cosmopolitan/libc/log/showcrashreports.c

81 lines
3.8 KiB
C

/*-*- 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 │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/bits/bits.h"
#include "libc/calls/calls.h"
#include "libc/calls/sigbits.h"
#include "libc/calls/typedef/sigaction_f.h"
#include "libc/dce.h"
#include "libc/log/internal.h"
#include "libc/log/log.h"
#include "libc/log/ubsan.internal.h"
#include "libc/macros.h"
#include "libc/nt/signals.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/sa.h"
#include "libc/sysv/consts/sig.h"
STATIC_YOINK("__die");
STATIC_YOINK("__ubsan_abort");
extern const unsigned char __oncrash_thunks[7][11];
/**
* Installs crash signal handlers.
*
* Normally, only functions calling die() will print backtraces. This
* function may be called at program startup to install handlers that
* will display similar information, for most types of crashes.
*
* - Backtraces
* - CPU state printout
* - Automatic debugger attachment
*
* Another trick this function enables, is you can press CTRL+\ to open
* the debugger GUI at any point while the program is running. It can be
* useful, for example, if a program is caught in an infinite loop.
*
* @see callexitontermination()
*/
void showcrashreports(void) {
size_t i;
struct sigaction sa;
/* <SYNC-LIST>: oncrashthunks.S */
kCrashSigs[0] = SIGQUIT; /* ctrl+\ aka ctrl+break */
kCrashSigs[1] = SIGFPE; /* 1 / 0 */
kCrashSigs[2] = SIGILL; /* illegal instruction */
kCrashSigs[3] = SIGSEGV; /* bad memory access */
kCrashSigs[4] = SIGTRAP; /* bad system call */
kCrashSigs[5] = SIGABRT; /* abort() called */
kCrashSigs[6] = SIGBUS; /* misaligned, noncanonical ptr, etc. */
/* </SYNC-LIST>: oncrashthunks.S */
memset(&sa, 0, sizeof(sa));
sa.sa_flags = SA_RESETHAND;
sigfillset(&sa.sa_mask);
for (i = 0; i < ARRAYLEN(kCrashSigs); ++i) {
sigdelset(&sa.sa_mask, kCrashSigs[i]);
}
for (i = 0; i < ARRAYLEN(kCrashSigs); ++i) {
if (kCrashSigs[i]) {
sa.sa_sigaction = (sigaction_f)__oncrash_thunks[i];
sigaction(kCrashSigs[i], &sa, &g_oldcrashacts[i]);
}
}
}