1	//===-- sanitizer_linux.cpp -----------------------------------------------===//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	// This file is shared between AddressSanitizer and ThreadSanitizer
10	// run-time libraries and implements linux-specific functions from
11	// sanitizer_libc.h.
12	//===----------------------------------------------------------------------===//
13
14	#include "sanitizer_platform.h"
15
16	#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
17	SANITIZER_SOLARIS
18
19	# include "sanitizer_common.h"
20	# include "sanitizer_flags.h"
21	# include "sanitizer_getauxval.h"
22	# include "sanitizer_internal_defs.h"
23	# include "sanitizer_libc.h"
24	# include "sanitizer_linux.h"
25	# include "sanitizer_mutex.h"
26	# include "sanitizer_placement_new.h"
27	# include "sanitizer_procmaps.h"
28
29	# if SANITIZER_LINUX && !SANITIZER_GO
30	# include <asm/param.h>
31	# endif
32
33	// For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat'
34	// format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
35	// access stat from asm/stat.h, without conflicting with definition in
36	// sys/stat.h, we use this trick.
37	# if SANITIZER_MIPS64
38	# include <asm/unistd.h>
39	# include <sys/types.h>
40	# define stat kernel_stat
41	# if SANITIZER_GO
42	# undef st_atime
43	# undef st_mtime
44	# undef st_ctime
45	# define st_atime st_atim
46	# define st_mtime st_mtim
47	# define st_ctime st_ctim
48	# endif
49	# include <asm/stat.h>
50	# undef stat
51	# endif
52
53	# include <dlfcn.h>
54	# include <errno.h>
55	# include <fcntl.h>
56	# include <link.h>
57	# include <pthread.h>
58	# include <sched.h>
59	# include <signal.h>
60	# include <sys/mman.h>
61	# if !SANITIZER_SOLARIS
62	# include <sys/ptrace.h>
63	# endif
64	# include <sys/resource.h>
65	# include <sys/stat.h>
66	# include <sys/syscall.h>
67	# include <sys/time.h>
68	# include <sys/types.h>
69	# include <ucontext.h>
70	# include <unistd.h>
71
72	# if SANITIZER_LINUX
73	# include <sys/utsname.h>
74	# endif
75
76	# if SANITIZER_LINUX && !SANITIZER_ANDROID
77	# include <sys/personality.h>
78	# endif
79
80	# if SANITIZER_LINUX && defined(__loongarch__)
81	# include <sys/sysmacros.h>
82	# endif
83
84	# if SANITIZER_FREEBSD
85	# include <machine/atomic.h>
86	# include <sys/exec.h>
87	# include <sys/procctl.h>
88	# include <sys/sysctl.h>
89	extern "C" {
90	// <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
91	// FreeBSD 9.2 and 10.0.
92	# include <sys/umtx.h>
93	}
94	# include <sys/thr.h>
95	# endif // SANITIZER_FREEBSD
96
97	# if SANITIZER_NETBSD
98	# include <limits.h> // For NAME_MAX
99	# include <sys/exec.h>
100	# include <sys/sysctl.h>
101	extern struct ps_strings *__ps_strings;
102	# endif // SANITIZER_NETBSD
103
104	# if SANITIZER_SOLARIS
105	# include <stdlib.h>
106	# include <thread.h>
107	# define environ _environ
108	# endif
109
110	extern char **environ;
111
112	# if SANITIZER_LINUX
113	// <linux/time.h>
114	struct kernel_timeval {
115	long tv_sec;
116	long tv_usec;
117	};
118
119	// <linux/futex.h> is broken on some linux distributions.
120	const int FUTEX_WAIT = 0;
121	const int FUTEX_WAKE = 1;
122	const int FUTEX_PRIVATE_FLAG = 128;
123	const int FUTEX_WAIT_PRIVATE = FUTEX_WAIT | FUTEX_PRIVATE_FLAG;
124	const int FUTEX_WAKE_PRIVATE = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
125	# endif // SANITIZER_LINUX
126
127	// Are we using 32-bit or 64-bit Linux syscalls?
128	// x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
129	// but it still needs to use 64-bit syscalls.
130	# if SANITIZER_LINUX && (defined(__x86_64__) || defined(__powerpc64__) || \
131	SANITIZER_WORDSIZE == 64 || \
132	(defined(__mips__) && _MIPS_SIM == _ABIN32))
133	# define SANITIZER_LINUX_USES_64BIT_SYSCALLS 1
134	# else
135	# define SANITIZER_LINUX_USES_64BIT_SYSCALLS 0
136	# endif
137
138	// Note : FreeBSD implemented both Linux and OpenBSD apis.
139	# if SANITIZER_LINUX && defined(__NR_getrandom)
140	# if !defined(GRND_NONBLOCK)
141	# define GRND_NONBLOCK 1
142	# endif
143	# define SANITIZER_USE_GETRANDOM 1
144	# else
145	# define SANITIZER_USE_GETRANDOM 0
146	# endif // SANITIZER_LINUX && defined(__NR_getrandom)
147
148	# if SANITIZER_FREEBSD
149	# define SANITIZER_USE_GETENTROPY 1
150	# endif
151
152	namespace __sanitizer {
153
154	void SetSigProcMask(__sanitizer_sigset_t *set, __sanitizer_sigset_t *oldset) {
155	CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, set, oldset));
156	}
157
158	void BlockSignals(__sanitizer_sigset_t *oldset) {
159	__sanitizer_sigset_t set;
160	internal_sigfillset(set: &set);
161	# if SANITIZER_LINUX && !SANITIZER_ANDROID
162	// Glibc uses SIGSETXID signal during setuid call. If this signal is blocked
163	// on any thread, setuid call hangs.
164	// See test/sanitizer_common/TestCases/Linux/setuid.c.
165	internal_sigdelset(set: &set, signum: 33);
166	# endif
167	# if SANITIZER_LINUX
168	// Seccomp-BPF-sandboxed processes rely on SIGSYS to handle trapped syscalls.
169	// If this signal is blocked, such calls cannot be handled and the process may
170	// hang.
171	internal_sigdelset(set: &set, signum: 31);
172	# endif
173	SetSigProcMask(set: &set, oldset);
174	}
175
176	ScopedBlockSignals::ScopedBlockSignals(__sanitizer_sigset_t *copy) {
177	BlockSignals(oldset: &saved_);
178	if (copy)
179	internal_memcpy(dest: copy, src: &saved_, n: sizeof(saved_));
180	}
181
182	ScopedBlockSignals::~ScopedBlockSignals() { SetSigProcMask(set: &saved_, oldset: nullptr); }
183
184	# if SANITIZER_LINUX && defined(__x86_64__)
185	# include "sanitizer_syscall_linux_x86_64.inc"
186	# elif SANITIZER_LINUX && SANITIZER_RISCV64
187	# include "sanitizer_syscall_linux_riscv64.inc"
188	# elif SANITIZER_LINUX && defined(__aarch64__)
189	# include "sanitizer_syscall_linux_aarch64.inc"
190	# elif SANITIZER_LINUX && defined(__arm__)
191	# include "sanitizer_syscall_linux_arm.inc"
192	# elif SANITIZER_LINUX && defined(__hexagon__)
193	# include "sanitizer_syscall_linux_hexagon.inc"
194	# elif SANITIZER_LINUX && SANITIZER_LOONGARCH64
195	# include "sanitizer_syscall_linux_loongarch64.inc"
196	# else
197	# include "sanitizer_syscall_generic.inc"
198	# endif
199
200	// --------------- sanitizer_libc.h
201	# if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
202	# if !SANITIZER_S390
203	uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
204	u64 offset) {
205	# if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
206	return internal_syscall(SYSCALL(mmap), arg1: (uptr)addr, arg2: length, arg3: prot, arg4: flags, arg5: fd,
207	arg6: offset);
208	# else
209	// mmap2 specifies file offset in 4096-byte units.
210	CHECK(IsAligned(offset, 4096));
211	return internal_syscall(SYSCALL(mmap2), addr, length, prot, flags, fd,
212	offset / 4096);
213	# endif
214	}
215	# endif // !SANITIZER_S390
216
217	uptr internal_munmap(void *addr, uptr length) {
218	return internal_syscall(SYSCALL(munmap), arg1: (uptr)addr, arg2: length);
219	}
220
221	# if SANITIZER_LINUX
222	uptr internal_mremap(void *old_address, uptr old_size, uptr new_size, int flags,
223	void *new_address) {
224	return internal_syscall(SYSCALL(mremap), arg1: (uptr)old_address, arg2: old_size,
225	arg3: new_size, arg4: flags, arg5: (uptr)new_address);
226	}
227	# endif
228
229	int internal_mprotect(void *addr, uptr length, int prot) {
230	return internal_syscall(SYSCALL(mprotect), arg1: (uptr)addr, arg2: length, arg3: prot);
231	}
232
233	int internal_madvise(uptr addr, uptr length, int advice) {
234	return internal_syscall(SYSCALL(madvise), arg1: addr, arg2: length, arg3: advice);
235	}
236
237	uptr internal_close(fd_t fd) { return internal_syscall(SYSCALL(close), arg1: fd); }
238
239	uptr internal_open(const char *filename, int flags) {
240	# if SANITIZER_LINUX
241	return internal_syscall(SYSCALL(openat), AT_FDCWD, arg2: (uptr)filename, arg3: flags);
242	# else
243	return internal_syscall(SYSCALL(open), (uptr)filename, flags);
244	# endif
245	}
246
247	uptr internal_open(const char *filename, int flags, u32 mode) {
248	# if SANITIZER_LINUX
249	return internal_syscall(SYSCALL(openat), AT_FDCWD, arg2: (uptr)filename, arg3: flags,
250	arg4: mode);
251	# else
252	return internal_syscall(SYSCALL(open), (uptr)filename, flags, mode);
253	# endif
254	}
255
256	uptr internal_read(fd_t fd, void *buf, uptr count) {
257	sptr res;
258	HANDLE_EINTR(res,
259	(sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf, count));
260	return res;
261	}
262
263	uptr internal_write(fd_t fd, const void *buf, uptr count) {
264	sptr res;
265	HANDLE_EINTR(res,
266	(sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf, count));
267	return res;
268	}
269
270	uptr internal_ftruncate(fd_t fd, uptr size) {
271	sptr res;
272	HANDLE_EINTR(res,
273	(sptr)internal_syscall(SYSCALL(ftruncate), fd, (OFF_T)size));
274	return res;
275	}
276
277	# if (!SANITIZER_LINUX_USES_64BIT_SYSCALLS || SANITIZER_SPARC) && \
278	SANITIZER_LINUX
279	static void stat64_to_stat(struct stat64 *in, struct stat *out) {
280	internal_memset(out, 0, sizeof(*out));
281	out->st_dev = in->st_dev;
282	out->st_ino = in->st_ino;
283	out->st_mode = in->st_mode;
284	out->st_nlink = in->st_nlink;
285	out->st_uid = in->st_uid;
286	out->st_gid = in->st_gid;
287	out->st_rdev = in->st_rdev;
288	out->st_size = in->st_size;
289	out->st_blksize = in->st_blksize;
290	out->st_blocks = in->st_blocks;
291	out->st_atime = in->st_atime;
292	out->st_mtime = in->st_mtime;
293	out->st_ctime = in->st_ctime;
294	}
295	# endif
296
297	# if SANITIZER_LINUX && defined(__loongarch__)
298	static void statx_to_stat(struct statx *in, struct stat *out) {
299	internal_memset(out, 0, sizeof(*out));
300	out->st_dev = makedev(in->stx_dev_major, in->stx_dev_minor);
301	out->st_ino = in->stx_ino;
302	out->st_mode = in->stx_mode;
303	out->st_nlink = in->stx_nlink;
304	out->st_uid = in->stx_uid;
305	out->st_gid = in->stx_gid;
306	out->st_rdev = makedev(in->stx_rdev_major, in->stx_rdev_minor);
307	out->st_size = in->stx_size;
308	out->st_blksize = in->stx_blksize;
309	out->st_blocks = in->stx_blocks;
310	out->st_atime = in->stx_atime.tv_sec;
311	out->st_atim.tv_nsec = in->stx_atime.tv_nsec;
312	out->st_mtime = in->stx_mtime.tv_sec;
313	out->st_mtim.tv_nsec = in->stx_mtime.tv_nsec;
314	out->st_ctime = in->stx_ctime.tv_sec;
315	out->st_ctim.tv_nsec = in->stx_ctime.tv_nsec;
316	}
317	# endif
318
319	# if SANITIZER_MIPS64
320	// Undefine compatibility macros from <sys/stat.h>
321	// so that they would not clash with the kernel_stat
322	// st_[a|m|c]time fields
323	# if !SANITIZER_GO
324	# undef st_atime
325	# undef st_mtime
326	# undef st_ctime
327	# endif
328	# if defined(SANITIZER_ANDROID)
329	// Bionic sys/stat.h defines additional macros
330	// for compatibility with the old NDKs and
331	// they clash with the kernel_stat structure
332	// st_[a|m|c]time_nsec fields.
333	# undef st_atime_nsec
334	# undef st_mtime_nsec
335	# undef st_ctime_nsec
336	# endif
337	static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
338	internal_memset(out, 0, sizeof(*out));
339	out->st_dev = in->st_dev;
340	out->st_ino = in->st_ino;
341	out->st_mode = in->st_mode;
342	out->st_nlink = in->st_nlink;
343	out->st_uid = in->st_uid;
344	out->st_gid = in->st_gid;
345	out->st_rdev = in->st_rdev;
346	out->st_size = in->st_size;
347	out->st_blksize = in->st_blksize;
348	out->st_blocks = in->st_blocks;
349	# if defined(__USE_MISC) || defined(__USE_XOPEN2K8) || \
350	defined(SANITIZER_ANDROID)
351	out->st_atim.tv_sec = in->st_atime;
352	out->st_atim.tv_nsec = in->st_atime_nsec;
353	out->st_mtim.tv_sec = in->st_mtime;
354	out->st_mtim.tv_nsec = in->st_mtime_nsec;
355	out->st_ctim.tv_sec = in->st_ctime;
356	out->st_ctim.tv_nsec = in->st_ctime_nsec;
357	# else
358	out->st_atime = in->st_atime;
359	out->st_atimensec = in->st_atime_nsec;
360	out->st_mtime = in->st_mtime;
361	out->st_mtimensec = in->st_mtime_nsec;
362	out->st_ctime = in->st_ctime;
363	out->st_atimensec = in->st_ctime_nsec;
364	# endif
365	}
366	# endif
367
368	uptr internal_stat(const char *path, void *buf) {
369	# if SANITIZER_FREEBSD
370	return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf, 0);
371	# elif SANITIZER_LINUX
372	# if defined(__loongarch__)
373	struct statx bufx;
374	int res = internal_syscall(SYSCALL(statx), AT_FDCWD, (uptr)path,
375	AT_NO_AUTOMOUNT, STATX_BASIC_STATS, (uptr)&bufx);
376	statx_to_stat(&bufx, (struct stat *)buf);
377	return res;
378	# elif (SANITIZER_WORDSIZE == 64 || SANITIZER_X32 || \
379	(defined(__mips__) && _MIPS_SIM == _ABIN32)) && \
380	!SANITIZER_SPARC
381	return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, arg2: (uptr)path, arg3: (uptr)buf,
382	arg4: 0);
383	# else
384	struct stat64 buf64;
385	int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
386	(uptr)&buf64, 0);
387	stat64_to_stat(&buf64, (struct stat *)buf);
388	return res;
389	# endif
390	# else
391	struct stat64 buf64;
392	int res = internal_syscall(SYSCALL(stat64), path, &buf64);
393	stat64_to_stat(&buf64, (struct stat *)buf);
394	return res;
395	# endif
396	}
397
398	uptr internal_lstat(const char *path, void *buf) {
399	# if SANITIZER_FREEBSD
400	return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path, (uptr)buf,
401	AT_SYMLINK_NOFOLLOW);
402	# elif SANITIZER_LINUX
403	# if defined(__loongarch__)
404	struct statx bufx;
405	int res = internal_syscall(SYSCALL(statx), AT_FDCWD, (uptr)path,
406	AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT,
407	STATX_BASIC_STATS, (uptr)&bufx);
408	statx_to_stat(&bufx, (struct stat *)buf);
409	return res;
410	# elif (defined(_LP64) || SANITIZER_X32 || \
411	(defined(__mips__) && _MIPS_SIM == _ABIN32)) && \
412	!SANITIZER_SPARC
413	return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, arg2: (uptr)path, arg3: (uptr)buf,
414	AT_SYMLINK_NOFOLLOW);
415	# else
416	struct stat64 buf64;
417	int res = internal_syscall(SYSCALL(fstatat64), AT_FDCWD, (uptr)path,
418	(uptr)&buf64, AT_SYMLINK_NOFOLLOW);
419	stat64_to_stat(&buf64, (struct stat *)buf);
420	return res;
421	# endif
422	# else
423	struct stat64 buf64;
424	int res = internal_syscall(SYSCALL(lstat64), path, &buf64);
425	stat64_to_stat(&buf64, (struct stat *)buf);
426	return res;
427	# endif
428	}
429
430	uptr internal_fstat(fd_t fd, void *buf) {
431	# if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
432	# if SANITIZER_MIPS64
433	// For mips64, fstat syscall fills buffer in the format of kernel_stat
434	struct kernel_stat kbuf;
435	int res = internal_syscall(SYSCALL(fstat), fd, &kbuf);
436	kernel_stat_to_stat(&kbuf, (struct stat *)buf);
437	return res;
438	# elif SANITIZER_LINUX && defined(__loongarch__)
439	struct statx bufx;
440	int res = internal_syscall(SYSCALL(statx), fd, "", AT_EMPTY_PATH,
441	STATX_BASIC_STATS, (uptr)&bufx);
442	statx_to_stat(&bufx, (struct stat *)buf);
443	return res;
444	# else
445	return internal_syscall(SYSCALL(fstat), arg1: fd, arg2: (uptr)buf);
446	# endif
447	# else
448	struct stat64 buf64;
449	int res = internal_syscall(SYSCALL(fstat64), fd, &buf64);
450	stat64_to_stat(&buf64, (struct stat *)buf);
451	return res;
452	# endif
453	}
454
455	uptr internal_filesize(fd_t fd) {
456	struct stat st;
457	if (internal_fstat(fd, buf: &st))
458	return -1;
459	return (uptr)st.st_size;
460	}
461
462	uptr internal_dup(int oldfd) { return internal_syscall(SYSCALL(dup), arg1: oldfd); }
463
464	uptr internal_dup2(int oldfd, int newfd) {
465	# if SANITIZER_LINUX
466	return internal_syscall(SYSCALL(dup3), arg1: oldfd, arg2: newfd, arg3: 0);
467	# else
468	return internal_syscall(SYSCALL(dup2), oldfd, newfd);
469	# endif
470	}
471
472	uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
473	# if SANITIZER_LINUX
474	return internal_syscall(SYSCALL(readlinkat), AT_FDCWD, arg2: (uptr)path, arg3: (uptr)buf,
475	arg4: bufsize);
476	# else
477	return internal_syscall(SYSCALL(readlink), (uptr)path, (uptr)buf, bufsize);
478	# endif
479	}
480
481	uptr internal_unlink(const char *path) {
482	# if SANITIZER_LINUX
483	return internal_syscall(SYSCALL(unlinkat), AT_FDCWD, arg2: (uptr)path, arg3: 0);
484	# else
485	return internal_syscall(SYSCALL(unlink), (uptr)path);
486	# endif
487	}
488
489	uptr internal_rename(const char *oldpath, const char *newpath) {
490	# if (defined(__riscv) || defined(__loongarch__)) && defined(__linux__)
491	return internal_syscall(SYSCALL(renameat2), AT_FDCWD, (uptr)oldpath, AT_FDCWD,
492	(uptr)newpath, 0);
493	# elif SANITIZER_LINUX
494	return internal_syscall(SYSCALL(renameat), AT_FDCWD, arg2: (uptr)oldpath, AT_FDCWD,
495	arg4: (uptr)newpath);
496	# else
497	return internal_syscall(SYSCALL(rename), (uptr)oldpath, (uptr)newpath);
498	# endif
499	}
500
501	uptr internal_sched_yield() { return internal_syscall(SYSCALL(sched_yield)); }
502
503	void internal_usleep(u64 useconds) {
504	struct timespec ts;
505	ts.tv_sec = useconds / 1000000;
506	ts.tv_nsec = (useconds % 1000000) * 1000;
507	internal_syscall(SYSCALL(nanosleep), arg1: &ts, arg2: &ts);
508	}
509
510	uptr internal_execve(const char *filename, char *const argv[],
511	char *const envp[]) {
512	return internal_syscall(SYSCALL(execve), arg1: (uptr)filename, arg2: (uptr)argv,
513	arg3: (uptr)envp);
514	}
515	# endif // !SANITIZER_SOLARIS && !SANITIZER_NETBSD
516
517	# if !SANITIZER_NETBSD
518	void internal__exit(int exitcode) {
519	# if SANITIZER_FREEBSD || SANITIZER_SOLARIS
520	internal_syscall(SYSCALL(exit), exitcode);
521	# else
522	internal_syscall(SYSCALL(exit_group), arg1: exitcode);
523	# endif
524	Die(); // Unreachable.
525	}
526	# endif // !SANITIZER_NETBSD
527
528	// ----------------- sanitizer_common.h
529	bool FileExists(const char *filename) {
530	if (ShouldMockFailureToOpen(path: filename))
531	return false;
532	struct stat st;
533	if (internal_stat(path: filename, buf: &st))
534	return false;
535	// Sanity check: filename is a regular file.
536	return S_ISREG(st.st_mode);
537	}
538
539	bool DirExists(const char *path) {
540	struct stat st;
541	if (internal_stat(path, buf: &st))
542	return false;
543	return S_ISDIR(st.st_mode);
544	}
545
546	# if !SANITIZER_NETBSD
547	tid_t GetTid() {
548	# if SANITIZER_FREEBSD
549	long Tid;
550	thr_self(&Tid);
551	return Tid;
552	# elif SANITIZER_SOLARIS
553	return thr_self();
554	# else
555	return internal_syscall(SYSCALL(gettid));
556	# endif
557	}
558
559	int TgKill(pid_t pid, tid_t tid, int sig) {
560	# if SANITIZER_LINUX
561	return internal_syscall(SYSCALL(tgkill), arg1: pid, arg2: tid, arg3: sig);
562	# elif SANITIZER_FREEBSD
563	return internal_syscall(SYSCALL(thr_kill2), pid, tid, sig);
564	# elif SANITIZER_SOLARIS
565	(void)pid;
566	return thr_kill(tid, sig);
567	# endif
568	}
569	# endif
570
571	# if SANITIZER_GLIBC
572	u64 NanoTime() {
573	kernel_timeval tv;
574	internal_memset(s: &tv, c: 0, n: sizeof(tv));
575	internal_syscall(SYSCALL(gettimeofday), arg1: &tv, arg2: 0);
576	return (u64)tv.tv_sec * 1000 * 1000 * 1000 + tv.tv_usec * 1000;
577	}
578	// Used by real_clock_gettime.
579	uptr internal_clock_gettime(__sanitizer_clockid_t clk_id, void *tp) {
580	return internal_syscall(SYSCALL(clock_gettime), arg1: clk_id, arg2: tp);
581	}
582	# elif !SANITIZER_SOLARIS && !SANITIZER_NETBSD
583	u64 NanoTime() {
584	struct timespec ts;
585	clock_gettime(CLOCK_REALTIME, &ts);
586	return (u64)ts.tv_sec * 1000 * 1000 * 1000 + ts.tv_nsec;
587	}
588	# endif
589
590	// Like getenv, but reads env directly from /proc (on Linux) or parses the
591	// 'environ' array (on some others) and does not use libc. This function
592	// should be called first inside __asan_init.
593	const char *GetEnv(const char *name) {
594	# if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_SOLARIS
595	if (::environ != 0) {
596	uptr NameLen = internal_strlen(name);
597	for (char **Env = ::environ; *Env != 0; Env++) {
598	if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
599	return (*Env) + NameLen + 1;
600	}
601	}
602	return 0; // Not found.
603	# elif SANITIZER_LINUX
604	static char *environ;
605	static uptr len;
606	static bool inited;
607	if (!inited) {
608	inited = true;
609	uptr environ_size;
610	if (!ReadFileToBuffer(file_name: "/proc/self/environ", buff: &environ, buff_size: &environ_size, read_len: &len))
611	environ = nullptr;
612	}
613	if (!environ || len == 0)
614	return nullptr;
615	uptr namelen = internal_strlen(s: name);
616	const char *p = environ;
617	while (*p != '\0') { // will happen at the \0\0 that terminates the buffer
618	// proc file has the format NAME=value\0NAME=value\0NAME=value\0...
619	const char *endp = (char *)internal_memchr(s: p, c: '\0', n: len - (p - environ));
620	if (!endp) // this entry isn't NUL terminated
621	return nullptr;
622	else if (!internal_memcmp(s1: p, s2: name, n: namelen) && p[namelen] == '=') // Match.
623	return p + namelen + 1; // point after =
624	p = endp + 1;
625	}
626	return nullptr; // Not found.
627	# else
628	# error "Unsupported platform"
629	# endif
630	}
631
632	# if !SANITIZER_FREEBSD && !SANITIZER_NETBSD && !SANITIZER_GO
633	extern "C" {
634	SANITIZER_WEAK_ATTRIBUTE extern void *__libc_stack_end;
635	}
636	# endif
637
638	# if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
639	static void ReadNullSepFileToArray(const char *path, char ***arr,
640	int arr_size) {
641	char *buff;
642	uptr buff_size;
643	uptr buff_len;
644	*arr = (char **)MmapOrDie(size: arr_size * sizeof(char *), mem_type: "NullSepFileArray");
645	if (!ReadFileToBuffer(file_name: path, buff: &buff, buff_size: &buff_size, read_len: &buff_len, max_len: 1024 * 1024)) {
646	(*arr)[0] = nullptr;
647	return;
648	}
649	(*arr)[0] = buff;
650	int count, i;
651	for (count = 1, i = 1;; i++) {
652	if (buff[i] == 0) {
653	if (buff[i + 1] == 0)
654	break;
655	(*arr)[count] = &buff[i + 1];
656	CHECK_LE(count, arr_size - 1); // FIXME: make this more flexible.
657	count++;
658	}
659	}
660	(*arr)[count] = nullptr;
661	}
662	# endif
663
664	static void GetArgsAndEnv(char ***argv, char ***envp) {
665	# if SANITIZER_FREEBSD
666	// On FreeBSD, retrieving the argument and environment arrays is done via the
667	// kern.ps_strings sysctl, which returns a pointer to a structure containing
668	// this information. See also <sys/exec.h>.
669	ps_strings *pss;
670	uptr sz = sizeof(pss);
671	if (internal_sysctlbyname("kern.ps_strings", &pss, &sz, NULL, 0) == -1) {
672	Printf("sysctl kern.ps_strings failed\n");
673	Die();
674	}
675	*argv = pss->ps_argvstr;
676	*envp = pss->ps_envstr;
677	# elif SANITIZER_NETBSD
678	*argv = __ps_strings->ps_argvstr;
679	*envp = __ps_strings->ps_envstr;
680	# else // SANITIZER_FREEBSD
681	# if !SANITIZER_GO
682	if (&__libc_stack_end) {
683	uptr *stack_end = (uptr *)__libc_stack_end;
684	// Normally argc can be obtained from *stack_end, however, on ARM glibc's
685	// _start clobbers it:
686	// https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/arm/start.S;hb=refs/heads/release/2.31/master#l75
687	// Do not special-case ARM and infer argc from argv everywhere.
688	int argc = 0;
689	while (stack_end[argc + 1]) argc++;
690	*argv = (char **)(stack_end + 1);
691	*envp = (char **)(stack_end + argc + 2);
692	} else {
693	# endif // !SANITIZER_GO
694	static const int kMaxArgv = 2000, kMaxEnvp = 2000;
695	ReadNullSepFileToArray(path: "/proc/self/cmdline", arr: argv, arr_size: kMaxArgv);
696	ReadNullSepFileToArray(path: "/proc/self/environ", arr: envp, arr_size: kMaxEnvp);
697	# if !SANITIZER_GO
698	}
699	# endif // !SANITIZER_GO
700	# endif // SANITIZER_FREEBSD
701	}
702
703	char **GetArgv() {
704	char **argv, **envp;
705	GetArgsAndEnv(argv: &argv, envp: &envp);
706	return argv;
707	}
708
709	char **GetEnviron() {
710	char **argv, **envp;
711	GetArgsAndEnv(argv: &argv, envp: &envp);
712	return envp;
713	}
714
715	# if !SANITIZER_SOLARIS
716	void FutexWait(atomic_uint32_t *p, u32 cmp) {
717	# if SANITIZER_FREEBSD
718	_umtx_op(p, UMTX_OP_WAIT_UINT, cmp, 0, 0);
719	# elif SANITIZER_NETBSD
720	sched_yield(); /* No userspace futex-like synchronization */
721	# else
722	internal_syscall(SYSCALL(futex), arg1: (uptr)p, arg2: FUTEX_WAIT_PRIVATE, arg3: cmp, arg4: 0, arg5: 0, arg6: 0);
723	# endif
724	}
725
726	void FutexWake(atomic_uint32_t *p, u32 count) {
727	# if SANITIZER_FREEBSD
728	_umtx_op(p, UMTX_OP_WAKE, count, 0, 0);
729	# elif SANITIZER_NETBSD
730	/* No userspace futex-like synchronization */
731	# else
732	internal_syscall(SYSCALL(futex), arg1: (uptr)p, arg2: FUTEX_WAKE_PRIVATE, arg3: count, arg4: 0, arg5: 0, arg6: 0);
733	# endif
734	}
735
736	# endif // !SANITIZER_SOLARIS
737
738	// ----------------- sanitizer_linux.h
739	// The actual size of this structure is specified by d_reclen.
740	// Note that getdents64 uses a different structure format. We only provide the
741	// 32-bit syscall here.
742	# if SANITIZER_NETBSD
743	// Not used
744	# else
745	struct linux_dirent {
746	# if SANITIZER_X32 || SANITIZER_LINUX
747	u64 d_ino;
748	u64 d_off;
749	# else
750	unsigned long d_ino;
751	unsigned long d_off;
752	# endif
753	unsigned short d_reclen;
754	# if SANITIZER_LINUX
755	unsigned char d_type;
756	# endif
757	char d_name[256];
758	};
759	# endif
760
761	# if !SANITIZER_SOLARIS && !SANITIZER_NETBSD
762	// Syscall wrappers.
763	uptr internal_ptrace(int request, int pid, void *addr, void *data) {
764	return internal_syscall(SYSCALL(ptrace), arg1: request, arg2: pid, arg3: (uptr)addr,
765	arg4: (uptr)data);
766	}
767
768	uptr internal_waitpid(int pid, int *status, int options) {
769	return internal_syscall(SYSCALL(wait4), arg1: pid, arg2: (uptr)status, arg3: options,
770	arg4: 0 /* rusage */);
771	}
772
773	uptr internal_getpid() { return internal_syscall(SYSCALL(getpid)); }
774
775	uptr internal_getppid() { return internal_syscall(SYSCALL(getppid)); }
776
777	int internal_dlinfo(void *handle, int request, void *p) {
778	# if SANITIZER_FREEBSD
779	return dlinfo(handle, request, p);
780	# else
781	UNIMPLEMENTED();
782	# endif
783	}
784
785	uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
786	# if SANITIZER_FREEBSD
787	return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL);
788	# elif SANITIZER_LINUX
789	return internal_syscall(SYSCALL(getdents64), arg1: fd, arg2: (uptr)dirp, arg3: count);
790	# else
791	return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
792	# endif
793	}
794
795	uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
796	return internal_syscall(SYSCALL(lseek), arg1: fd, arg2: offset, arg3: whence);
797	}
798
799	# if SANITIZER_LINUX
800	uptr internal_prctl(int option, uptr arg2, uptr arg3, uptr arg4, uptr arg5) {
801	return internal_syscall(SYSCALL(prctl), arg1: option, arg2, arg3, arg4, arg5);
802	}
803	# if defined(__x86_64__)
804	# include <asm/unistd_64.h>
805	// Currently internal_arch_prctl() is only needed on x86_64.
806	uptr internal_arch_prctl(int option, uptr arg2) {
807	return internal_syscall(__NR_arch_prctl, arg1: option, arg2);
808	}
809	# endif
810	# endif
811
812	uptr internal_sigaltstack(const void *ss, void *oss) {
813	return internal_syscall(SYSCALL(sigaltstack), arg1: (uptr)ss, arg2: (uptr)oss);
814	}
815
816	int internal_fork() {
817	# if SANITIZER_LINUX
818	# if SANITIZER_S390
819	return internal_syscall(SYSCALL(clone), 0, SIGCHLD);
820	# else
821	return internal_syscall(SYSCALL(clone), SIGCHLD, arg2: 0);
822	# endif
823	# else
824	return internal_syscall(SYSCALL(fork));
825	# endif
826	}
827
828	# if SANITIZER_FREEBSD
829	int internal_sysctl(const int *name, unsigned int namelen, void *oldp,
830	uptr *oldlenp, const void *newp, uptr newlen) {
831	return internal_syscall(SYSCALL(__sysctl), name, namelen, oldp,
832	(size_t *)oldlenp, newp, (size_t)newlen);
833	}
834
835	int internal_sysctlbyname(const char *sname, void *oldp, uptr *oldlenp,
836	const void *newp, uptr newlen) {
837	// Note: this function can be called during startup, so we need to avoid
838	// calling any interceptable functions. On FreeBSD >= 1300045 sysctlbyname()
839	// is a real syscall, but for older versions it calls sysctlnametomib()
840	// followed by sysctl(). To avoid calling the intercepted version and
841	// asserting if this happens during startup, call the real sysctlnametomib()
842	// followed by internal_sysctl() if the syscall is not available.
843	# ifdef SYS___sysctlbyname
844	return internal_syscall(SYSCALL(__sysctlbyname), sname,
845	internal_strlen(sname), oldp, (size_t *)oldlenp, newp,
846	(size_t)newlen);
847	# else
848	static decltype(sysctlnametomib) *real_sysctlnametomib = nullptr;
849	if (!real_sysctlnametomib)
850	real_sysctlnametomib =
851	(decltype(sysctlnametomib) *)dlsym(RTLD_NEXT, "sysctlnametomib");
852	CHECK(real_sysctlnametomib);
853
854	int oid[CTL_MAXNAME];
855	size_t len = CTL_MAXNAME;
856	if (real_sysctlnametomib(sname, oid, &len) == -1)
857	return (-1);
858	return internal_sysctl(oid, len, oldp, oldlenp, newp, newlen);
859	# endif
860	}
861	# endif
862
863	# if SANITIZER_LINUX
864	# define SA_RESTORER 0x04000000
865	// Doesn't set sa_restorer if the caller did not set it, so use with caution
866	//(see below).
867	int internal_sigaction_norestorer(int signum, const void *act, void *oldact) {
868	__sanitizer_kernel_sigaction_t k_act, k_oldact;
869	internal_memset(s: &k_act, c: 0, n: sizeof(__sanitizer_kernel_sigaction_t));
870	internal_memset(s: &k_oldact, c: 0, n: sizeof(__sanitizer_kernel_sigaction_t));
871	const __sanitizer_sigaction *u_act = (const __sanitizer_sigaction *)act;
872	__sanitizer_sigaction *u_oldact = (__sanitizer_sigaction *)oldact;
873	if (u_act) {
874	k_act.handler = u_act->handler;
875	k_act.sigaction = u_act->sigaction;
876	internal_memcpy(dest: &k_act.sa_mask, src: &u_act->sa_mask,
877	n: sizeof(__sanitizer_kernel_sigset_t));
878	// Without SA_RESTORER kernel ignores the calls (probably returns EINVAL).
879	k_act.sa_flags = u_act->sa_flags | SA_RESTORER;
880	// FIXME: most often sa_restorer is unset, however the kernel requires it
881	// to point to a valid signal restorer that calls the rt_sigreturn syscall.
882	// If sa_restorer passed to the kernel is NULL, the program may crash upon
883	// signal delivery or fail to unwind the stack in the signal handler.
884	// libc implementation of sigaction() passes its own restorer to
885	// rt_sigaction, so we need to do the same (we'll need to reimplement the
886	// restorers; for x86_64 the restorer address can be obtained from
887	// oldact->sa_restorer upon a call to sigaction(xxx, NULL, oldact).
888	# if !SANITIZER_ANDROID || !SANITIZER_MIPS32
889	k_act.sa_restorer = u_act->sa_restorer;
890	# endif
891	}
892
893	uptr result = internal_syscall(SYSCALL(rt_sigaction), arg1: (uptr)signum,
894	arg2: (uptr)(u_act ? &k_act : nullptr),
895	arg3: (uptr)(u_oldact ? &k_oldact : nullptr),
896	arg4: (uptr)sizeof(__sanitizer_kernel_sigset_t));
897
898	if ((result == 0) && u_oldact) {
899	u_oldact->handler = k_oldact.handler;
900	u_oldact->sigaction = k_oldact.sigaction;
901	internal_memcpy(dest: &u_oldact->sa_mask, src: &k_oldact.sa_mask,
902	n: sizeof(__sanitizer_kernel_sigset_t));
903	u_oldact->sa_flags = k_oldact.sa_flags;
904	# if !SANITIZER_ANDROID || !SANITIZER_MIPS32
905	u_oldact->sa_restorer = k_oldact.sa_restorer;
906	# endif
907	}
908	return result;
909	}
910	# endif // SANITIZER_LINUX
911
912	uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
913	__sanitizer_sigset_t *oldset) {
914	# if SANITIZER_FREEBSD
915	return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
916	# else
917	__sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
918	__sanitizer_kernel_sigset_t *k_oldset = (__sanitizer_kernel_sigset_t *)oldset;
919	return internal_syscall(SYSCALL(rt_sigprocmask), arg1: (uptr)how, arg2: (uptr)k_set,
920	arg3: (uptr)k_oldset, arg4: sizeof(__sanitizer_kernel_sigset_t));
921	# endif
922	}
923
924	void internal_sigfillset(__sanitizer_sigset_t *set) {
925	internal_memset(s: set, c: 0xff, n: sizeof(*set));
926	}
927
928	void internal_sigemptyset(__sanitizer_sigset_t *set) {
929	internal_memset(s: set, c: 0, n: sizeof(*set));
930	}
931
932	# if SANITIZER_LINUX
933	void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
934	signum -= 1;
935	CHECK_GE(signum, 0);
936	CHECK_LT(signum, sizeof(*set) * 8);
937	__sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
938	const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
939	const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
940	k_set->sig[idx] &= ~((uptr)1 << bit);
941	}
942
943	bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
944	signum -= 1;
945	CHECK_GE(signum, 0);
946	CHECK_LT(signum, sizeof(*set) * 8);
947	__sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
948	const uptr idx = signum / (sizeof(k_set->sig[0]) * 8);
949	const uptr bit = signum % (sizeof(k_set->sig[0]) * 8);
950	return k_set->sig[idx] & ((uptr)1 << bit);
951	}
952	# elif SANITIZER_FREEBSD
953	uptr internal_procctl(int type, int id, int cmd, void *data) {
954	return internal_syscall(SYSCALL(procctl), type, id, cmd, data);
955	}
956
957	void internal_sigdelset(__sanitizer_sigset_t *set, int signum) {
958	sigset_t *rset = reinterpret_cast<sigset_t *>(set);
959	sigdelset(rset, signum);
960	}
961
962	bool internal_sigismember(__sanitizer_sigset_t *set, int signum) {
963	sigset_t *rset = reinterpret_cast<sigset_t *>(set);
964	return sigismember(rset, signum);
965	}
966	# endif
967	# endif // !SANITIZER_SOLARIS
968
969	# if !SANITIZER_NETBSD
970	// ThreadLister implementation.
971	ThreadLister::ThreadLister(pid_t pid) : pid_(pid), buffer_(4096) {
972	char task_directory_path[80];
973	internal_snprintf(buffer: task_directory_path, length: sizeof(task_directory_path),
974	format: "/proc/%d/task/", pid);
975	descriptor_ = internal_open(filename: task_directory_path, O_RDONLY | O_DIRECTORY);
976	if (internal_iserror(retval: descriptor_)) {
977	Report(format: "Can't open /proc/%d/task for reading.\n", pid);
978	}
979	}
980
981	ThreadLister::Result ThreadLister::ListThreads(
982	InternalMmapVector<tid_t> *threads) {
983	if (internal_iserror(retval: descriptor_))
984	return Error;
985	internal_lseek(fd: descriptor_, offset: 0, SEEK_SET);
986	threads->clear();
987
988	Result result = Ok;
989	for (bool first_read = true;; first_read = false) {
990	// Resize to max capacity if it was downsized by IsAlive.
991	buffer_.resize(new_size: buffer_.capacity());
992	CHECK_GE(buffer_.size(), 4096);
993	uptr read = internal_getdents(
994	fd: descriptor_, dirp: (struct linux_dirent *)buffer_.data(), count: buffer_.size());
995	if (!read)
996	return result;
997	if (internal_iserror(retval: read)) {
998	Report(format: "Can't read directory entries from /proc/%d/task.\n", pid_);
999	return Error;
1000	}
1001
1002	for (uptr begin = (uptr)buffer_.data(), end = begin + read; begin < end;) {
1003	struct linux_dirent *entry = (struct linux_dirent *)begin;
1004	begin += entry->d_reclen;
1005	if (entry->d_ino == 1) {
1006	// Inode 1 is for bad blocks and also can be a reason for early return.
1007	// Should be emitted if kernel tried to output terminating thread.
1008	// See proc_task_readdir implementation in Linux.
1009	result = Incomplete;
1010	}
1011	if (entry->d_ino && *entry->d_name >= '0' && *entry->d_name <= '9')
1012	threads->push_back(element: internal_atoll(nptr: entry->d_name));
1013	}
1014
1015	// Now we are going to detect short-read or early EOF. In such cases Linux
1016	// can return inconsistent list with missing alive threads.
1017	// Code will just remember that the list can be incomplete but it will
1018	// continue reads to return as much as possible.
1019	if (!first_read) {
1020	// The first one was a short-read by definition.
1021	result = Incomplete;
1022	} else if (read > buffer_.size() - 1024) {
1023	// Read was close to the buffer size. So double the size and assume the
1024	// worst.
1025	buffer_.resize(new_size: buffer_.size() * 2);
1026	result = Incomplete;
1027	} else if (!threads->empty() && !IsAlive(tid: threads->back())) {
1028	// Maybe Linux early returned from read on terminated thread (!pid_alive)
1029	// and failed to restore read position.
1030	// See next_tid and proc_task_instantiate in Linux.
1031	result = Incomplete;
1032	}
1033	}
1034	}
1035
1036	bool ThreadLister::IsAlive(int tid) {
1037	// /proc/%d/task/%d/status uses same call to detect alive threads as
1038	// proc_task_readdir. See task_state implementation in Linux.
1039	char path[80];
1040	internal_snprintf(buffer: path, length: sizeof(path), format: "/proc/%d/task/%d/status", pid_, tid);
1041	if (!ReadFileToVector(file_name: path, buff: &buffer_) || buffer_.empty())
1042	return false;
1043	buffer_.push_back(element: 0);
1044	static const char kPrefix[] = "\nPPid:";
1045	const char *field = internal_strstr(haystack: buffer_.data(), needle: kPrefix);
1046	if (!field)
1047	return false;
1048	field += internal_strlen(s: kPrefix);
1049	return (int)internal_atoll(nptr: field) != 0;
1050	}
1051
1052	ThreadLister::~ThreadLister() {
1053	if (!internal_iserror(retval: descriptor_))
1054	internal_close(fd: descriptor_);
1055	}
1056	# endif
1057
1058	# if SANITIZER_WORDSIZE == 32
1059	// Take care of unusable kernel area in top gigabyte.
1060	static uptr GetKernelAreaSize() {
1061	# if SANITIZER_LINUX && !SANITIZER_X32
1062	const uptr gbyte = 1UL << 30;
1063
1064	// Firstly check if there are writable segments
1065	// mapped to top gigabyte (e.g. stack).
1066	MemoryMappingLayout proc_maps(/*cache_enabled*/ true);
1067	if (proc_maps.Error())
1068	return 0;
1069	MemoryMappedSegment segment;
1070	while (proc_maps.Next(&segment)) {
1071	if ((segment.end >= 3 * gbyte) && segment.IsWritable())
1072	return 0;
1073	}
1074
1075	# if !SANITIZER_ANDROID
1076	// Even if nothing is mapped, top Gb may still be accessible
1077	// if we are running on 64-bit kernel.
1078	// Uname may report misleading results if personality type
1079	// is modified (e.g. under schroot) so check this as well.
1080	struct utsname uname_info;
1081	int pers = personality(0xffffffffUL);
1082	if (!(pers & PER_MASK) && internal_uname(&uname_info) == 0 &&
1083	internal_strstr(uname_info.machine, "64"))
1084	return 0;
1085	# endif // SANITIZER_ANDROID
1086
1087	// Top gigabyte is reserved for kernel.
1088	return gbyte;
1089	# else
1090	return 0;
1091	# endif // SANITIZER_LINUX && !SANITIZER_X32
1092	}
1093	# endif // SANITIZER_WORDSIZE == 32
1094
1095	uptr GetMaxVirtualAddress() {
1096	# if SANITIZER_NETBSD && defined(__x86_64__)
1097	return 0x7f7ffffff000ULL; // (0x00007f8000000000 - PAGE_SIZE)
1098	# elif SANITIZER_WORDSIZE == 64
1099	# if defined(__powerpc64__) || defined(__aarch64__) || defined(__loongarch__)
1100	// On PowerPC64 we have two different address space layouts: 44- and 46-bit.
1101	// We somehow need to figure out which one we are using now and choose
1102	// one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
1103	// Note that with 'ulimit -s unlimited' the stack is moved away from the top
1104	// of the address space, so simply checking the stack address is not enough.
1105	// This should (does) work for both PowerPC64 Endian modes.
1106	// Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
1107	// loongarch64 also has multiple address space layouts: default is 47-bit.
1108	return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
1109	# elif SANITIZER_RISCV64
1110	return (1ULL << 38) - 1;
1111	# elif SANITIZER_MIPS64
1112	return (1ULL << 40) - 1; // 0x000000ffffffffffUL;
1113	# elif defined(__s390x__)
1114	return (1ULL << 53) - 1; // 0x001fffffffffffffUL;
1115	# elif defined(__sparc__)
1116	return ~(uptr)0;
1117	# else
1118	return (1ULL << 47) - 1; // 0x00007fffffffffffUL;
1119	# endif
1120	# else // SANITIZER_WORDSIZE == 32
1121	# if defined(__s390__)
1122	return (1ULL << 31) - 1; // 0x7fffffff;
1123	# else
1124	return (1ULL << 32) - 1; // 0xffffffff;
1125	# endif
1126	# endif // SANITIZER_WORDSIZE
1127	}
1128
1129	uptr GetMaxUserVirtualAddress() {
1130	uptr addr = GetMaxVirtualAddress();
1131	# if SANITIZER_WORDSIZE == 32 && !defined(__s390__)
1132	if (!common_flags()->full_address_space)
1133	addr -= GetKernelAreaSize();
1134	CHECK_LT(reinterpret_cast<uptr>(&addr), addr);
1135	# endif
1136	return addr;
1137	}
1138
1139	# if !SANITIZER_ANDROID
1140	uptr GetPageSize() {
1141	# if SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__)) && \
1142	defined(EXEC_PAGESIZE)
1143	return EXEC_PAGESIZE;
1144	# elif SANITIZER_FREEBSD || SANITIZER_NETBSD
1145	// Use sysctl as sysconf can trigger interceptors internally.
1146	int pz = 0;
1147	uptr pzl = sizeof(pz);
1148	int mib[2] = {CTL_HW, HW_PAGESIZE};
1149	int rv = internal_sysctl(mib, 2, &pz, &pzl, nullptr, 0);
1150	CHECK_EQ(rv, 0);
1151	return (uptr)pz;
1152	# elif SANITIZER_USE_GETAUXVAL
1153	return getauxval(AT_PAGESZ);
1154	# else
1155	return sysconf(_SC_PAGESIZE); // EXEC_PAGESIZE may not be trustworthy.
1156	# endif
1157	}
1158	# endif // !SANITIZER_ANDROID
1159
1160	uptr ReadBinaryName(/*out*/ char *buf, uptr buf_len) {
1161	# if SANITIZER_SOLARIS
1162	const char *default_module_name = getexecname();
1163	CHECK_NE(default_module_name, NULL);
1164	return internal_snprintf(buf, buf_len, "%s", default_module_name);
1165	# else
1166	# if SANITIZER_FREEBSD || SANITIZER_NETBSD
1167	# if SANITIZER_FREEBSD
1168	const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
1169	# else
1170	const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
1171	# endif
1172	const char *default_module_name = "kern.proc.pathname";
1173	uptr Size = buf_len;
1174	bool IsErr =
1175	(internal_sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
1176	int readlink_error = IsErr ? errno : 0;
1177	uptr module_name_len = Size;
1178	# else
1179	const char *default_module_name = "/proc/self/exe";
1180	uptr module_name_len = internal_readlink(path: default_module_name, buf, bufsize: buf_len);
1181	int readlink_error;
1182	bool IsErr = internal_iserror(retval: module_name_len, rverrno: &readlink_error);
1183	# endif // SANITIZER_SOLARIS
1184	if (IsErr) {
1185	// We can't read binary name for some reason, assume it's unknown.
1186	Report(
1187	format: "WARNING: reading executable name failed with errno %d, "
1188	"some stack frames may not be symbolized\n",
1189	readlink_error);
1190	module_name_len =
1191	internal_snprintf(buffer: buf, length: buf_len, format: "%s", default_module_name);
1192	CHECK_LT(module_name_len, buf_len);
1193	}
1194	return module_name_len;
1195	# endif
1196	}
1197
1198	uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
1199	# if SANITIZER_LINUX
1200	char *tmpbuf;
1201	uptr tmpsize;
1202	uptr tmplen;
1203	if (ReadFileToBuffer(file_name: "/proc/self/cmdline", buff: &tmpbuf, buff_size: &tmpsize, read_len: &tmplen,
1204	max_len: 1024 * 1024)) {
1205	internal_strncpy(dst: buf, src: tmpbuf, n: buf_len);
1206	UnmapOrDie(addr: tmpbuf, size: tmpsize);
1207	return internal_strlen(s: buf);
1208	}
1209	# endif
1210	return ReadBinaryName(buf, buf_len);
1211	}
1212
1213	// Match full names of the form /path/to/base_name{-,.}*
1214	bool LibraryNameIs(const char *full_name, const char *base_name) {
1215	const char *name = full_name;
1216	// Strip path.
1217	while (*name != '\0') name++;
1218	while (name > full_name && *name != '/') name--;
1219	if (*name == '/')
1220	name++;
1221	uptr base_name_length = internal_strlen(s: base_name);
1222	if (internal_strncmp(s1: name, s2: base_name, n: base_name_length))
1223	return false;
1224	return (name[base_name_length] == '-' || name[base_name_length] == '.');
1225	}
1226
1227	# if !SANITIZER_ANDROID
1228	// Call cb for each region mapped by map.
1229	void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr)) {
1230	CHECK_NE(map, nullptr);
1231	# if !SANITIZER_FREEBSD
1232	typedef ElfW(Phdr) Elf_Phdr;
1233	typedef ElfW(Ehdr) Elf_Ehdr;
1234	# endif // !SANITIZER_FREEBSD
1235	char *base = (char *)map->l_addr;
1236	Elf_Ehdr *ehdr = (Elf_Ehdr *)base;
1237	char *phdrs = base + ehdr->e_phoff;
1238	char *phdrs_end = phdrs + ehdr->e_phnum * ehdr->e_phentsize;
1239
1240	// Find the segment with the minimum base so we can "relocate" the p_vaddr
1241	// fields. Typically ET_DYN objects (DSOs) have base of zero and ET_EXEC
1242	// objects have a non-zero base.
1243	uptr preferred_base = (uptr)-1;
1244	for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1245	Elf_Phdr *phdr = (Elf_Phdr *)iter;
1246	if (phdr->p_type == PT_LOAD && preferred_base > (uptr)phdr->p_vaddr)
1247	preferred_base = (uptr)phdr->p_vaddr;
1248	}
1249
1250	// Compute the delta from the real base to get a relocation delta.
1251	sptr delta = (uptr)base - preferred_base;
1252	// Now we can figure out what the loader really mapped.
1253	for (char *iter = phdrs; iter != phdrs_end; iter += ehdr->e_phentsize) {
1254	Elf_Phdr *phdr = (Elf_Phdr *)iter;
1255	if (phdr->p_type == PT_LOAD) {
1256	uptr seg_start = phdr->p_vaddr + delta;
1257	uptr seg_end = seg_start + phdr->p_memsz;
1258	// None of these values are aligned. We consider the ragged edges of the
1259	// load command as defined, since they are mapped from the file.
1260	seg_start = RoundDownTo(x: seg_start, boundary: GetPageSizeCached());
1261	seg_end = RoundUpTo(size: seg_end, boundary: GetPageSizeCached());
1262	cb((void *)seg_start, seg_end - seg_start);
1263	}
1264	}
1265	}
1266	# endif
1267
1268	# if SANITIZER_LINUX
1269	# if defined(__x86_64__)
1270	// We cannot use glibc's clone wrapper, because it messes with the child
1271	// task's TLS. It writes the PID and TID of the child task to its thread
1272	// descriptor, but in our case the child task shares the thread descriptor with
1273	// the parent (because we don't know how to allocate a new thread
1274	// descriptor to keep glibc happy). So the stock version of clone(), when
1275	// used with CLONE_VM, would end up corrupting the parent's thread descriptor.
1276	uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1277	int *parent_tidptr, void *newtls, int *child_tidptr) {
1278	long long res;
1279	if (!fn || !child_stack)
1280	return -EINVAL;
1281	CHECK_EQ(0, (uptr)child_stack % 16);
1282	child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1283	((unsigned long long *)child_stack)[0] = (uptr)fn;
1284	((unsigned long long *)child_stack)[1] = (uptr)arg;
1285	register void *r8 __asm__("r8") = newtls;
1286	register int *r10 __asm__("r10") = child_tidptr;
1287	__asm__ __volatile__(
1288	/* %rax = syscall(%rax = SYSCALL(clone),
1289	* %rdi = flags,
1290	* %rsi = child_stack,
1291	* %rdx = parent_tidptr,
1292	* %r8 = new_tls,
1293	* %r10 = child_tidptr)
1294	*/
1295	"syscall\n"
1296
1297	/* if (%rax != 0)
1298	* return;
1299	*/
1300	"testq %%rax,%%rax\n"
1301	"jnz 1f\n"
1302
1303	/* In the child. Terminate unwind chain. */
1304	// XXX: We should also terminate the CFI unwind chain
1305	// here. Unfortunately clang 3.2 doesn't support the
1306	// necessary CFI directives, so we skip that part.
1307	"xorq %%rbp,%%rbp\n"
1308
1309	/* Call "fn(arg)". */
1310	"popq %%rax\n"
1311	"popq %%rdi\n"
1312	"call *%%rax\n"
1313
1314	/* Call _exit(%rax). */
1315	"movq %%rax,%%rdi\n"
1316	"movq %2,%%rax\n"
1317	"syscall\n"
1318
1319	/* Return to parent. */
1320	"1:\n"
1321	: "=a"(res)
1322	: "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), "S"(child_stack), "D"(flags),
1323	"d"(parent_tidptr), "r"(r8), "r"(r10)
1324	: "memory", "r11", "rcx");
1325	return res;
1326	}
1327	# elif defined(__mips__)
1328	uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1329	int *parent_tidptr, void *newtls, int *child_tidptr) {
1330	long long res;
1331	if (!fn || !child_stack)
1332	return -EINVAL;
1333	CHECK_EQ(0, (uptr)child_stack % 16);
1334	child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1335	((unsigned long long *)child_stack)[0] = (uptr)fn;
1336	((unsigned long long *)child_stack)[1] = (uptr)arg;
1337	register void *a3 __asm__("$7") = newtls;
1338	register int *a4 __asm__("$8") = child_tidptr;
1339	// We don't have proper CFI directives here because it requires alot of code
1340	// for very marginal benefits.
1341	__asm__ __volatile__(
1342	/* $v0 = syscall($v0 = __NR_clone,
1343	* $a0 = flags,
1344	* $a1 = child_stack,
1345	* $a2 = parent_tidptr,
1346	* $a3 = new_tls,
1347	* $a4 = child_tidptr)
1348	*/
1349	".cprestore 16;\n"
1350	"move $4,%1;\n"
1351	"move $5,%2;\n"
1352	"move $6,%3;\n"
1353	"move $7,%4;\n"
1354	/* Store the fifth argument on stack
1355	* if we are using 32-bit abi.
1356	*/
1357	# if SANITIZER_WORDSIZE == 32
1358	"lw %5,16($29);\n"
1359	# else
1360	"move $8,%5;\n"
1361	# endif
1362	"li $2,%6;\n"
1363	"syscall;\n"
1364
1365	/* if ($v0 != 0)
1366	* return;
1367	*/
1368	"bnez $2,1f;\n"
1369
1370	/* Call "fn(arg)". */
1371	# if SANITIZER_WORDSIZE == 32
1372	# ifdef __BIG_ENDIAN__
1373	"lw $25,4($29);\n"
1374	"lw $4,12($29);\n"
1375	# else
1376	"lw $25,0($29);\n"
1377	"lw $4,8($29);\n"
1378	# endif
1379	# else
1380	"ld $25,0($29);\n"
1381	"ld $4,8($29);\n"
1382	# endif
1383	"jal $25;\n"
1384
1385	/* Call _exit($v0). */
1386	"move $4,$2;\n"
1387	"li $2,%7;\n"
1388	"syscall;\n"
1389
1390	/* Return to parent. */
1391	"1:\n"
1392	: "=r"(res)
1393	: "r"(flags), "r"(child_stack), "r"(parent_tidptr), "r"(a3), "r"(a4),
1394	"i"(__NR_clone), "i"(__NR_exit)
1395	: "memory", "$29");
1396	return res;
1397	}
1398	# elif SANITIZER_RISCV64
1399	uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1400	int *parent_tidptr, void *newtls, int *child_tidptr) {
1401	if (!fn || !child_stack)
1402	return -EINVAL;
1403
1404	CHECK_EQ(0, (uptr)child_stack % 16);
1405
1406	register int res __asm__("a0");
1407	register int __flags __asm__("a0") = flags;
1408	register void *__stack __asm__("a1") = child_stack;
1409	register int *__ptid __asm__("a2") = parent_tidptr;
1410	register void *__tls __asm__("a3") = newtls;
1411	register int *__ctid __asm__("a4") = child_tidptr;
1412	register int (*__fn)(void *) __asm__("a5") = fn;
1413	register void *__arg __asm__("a6") = arg;
1414	register int nr_clone __asm__("a7") = __NR_clone;
1415
1416	__asm__ __volatile__(
1417	"ecall\n"
1418
1419	/* if (a0 != 0)
1420	* return a0;
1421	*/
1422	"bnez a0, 1f\n"
1423
1424	// In the child, now. Call "fn(arg)".
1425	"mv a0, a6\n"
1426	"jalr a5\n"
1427
1428	// Call _exit(a0).
1429	"addi a7, zero, %9\n"
1430	"ecall\n"
1431	"1:\n"
1432
1433	: "=r"(res)
1434	: "0"(__flags), "r"(__stack), "r"(__ptid), "r"(__tls), "r"(__ctid),
1435	"r"(__fn), "r"(__arg), "r"(nr_clone), "i"(__NR_exit)
1436	: "memory");
1437	return res;
1438	}
1439	# elif defined(__aarch64__)
1440	uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1441	int *parent_tidptr, void *newtls, int *child_tidptr) {
1442	register long long res __asm__("x0");
1443	if (!fn || !child_stack)
1444	return -EINVAL;
1445	CHECK_EQ(0, (uptr)child_stack % 16);
1446	child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
1447	((unsigned long long *)child_stack)[0] = (uptr)fn;
1448	((unsigned long long *)child_stack)[1] = (uptr)arg;
1449
1450	register int (*__fn)(void *) __asm__("x0") = fn;
1451	register void *__stack __asm__("x1") = child_stack;
1452	register int __flags __asm__("x2") = flags;
1453	register void *__arg __asm__("x3") = arg;
1454	register int *__ptid __asm__("x4") = parent_tidptr;
1455	register void *__tls __asm__("x5") = newtls;
1456	register int *__ctid __asm__("x6") = child_tidptr;
1457
1458	__asm__ __volatile__(
1459	"mov x0,x2\n" /* flags */
1460	"mov x2,x4\n" /* ptid */
1461	"mov x3,x5\n" /* tls */
1462	"mov x4,x6\n" /* ctid */
1463	"mov x8,%9\n" /* clone */
1464
1465	"svc 0x0\n"
1466
1467	/* if (%r0 != 0)
1468	* return %r0;
1469	*/
1470	"cmp x0, #0\n"
1471	"bne 1f\n"
1472
1473	/* In the child, now. Call "fn(arg)". */
1474	"ldp x1, x0, [sp], #16\n"
1475	"blr x1\n"
1476
1477	/* Call _exit(%r0). */
1478	"mov x8, %10\n"
1479	"svc 0x0\n"
1480	"1:\n"
1481
1482	: "=r"(res)
1483	: "i"(-EINVAL), "r"(__fn), "r"(__stack), "r"(__flags), "r"(__arg),
1484	"r"(__ptid), "r"(__tls), "r"(__ctid), "i"(__NR_clone), "i"(__NR_exit)
1485	: "x30", "memory");
1486	return res;
1487	}
1488	# elif SANITIZER_LOONGARCH64
1489	uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1490	int *parent_tidptr, void *newtls, int *child_tidptr) {
1491	if (!fn || !child_stack)
1492	return -EINVAL;
1493
1494	CHECK_EQ(0, (uptr)child_stack % 16);
1495
1496	register int res __asm__("$a0");
1497	register int __flags __asm__("$a0") = flags;
1498	register void *__stack __asm__("$a1") = child_stack;
1499	register int *__ptid __asm__("$a2") = parent_tidptr;
1500	register int *__ctid __asm__("$a3") = child_tidptr;
1501	register void *__tls __asm__("$a4") = newtls;
1502	register int (*__fn)(void *) __asm__("$a5") = fn;
1503	register void *__arg __asm__("$a6") = arg;
1504	register int nr_clone __asm__("$a7") = __NR_clone;
1505
1506	__asm__ __volatile__(
1507	"syscall 0\n"
1508
1509	// if ($a0 != 0)
1510	// return $a0;
1511	"bnez $a0, 1f\n"
1512
1513	// In the child, now. Call "fn(arg)".
1514	"move $a0, $a6\n"
1515	"jirl $ra, $a5, 0\n"
1516
1517	// Call _exit($a0).
1518	"addi.d $a7, $zero, %9\n"
1519	"syscall 0\n"
1520
1521	"1:\n"
1522
1523	: "=r"(res)
1524	: "0"(__flags), "r"(__stack), "r"(__ptid), "r"(__ctid), "r"(__tls),
1525	"r"(__fn), "r"(__arg), "r"(nr_clone), "i"(__NR_exit)
1526	: "memory", "$t0", "$t1", "$t2", "$t3", "$t4", "$t5", "$t6", "$t7",
1527	"$t8");
1528	return res;
1529	}
1530	# elif defined(__powerpc64__)
1531	uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1532	int *parent_tidptr, void *newtls, int *child_tidptr) {
1533	long long res;
1534	// Stack frame structure.
1535	# if SANITIZER_PPC64V1
1536	// Back chain == 0 (SP + 112)
1537	// Frame (112 bytes):
1538	// Parameter save area (SP + 48), 8 doublewords
1539	// TOC save area (SP + 40)
1540	// Link editor doubleword (SP + 32)
1541	// Compiler doubleword (SP + 24)
1542	// LR save area (SP + 16)
1543	// CR save area (SP + 8)
1544	// Back chain (SP + 0)
1545	# define FRAME_SIZE 112
1546	# define FRAME_TOC_SAVE_OFFSET 40
1547	# elif SANITIZER_PPC64V2
1548	// Back chain == 0 (SP + 32)
1549	// Frame (32 bytes):
1550	// TOC save area (SP + 24)
1551	// LR save area (SP + 16)
1552	// CR save area (SP + 8)
1553	// Back chain (SP + 0)
1554	# define FRAME_SIZE 32
1555	# define FRAME_TOC_SAVE_OFFSET 24
1556	# else
1557	# error "Unsupported PPC64 ABI"
1558	# endif
1559	if (!fn || !child_stack)
1560	return -EINVAL;
1561	CHECK_EQ(0, (uptr)child_stack % 16);
1562
1563	register int (*__fn)(void *) __asm__("r3") = fn;
1564	register void *__cstack __asm__("r4") = child_stack;
1565	register int __flags __asm__("r5") = flags;
1566	register void *__arg __asm__("r6") = arg;
1567	register int *__ptidptr __asm__("r7") = parent_tidptr;
1568	register void *__newtls __asm__("r8") = newtls;
1569	register int *__ctidptr __asm__("r9") = child_tidptr;
1570
1571	__asm__ __volatile__(
1572	/* fn and arg are saved across the syscall */
1573	"mr 28, %5\n\t"
1574	"mr 27, %8\n\t"
1575
1576	/* syscall
1577	r0 == __NR_clone
1578	r3 == flags
1579	r4 == child_stack
1580	r5 == parent_tidptr
1581	r6 == newtls
1582	r7 == child_tidptr */
1583	"mr 3, %7\n\t"
1584	"mr 5, %9\n\t"
1585	"mr 6, %10\n\t"
1586	"mr 7, %11\n\t"
1587	"li 0, %3\n\t"
1588	"sc\n\t"
1589
1590	/* Test if syscall was successful */
1591	"cmpdi cr1, 3, 0\n\t"
1592	"crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
1593	"bne- cr1, 1f\n\t"
1594
1595	/* Set up stack frame */
1596	"li 29, 0\n\t"
1597	"stdu 29, -8(1)\n\t"
1598	"stdu 1, -%12(1)\n\t"
1599	/* Do the function call */
1600	"std 2, %13(1)\n\t"
1601	# if SANITIZER_PPC64V1
1602	"ld 0, 0(28)\n\t"
1603	"ld 2, 8(28)\n\t"
1604	"mtctr 0\n\t"
1605	# elif SANITIZER_PPC64V2
1606	"mr 12, 28\n\t"
1607	"mtctr 12\n\t"
1608	# else
1609	# error "Unsupported PPC64 ABI"
1610	# endif
1611	"mr 3, 27\n\t"
1612	"bctrl\n\t"
1613	"ld 2, %13(1)\n\t"
1614
1615	/* Call _exit(r3) */
1616	"li 0, %4\n\t"
1617	"sc\n\t"
1618
1619	/* Return to parent */
1620	"1:\n\t"
1621	"mr %0, 3\n\t"
1622	: "=r"(res)
1623	: "0"(-1), "i"(EINVAL), "i"(__NR_clone), "i"(__NR_exit), "r"(__fn),
1624	"r"(__cstack), "r"(__flags), "r"(__arg), "r"(__ptidptr), "r"(__newtls),
1625	"r"(__ctidptr), "i"(FRAME_SIZE), "i"(FRAME_TOC_SAVE_OFFSET)
1626	: "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29");
1627	return res;
1628	}
1629	# elif defined(__i386__)
1630	uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1631	int *parent_tidptr, void *newtls, int *child_tidptr) {
1632	int res;
1633	if (!fn || !child_stack)
1634	return -EINVAL;
1635	CHECK_EQ(0, (uptr)child_stack % 16);
1636	child_stack = (char *)child_stack - 7 * sizeof(unsigned int);
1637	((unsigned int *)child_stack)[0] = (uptr)flags;
1638	((unsigned int *)child_stack)[1] = (uptr)0;
1639	((unsigned int *)child_stack)[2] = (uptr)fn;
1640	((unsigned int *)child_stack)[3] = (uptr)arg;
1641	__asm__ __volatile__(
1642	/* %eax = syscall(%eax = SYSCALL(clone),
1643	* %ebx = flags,
1644	* %ecx = child_stack,
1645	* %edx = parent_tidptr,
1646	* %esi = new_tls,
1647	* %edi = child_tidptr)
1648	*/
1649
1650	/* Obtain flags */
1651	"movl (%%ecx), %%ebx\n"
1652	/* Do the system call */
1653	"pushl %%ebx\n"
1654	"pushl %%esi\n"
1655	"pushl %%edi\n"
1656	/* Remember the flag value. */
1657	"movl %%ebx, (%%ecx)\n"
1658	"int $0x80\n"
1659	"popl %%edi\n"
1660	"popl %%esi\n"
1661	"popl %%ebx\n"
1662
1663	/* if (%eax != 0)
1664	* return;
1665	*/
1666
1667	"test %%eax,%%eax\n"
1668	"jnz 1f\n"
1669
1670	/* terminate the stack frame */
1671	"xorl %%ebp,%%ebp\n"
1672	/* Call FN. */
1673	"call *%%ebx\n"
1674	# ifdef PIC
1675	"call here\n"
1676	"here:\n"
1677	"popl %%ebx\n"
1678	"addl $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n"
1679	# endif
1680	/* Call exit */
1681	"movl %%eax, %%ebx\n"
1682	"movl %2, %%eax\n"
1683	"int $0x80\n"
1684	"1:\n"
1685	: "=a"(res)
1686	: "a"(SYSCALL(clone)), "i"(SYSCALL(exit)), "c"(child_stack),
1687	"d"(parent_tidptr), "S"(newtls), "D"(child_tidptr)
1688	: "memory");
1689	return res;
1690	}
1691	# elif defined(__arm__)
1692	uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
1693	int *parent_tidptr, void *newtls, int *child_tidptr) {
1694	unsigned int res;
1695	if (!fn || !child_stack)
1696	return -EINVAL;
1697	child_stack = (char *)child_stack - 2 * sizeof(unsigned int);
1698	((unsigned int *)child_stack)[0] = (uptr)fn;
1699	((unsigned int *)child_stack)[1] = (uptr)arg;
1700	register int r0 __asm__("r0") = flags;
1701	register void *r1 __asm__("r1") = child_stack;
1702	register int *r2 __asm__("r2") = parent_tidptr;
1703	register void *r3 __asm__("r3") = newtls;
1704	register int *r4 __asm__("r4") = child_tidptr;
1705	register int r7 __asm__("r7") = __NR_clone;
1706
1707	# if __ARM_ARCH > 4 || defined(__ARM_ARCH_4T__)
1708	# define ARCH_HAS_BX
1709	# endif
1710	# if __ARM_ARCH > 4
1711	# define ARCH_HAS_BLX
1712	# endif
1713
1714	# ifdef ARCH_HAS_BX
1715	# ifdef ARCH_HAS_BLX
1716	# define BLX(R) "blx " #R "\n"
1717	# else
1718	# define BLX(R) "mov lr, pc; bx " #R "\n"
1719	# endif
1720	# else
1721	# define BLX(R) "mov lr, pc; mov pc," #R "\n"
1722	# endif
1723
1724	__asm__ __volatile__(
1725	/* %r0 = syscall(%r7 = SYSCALL(clone),
1726	* %r0 = flags,
1727	* %r1 = child_stack,
1728	* %r2 = parent_tidptr,
1729	* %r3 = new_tls,
1730	* %r4 = child_tidptr)
1731	*/
1732
1733	/* Do the system call */
1734	"swi 0x0\n"
1735
1736	/* if (%r0 != 0)
1737	* return %r0;
1738	*/
1739	"cmp r0, #0\n"
1740	"bne 1f\n"
1741
1742	/* In the child, now. Call "fn(arg)". */
1743	"ldr r0, [sp, #4]\n"
1744	"ldr ip, [sp], #8\n" BLX(ip)
1745	/* Call _exit(%r0). */
1746	"mov r7, %7\n"
1747	"swi 0x0\n"
1748	"1:\n"
1749	"mov %0, r0\n"
1750	: "=r"(res)
1751	: "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7), "i"(__NR_exit)
1752	: "memory");
1753	return res;
1754	}
1755	# endif
1756	# endif // SANITIZER_LINUX
1757
1758	# if SANITIZER_LINUX
1759	int internal_uname(struct utsname *buf) {
1760	return internal_syscall(SYSCALL(uname), arg1: buf);
1761	}
1762	# endif
1763
1764	# if SANITIZER_ANDROID
1765	# if __ANDROID_API__ < 21
1766	extern "C" __attribute__((weak)) int dl_iterate_phdr(
1767	int (*)(struct dl_phdr_info *, size_t, void *), void *);
1768	# endif
1769
1770	static int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size,
1771	void *data) {
1772	// Any name starting with "lib" indicates a bug in L where library base names
1773	// are returned instead of paths.
1774	if (info->dlpi_name && info->dlpi_name[0] == 'l' &&
1775	info->dlpi_name[1] == 'i' && info->dlpi_name[2] == 'b') {
1776	*(bool *)data = true;
1777	return 1;
1778	}
1779	return 0;
1780	}
1781
1782	static atomic_uint32_t android_api_level;
1783
1784	static AndroidApiLevel AndroidDetectApiLevelStatic() {
1785	# if __ANDROID_API__ <= 19
1786	return ANDROID_KITKAT;
1787	# elif __ANDROID_API__ <= 22
1788	return ANDROID_LOLLIPOP_MR1;
1789	# else
1790	return ANDROID_POST_LOLLIPOP;
1791	# endif
1792	}
1793
1794	static AndroidApiLevel AndroidDetectApiLevel() {
1795	if (!&dl_iterate_phdr)
1796	return ANDROID_KITKAT; // K or lower
1797	bool base_name_seen = false;
1798	dl_iterate_phdr(dl_iterate_phdr_test_cb, &base_name_seen);
1799	if (base_name_seen)
1800	return ANDROID_LOLLIPOP_MR1; // L MR1
1801	return ANDROID_POST_LOLLIPOP; // post-L
1802	// Plain L (API level 21) is completely broken wrt ASan and not very
1803	// interesting to detect.
1804	}
1805
1806	extern "C" __attribute__((weak)) void *_DYNAMIC;
1807
1808	AndroidApiLevel AndroidGetApiLevel() {
1809	AndroidApiLevel level =
1810	(AndroidApiLevel)atomic_load(&android_api_level, memory_order_relaxed);
1811	if (level)
1812	return level;
1813	level = &_DYNAMIC == nullptr ? AndroidDetectApiLevelStatic()
1814	: AndroidDetectApiLevel();
1815	atomic_store(&android_api_level, level, memory_order_relaxed);
1816	return level;
1817	}
1818
1819	# endif
1820
1821	static HandleSignalMode GetHandleSignalModeImpl(int signum) {
1822	switch (signum) {
1823	case SIGABRT:
1824	return common_flags()->handle_abort;
1825	case SIGILL:
1826	return common_flags()->handle_sigill;
1827	case SIGTRAP:
1828	return common_flags()->handle_sigtrap;
1829	case SIGFPE:
1830	return common_flags()->handle_sigfpe;
1831	case SIGSEGV:
1832	return common_flags()->handle_segv;
1833	case SIGBUS:
1834	return common_flags()->handle_sigbus;
1835	}
1836	return kHandleSignalNo;
1837	}
1838
1839	HandleSignalMode GetHandleSignalMode(int signum) {
1840	HandleSignalMode result = GetHandleSignalModeImpl(signum);
1841	if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
1842	return kHandleSignalExclusive;
1843	return result;
1844	}
1845
1846	# if !SANITIZER_GO
1847	void *internal_start_thread(void *(*func)(void *arg), void *arg) {
1848	if (&real_pthread_create == 0)
1849	return nullptr;
1850	// Start the thread with signals blocked, otherwise it can steal user signals.
1851	ScopedBlockSignals block(nullptr);
1852	void *th;
1853	real_pthread_create(th: &th, attr: nullptr, callback: func, param: arg);
1854	return th;
1855	}
1856
1857	void internal_join_thread(void *th) {
1858	if (&real_pthread_join)
1859	real_pthread_join(th, ret: nullptr);
1860	}
1861	# else
1862	void *internal_start_thread(void *(*func)(void *), void *arg) { return 0; }
1863
1864	void internal_join_thread(void *th) {}
1865	# endif
1866
1867	# if SANITIZER_LINUX && defined(__aarch64__)
1868	// Android headers in the older NDK releases miss this definition.
1869	struct __sanitizer_esr_context {
1870	struct _aarch64_ctx head;
1871	uint64_t esr;
1872	};
1873
1874	static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
1875	static const u32 kEsrMagic = 0x45535201;
1876	u8 *aux = reinterpret_cast<u8 *>(ucontext->uc_mcontext.__reserved);
1877	while (true) {
1878	_aarch64_ctx *ctx = (_aarch64_ctx *)aux;
1879	if (ctx->size == 0)
1880	break;
1881	if (ctx->magic == kEsrMagic) {
1882	*esr = ((__sanitizer_esr_context *)ctx)->esr;
1883	return true;
1884	}
1885	aux += ctx->size;
1886	}
1887	return false;
1888	}
1889	# elif SANITIZER_FREEBSD && defined(__aarch64__)
1890	// FreeBSD doesn't provide ESR in the ucontext.
1891	static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) { return false; }
1892	# endif
1893
1894	using Context = ucontext_t;
1895
1896	SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
1897	Context *ucontext = (Context *)context;
1898	# if defined(__x86_64__) || defined(__i386__)
1899	static const uptr PF_WRITE = 1U << 1;
1900	# if SANITIZER_FREEBSD
1901	uptr err = ucontext->uc_mcontext.mc_err;
1902	# elif SANITIZER_NETBSD
1903	uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR];
1904	# elif SANITIZER_SOLARIS && defined(__i386__)
1905	const int Err = 13;
1906	uptr err = ucontext->uc_mcontext.gregs[Err];
1907	# else
1908	uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
1909	# endif // SANITIZER_FREEBSD
1910	return err & PF_WRITE ? Write : Read;
1911	# elif defined(__mips__)
1912	uint32_t *exception_source;
1913	uint32_t faulty_instruction;
1914	uint32_t op_code;
1915
1916	exception_source = (uint32_t *)ucontext->uc_mcontext.pc;
1917	faulty_instruction = (uint32_t)(*exception_source);
1918
1919	op_code = (faulty_instruction >> 26) & 0x3f;
1920
1921	// FIXME: Add support for FPU, microMIPS, DSP, MSA memory instructions.
1922	switch (op_code) {
1923	case 0x28: // sb
1924	case 0x29: // sh
1925	case 0x2b: // sw
1926	case 0x3f: // sd
1927	# if __mips_isa_rev < 6
1928	case 0x2c: // sdl
1929	case 0x2d: // sdr
1930	case 0x2a: // swl
1931	case 0x2e: // swr
1932	# endif
1933	return SignalContext::Write;
1934
1935	case 0x20: // lb
1936	case 0x24: // lbu
1937	case 0x21: // lh
1938	case 0x25: // lhu
1939	case 0x23: // lw
1940	case 0x27: // lwu
1941	case 0x37: // ld
1942	# if __mips_isa_rev < 6
1943	case 0x1a: // ldl
1944	case 0x1b: // ldr
1945	case 0x22: // lwl
1946	case 0x26: // lwr
1947	# endif
1948	return SignalContext::Read;
1949	# if __mips_isa_rev == 6
1950	case 0x3b: // pcrel
1951	op_code = (faulty_instruction >> 19) & 0x3;
1952	switch (op_code) {
1953	case 0x1: // lwpc
1954	case 0x2: // lwupc
1955	return SignalContext::Read;
1956	}
1957	# endif
1958	}
1959	return SignalContext::Unknown;
1960	# elif defined(__arm__)
1961	static const uptr FSR_WRITE = 1U << 11;
1962	uptr fsr = ucontext->uc_mcontext.error_code;
1963	return fsr & FSR_WRITE ? Write : Read;
1964	# elif defined(__aarch64__)
1965	static const u64 ESR_ELx_WNR = 1U << 6;
1966	u64 esr;
1967	if (!Aarch64GetESR(ucontext, &esr))
1968	return Unknown;
1969	return esr & ESR_ELx_WNR ? Write : Read;
1970	# elif defined(__loongarch__)
1971	u32 flags = ucontext->uc_mcontext.__flags;
1972	if (flags & SC_ADDRERR_RD)
1973	return SignalContext::Read;
1974	if (flags & SC_ADDRERR_WR)
1975	return SignalContext::Write;
1976	return SignalContext::Unknown;
1977	# elif defined(__sparc__)
1978	// Decode the instruction to determine the access type.
1979	// From OpenSolaris $SRC/uts/sun4/os/trap.c (get_accesstype).
1980	# if SANITIZER_SOLARIS
1981	uptr pc = ucontext->uc_mcontext.gregs[REG_PC];
1982	# else
1983	// Historical BSDism here.
1984	struct sigcontext *scontext = (struct sigcontext *)context;
1985	# if defined(__arch64__)
1986	uptr pc = scontext->sigc_regs.tpc;
1987	# else
1988	uptr pc = scontext->si_regs.pc;
1989	# endif
1990	# endif
1991	u32 instr = *(u32 *)pc;
1992	return (instr >> 21) & 1 ? Write : Read;
1993	# elif defined(__riscv)
1994	# if SANITIZER_FREEBSD
1995	unsigned long pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc;
1996	# else
1997	unsigned long pc = ucontext->uc_mcontext.__gregs[REG_PC];
1998	# endif
1999	unsigned faulty_instruction = *(uint16_t *)pc;
2000
2001	# if defined(__riscv_compressed)
2002	if ((faulty_instruction & 0x3) != 0x3) { // it's a compressed instruction
2003	// set op_bits to the instruction bits [1, 0, 15, 14, 13]
2004	unsigned op_bits =
2005	((faulty_instruction & 0x3) << 3) | (faulty_instruction >> 13);
2006	unsigned rd = faulty_instruction & 0xF80; // bits 7-11, inclusive
2007	switch (op_bits) {
2008	case 0b10'010: // c.lwsp (rd != x0)
2009	# if __riscv_xlen == 64
2010	case 0b10'011: // c.ldsp (rd != x0)
2011	# endif
2012	return rd ? SignalContext::Read : SignalContext::Unknown;
2013	case 0b00'010: // c.lw
2014	# if __riscv_flen >= 32 && __riscv_xlen == 32
2015	case 0b10'011: // c.flwsp
2016	# endif
2017	# if __riscv_flen >= 32 || __riscv_xlen == 64
2018	case 0b00'011: // c.flw / c.ld
2019	# endif
2020	# if __riscv_flen == 64
2021	case 0b00'001: // c.fld
2022	case 0b10'001: // c.fldsp
2023	# endif
2024	return SignalContext::Read;
2025	case 0b00'110: // c.sw
2026	case 0b10'110: // c.swsp
2027	# if __riscv_flen >= 32 || __riscv_xlen == 64
2028	case 0b00'111: // c.fsw / c.sd
2029	case 0b10'111: // c.fswsp / c.sdsp
2030	# endif
2031	# if __riscv_flen == 64
2032	case 0b00'101: // c.fsd
2033	case 0b10'101: // c.fsdsp
2034	# endif
2035	return SignalContext::Write;
2036	default:
2037	return SignalContext::Unknown;
2038	}
2039	}
2040	# endif
2041
2042	unsigned opcode = faulty_instruction & 0x7f; // lower 7 bits
2043	unsigned funct3 = (faulty_instruction >> 12) & 0x7; // bits 12-14, inclusive
2044	switch (opcode) {
2045	case 0b0000011: // loads
2046	switch (funct3) {
2047	case 0b000: // lb
2048	case 0b001: // lh
2049	case 0b010: // lw
2050	# if __riscv_xlen == 64
2051	case 0b011: // ld
2052	# endif
2053	case 0b100: // lbu
2054	case 0b101: // lhu
2055	return SignalContext::Read;
2056	default:
2057	return SignalContext::Unknown;
2058	}
2059	case 0b0100011: // stores
2060	switch (funct3) {
2061	case 0b000: // sb
2062	case 0b001: // sh
2063	case 0b010: // sw
2064	# if __riscv_xlen == 64
2065	case 0b011: // sd
2066	# endif
2067	return SignalContext::Write;
2068	default:
2069	return SignalContext::Unknown;
2070	}
2071	# if __riscv_flen >= 32
2072	case 0b0000111: // floating-point loads
2073	switch (funct3) {
2074	case 0b010: // flw
2075	# if __riscv_flen == 64
2076	case 0b011: // fld
2077	# endif
2078	return SignalContext::Read;
2079	default:
2080	return SignalContext::Unknown;
2081	}
2082	case 0b0100111: // floating-point stores
2083	switch (funct3) {
2084	case 0b010: // fsw
2085	# if __riscv_flen == 64
2086	case 0b011: // fsd
2087	# endif
2088	return SignalContext::Write;
2089	default:
2090	return SignalContext::Unknown;
2091	}
2092	# endif
2093	default:
2094	return SignalContext::Unknown;
2095	}
2096	# else
2097	(void)ucontext;
2098	return Unknown; // FIXME: Implement.
2099	# endif
2100	}
2101
2102	bool SignalContext::IsTrueFaultingAddress() const {
2103	auto si = static_cast<const siginfo_t *>(siginfo);
2104	// SIGSEGV signals without a true fault address have si_code set to 128.
2105	return si->si_signo == SIGSEGV && si->si_code != 128;
2106	}
2107
2108	void SignalContext::DumpAllRegisters(void *context) {
2109	// FIXME: Implement this.
2110	}
2111
2112	static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
2113	# if SANITIZER_NETBSD
2114	// This covers all NetBSD architectures
2115	ucontext_t *ucontext = (ucontext_t *)context;
2116	*pc = _UC_MACHINE_PC(ucontext);
2117	*bp = _UC_MACHINE_FP(ucontext);
2118	*sp = _UC_MACHINE_SP(ucontext);
2119	# elif defined(__arm__)
2120	ucontext_t *ucontext = (ucontext_t *)context;
2121	*pc = ucontext->uc_mcontext.arm_pc;
2122	*bp = ucontext->uc_mcontext.arm_fp;
2123	*sp = ucontext->uc_mcontext.arm_sp;
2124	# elif defined(__aarch64__)
2125	# if SANITIZER_FREEBSD
2126	ucontext_t *ucontext = (ucontext_t *)context;
2127	*pc = ucontext->uc_mcontext.mc_gpregs.gp_elr;
2128	*bp = ucontext->uc_mcontext.mc_gpregs.gp_x[29];
2129	*sp = ucontext->uc_mcontext.mc_gpregs.gp_sp;
2130	# else
2131	ucontext_t *ucontext = (ucontext_t *)context;
2132	*pc = ucontext->uc_mcontext.pc;
2133	*bp = ucontext->uc_mcontext.regs[29];
2134	*sp = ucontext->uc_mcontext.sp;
2135	# endif
2136	# elif defined(__hppa__)
2137	ucontext_t *ucontext = (ucontext_t *)context;
2138	*pc = ucontext->uc_mcontext.sc_iaoq[0];
2139	/* GCC uses %r3 whenever a frame pointer is needed. */
2140	*bp = ucontext->uc_mcontext.sc_gr[3];
2141	*sp = ucontext->uc_mcontext.sc_gr[30];
2142	# elif defined(__x86_64__)
2143	# if SANITIZER_FREEBSD
2144	ucontext_t *ucontext = (ucontext_t *)context;
2145	*pc = ucontext->uc_mcontext.mc_rip;
2146	*bp = ucontext->uc_mcontext.mc_rbp;
2147	*sp = ucontext->uc_mcontext.mc_rsp;
2148	# else
2149	ucontext_t *ucontext = (ucontext_t *)context;
2150	*pc = ucontext->uc_mcontext.gregs[REG_RIP];
2151	*bp = ucontext->uc_mcontext.gregs[REG_RBP];
2152	*sp = ucontext->uc_mcontext.gregs[REG_RSP];
2153	# endif
2154	# elif defined(__i386__)
2155	# if SANITIZER_FREEBSD
2156	ucontext_t *ucontext = (ucontext_t *)context;
2157	*pc = ucontext->uc_mcontext.mc_eip;
2158	*bp = ucontext->uc_mcontext.mc_ebp;
2159	*sp = ucontext->uc_mcontext.mc_esp;
2160	# else
2161	ucontext_t *ucontext = (ucontext_t *)context;
2162	# if SANITIZER_SOLARIS
2163	/* Use the numeric values: the symbolic ones are undefined by llvm
2164	include/llvm/Support/Solaris.h. */
2165	# ifndef REG_EIP
2166	# define REG_EIP 14 // REG_PC
2167	# endif
2168	# ifndef REG_EBP
2169	# define REG_EBP 6 // REG_FP
2170	# endif
2171	# ifndef REG_UESP
2172	# define REG_UESP 17 // REG_SP
2173	# endif
2174	# endif
2175	*pc = ucontext->uc_mcontext.gregs[REG_EIP];
2176	*bp = ucontext->uc_mcontext.gregs[REG_EBP];
2177	*sp = ucontext->uc_mcontext.gregs[REG_UESP];
2178	# endif
2179	# elif defined(__powerpc__) || defined(__powerpc64__)
2180	# if SANITIZER_FREEBSD
2181	ucontext_t *ucontext = (ucontext_t *)context;
2182	*pc = ucontext->uc_mcontext.mc_srr0;
2183	*sp = ucontext->uc_mcontext.mc_frame[1];
2184	*bp = ucontext->uc_mcontext.mc_frame[31];
2185	# else
2186	ucontext_t *ucontext = (ucontext_t *)context;
2187	*pc = ucontext->uc_mcontext.regs->nip;
2188	*sp = ucontext->uc_mcontext.regs->gpr[PT_R1];
2189	// The powerpc{,64}-linux ABIs do not specify r31 as the frame
2190	// pointer, but GCC always uses r31 when we need a frame pointer.
2191	*bp = ucontext->uc_mcontext.regs->gpr[PT_R31];
2192	# endif
2193	# elif defined(__sparc__)
2194	# if defined(__arch64__) || defined(__sparcv9)
2195	# define STACK_BIAS 2047
2196	# else
2197	# define STACK_BIAS 0
2198	# endif
2199	# if SANITIZER_SOLARIS
2200	ucontext_t *ucontext = (ucontext_t *)context;
2201	*pc = ucontext->uc_mcontext.gregs[REG_PC];
2202	*sp = ucontext->uc_mcontext.gregs[REG_O6] + STACK_BIAS;
2203	# else
2204	// Historical BSDism here.
2205	struct sigcontext *scontext = (struct sigcontext *)context;
2206	# if defined(__arch64__)
2207	*pc = scontext->sigc_regs.tpc;
2208	*sp = scontext->sigc_regs.u_regs[14] + STACK_BIAS;
2209	# else
2210	*pc = scontext->si_regs.pc;
2211	*sp = scontext->si_regs.u_regs[14];
2212	# endif
2213	# endif
2214	*bp = (uptr)((uhwptr *)*sp)[14] + STACK_BIAS;
2215	# elif defined(__mips__)
2216	ucontext_t *ucontext = (ucontext_t *)context;
2217	*pc = ucontext->uc_mcontext.pc;
2218	*bp = ucontext->uc_mcontext.gregs[30];
2219	*sp = ucontext->uc_mcontext.gregs[29];
2220	# elif defined(__s390__)
2221	ucontext_t *ucontext = (ucontext_t *)context;
2222	# if defined(__s390x__)
2223	*pc = ucontext->uc_mcontext.psw.addr;
2224	# else
2225	*pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
2226	# endif
2227	*bp = ucontext->uc_mcontext.gregs[11];
2228	*sp = ucontext->uc_mcontext.gregs[15];
2229	# elif defined(__riscv)
2230	ucontext_t *ucontext = (ucontext_t *)context;
2231	# if SANITIZER_FREEBSD
2232	*pc = ucontext->uc_mcontext.mc_gpregs.gp_sepc;
2233	*bp = ucontext->uc_mcontext.mc_gpregs.gp_s[0];
2234	*sp = ucontext->uc_mcontext.mc_gpregs.gp_sp;
2235	# else
2236	*pc = ucontext->uc_mcontext.__gregs[REG_PC];
2237	*bp = ucontext->uc_mcontext.__gregs[REG_S0];
2238	*sp = ucontext->uc_mcontext.__gregs[REG_SP];
2239	# endif
2240	# elif defined(__hexagon__)
2241	ucontext_t *ucontext = (ucontext_t *)context;
2242	*pc = ucontext->uc_mcontext.pc;
2243	*bp = ucontext->uc_mcontext.r30;
2244	*sp = ucontext->uc_mcontext.r29;
2245	# elif defined(__loongarch__)
2246	ucontext_t *ucontext = (ucontext_t *)context;
2247	*pc = ucontext->uc_mcontext.__pc;
2248	*bp = ucontext->uc_mcontext.__gregs[22];
2249	*sp = ucontext->uc_mcontext.__gregs[3];
2250	# else
2251	# error "Unsupported arch"
2252	# endif
2253	}
2254
2255	void SignalContext::InitPcSpBp() { GetPcSpBp(context, pc: &pc, sp: &sp, bp: &bp); }
2256
2257	void InitializePlatformEarly() {
2258	// Do nothing.
2259	}
2260
2261	void CheckASLR() {
2262	# if SANITIZER_NETBSD
2263	int mib[3];
2264	int paxflags;
2265	uptr len = sizeof(paxflags);
2266
2267	mib[0] = CTL_PROC;
2268	mib[1] = internal_getpid();
2269	mib[2] = PROC_PID_PAXFLAGS;
2270
2271	if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2272	Printf("sysctl failed\n");
2273	Die();
2274	}
2275
2276	if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_ASLR)) {
2277	Printf(
2278	"This sanitizer is not compatible with enabled ASLR.\n"
2279	"To disable ASLR, please run \"paxctl +a %s\" and try again.\n",
2280	GetArgv()[0]);
2281	Die();
2282	}
2283	# elif SANITIZER_FREEBSD
2284	int aslr_status;
2285	int r = internal_procctl(P_PID, 0, PROC_ASLR_STATUS, &aslr_status);
2286	if (UNLIKELY(r == -1)) {
2287	// We're making things less 'dramatic' here since
2288	// the cmd is not necessarily guaranteed to be here
2289	// just yet regarding FreeBSD release
2290	return;
2291	}
2292	if ((aslr_status & PROC_ASLR_ACTIVE) != 0) {
2293	VReport(1,
2294	"This sanitizer is not compatible with enabled ASLR "
2295	"and binaries compiled with PIE\n"
2296	"ASLR will be disabled and the program re-executed.\n");
2297	int aslr_ctl = PROC_ASLR_FORCE_DISABLE;
2298	CHECK_NE(internal_procctl(P_PID, 0, PROC_ASLR_CTL, &aslr_ctl), -1);
2299	ReExec();
2300	}
2301	# elif SANITIZER_PPC64V2
2302	// Disable ASLR for Linux PPC64LE.
2303	int old_personality = personality(0xffffffff);
2304	if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
2305	VReport(1,
2306	"WARNING: Program is being run with address space layout "
2307	"randomization (ASLR) enabled which prevents the thread and "
2308	"memory sanitizers from working on powerpc64le.\n"
2309	"ASLR will be disabled and the program re-executed.\n");
2310	CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
2311	ReExec();
2312	}
2313	# else
2314	// Do nothing
2315	# endif
2316	}
2317
2318	void CheckMPROTECT() {
2319	# if SANITIZER_NETBSD
2320	int mib[3];
2321	int paxflags;
2322	uptr len = sizeof(paxflags);
2323
2324	mib[0] = CTL_PROC;
2325	mib[1] = internal_getpid();
2326	mib[2] = PROC_PID_PAXFLAGS;
2327
2328	if (UNLIKELY(internal_sysctl(mib, 3, &paxflags, &len, NULL, 0) == -1)) {
2329	Printf("sysctl failed\n");
2330	Die();
2331	}
2332
2333	if (UNLIKELY(paxflags & CTL_PROC_PAXFLAGS_MPROTECT)) {
2334	Printf("This sanitizer is not compatible with enabled MPROTECT\n");
2335	Die();
2336	}
2337	# else
2338	// Do nothing
2339	# endif
2340	}
2341
2342	void CheckNoDeepBind(const char *filename, int flag) {
2343	# ifdef RTLD_DEEPBIND
2344	if (flag & RTLD_DEEPBIND) {
2345	Report(
2346	format: "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag"
2347	" which is incompatible with sanitizer runtime "
2348	"(see https://github.com/google/sanitizers/issues/611 for details"
2349	"). If you want to run %s library under sanitizers please remove "
2350	"RTLD_DEEPBIND from dlopen flags.\n",
2351	filename, filename);
2352	Die();
2353	}
2354	# endif
2355	}
2356
2357	uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
2358	uptr *largest_gap_found,
2359	uptr *max_occupied_addr) {
2360	UNREACHABLE("FindAvailableMemoryRange is not available");
2361	return 0;
2362	}
2363
2364	bool GetRandom(void *buffer, uptr length, bool blocking) {
2365	if (!buffer || !length || length > 256)
2366	return false;
2367	# if SANITIZER_USE_GETENTROPY
2368	uptr rnd = getentropy(buffer, length);
2369	int rverrno = 0;
2370	if (internal_iserror(rnd, &rverrno) && rverrno == EFAULT)
2371	return false;
2372	else if (rnd == 0)
2373	return true;
2374	# endif // SANITIZER_USE_GETENTROPY
2375
2376	# if SANITIZER_USE_GETRANDOM
2377	static atomic_uint8_t skip_getrandom_syscall;
2378	if (!atomic_load_relaxed(a: &skip_getrandom_syscall)) {
2379	// Up to 256 bytes, getrandom will not be interrupted.
2380	uptr res = internal_syscall(SYSCALL(getrandom), arg1: buffer, arg2: length,
2381	arg3: blocking ? 0 : GRND_NONBLOCK);
2382	int rverrno = 0;
2383	if (internal_iserror(retval: res, rverrno: &rverrno) && rverrno == ENOSYS)
2384	atomic_store_relaxed(a: &skip_getrandom_syscall, v: 1);
2385	else if (res == length)
2386	return true;
2387	}
2388	# endif // SANITIZER_USE_GETRANDOM
2389	// Up to 256 bytes, a read off /dev/urandom will not be interrupted.
2390	// blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
2391	uptr fd = internal_open(filename: "/dev/urandom", O_RDONLY);
2392	if (internal_iserror(retval: fd))
2393	return false;
2394	uptr res = internal_read(fd, buf: buffer, count: length);
2395	if (internal_iserror(retval: res))
2396	return false;
2397	internal_close(fd);
2398	return true;
2399	}
2400
2401	} // namespace __sanitizer
2402
2403	#endif
2404