/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/alg/alg.h"
#include "libc/alg/bisectcarleft.internal.h"
#include "libc/bits/safemacros.internal.h"
#include "libc/bits/weaken.h"
#include "libc/calls/calls.h"
#include "libc/calls/sigbits.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/fmt/conv.h"
#include "libc/fmt/fmt.h"
#include "libc/fmt/itoa.h"
#include "libc/log/backtrace.internal.h"
#include "libc/log/libfatal.internal.h"
#include "libc/log/log.h"
#include "libc/nexgen32e/gc.internal.h"
#include "libc/runtime/gc.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/stack.h"
#include "libc/runtime/symbols.internal.h"
#include "libc/stdio/append.internal.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/fileno.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/sig.h"
#include "libc/x/x.h"
#define kBacktraceMaxFrames 128
#define kBacktraceBufSize ((kBacktraceMaxFrames - 1) * (18 + 1))
static noasan int PrintBacktraceUsingAddr2line(int fd,
const struct StackFrame *bp) {
ssize_t got;
intptr_t addr;
size_t i, j, gi;
int ws, pid, pipefds[2];
struct Garbages *garbage;
sigset_t chldmask, savemask;
const struct StackFrame *frame;
char *debugbin, *p1, *p2, *p3, *addr2line;
char buf[kBacktraceBufSize], *argv[kBacktraceMaxFrames];
if (IsOpenbsd()) return -1;
if (IsWindows()) return -1;
if (!(debugbin = FindDebugBinary())) return -1;
if (!(addr2line = GetAddr2linePath())) return -1;
i = 0;
j = 0;
argv[i++] = "addr2line";
argv[i++] = "-a"; /* filter out w/ shell script wrapper for old versions */
argv[i++] = "-pCife";
argv[i++] = debugbin;
garbage = weaken(__garbage);
gi = garbage ? garbage->i : 0;
for (frame = bp; frame && i < kBacktraceMaxFrames - 1; frame = frame->next) {
addr = frame->addr;
if (addr == weakaddr("__gc")) {
do {
--gi;
} while ((addr = garbage->p[gi].ret) == weakaddr("__gc"));
}
argv[i++] = buf + j;
buf[j++] = '0';
buf[j++] = 'x';
j += uint64toarray_radix16(addr - 1, buf + j) + 1;
}
argv[i++] = NULL;
sigemptyset(&chldmask);
sigaddset(&chldmask, SIGCHLD);
sigprocmask(SIG_BLOCK, &chldmask, &savemask);
pipe(pipefds);
if (!(pid = vfork())) {
sigprocmask(SIG_SETMASK, &savemask, NULL);
dup2(pipefds[1], 1);
close(pipefds[0]);
close(pipefds[1]);
execvp(addr2line, argv);
_exit(127);
}
close(pipefds[1]);
while ((got = read(pipefds[0], buf, kBacktraceBufSize)) > 0) {
p1 = buf;
p3 = p1 + got;
/*
* Remove deep libc error reporting facilities from backtraces.
*
* For example, if the following shows up in Emacs:
*
* 40d097: __die at libc/log/die.c:33
* 434daa: __asan_die at libc/intrin/asan.c:483
* 435146: __asan_report_memory_fault at libc/intrin/asan.c:524
* 435b32: __asan_report_store at libc/intrin/asan.c:719
* 43472e: __asan_report_store1 at libc/intrin/somanyasan.S:118
* 40c3a9: GetCipherSuite at net/https/getciphersuite.c:80
* 4383a5: GetCipherSuite_test at test/net/https/getciphersuite.c:23
* ...
*
* Then it's unpleasant to need to press C-x C-n six times.
*/
#if 0
while ((p2 = memchr(p1, '\n', p3 - p1))) {
if (memmem(p1, p2 - p1, ": __asan_", 9) ||
memmem(p1, p2 - p1, ": __die", 7)) {
memmove(p1, p2 + 1, p3 - (p2 + 1));
p3 -= p2 + 1 - p1;
} else {
p1 = p2 + 1;
break;
}
}
#endif
/*
* remove racist output from gnu tooling, that can't be disabled
* otherwise, since it breaks other tools like emacs that aren't
* equipped to ignore it, and what's most problematic is that
* addr2line somehow manages to put the racism onto the one line
* in the backtrace we actually care about.
*/
for (got = p3 - buf, p1 = buf; got;) {
if ((p2 = memmem(p1, got, " (discriminator ",
strlen(" (discriminator ") - 1)) &&
(p3 = memchr(p2, '\n', got - (p2 - p1)))) {
if (p3 > p2 && p3[-1] == '\r') --p3;
__write(p1, p2 - p1);
got -= p3 - p1;
p1 += p3 - p1;
} else {
__write(p1, got);
break;
}
}
}
close(pipefds[0]);
while (waitpid(pid, &ws, 0) == -1) {
if (errno == EINTR) continue;
return -1;
}
sigprocmask(SIG_SETMASK, &savemask, NULL);
if (WIFEXITED(ws) && !WEXITSTATUS(ws)) {
return 0;
} else {
return -1;
}
}
static noasan int PrintBacktrace(int fd, const struct StackFrame *bp) {
if (!IsTiny()) {
if (PrintBacktraceUsingAddr2line(fd, bp) != -1) {
return 0;
}
}
return PrintBacktraceUsingSymbols(fd, bp, GetSymbolTable());
}
noasan void ShowBacktrace(int fd, const struct StackFrame *bp) {
/* asan runtime depends on this function */
static bool noreentry;
++g_ftrace;
if (!bp) bp = __builtin_frame_address(0);
if (!noreentry) {
noreentry = true;
PrintBacktrace(fd, bp);
noreentry = false;
}
--g_ftrace;
}