t fd, uptr size) {
sptr res;
#if SANITIZER_NETBSD
HANDLE_EINTR(res, internal_syscall64(SYSCALL(ftruncate), fd, 0, (s64)size));
#else
HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd,
(OFF_T)size));
#endif
return res;
}
#if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX
static void stat64_to_stat(struct stat64 *in, struct stat *out) {
internal_memset(out, 0, sizeof(*out));
out->st_dev = in->st_dev;
out->st_ino = in->st_ino;
out->st_mode = in->st_mode;
out->st_nlink = in->st_nlink;
out->st_uid = in->st_uid;
out->st_gid = in->st_gid;
out->st_rdev = in->st_rdev;
out->st_size = in->st_size;
out->st_blksize = in->st_blksize;
out->st_blocks = in->st_blocks;
out->st_atime = in->st_atime;
out->st_mtime = in->st_mtime;
out->st_ctime = in->st_ctime;
}
#endif
#if defined(__mips64)
// Undefine compatibility macros from <sys/stat.h>
// so that they would not clash with the kernel_stat
// st_[a|m|c]time fields
#undef st_atime
#undef st_mtime
#undef st_ctime
#if defined(SANITIZER_ANDROID)
// Bionic sys/stat.h defines additional macros
// for compatibility with the old NDKs and
// they clash with the kernel_stat structure
// st_[a|m|c]time_nsec fields.
#undef st_atime_nsec
#undef st_mtime_nsec
#undef st_ctime_nsec
#endif
static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
internal_memset(out, 0, sizeof(*out));
out->st_dev = in->st_dev;
out->st_ino = in->st_ino;
out->st_mode = in->st_mode;
out->st_nlink = in->st_nlink;
out->st_uid = in->st_uid;
out->st_gid = in->st_gid;
out->st_rdev = in->st_rdev;
out->st_size = in->st_size;
out->st_blksize = in->st_blksize;
out->st_blocks = in->st_blocks;
#if defined(__USE_MISC) || \
defined(__USE_XOPEN2K8) || \
defined(SANITIZER_ANDROID)
out->st_atim.tv_sec = in->st_atime;
out->st_atim.tv_nsec = in->st_atime_nsec;
out->st_mtim.tv_sec = in->st_mtime;
out->st_mtim.tv_nsec = in->st_mtime_nsec;
out->st_ctim.tv_sec = in->st_ctime;
out->st_ctim.tv_nsec = in->st_ctime_nsec;
#else
out->st_atime = in->st_atime;
out->st_atimensec = in->st_atime_nsec;
out->st_mtime = in->st_mtime;
out->st_mtimensec = in->st_mtime_nsec;
out->st_ctime = in->st_ctime;
out->st_atimensec = in->st_ctime_nsec;
#endif
}
#endif
uptr internal_stat(const char *path, void *buf) {
#if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD
return internal_syscall_ptr(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
0);
#elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
0);
#elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
# if defined(__mips64)
// For mips64, stat syscall fills buffer in the format of kernel_stat
struct kernel_stat kbuf;
int res = internal_syscall(SYSCALL(stat), path, &kbuf);
kernel_stat_to_stat(&kbuf, (struct stat *)buf);
return res;
# else
return internal_syscall(SYSCALL(stat), (uptr)path, (uptr)buf);
# endif
#else
struct stat64 buf64;
int res = internal_syscall(SYSCALL(stat64), path, &buf64);
stat64_to_stat(&buf64, (struct stat *)buf);
return res;
#endif
}
uptr internal_lstat(const char *path, void *buf) {
#if SANITIZER_NETBSD
return internal_syscall_ptr(SYSCALL(lstat), path, buf);
#elif SANITIZER_FREEBSD || SANITIZER_OPENBSD
return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
AT_SYMLINK_NOFOLLOW);
#elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path, (uptr)buf,
AT_SYMLINK_NOFOLLOW);
#elif SANITIZER_LINUX_USES_64BIT_SYSCALLS
# if SANITIZER_MIPS64
// For mips64, lstat syscall fills buffer in the format of kernel_stat
struct kernel_stat kbuf;
int res = internal_syscall(SYSCALL(lstat), path, &kbuf);
kernel_stat_to_stat(&kbuf, (struct stat *)buf);
return res;
# else
return internal_syscall(SYSCALL(lstat), (uptr)path, (uptr)buf);
# endif
#else
struct stat64 buf64;
int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
stat64_to_stat(&buf64, (struct stat *)buf);
return res;
#endif
}
uptr internal_fstat(fd_t fd, void *buf) {
#if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD || \
SANITIZER_LINUX_USES_64BIT_SYSCALLS
#if SANITIZER_MIPS64 && !SANITIZER_NETBSD && !SANITIZER_OPENBSD
// For mips64, fstat syscall fills buffer in the format of kernel_stat
struct kernel_stat kbuf;
int res = internal_syscall(SYSCALL(fstat), fd, &kbuf);
kernel_stat_to_stat(&kbuf, (struct stat *)buf);
return res;
# else
return internal_syscall_ptr(SYSCALL(fstat), fd, (uptr)buf);
# endif
#else
struct stat64 buf64;
int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
stat64_to_stat(&buf64, (struct stat *)buf);
return res;
#endif
}
uptr internal_filesize(fd_t fd) {
struct stat st;
if (internal_fstat(fd, &st))
return -1;
return (uptr)st.st_size;
}
uptr internal_dup2(int oldfd, int newfd) {
#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
return internal_syscall(SYSCALL(dup3), oldfd, newfd, 0);
#else
return internal_syscall(SYSCALL(dup2), oldfd, newfd);
#endif
}
uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, (uptr)path, (uptr)buf,
bufsize);
#elif SANITIZER_OPENBSD
return internal_syscall_ptr(SYSCALL(readlinkat), AT_FDCWD, (uptr)path,
(uptr)buf, bufsize);
#else
return internal_syscall_ptr(SYSCALL(readlink), path, buf, bufsize);
#endif
}
uptr internal_unlink(const char *path) {
#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD
return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, (uptr)path, 0);
#else
return internal_syscall_ptr(SYSCALL(unlink), (uptr)path);
#endif
}
uptr internal_rename(const char *oldpath, const char *newpath) {
#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS || SANITIZER_OPENBSD
return internal_syscall(SYSCALL(renameat), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
(uptr)newpath);
#else
return internal_syscall_ptr(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
#endif
}
uptr internal_sched_yield() {
return internal_syscall(SYSCALL(sched_yield));
}
void internal__exit(int exitcode) {
#if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD
internal_syscall(SYSCALL(exit), exitcode);
#else
internal_syscall(SYSCALL(exit_group), exitcode);
#endif
Die(); // Unreachable.
}
unsigned int internal_sleep(unsigned int seconds) {
struct timespec ts;
ts.tv_sec = 1;
ts.tv_nsec = 0;
int res = internal_syscall_ptr(SYSCALL(nanosleep), &ts, &ts);
if (res) return ts.tv_sec;
return 0;
}
uptr internal_execve(const char *filename, char *const argv[],
char *const envp[]) {
return internal_syscall_ptr(SYSCALL(execve), (uptr)filename, (uptr)argv,
(uptr)envp);
}
#endif // !SANITIZER_SOLARIS
// ----------------- sanitizer_common.h
bool FileExists(const char *filename) {
struct stat st;
#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
if (internal_syscall(SYSCALL(newfstatat), AT_FDCWD, filename, &st, 0))
#else
if (internal_stat(filename, &st))
#endif
return false;
// Sanity check: filename is a regular file.
return S_ISREG(st.st_mode);
}
tid_t GetTid() {
#if SANITIZER_FREEBSD
long Tid;
thr_self(&Tid);
return Tid;
#elif SANITIZER_OPENBSD
return internal_syscall(SYSCALL(getthrid));
#elif SANITIZER_NETBSD
return _lwp_self();
#elif SANITIZER_SOLARIS
return thr_self();
#else
return internal_syscall(SYSCALL(gettid));
#endif
}
#if !SANITIZER_SOLARIS
u64 NanoTime() {
#if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD
timeval tv;
#else
kernel_timeval tv;
#endif
internal_memset(&tv, 0, sizeof(tv));
internal_syscall_ptr(SYSCALL(gettimeofday), &tv, 0);
return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000;
}
uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) {
return internal_syscall_ptr(SYSCALL(clock_gettime), clk_id, tp);
}
#endif // !SANITIZER_SOLARIS
// Like getenv, but reads env directly from /proc (on Linux) or parses the
// 'environ' array (on some others) and does not use libc. This function
// should be called first inside __asan_init.
const char *GetEnv(const char *name) {
#if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD || \
SANITIZER_SOLARIS
if (::environ != 0) {
uptr NameLen = internal_strlen(name);
for (char **Env = ::environ; *Env != 0; Env++) {
if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
return (*Env) + NameLen + 1;
}
}
return 0; // Not found.
#elif SANITIZER_LINUX
static char *environ;
static uptr len;
static bool inited;
if (!inited) {
inited = true;
uptr environ_size;
if (!ReadFileToBuffer("/proc/self/environ", &environ, &environ_size, &len))
environ = nullptr;
}
if (!environ || len == 0) return nullptr;
uptr namelen = internal_strlen(name);
const char *p = environ;
while (*p != '\0') { // will happen at the \0\0 that terminates the buffer
// proc file has the format NAME=value\0NAME=value\0NAME=value\0...
const char* endp =
(char*)internal_memchr(p, '\0', len - (p - environ));
if (!endp) // this entry isn't NUL terminated
return nullptr;
else if (!internal_memcmp(p, name, namelen) && p[namelen] == '=') // Match.
return p + namelen + 1; // point after =
p = endp + 1;
}
return nullptr; // Not found.
#else
#error "Unsupported platform"
#endif
}
#if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_OPENBSD
extern "C" {
SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
}
#endif
#if !SANITIZER_GO && !SANITIZER_FREEBSD && !SANITIZER_NETBSD && \
!SANITIZER_OPENBSD
static void ReadNullSepFileToArray(const char *path, char ***arr,
int arr_size) {
char *buff;
uptr buff_size;
uptr buff_len;
*arr = (char **)MmapOrDie(arr_size * sizeof(char *), "NullSepFileArray");
if (!ReadFileToBuffer(path, &buff, &buff_size, &buff_len, 1024 * 1024)) {
(*arr)[0] = nullptr;
return;
}
(*arr)[0] = buff;
int count, i;
for (count = 1, i = 1; ; i++) {
if (buff[i] == 0) {
if (buff[i+1] == 0) break;
(*arr)[count] = &buff[i+1];
CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible.
count++;
}
}
(*arr)[count] = nullptr;
}
#endif
#if !SANITIZER_OPENBSD
static void GetArgsAndEnv(char ***argv, char ***envp) {
#if SANITIZER_FREEBSD
// On FreeBSD, retrieving the argument and environment arrays is done via the
// kern.ps_strings sysctl, which returns a pointer to a structure containing
// this information. See also <sys/exec.h>.
ps_strings *pss;
size_t sz = sizeof(pss);
if (sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) {
Printf("sysctl kern.ps_strings failed\n");
Die();
}
*argv = pss->ps_argvstr;
*envp = pss->ps_envstr;
#elif SANITIZER_NETBSD
*argv = __ps_strings->ps_argvstr;
*envp = __ps_strings->ps_envstr;
#else // SANITIZER_FREEBSD
#if !SANITIZER_GO
if (&__libc_stack_end) {
#endif // !SANITIZER_GO
uptr* stack_end = (uptr*)__libc_stack_end;
int argc = *stack_end;
*argv = (char**)(stack_end + 1);
*envp = (char**)(stack_end + argc + 2);
#if !SANITIZER_GO
} else {
static const int kMaxArgv = 2000, kMaxEnvp = 2000;
ReadNullSepFileToArray("/proc/self/cmdline", argv, kMaxArgv);
ReadNullSepFileToArray("/proc/self/environ", envp, kMaxEnvp);
}
#endif // !SANITIZER_GO
#endif // SANITIZER_FREEBSD
}
char **GetArgv() {
char **argv, **envp;
GetArgsAndEnv(&argv, &envp);
return argv;
}
void ReExec() {
char **argv, **envp;
const char *pathname = "/proc/self/exe";
#if SANITIZER_NETBSD
static const int name[] = {
CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME,
};
char path[400];
size_t len;
len = sizeof(path);
if (sysctl(name, ARRAY_SIZE(name), path, &len, NULL, 0) != -1)
pathname = path;
#elif SANITIZER_SOLARIS
pathname = getexecname();
CHECK_NE(pathname, NULL);
#endif
GetArgsAndEnv(&argv, &envp);
uptr rv = internal_execve(pathname, argv, envp);
int rverrno;
CHECK_EQ(internal_iserror(rv, &rverrno), true);
Printf("execve failed, errno %d\n", rverrno);
Die();
}
#endif
#if !SANITIZER_SOLARIS
enum MutexState {
MtxUnlocked = 0,
MtxLocked = 1,
MtxSleeping = 2
};
BlockingMutex::BlockingMutex() {
internal_memset(this, 0, sizeof(*this));
}
void BlockingMutex::Lock() {
CHECK_EQ(owner_, 0);
atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked)
return;
while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) {
#if SANITIZER_FREEBSD
_umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0);
#elif SANITIZER_NETBSD
sched_yield(); /* No userspace futex-like synchronization */
#else
internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT, MtxSleeping, 0, 0, 0);
#endif
}
}
void BlockingMutex::Unlock() {
atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release);
CHECK_NE(v, MtxUnlocked);
if (v == MtxSleeping) {
#if SANITIZER_FREEBSD
_umtx_op(m, UMTX_OP_WAKE, 1, 0, 0);
#elif SANITIZER_NETBSD
/* No userspace futex-like synchronization */
#else
internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE, 1, 0, 0, 0);
#endif
}
}
void BlockingMutex::CheckLocked() {
atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
}
#endif // !SANITIZER_SOLARIS
// ----------------- sanitizer_linux.h
// The actual size of this structure is specified by d_reclen.
// Note that getdents64 uses a different structure format. We only provide the
// 32-bit syscall here.
#if SANITIZER_NETBSD || SANITIZER_OPENBSD
// struct dirent is different for Linux and us. At this moment, we use only
// d_fileno (Linux call this d_ino), d_reclen, and d_name.
struct linux_dirent {
u64 d_ino; // d_fileno
u16 d_reclen;
u16 d_namlen; // not used
u8 d_type; // not used
char d_name[NAME_MAX + 1];
};
#else
struct linux_dirent {
#if SANITIZER_X32 || defined(__aarch64__)
u64 d_ino;
u64 d_off;
#else
unsigned long d_ino;
unsigned long d_off;
#endif
unsigned short d_reclen;
#ifdef __aarch64__
unsigned char d_type;
#endif
char d_name[256];
};
#endif
#if !SANITIZER_SOLARIS
// Syscall wrappers.
uptr internal_ptrace(int request, int pid, void *addr, void *data) {
#if SANITIZER_NETBSD
// XXX We need additional work for ptrace:
// - for request, we use PT_FOO whereas Linux uses PTRACE_FOO
// - data is int for us, but void * for Linux
// - Linux sometimes uses data in the case where we use addr instead
// At this moment, this function is used only within
// "#if SANITIZER_LINUX && defined(__x86_64__)" block in
// sanitizer_stoptheworld_linux_libcdep.cc.
return internal_syscall_ptr(SYSCALL(ptrace), request, pid, (uptr)addr,
(uptr)data);
#else
return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
(uptr)data);
#endif
}
uptr internal_waitpid(int pid, int *status, int options) {
return internal_syscall_ptr(SYSCALL(wait4), pid, (uptr)status, options,
0 /* rusage */);
}
uptr internal_getpid() {
return internal_syscall(SYSCALL(getpid));
}
uptr internal_getppid() {
return internal_syscall(SYSCALL(getppid));
}
uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
#if SANITIZER_FREEBSD
return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL);
#elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
#else
return internal_syscall_ptr(SYSCALL(getdents), fd, (uptr)dirp, count);
#endif
}
uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
#if SANITIZER_NETBSD
return internal_syscall64(SYSCALL(lseek), fd, 0, offset, whence);
#else
return internal_syscall(SYSCALL(lseek), fd, offset, whence);
#endif
}
#if SANITIZER_LINUX
uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
return internal_syscall(SYSCALL(prctl), option, arg2, arg3, arg4, arg5);
}
#endif
uptr internal_sigaltstack(const void *ss, void *oss) {
return internal_syscall_ptr(SYSCALL(sigaltstack), (uptr)ss, (uptr)oss);
}
int internal_fork() {
#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
return internal_syscall(SYSCALL(clone), SIGCHLD, 0);
#else
return internal_syscall(SYSCALL(fork));
#endif
}
#if SANITIZER_LINUX
#define SA_RESTORER 0x04000000
// Doesn't set sa_restorer if the caller did not set it, so use with caution
//(see below).
int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
__sanitizer_kernel_sigaction_t k_act, k_oldact;
internal_memset(&k_act, 0, sizeof(__sanitizer_kernel_sigaction_t));
internal_memset(&k_oldact, 0, sizeof(__sanitizer_kernel_sigaction_t));
const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
__sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
if (u_act) {
k_act.handler = u_act->handler;
k_act.sigaction = u_act->sigaction;
internal_memcpy(&k_act.sa_mask, &u_act->sa_mask,
sizeof(__sanitizer_kernel_sigset_t));
// Without SA_RESTORER kernel ignores the calls (probably returns EINVAL).
k_act.sa_flags = u_act->sa_flags | SA_RESTORER;
// FIXME: most often sa_restorer is unset, however the kernel requires it
// to point to a valid signal restorer that calls the rt_sigreturn syscall.
// If sa_restorer passed to the kernel is NULL, the program may crash upon
// signal delivery or fail to unwind the stack in the signal handler.
// libc implementation of sigaction() passes its own restorer to
// rt_sigaction, so we need to do the same (we'll need to reimplement the
// restorers; for x86_64 the restorer address can be obtained from
// oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
#if !SANITIZER_ANDROID || !SANITIZER_MIPS32
k_act.sa_restorer = u_act->sa_restorer;
#endif
}
uptr result = internal_syscall(SYSCALL(rt_sigaction), (uptr)signum,
(uptr)(u_act ? &k_act : nullptr),
(uptr)(u_oldact ? &k_oldact : nullptr),
(uptr)sizeof(__sanitizer_kernel_sigset_t));
if ((result == 0) && u_oldact) {
u_oldact->handler = k_oldact.handler;
u_oldact->sigaction = k_oldact.sigaction;
internal_memcpy(&u_oldact->sa_mask, &k_oldact.sa_mask,
sizeof(__sanitizer_kernel_sigset_t));
u_oldact->sa_flags = k_oldact.sa_flags;
#if !SANITIZER_ANDROID || !SANITIZER_MIPS32
u_oldact->sa_restorer = k_oldact.sa_restorer;
#endif
}
return result;
}
// Invokes sigaction via a raw syscall with a restorer, but does not support
// all platforms yet.
// We disable for Go simply because we have not yet added to buildgo.sh.
#if (defined(__x86_64__) || SANITIZER_MIPS64) && !SANITIZER_GO
int internal_sigaction_syscall(int signum, const void *act, void *oldact) {
if (act == nullptr)
return internal_sigaction_norestorer(signum, act, oldact);
__sanitizer_sigaction u_adjust;
internal_memcpy(&u_adjust, act, sizeof(u_adjust));
#if !SANITIZER_ANDROID || !SANITIZER_MIPS32
if (u_adjust.sa_restorer == nullptr) {
u_adjust.sa_restorer = internal_sigreturn;
}
#endif
return internal_sigaction_norestorer(signum, (const void *)&u_adjust, oldact);
}
#endif // defined(__x86_64__) && !SANITIZER_GO
#endif // SANITIZER_LINUX
uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
__sanitizer_sigset_t *oldset) {
#if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_OPENBSD
return internal_syscall_ptr(SYSCALL(sigprocmask), how, set, oldset);
#else
__sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
__sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
return internal_syscall(SYSCALL(rt_sigprocmask), (uptr)how,
(uptr)&k_set->sig[0], (uptr)&k_oldset->sig[0],
sizeof(__sanitizer_kernel_sigset_t));
#endif
}
void internal_sigfillset(__sanitizer_sigset_t *set) {
internal_memset(set, 0xff, sizeof(*set));
}
void internal_sigemptyset(__sanitizer_sigset_t *set) {
internal_memset(set, 0, sizeof(*set));
}
#if SANITIZER_LINUX
void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
signum -= 1;
CHECK_GE(signum, 0);
CHECK_LT(signum, sizeof(*set) * 8);
__sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
k_set->sig[idx] &= ~(1 << bit);
}
bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
signum -= 1;
CHECK_GE(signum, 0);
CHECK_LT(signum, sizeof(*set) * 8);
__sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
return k_set->sig[idx] & (1 << bit);
}
#endif // SANITIZER_LINUX
#endif // !SANITIZER_SOLARIS
// ThreadLister implementation.
ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) {
char task_directory_path[80];
internal_snprintf(task_directory_path, sizeof(task_directory_path),
"/proc/%d/task/", pid);
descriptor_ = internal_open(task_directory_path, O_RDONLY | O_DIRECTORY);
if (internal_iserror(descriptor_)) {
Report("Can't open /proc/%d/task for reading.\n", pid);
}
}
ThreadLister::Result ThreadLister::ListThreads(
InternalMmapVector<tid_t> *threads) {
if (internal_iserror(descriptor_))
return Error;
internal_lseek(descriptor_, 0, SEEK_SET);
threads->clear();
Result result = Ok;
for (bool first_read = true;; first_read = false) {
// Resize to max capacity if it was downsized by IsAlive.
buffer_.resize(buffer_.capacity());
CHECK_GE(buffer_.size(), 4096);
uptr read = internal_getdents(
descriptor_, (struct linux_dirent *)buffer_.data(), buffer_.size());
if (!read)
return result;
if (internal_iserror(read)) {
Report("Can't read directory entries from /proc/%d/task.\n", pid_);
return Error;
}
for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) {
struct linux_dirent *entry = (struct linux_dirent *)begin;
begin += entry->d_reclen;
if (entry->d_ino == 1) {
// Inode 1 is for bad blocks and also can be a reason for early return.
// Should be emitted if kernel tried to output terminating thread.
// See proc_task_readdir implementation in Linux.
result = Incomplete;
}
if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9')
threads->push_back(internal_atoll(entry->d_name));
}
// Now we are going to detect short-read or early EOF. In such cases Linux
// can return inconsistent list with missing alive threads.
// Code will just remember that the list can be incomplete but it will
// continue reads to return as much as possible.
if (!first_read) {
// The first one was a short-read by definition.
result = Incomplete;
} else if (read > buffer_.size() - 1024) {
// Read was close to the buffer size. So double the size and assume the
// worst.
buffer_.resize(buffer_.size() * 2);
result = Incomplete;
} else if (!threads->empty() && !IsAlive(threads->back())) {
// Maybe Linux early returned from read on terminated thread (!pid_alive)
// and failed to restore read position.
// See next_tid and proc_task_instantiate in Linux.
result = Incomplete;
}
}
}
bool ThreadLister::IsAlive(int tid) {
// /proc/%d/task/%d/status uses same call to detect alive threads as
// proc_task_readdir. See task_state implementation in Linux.
char path[80];
internal_snprintf(path, sizeof(path), "/proc/%d/task/%d/status", pid_, tid);
if (!ReadFileToVector(path, &buffer_) || buffer_.empty())
return false;
buffer_.push_back(0);
static const char kPrefix[] = "\nPPid:";
const char *field = internal_strstr(buffer_.data(), kPrefix);
if (!field)
return false;
field += internal_strlen(kPrefix);
return (int)internal_atoll(field) != 0;
}
ThreadLister::~ThreadLister() {
if (!internal_iserror(descriptor_))
internal_close(descriptor_);
}
#if SANITIZER_WORDSIZE == 32
// Take care of unusable kernel area in top gigabyte.
static uptr GetKernelAreaSize() {
#if SANITIZER_LINUX && !SANITIZER_X32
const uptr gbyte = 1UL << 30;
// Firstly check if there are writable segments
// mapped to top gigabyte (e.g. stack).
MemoryMappingLayout proc_maps(/*cache_enabled*/true);
MemoryMappedSegment segment;
while (proc_maps.Next(&segment)) {
if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0;
}
#if !SANITIZER_ANDROID
// Even if nothing is mapped, top Gb may still be accessible
// if we are running on 64-bit kernel.
// Uname may report misleading results if personality type
// is modified (e.g. under schroot) so check this as well.
struct utsname uname_info;
int pers = personality(0xffffffffUL);
if (!(pers & PER_MASK)
&& uname(&uname_info) == 0
&& internal_strstr(uname_info.machine, "64"))
return 0;
#endif // SANITIZER_ANDROID
// Top gigabyte is reserved for kernel.
return gbyte;
#else
return 0;
#endif // SANITIZER_LINUX && !SANITIZER_X32
}
#endif // SANITIZER_WORDSIZE == 32
uptr GetMaxVirtualAddress() {
#if (SANITIZER_NETBSD || SANITIZER_OPENBSD) && defined(__x86_64__)
return 0x7f7ffffff000ULL; // (0x00007f8000000000 - PAGE_SIZE)
#elif SANITIZER_WORDSIZE == 64
# if defined(__powerpc64__) || defined(__aarch64__)
// On PowerPC64 we have two different address space layouts: 44- and 46-bit.
// We somehow need to figure out which one we are using now and choose
// one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
// Note that with 'ulimit -s unlimited' the stack is moved away from the top
// of the address space, so simply checking the stack address is not enough.
// This should (does) work for both PowerPC64 Endian modes.
// Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
# elif defined(__mips64)
return (1ULL << 40) - 1; // 0x000000ffffffffffUL;
# elif defined(__s390x__)
return (1ULL << 53) - 1; // 0x001fffffffffffffUL;
# else
return (1ULL << 47) - 1; // 0x00007fffffffffffUL;
# endif
#else // SANITIZER_WORDSIZE == 32
# if defined(__s390__)
return (1ULL << 31) - 1; // 0x7fffffff;
# else
return (1ULL << 32) - 1; // 0xffffffff;
# endif
#endif // SANITIZER_WORDSIZE
}
uptr GetMaxUserVirtualAddress() {
uptr addr = GetMaxVirtualAddress();
#if SANITIZER_WORDSIZE == 32 && !defined(__s390__)
if (!common_flags()->full_address_space)
addr -= GetKernelAreaSize();
CHECK_LT(reinterpret_cast<uptr>(&addr), addr);
#endif
return addr;
}
uptr GetPageSize() {
// Android post-M sysconf(_SC_PAGESIZE) crashes if called from .preinit_array.
#if SANITIZER_ANDROID
return 4096;
#elif SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__))
return EXEC_PAGESIZE;
#elif SANITIZER_USE_GETAUXVAL
return getauxval(AT_PAGESZ);
#else
return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy.
#endif
}
#if !SANITIZER_OPENBSD
uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
#if SANITIZER_SOLARIS
const char *default_module_name = getexecname();
CHECK_NE(default_module_name, NULL);
return internal_snprintf(buf, buf_len, "%s", default_module_name);
#else
#if SANITIZER_FREEBSD || SANITIZER_NETBSD
#if SANITIZER_FREEBSD
const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
#else
const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
#endif
const char *default_module_name = "kern.proc.pathname";
size_t Size = buf_len;
bool IsErr = (sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
int readlink_error = IsErr ? errno : 0;
uptr module_name_len = Size;
#else
const char *default_module_name = "/proc/self/exe";
uptr module_name_len = internal_readlink(
default_module_name, buf, buf_len);
int readlink_error;
bool IsErr = internal_iserror(module_name_len, &readlink_error);
#endif // SANITIZER_SOLARIS
if (IsErr) {
// We can't read binary name for some reason, assume it's unknown.
Report("WARNING: reading executable name failed with errno %d, "
"some stack frames may not be symbolized\n", readlink_error);
module_name_len = internal_snprintf(buf, buf_len, "%s",
default_module_name);
CHECK_LT(module_name_len, buf_len);
}
return module_name_len;
#endif
}
#endif // !SANITIZER_OPENBSD
uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
#if SANITIZER_LINUX
char *tmpbuf;
uptr tmpsize;
uptr tmplen;
if (ReadFileToBuffer("/proc/self/cmdline", &tmpbuf, &tmpsize, &tmplen,
1024 * 1024)) {
internal_strncpy(buf, tmpbuf, buf_len);
UnmapOrDie(tmpbuf, tmpsize);
return internal_strlen(buf);
}
#endif
return ReadBinaryName(buf, buf_len);
}
// Match full names of the form /path/to/base_name{-,.}*
bool LibraryNameIs(const char *full_name, const char *base_name) {
const char *name = full_name;
// Strip path.
while (*name != '\0') name++;
while (name > full_name && *name != '/') name--;
if (*name == '/') name++;
uptr base_name_length = internal_strlen(base_name);
if (internal_strncmp(name, base_name, base_name_length)) return false;
return (name[base_name_length] == '-' || name[base_name_length] == '.');
}
#if !SANITIZER_ANDROID
// Call cb for each region mapped by map.
void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
CHECK_NE(map, nullptr);
#if !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
typedef ElfW(Phdr) Elf_Phdr;
typedef ElfW(Ehdr) Elf_Ehdr;
#endif // !SANITIZER_FREEBSD && !SANITIZER_OPENBSD
char *base = (char *)map->l_addr;
Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
char *phdrs = base + ehdr->e_phoff;
char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
// Find the segment with the minimum base so we can "relocate" the p_vaddr
// fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
// objects have a non-zero base.
uptr preferred_base = (uptr)-1;
for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
Elf_Phdr *phdr = (Elf_Phdr *)iter;
if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
preferred_base = (uptr)phdr->p_vaddr;
}
// Compute the delta from the real base to get a relocation delta.
sptr delta = (uptr)base - preferred_base;
// Now we can figure out what the loader really mapped.
for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
Elf_Phdr *phdr = (Elf_Phdr *)iter;
if (phdr->p_type == PT_LOAD) {
uptr seg_start = phdr->p_vaddr + delta;
uptr seg_end = seg_start + phdr->p_memsz;
// None of these values are aligned. We consider the ragged edges of the
// load command as defined, since they are mapped from the file.
seg_start = RoundDownTo(seg_start, GetPageSizeCached());
seg_end = RoundUpTo(seg_end, GetPageSizeCached());
cb((void *)seg_start, seg_end - seg_start);
}
}
}
#endif
#if defined(__x86_64__) && SANITIZER_LINUX
// We cannot use glibc's clone wrapper, because it messes with the child
// task's TLS. It writes the PID and TID of the child task to its thread
// descriptor, but in our case the child task shares the thread descriptor with
// the parent (because we don't know how to allocate a new thread
// descriptor to keep glibc happy). So the stock version of clone(), when
// used with CLONE_VM, would end up corrupting the parent's thread descriptor.
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
int *parent_tidptr, void *newtls, int *child_tidptr) {
long long res;
if (!fn || !child_stack)
return -EINVAL;
CHECK_EQ(0, (uptr)child_stack % 16);
child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
((unsigned long long *)child_stack)[0] = (uptr)fn;
((unsigned long long *)child_stack)[1] = (uptr)arg;
register void *r8 __asm__("r8") = newtls;
register int *r10 __asm__("r10") = child_tidptr;
__asm__ __volatile__(
/* %rax = syscall(%rax = SYSCALL(clone),
* %rdi = flags,
* %rsi = child_stack,
* %rdx = parent_tidptr,
* %r8 = new_tls,
* %r10 = child_tidptr)
*/
"syscall\n"
/* if (%rax != 0)
* return;
*/
"testq %%rax,%%rax\n"
"jnz 1f\n"
/* In the child. Terminate unwind chain. */
// XXX: We should also terminate the CFI unwind chain
// here. Unfortunately clang 3.2 doesn't support the
// necessary CFI directives, so we skip that part.
"xorq %%rbp,%%rbp\n"
/* Call "fn(arg)". */
"popq %%rax\n"
"popq %%rdi\n"
"call *%%rax\n"
/* Call _exit(%rax). */
"movq %%rax,%%rdi\n"
"movq %2,%%rax\n"
"syscall\n"
/* Return to parent. */
"1:\n"
: "=a" (res)
: "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
"S"(child_stack),
"D"(flags),
"d"(parent_tidptr),
"r"(r8),
"r"(r10)
: "rsp", "memory", "r11", "rcx");
return res;
}
#elif defined(__mips__)
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
int *parent_tidptr, void *newtls, int *child_tidptr) {
long long res;
if (!fn || !child_stack)
return -EINVAL;
CHECK_EQ(0, (uptr)child_stack % 16);
child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
((unsigned long long *)child_stack)[0] = (uptr)fn;
((unsigned long long *)child_stack)[1] = (uptr)arg;
register void *a3 __asm__("$7") = newtls;
register int *a4 __asm__("$8") = child_tidptr;
// We don't have proper CFI directives here because it requires alot of code
// for very marginal benefits.
__asm__ __volatile__(
/* $v0 = syscall($v0 = __NR_clone,
* $a0 = flags,
* $a1 = child_stack,
* $a2 = parent_tidptr,
* $a3 = new_tls,
* $a4 = child_tidptr)
*/
".cprestore 16;\n"
"move $4,%1;\n"
"move $5,%2;\n"
"move $6,%3;\n"
"move $7,%4;\n"
/* Store the fifth argument on stack
* if we are using 32-bit abi.
*/
#if SANITIZER_WORDSIZE == 32
"lw %5,16($29);\n"
#else
"move $8,%5;\n"
#endif
"li $2,%6;\n"
"syscall;\n"
/* if ($v0 != 0)
* return;
*/
"bnez $2,1f;\n"
/* Call "fn(arg)". */
#if SANITIZER_WORDSIZE == 32
#ifdef __BIG_ENDIAN__
"lw $25,4($29);\n"
"lw $4,12($29);\n"
#else
"lw $25,0($29);\n"
"lw $4,8($29);\n"
#endif
#else
"ld $25,0($29);\n"
"ld $4,8($29);\n"
#endif
"jal $25;\n"
/* Call _exit($v0). */
"move $4,$2;\n"
"li $2,%7;\n"
"syscall;\n"
/* Return to parent. */
"1:\n"
: "=r" (res)
: "r"(flags),
"r"(child_stack),
"r"(parent_tidptr),
"r"(a3),
"r"(a4),
"i"(__NR_clone),
"i"(__NR_exit)
: "memory", "$29" );
return res;
}
#elif defined(__aarch64__)
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
int *parent_tidptr, void *newtls, int *child_tidptr) {
long long res;
if (!fn || !child_stack)
return -EINVAL;
CHECK_EQ(0, (uptr)child_stack % 16);
child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
((unsigned long long *)child_stack)[0] = (uptr)fn;
((unsigned long long *)child_stack)[1] = (uptr)arg;
register int (*__fn)(void *) __asm__("x0") = fn;
register void *__stack __asm__("x1") = child_stack;
register int __flags __asm__("x2") = flags;
register void *__arg __asm__("x3") = arg;
register int *__ptid __asm__("x4") = parent_tidptr;
register void *__tls __asm__("x5") = newtls;
register int *__ctid __asm__("x6") = child_tidptr;
__asm__ __volatile__(
"mov x0,x2\n" /* flags */
"mov x2,x4\n" /* ptid */
"mov x3,x5\n" /* tls */
"mov x4,x6\n" /* ctid */
"mov x8,%9\n" /* clone */
"svc 0x0\n"
/* if (%r0 != 0)
* return %r0;
*/
"cmp x0, #0\n"
"bne 1f\n"
/* In the child, now. Call "fn(arg)". */
"ldp x1, x0, [sp], #16\n"
"blr x1\n"
/* Call _exit(%r0). */
"mov x8, %10\n"
"svc 0x0\n"
"1:\n"
: "=r" (res)
: "i"(-EINVAL),
"r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg),
"r"(__ptid), "r"(__tls), "r"(__ctid),
"i"(__NR_clone), "i"(__NR_exit)
: "x30", "memory");
return res;
}
#elif defined(__powerpc64__)
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
int *parent_tidptr, void *newtls, int *child_tidptr) {
long long res;
// Stack frame structure.
#if SANITIZER_PPC64V1
// Back chain == 0 (SP + 112)
// Frame (112 bytes):
// Parameter save area (SP + 48), 8 doublewords
// TOC save area (SP + 40)
// Link editor doubleword (SP + 32)
// Compiler doubleword (SP + 24)
// LR save area (SP + 16)
// CR save area (SP + 8)
// Back chain (SP + 0)
# define FRAME_SIZE 112
# define FRAME_TOC_SAVE_OFFSET 40
#elif SANITIZER_PPC64V2
// Back chain == 0 (SP + 32)
// Frame (32 bytes):
// TOC save area (SP + 24)
// LR save area (SP + 16)
// CR save area (SP + 8)
// Back chain (SP + 0)
# define FRAME_SIZE 32
# define FRAME_TOC_SAVE_OFFSET 24
#else
# error "Unsupported PPC64 ABI"
#endif
if (!fn || !child_stack)
return -EINVAL;
CHECK_EQ(0, (uptr)child_stack % 16);
register int (*__fn)(void *) __asm__("r3") = fn;
register void *__cstack __asm__("r4") = child_stack;
register int __flags __asm__("r5") = flags;
register void *__arg __asm__("r6") = arg;
register int *__ptidptr __asm__("r7") = parent_tidptr;
register void *__newtls __asm__("r8") = newtls;
register int *__ctidptr __asm__("r9") = child_tidptr;
__asm__ __volatile__(
/* fn and arg are saved across the syscall */
"mr 28, %5\n\t"
"mr 27, %8\n\t"
/* syscall
r0 == __NR_clone
r3 == flags
r4 == child_stack
r5 == parent_tidptr
r6 == newtls
r7 == child_tidptr */
"mr 3, %7\n\t"
"mr 5, %9\n\t"
"mr 6, %10\n\t"
"mr 7, %11\n\t"
"li 0, %3\n\t"
"sc\n\t"
/* Test if syscall was successful */
"cmpdi cr1, 3, 0\n\t"
"crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
"bne- cr1, 1f\n\t"
/* Set up stack frame */
"li 29, 0\n\t"
"stdu 29, -8(1)\n\t"
"stdu 1, -%12(1)\n\t"
/* Do the function call */
"std 2, %13(1)\n\t"
#if SANITIZER_PPC64V1
"ld 0, 0(28)\n\t"
"ld 2, 8(28)\n\t"
"mtctr 0\n\t"
#elif SANITIZER_PPC64V2
"mr 12, 28\n\t"
"mtctr 12\n\t"
#else
# error "Unsupported PPC64 ABI"
#endif
"mr 3, 27\n\t"
"bctrl\n\t"
"ld 2, %13(1)\n\t"
/* Call _exit(r3) */
"li 0, %4\n\t"
"sc\n\t"
/* Return to parent */
"1:\n\t"
"mr %0, 3\n\t"
: "=r" (res)
: "0" (-1),
"i" (EINVAL),
"i" (__NR_clone),
"i" (__NR_exit),
"r" (__fn),
"r" (__cstack),
"r" (__flags),
"r" (__arg),
"r" (__ptidptr),
"r" (__newtls),
"r" (__ctidptr),
"i" (FRAME_SIZE),
"i" (FRAME_TOC_SAVE_OFFSET)
: "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29");
return res;
}
#elif defined(__i386__) && SANITIZER_LINUX
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
int *parent_tidptr, void *newtls, int *child_tidptr) {
int res;
if (!fn || !child_stack)
return -EINVAL;
CHECK_EQ(0, (uptr)child_stack % 16);
child_stack = (char *)child_stack - 7 * sizeof(unsigned int);
((unsigned int *)child_stack)[0] = (uptr)flags;
((unsigned int *)child_stack)[1] = (uptr)0;
((unsigned int *)child_stack)[2] = (uptr)fn;
((unsigned int *)child_stack)[3] = (uptr)arg;
__asm__ __volatile__(
/* %eax = syscall(%eax = SYSCALL(clone),
* %ebx = flags,
* %ecx = child_stack,
* %edx = parent_tidptr,
* %esi = new_tls,
* %edi = child_tidptr)
*/
/* Obtain flags */
"movl (%%ecx), %%ebx\n"
/* Do the system call */
"pushl %%ebx\n"
"pushl %%esi\n"
"pushl %%edi\n"
/* Remember the flag value. */
"movl %%ebx, (%%ecx)\n"
"int $0x80\n"
"popl %%edi\n"
"popl %%esi\n"
"popl %%ebx\n"
/* if (%eax != 0)
* return;
*/
"test %%eax,%%eax\n"
"jnz 1f\n"
/* terminate the stack frame */
"xorl %%ebp,%%ebp\n"
/* Call FN. */
"call *%%ebx\n"
#ifdef PIC
"call here\n"
"here:\n"
"popl %%ebx\n"
"addl $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n"
#endif
/* Call exit */
"movl %%eax, %%ebx\n"
"movl %2, %%eax\n"
"int $0x80\n"
"1:\n"
: "=a" (res)
: "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
"c"(child_stack),
"d"(parent_tidptr),
"S"(newtls),
"D"(child_tidptr)
: "memory");
return res;
}
#elif defined(__arm__) && SANITIZER_LINUX
uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
int *parent_tidptr, void *newtls, int *child_tidptr) {
unsigned int res;
if (!fn || !child_stack)
return -EINVAL;
child_stack = (char *)child_stack - 2 * sizeof(unsigned int);
((unsigned int *)child_stack)[0] = (uptr)fn;
((unsigned int *)child_stack)[1] = (uptr)arg;
register int r0 __asm__("r0") = flags;
register void *r1 __asm__("r1") = child_stack;
register int *r2 __asm__("r2") = parent_tidptr;
register void *r3 __asm__("r3") = newtls;
register int *r4 __asm__("r4") = child_tidptr;
register int r7 __asm__("r7") = __NR_clone;
#if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__)
# define ARCH_HAS_BX
#endif
#if __ARM_ARCH > 4
# define ARCH_HAS_BLX
#endif
#ifdef ARCH_HAS_BX
# ifdef ARCH_HAS_BLX
# define BLX(R) "blx " #R "\n"
# else
# define BLX(R) "mov lr, pc; bx " #R "\n"
# endif
#else
# define BLX(R) "mov lr, pc; mov pc," #R "\n"
#endif
__asm__ __volatile__(
/* %r0 = syscall(%r7 = SYSCALL(clone),
* %r0 = flags,
* %r1 = child_stack,
* %r2 = parent_tidptr,
* %r3 = new_tls,
* %r4 = child_tidptr)
*/
/* Do the system call */
"swi 0x0\n"
/* if (%r0 != 0)
* return %r0;
*/
"cmp r0, #0\n"
"bne 1f\n"
/* In the child, now. Call "fn(arg)". */
"ldr r0, [sp, #4]\n"
"ldr ip, [sp], #8\n"
BLX(ip)
/* Call _exit(%r0). */
"mov r7, %7\n"
"swi 0x0\n"
"1:\n"
"mov %0, r0\n"
: "=r"(res)
: "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7),
"i"(__NR_exit)
: "memory");
return res;
}
#endif // defined(__x86_64__) && SANITIZER_LINUX
#if SANITIZER_ANDROID
#if __ANDROID_API__ < 21
extern "C" __attribute__((weak)) int dl_iterate_phdr(
int (*)(struct dl_phdr_info *, size_t, void *), void *);
#endif
static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size,
void *data) {
// Any name starting with "lib" indicates a bug in L where library base names
// are returned instead of paths.
if (info->dlpi_name && info->dlpi_name[0] == 'l' &&
info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') {
*(bool *)data = true;
return 1;
}
return 0;
}
static atomic_uint32_t android_api_level;
static AndroidApiLevel AndroidDetectApiLevel() {
if (!&dl_iterate_phdr)
return ANDROID_KITKAT; // K or lower
bool base_name_seen = false;
dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen);
if (base_name_seen)
return ANDROID_LOLLIPOP_MR1; // L MR1
return ANDROID_POST_LOLLIPOP; // post-L
// Plain L (API level 21) is completely broken wrt ASan and not very
// interesting to detect.
}
AndroidApiLevel AndroidGetApiLevel() {
AndroidApiLevel level =
(AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed);
if (level) return level;
level = AndroidDetectApiLevel();
atomic_store(&android_api_level, level, memory_order_relaxed);
return level;
}
#endif
static HandleSignalMode GetHandleSignalModeImpl(int signum) {
switch (signum) {
case SIGABRT:
return common_flags()->handle_abort;
case SIGILL:
return common_flags()->handle_sigill;
case SIGTRAP:
return common_flags()->handle_sigtrap;
case SIGFPE:
return common_flags()->handle_sigfpe;
case SIGSEGV:
return common_flags()->handle_segv;
case SIGBUS:
return common_flags()->handle_sigbus;
}
return kHandleSignalNo;
}
HandleSignalMode GetHandleSignalMode(int signum) {
HandleSignalMode result = GetHandleSignalModeImpl(signum);
if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
return kHandleSignalExclusive;
return result;
}
#if !SANITIZER_GO
void *internal_start_thread(void(*func)(void *arg), void *arg) {
// Start the thread with signals blocked, otherwise it can steal user signals.
__sanitizer_sigset_t set, old;
internal_sigfillset(&set);
#if SANITIZER_LINUX && !SANITIZER_ANDROID
// Glibc uses SIGSETXID signal during setuid call. If this signal is blocked
// on any thread, setuid call hangs (see test/tsan/setuid.c).
internal_sigdelset(&set, 33);
#endif
internal_sigprocmask(SIG_SETMASK, &set, &old);
void *th;
real_pthread_create(&th, nullptr, (void*(*)(void *arg))func, arg);
internal_sigprocmask(SIG_SETMASK, &old, nullptr);
return th;
}
void internal_join_thread(void *th) {
real_pthread_join(th, nullptr);
}
#else
void *internal_start_thread(void (*func)(void *), void *arg) { return 0; }
void internal_join_thread(void *th) {}
#endif
#if defined(__aarch64__)
// Android headers in the older NDK releases miss this definition.
struct __sanitizer_esr_context {
struct _aarch64_ctx head;
uint64_t esr;
};
static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
static const u32 kEsrMagic = 0x45535201;
u8 *aux = ucontext->uc_mcontext.__reserved;
while (true) {
_aarch64_ctx *ctx = (_aarch64_ctx *)aux;
if (ctx->size == 0) break;
if (ctx->magic == kEsrMagic) {
*esr = ((__sanitizer_esr_context *)ctx)->esr;
return true;
}
aux += ctx->size;
}
return false;
}
#endif
#if SANITIZER_OPENBSD
using Context = sigcontext;
#else
using Context = ucontext_t;
#endif
SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
Context *ucontext = (Context *)context;
#if defined(__x86_64__) || defined(__i386__)
static const uptr PF_WRITE = 1U << 1;
#if SANITIZER_FREEBSD
uptr err = ucontext->uc_mcontext.mc_err;
#elif SANITIZER_NETBSD
uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR];
#elif SANITIZER_OPENBSD
uptr err = ucontext->sc_err;
#elif SANITIZER_SOLARIS && defined(__i386__)
const int Err = 13;
uptr err = ucontext->uc_mcontext.gregs[Err];
#else
uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
#endif // SANITIZER_FREEBSD
return err & PF_WRITE ? WRITE : READ;
#elif defined(__mips__)
uint32_t *exception_source;
uint32_t faulty_instruction;
uint32_t op_code;
exception_source = (uint32_t *)ucontext->uc_mcontext.pc;
faulty_instruction = (uint32_t)(*exception_source);
op_code = (faulty_instruction >> 26) & 0x3f;
// FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions.
switch (op_code) {
case 0x28: // sb
case 0x29: // sh
case 0x2b: // sw
case 0x3f: // sd
#if __mips_isa_rev < 6
case 0x2c: // sdl
case 0x2d: // sdr
case 0x2a: // swl
case 0x2e: // swr
#endif
return SignalContext::WRITE;
case 0x20: // lb
case 0x24: // lbu
case 0x21: // lh
case 0x25: // lhu
case 0x23: // lw
case 0x27: // lwu
case 0x37: // ld
#if __mips_isa_rev < 6
case 0x1a: // ldl
case 0x1b: // ldr
case 0x22: // lwl
case 0x26: // lwr
#endif
return SignalContext::READ;
#if __mips_isa_rev == 6
case 0x3b: // pcrel
op_code = (faulty_instruction >> 19) & 0x3;
switch (op_code) {
case 0x1: // lwpc
case 0x2: // lwupc
return SignalContext::READ;
}
#endif
}
return SignalContext::UNKNOWN;
#elif defined(__arm__)
static const uptr FSR_WRITE = 1U << 11;
uptr fsr = ucontext->uc_mcontext.error_code;
return fsr & FSR_WRITE ? WRITE : READ;
#elif defined(__aarch64__)
static const u64 ESR_ELx_WNR = 1U << 6;
u64 esr;
if (!Aarch64GetESR(ucontext, &esr)) return UNKNOWN;
return esr & ESR_ELx_WNR ? WRITE : READ;
#elif SANITIZER_SOLARIS && defined(__sparc__)
// Decode the instruction to determine the access type.
// From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
uptr pc = ucontext->uc_mcontext.gregs[REG_PC];
u32 instr = *(u32 *)pc;
return (instr >> 21) & 1 ? WRITE: READ;
#else
(void)ucontext;
return UNKNOWN; // FIXME: Implement.
#endif
}
void SignalContext::DumpAllRegisters(void *context) {
// FIXME: Implement this.
}
static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
#if SANITIZER_NETBSD
// This covers all NetBSD architectures
ucontext_t *ucontext = (ucontext_t *)context;
*pc = _UC_MACHINE_PC(ucontext);
*bp = _UC_MACHINE_FP(ucontext);
*sp = _UC_MACHINE_SP(ucontext);
#elif defined(__arm__)
ucontext_t *ucontext = (ucontext_t*)context;
*pc = ucontext->uc_mcontext.arm_pc;
*bp = ucontext->uc_mcontext.arm_fp;
*sp = ucontext->uc_mcontext.arm_sp;
#elif defined(__aarch64__)
ucontext_t *ucontext = (ucontext_t*)context;
*pc = ucontext->uc_mcontext.pc;
*bp = ucontext->uc_mcontext.regs[29];
*sp = ucontext->uc_mcontext.sp;
#elif defined(__hppa__)
ucontext_t *ucontext = (ucontext_t*)context;
*pc = ucontext->uc_mcontext.sc_iaoq[0];
/* GCC uses %r3 whenever a frame pointer is needed. */
*bp = ucontext->uc_mcontext.sc_gr[3];
*sp = ucontext->uc_mcontext.sc_gr[30];
#elif defined(__x86_64__)
# if SANITIZER_FREEBSD
ucontext_t *ucontext = (ucontext_t*)context;
*pc = ucontext->uc_mcontext.mc_rip;
*bp = ucontext->uc_mcontext.mc_rbp;
*sp = ucontext->uc_mcontext.mc_rsp;
#elif SANITIZER_OPENBSD
sigcontext *ucontext = (sigcontext *)context;
*pc = ucontext->sc_rip;
*bp = ucontext->sc_rbp;
*sp = ucontext->sc_rsp;
# else
ucontext_t *ucontext = (ucontext_t*)context;
*pc = ucontext->uc_mcontext.gregs[REG_RIP];
*bp = ucontext->uc_mcontext.gregs[REG_RBP];
*sp = ucontext->uc_mcontext.gregs[REG_RSP];
# endif
#elif defined(__i386__)
# if SANITIZER_FREEBSD
ucontext_t *ucontext = (ucontext_t*)context;
*pc = ucontext->uc_mcontext.mc_eip;
*bp = ucontext->uc_mcontext.mc_ebp;
*sp = ucontext->uc_mcontext.mc_esp;
#elif SANITIZER_OPENBSD
sigcontext *ucontext = (sigcontext *)context;
*pc = ucontext->sc_eip;
*bp = ucontext->sc_ebp;
*sp = ucontext->sc_esp;
# else
ucontext_t *ucontext = (ucontext_t*)context;
# if SANITIZER_SOLARIS
/* Use the numeric values: the symbolic ones are undefined by llvm
include/llvm/Support/Solaris.h. */
# ifndef REG_EIP
# define REG_EIP 14 // REG_PC
# endif
# ifndef REG_EBP
# define REG_EBP 6 // REG_FP
# endif
# ifndef REG_ESP
# define REG_ESP 17 // REG_SP
# endif
# endif
*pc = ucontext->uc_mcontext.gregs[REG_EIP];
*bp = ucontext->uc_mcontext.gregs[REG_EBP];
*sp = ucontext->uc_mcontext.gregs[REG_ESP];
# endif
#elif defined(__powerpc__) || defined(__powerpc64__)
ucontext_t *ucontext = (ucontext_t*)context;
*pc = ucontext->uc_mcontext.regs->nip;
*sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
// The powerpc{,64}-linux ABIs do not specify r31 as the frame
// pointer, but GCC always uses r31 when we need a frame pointer.
*bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
#elif defined(__sparc__)
ucontext_t *ucontext = (ucontext_t*)context;
uptr *stk_ptr;
# if defined (__sparcv9)
# ifndef MC_PC
# define MC_PC REG_PC
# endif
# ifndef MC_O6
# define MC_O6 REG_O6
# endif
# ifdef SANITIZER_SOLARIS
# define mc_gregs gregs
# endif
*pc = ucontext->uc_mcontext.mc_gregs[MC_PC];
*sp = ucontext->uc_mcontext.mc_gregs[MC_O6];
stk_ptr = (uptr *) (*sp + 2047);
*bp = stk_ptr[15];
# else
*pc = ucontext->uc_mcontext.gregs[REG_PC];
*sp = ucontext->uc_mcontext.gregs[REG_O6];
stk_ptr = (uptr *) *sp;
*bp = stk_ptr[15];
# endif
#elif defined(__mips__)
ucontext_t *ucontext = (ucontext_t*)context;
*pc = ucontext->uc_mcontext.pc;
*bp = ucontext->uc_mcontext.gregs[30];
*sp = ucontext->uc_mcontext.gregs[29];
#elif defined(__s390__)
ucontext_t *ucontext = (ucontext_t*)context;
# if defined(__s390x__)
*pc = ucontext->uc_mcontext.psw.addr;
# else
*pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
# endif
*bp = ucontext->uc_mcontext.gregs[11];
*sp = ucontext->uc_mcontext.gregs[15];
#else
# error "Unsupported arch"
#endif
}
void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
void MaybeReexec() {
// No need to re-exec on Linux.
}
void CheckASLR() {
#if SANITIZER_NETBSD
int mib[3];
int paxflags;
size_t len = sizeof(paxflags);
mib[0] = CTL_PROC;
mib[1] = internal_getpid();
mib[2] = PROC_PID_PAXFLAGS;
if (UNLIKELY(sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
Printf("sysctl failed\n");
Die();
}
if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) {
Printf("This sanitizer is not compatible with enabled ASLR\n");
Die();
}
#else
// Do nothing
#endif
}
void PrintModuleMap() { }
void CheckNoDeepBind(const char *filename, int flag) {
#ifdef RTLD_DEEPBIND
if (flag & RTLD_DEEPBIND) {
Report(
"You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag"
" which is incompatibe with sanitizer runtime "
"(see https://github.com/google/sanitizers/issues/611 for details"
"). If you want to run %s library under sanitizers please remove "
"RTLD_DEEPBIND from dlopen flags.\n",
filename, filename);
Die();
}
#endif
}
uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
uptr *largest_gap_found,
uptr *max_occupied_addr) {
UNREACHABLE("FindAvailableMemoryRange is not available");
return 0;
}
bool GetRandom(void *buffer, uptr length, bool blocking) {
if (!buffer || !length || length > 256)
return false;
#if SANITIZER_USE_GETENTROPY
uptr rnd = getentropy(buffer, length);
int rverrno = 0;
if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT)
return false;
else if (rnd == 0)
return true;
#endif // SANITIZER_USE_GETENTROPY
#if SANITIZER_USE_GETRANDOM
static atomic_uint8_t skip_getrandom_syscall;
if (!atomic_load_relaxed(&skip_getrandom_syscall)) {
// Up to 256 bytes, getrandom will not be interrupted.
uptr res = internal_syscall(SYSCALL(getrandom), buffer, length,
blocking ? 0 : GRND_NONBLOCK);
int rverrno = 0;
if (internal_iserror(res, &rverrno) && rverrno == ENOSYS)
atomic_store_relaxed(&skip_getrandom_syscall, 1);
else if (res == length)
return true;
}
#endif // SANITIZER_USE_GETRANDOM
// Up to 256 bytes, a read off /dev/urandom will not be interrupted.
// blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
uptr fd = internal_open("/dev/urandom", O_RDONLY);
if (internal_iserror(fd))
return false;
uptr res = internal_read(fd, buffer, length);
if (internal_iserror(res))
return false;
internal_close(fd);
return true;
}
} // namespace __sanitizer
#endif