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Implement crash reporting for AARCH64

Browse source 
The ShowCrashReports() feature for aarch64 should work even better than
the x86 crash reports. Thanks to the benefit of hindsight these reports
should be rock solid reliable and beautiful to read.

This change also improves the syscall polyfills for aarch64. Some of the
sys_foo() functions have been removed, usually because they're legacy or
downright footguns not worth building.
This commit is contained in:
Justine Tunney 2023-05-12 05:47:54 -07:00
parent 285e8a2348
commit 1f2a5a8fc1
No known key found for this signature in database
GPG key ID: BE714B4575D6E328
42 changed files with 540 additions and 247 deletions
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28
libc/log/addr2linepath.c
View file

@ -16,8 +16,34 @@
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/log/log.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
static const char *TryMonoRepoPath(const char *var, const char *path) {
const char buf[PATH_MAX];
if (getenv(var)) return 0;
if (!isexecutable(path)) return 0;
if (*path != '/') {
if (getcwd(buf, sizeof(buf)) <= 0) return 0;
strlcat(buf, "/", sizeof(buf));
strlcat(buf, path, sizeof(buf));
path = buf;
}
setenv(var, path, false);
return getenv(var);
}
const char *GetAddr2linePath(void) {
return commandvenv("ADDR2LINE", "addr2line");
const char *s = 0;
#ifdef __x86_64__
s = TryMonoRepoPath("ADDR2LINE",
"o/third_party/gcc/bin/x86_64-linux-musl-addr2line");
#elif defined(__aarch64__)
s = TryMonoRepoPath("ADDR2LINE",
"o/third_party/gcc/bin/aarch64-linux-musl-addr2line");
#endif
if (!s) s = commandvenv("ADDR2LINE", "addr2line");
return s;
}

4
libc/log/backtrace2.c
View file

@ -117,13 +117,13 @@ static int PrintBacktraceUsingAddr2line(int fd, const struct StackFrame *bp) {
if (sys_pipe2(pipefds, O_CLOEXEC) == -1) {
return -1;
}
if ((pid = __sys_fork().ax) == -1) {
if ((pid = sys_fork()) == -1) {
sys_close(pipefds[0]);
sys_close(pipefds[1]);
return -1;
}
if (!pid) {
sys_dup2(pipefds[1], 1);
sys_dup2(pipefds[1], 1, 0);
sys_execve(addr2line, argv, environ);
_Exit(127);
}

34
libc/log/backtrace3.c
View file

@ -67,25 +67,33 @@ noinstrument noasan int PrintBacktraceUsingSymbols(int fd,
break;
}
addr = frame->addr;
if (!addr) break;
if (addr == (intptr_t)_weaken(__gc)) {
do {
--gi;
} while ((addr = garbage->p[gi].ret) == (intptr_t)_weaken(__gc));
}
/*
* we subtract one to handle the case of noreturn functions with a
* call instruction at the end, since %rip in such cases will point
* to the start of the next function. generally %rip always points
* to the byte after the instruction. one exception is in case like
* __restore_rt where the kernel creates a stack frame that points
* to the beginning of the function.
*/
if ((symbol = __get_symbol(st, addr - 1)) != -1 ||
(symbol = __get_symbol(st, addr - 0)) != -1) {
addend = addr - st->addr_base;
addend -= st->symbols[symbol].x;
if (addr) {
if (
#ifdef __x86_64__
/*
* we subtract one to handle the case of noreturn functions
* with a call instruction at the end, since %rip in such
* cases will point to the start of the next function.
* generally %rip always points to the byte after the
* instruction. one exception is in case like __restore_rt
* where the kernel creates a stack frame that points to the
* beginning of the function.
*/
(symbol = __get_symbol(st, addr - 1)) != -1 ||
#endif
(symbol = __get_symbol(st, addr)) != -1) {
addend = addr - st->addr_base;
addend -= st->symbols[symbol].x;
} else {
addend = 0;
}
} else {
symbol = 0;
addend = 0;
}
kprintf("%012lx %lx %s%+d\n", frame, addr, __get_symbol_name(st, symbol),

5
libc/log/internal.h
View file

@ -1,19 +1,18 @@
#ifndef COSMOPOLITAN_LIBC_LOG_INTERNAL_H_
#define COSMOPOLITAN_LIBC_LOG_INTERNAL_H_
#include "libc/calls/struct/siginfo.h"
#include "libc/calls/ucontext.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
extern _Hide bool __nocolor;
extern _Hide int kCrashSigs[8];
extern _Hide bool _wantcrashreports;
extern _Hide bool g_isrunningundermake;
void __start_fatal(const char *, int) _Hide;
void __oncrash(int, struct siginfo *, struct ucontext *) relegated;
void __restore_tty(void);
void RestoreDefaultCrashSignalHandlers(void);
void __oncrash_amd64(int, struct siginfo *, void *) relegated;
void __oncrash_arm64(int, struct siginfo *, void *) relegated;
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */

3
libc/log/log.mk
View file

@ -77,7 +77,8 @@ o/$(MODE)/libc/log/checkaligned.o \
o/$(MODE)/libc/log/checkfail.o \
o/$(MODE)/libc/log/checkfail_ndebug.o \
o/$(MODE)/libc/log/restoretty.o \
o/$(MODE)/libc/log/oncrash.o \
o/$(MODE)/libc/log/oncrash_amd64.o \
o/$(MODE)/libc/log/oncrash_arm64.o \
o/$(MODE)/libc/log/onkill.o \
o/$(MODE)/libc/log/startfatal.o \
o/$(MODE)/libc/log/startfatal_ndebug.o \

17
libc/log/oncrash.c → libc/log/oncrash_amd64.c
View file

@ -46,16 +46,10 @@
#include "libc/thread/thread.h"
#include "libc/thread/tls.h"
#include "third_party/libcxx/math.h"
#ifdef __x86_64__
/**
* @fileoverview Abnormal termination handling & GUI debugging.
* @see libc/onkill.c
*/
STATIC_YOINK("strerror_wr"); /* for kprintf %m */
STATIC_YOINK("strsignal"); /* for kprintf %G */
STATIC_YOINK("strerror_wr"); // for kprintf %m
STATIC_YOINK("strsignal_r"); // for kprintf %G
static const char kGregOrder[17] forcealign(1) = {
13, 11, 8, 14, 12, 9, 10, 15, 16, 0, 1, 2, 3, 4, 5, 6, 7,
@ -69,8 +63,6 @@ static const char kGregNames[17][4] forcealign(1) = {
static const char kCpuFlags[12] forcealign(1) = "CVPRAKZSTIDO";
static const char kFpuExceptions[6] forcealign(1) = "IDZOUP";
int kCrashSigs[8];
relegated static void ShowFunctionCalls(ucontext_t *ctx) {
struct StackFrame *bp;
struct StackFrame goodframe;
@ -298,11 +290,12 @@ static wontreturn relegated noinstrument void __minicrash(int sig,
* @threadsafe
* @vforksafe
*/
relegated void __oncrash(int sig, struct siginfo *si, ucontext_t *ctx) {
relegated void __oncrash_amd64(int sig, struct siginfo *si, void *arg) {
int bZero;
intptr_t rip;
int me, owner;
int gdbpid, err;
ucontext_t *ctx = arg;
static atomic_int once;
static atomic_int once2;
STRACE("__oncrash rip %x", ctx->uc_mcontext.rip);
@ -321,7 +314,7 @@ relegated void __oncrash(int sig, struct siginfo *si, ucontext_t *ctx) {
} else if (__nocolor || g_isrunningundermake) {
gdbpid = -1;
} else if (!IsTiny() && IsLinux() && FindDebugBinary() && !__isworker) {
RestoreDefaultCrashSignalHandlers();
// RestoreDefaultCrashSignalHandlers();
gdbpid = AttachDebugger(
((sig == SIGTRAP || sig == SIGQUIT) &&
(rip >= (intptr_t)&_base && rip < (intptr_t)&_etext))

277
libc/log/oncrash_arm64.c Normal file
View file

@ -0,0 +1,277 @@
/*-*- 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 2023 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/calls/calls.h"
#include "libc/calls/struct/rusage.internal.h"
#include "libc/calls/struct/siginfo.h"
#include "libc/calls/struct/sigset.h"
#include "libc/calls/struct/sigset.internal.h"
#include "libc/calls/struct/utsname.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/calls/ucontext.h"
#include "libc/errno.h"
#include "libc/intrin/kprintf.h"
#include "libc/log/internal.h"
#include "libc/log/log.h"
#include "libc/macros.internal.h"
#include "libc/nexgen32e/stackframe.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/stack.h"
#include "libc/runtime/symbols.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/sig.h"
#include "libc/thread/thread.h"
#ifdef __aarch64__
STATIC_YOINK("strerror_wr"); // for kprintf %m
STATIC_YOINK("strsignal_r"); // for kprintf %G
#define RESET "\e[0m"
#define STRONG "\e[30;101m"
#define RED "\e[31;1m"
#define GREEN "\e[32;1m"
#define BLUE "\e[34;1m"
#define YELLOW "\e[33;1m"
#define MAGENTA "\e[35;1m"
struct Buffer {
char *p;
int n;
int i;
};
static void Append(struct Buffer *b, const char *fmt, ...) {
va_list va;
va_start(va, fmt);
b->i += kvsnprintf(b->p + b->i, b->n - b->i, fmt, va);
va_end(va);
}
static const char *ColorRegister(int r) {
if (__nocolor) return "";
switch (r) {
case 0: // arg / res
case 1: // arg / res
case 2: // arg / res
case 3: // arg / res
case 4: // arg / res
case 5: // arg / res
case 6: // arg / res
case 7: // arg / res
return GREEN;
case 9: // volatile
case 10: // volatile
case 11: // volatile
case 12: // volatile
case 13: // volatile
case 14: // volatile
case 15: // volatile
return BLUE;
case 19: // saved
case 20: // saved
case 21: // saved
case 22: // saved
case 23: // saved
case 24: // saved
case 25: // saved
case 26: // saved
case 27: // saved
case 28: // saved
return MAGENTA;
case 29: // frame pointer
case 30: // return pointer
case 31: // stack pointer
return RED;
default: // miscellaneous registers
return YELLOW;
}
}
static bool AppendFileLine(struct Buffer *b, const char *addr2line,
const char *debugbin, long addr) {
ssize_t rc;
char buf[128];
int j, k, ws, pid, pfd[2];
if (!debugbin || !*debugbin) return false;
if (!addr2line || !*addr2line) return false;
if (sys_pipe(pfd)) return false;
ksnprintf(buf, sizeof(buf), "%lx", addr);
if ((pid = vfork()) == -1) {
sys_close(pfd[1]);
sys_close(pfd[0]);
return false;
}
if (!pid) {
sys_close(pfd[0]);
sys_dup2(pfd[1], 1, 0);
sys_close(2);
__sys_execve(addr2line,
(char *const[]){addr2line, "-pifCe", debugbin, buf, 0},
(char *const[]){0});
_Exit(127);
}
sys_close(pfd[1]);
// copy addr2line stdout to buffer. normally it is "file:line\n".
// however additional lines can get created for inline functions.
j = b->i;
Append(b, "in ");
k = b->i;
while ((rc = sys_read(pfd[0], buf, sizeof(buf))) > 0) {
Append(b, "%.*s", (int)rc, buf);
}
sys_close(pfd[0]);
if (sys_wait4(pid, &ws, 0, 0) != -1 && !ws && b->p[k] != ':' &&
b->p[k] != '?' && b->p[b->i - 1] == '\n') {
--b->i; // chomp last newline
return true;
} else {
b->i = j; // otherwise reset the buffer
return false;
}
}
relegated void __oncrash_arm64(int sig, struct siginfo *si, void *arg) {
char buf[10000];
static _Thread_local bool once;
struct Buffer b[1] = {{buf, sizeof(buf)}};
b->p[b->i++] = '\n';
if (!once) {
int i, j;
const char *kind;
const char *reset;
const char *strong;
ucontext_t *ctx = arg;
char host[64] = "unknown";
struct utsname names = {0};
once = true;
ftrace_enabled(-1);
strace_enabled(-1);
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0);
__restore_tty();
uname(&names);
gethostname(host, sizeof(host));
reset = !__nocolor ? RESET : "";
strong = !__nocolor ? STRONG : "";
if (ctx && (ctx->uc_mcontext.sp & (GetStackSize() - 1)) <= GUARDSIZE) {
kind = "Stack Overflow";
} else {
kind = GetSiCodeName(sig, si->si_code);
}
Append(b,
"%serror%s: Uncaught %G (%s) on %s pid %d tid %d\n"
" %s\n"
" %m\n"
" %s %s %s %s\n",
strong, reset, sig, kind, host, getpid(), gettid(),
program_invocation_name, names.sysname, names.version,
names.nodename, names.release, "yo");
if (ctx) {
long pc;
char line[256];
int addend, symbol;
const char *debugbin;
const char *addr2line;
struct StackFrame *fp;
struct SymbolTable *st;
st = GetSymbolTable();
debugbin = FindDebugBinary();
addr2line = GetAddr2linePath();
if (ctx->uc_mcontext.fault_address) {
Append(b, " fault_address = %#lx\n", ctx->uc_mcontext.fault_address);
}
// PRINT REGISTERS
for (i = 0; i < 8; ++i) {
Append(b, " ");
for (j = 0; j < 4; ++j) {
int r = 8 * j + i;
if (j) Append(b, " ");
Append(b, "%s%016lx%s %sr%d", ColorRegister(r),
ctx->uc_mcontext.regs[r], reset, r == 8 || r == 9 ? " " : "",
r);
}
Append(b, "\n");
}
// PRINT CURRENT LOCATION
pc = ctx->uc_mcontext.pc;
Append(b, " %016lx sp %lx pc", ctx->uc_mcontext.sp, pc);
if (pc && (symbol = __get_symbol(st, pc))) {
addend = pc - st->addr_base;
addend -= st->symbols[symbol].x;
Append(b, " ");
if (!AppendFileLine(b, addr2line, debugbin, pc)) {
Append(b, "%s", __get_symbol_name(st, symbol));
if (addend) Append(b, "%+d", addend);
}
}
Append(b, "\n");
// PRINT LINKED LOCATION
pc = ctx->uc_mcontext.regs[30];
Append(b, " %016lx sp %lx lr", ctx->uc_mcontext.sp, pc);
if (pc && (symbol = __get_symbol(st, pc))) {
addend = pc - st->addr_base;
addend -= st->symbols[symbol].x;
Append(b, " ");
if (!AppendFileLine(b, addr2line, debugbin, pc)) {
Append(b, "%s", __get_symbol_name(st, symbol));
if (addend) Append(b, "%+d", addend);
}
}
Append(b, "\n");
// PRINT FRAME POINTERS
fp = (struct StackFrame *)ctx->uc_mcontext.regs[29];
for (i = 0; fp; fp = fp->next) {
if (kisdangerous(fp)) {
Append(b, " %016lx <dangerous fp>\n", fp);
break;
}
if (++i == 100) {
Append(b, " <truncated backtrace>\n");
break;
}
if ((pc = fp->addr)) {
if ((symbol = __get_symbol(st, pc))) {
addend = pc - st->addr_base;
addend -= st->symbols[symbol].x;
} else {
addend = 0;
}
} else {
symbol = 0;
addend = 0;
}
Append(b, " %016lx fp %lx lr ", fp, pc);
if (!AppendFileLine(b, addr2line, debugbin, pc)) {
Append(b, "%s", __get_symbol_name(st, symbol));
if (addend) Append(b, "%+d", addend);
}
Append(b, "\n");
}
}
} else {
Append(b, "got %G while crashing!\n");
}
sys_write(2, b->p, MIN(b->i, b->n));
_Exit(128 + sig);
}
#endif /* __aarch64__ */

103
libc/log/oncrashthunks.S
View file

@ -1,103 +0,0 @@
/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
│vi: set et ft=asm ts=8 tw=8 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/macros.internal.h"
// These function names make it a bit more obvious which signal
// caused the crash, particularly in the GDB GUI. They're coded
// into an array to pinch pennies on code size registering them.
__oncrash_thunks:
// <SYNC-LIST>: showcrashreports.c, oncrashthunks.S, oncrash.c, internal.h
.org 11*0
__oncrash_sigquit:
push %rbp
mov %rsp,%rbp
call __oncrash
pop %rbp
ret
.endfn __oncrash_sigquit,globl
.org 11*1
__oncrash_sigfpe:
push %rbp
mov %rsp,%rbp
call __oncrash
pop %rbp
ret
.endfn __oncrash_sigfpe,globl
.org 11*2
__oncrash_sigill:
push %rbp
mov %rsp,%rbp
call __oncrash
pop %rbp
ret
.endfn __oncrash_sigill,globl
.org 11*3
__oncrash_sigsegv:
push %rbp
mov %rsp,%rbp
call __oncrash
pop %rbp
ret
.endfn __oncrash_sigsegv,globl
.org 11*4
__oncrash_sigtrap:
push %rbp
mov %rsp,%rbp
call __oncrash
pop %rbp
ret
.endfn __oncrash_sigtrap,globl
.org 11*5
__oncrash_sigabrt:
push %rbp
mov %rsp,%rbp
call __oncrash
pop %rbp
ret
.endfn __oncrash_sigabrt,globl
.org 11*6
__oncrash_sigbus:
push %rbp
mov %rsp,%rbp
call __oncrash
pop %rbp
ret
.endfn __oncrash_sigbus,globl
.org 11*7
__oncrash_sigurg:
push %rbp
mov %rsp,%rbp
call __oncrash
pop %rbp
ret
.endfn __oncrash_sigurg,globl
// </SYNC-LIST>: showcrashreports.c, oncrashthunks.S, oncrash.c, internal.h
.endobj __oncrash_thunks,globl

130
libc/log/showcrashreports.c
View file

@ -25,6 +25,8 @@
#include "libc/log/internal.h"
#include "libc/log/log.h"
#include "libc/macros.internal.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/stack.h"
#include "libc/runtime/symbols.internal.h"
#include "libc/str/str.h"
@ -34,8 +36,6 @@
#include "libc/sysv/consts/sig.h"
#include "libc/sysv/consts/ss.h"
#ifdef __x86_64__
STATIC_YOINK("zipos"); // for symtab
STATIC_YOINK("__die"); // for backtracing
STATIC_YOINK("ShowBacktrace"); // for backtracing
@ -44,44 +44,80 @@ STATIC_YOINK("PrintBacktraceUsingSymbols"); // for backtracing
STATIC_YOINK("malloc_inspect_all"); // for asan memory origin
STATIC_YOINK("GetSymbolByAddr"); // for asan memory origin
static struct sigaction g_oldcrashacts[8];
extern const unsigned char __oncrash_thunks[8][11];
struct CrashHandler {
int sig;
struct sigaction old;
};
static void InstallCrashHandlers(int extraflags) {
int e;
size_t i;
struct sigaction sa;
bzero(&sa, sizeof(sa));
sigfillset(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO | SA_NODEFER | extraflags;
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];
e = errno;
sigaction(kCrashSigs[i], &sa, &g_oldcrashacts[i]);
errno = e;
}
}
static inline void __oncrash(int sig, struct siginfo *si, void *arg) {
#ifdef __x86_64__
__oncrash_amd64(sig, si, arg);
#elif defined(__aarch64__)
__oncrash_arm64(sig, si, arg);
#else
abort();
#endif
}
relegated void RestoreDefaultCrashSignalHandlers(void) {
static void __got_sigquit(int sig, struct siginfo *si, void *arg) {
__oncrash(sig, si, arg);
}
static void __got_sigfpe(int sig, struct siginfo *si, void *arg) {
__oncrash(sig, si, arg);
}
static void __got_sigill(int sig, struct siginfo *si, void *arg) {
__oncrash(sig, si, arg);
}
static void __got_sigsegv(int sig, struct siginfo *si, void *arg) {
__oncrash(sig, si, arg);
}
static void __got_sigtrap(int sig, struct siginfo *si, void *arg) {
__oncrash(sig, si, arg);
}
static void __got_sigabrt(int sig, struct siginfo *si, void *arg) {
__oncrash(sig, si, arg);
}
static void __got_sigbus(int sig, struct siginfo *si, void *arg) {
__oncrash(sig, si, arg);
}
static void __got_sigurg(int sig, struct siginfo *si, void *arg) {
__oncrash(sig, si, arg);
}
static void RemoveCrashHandler(void *arg) {
int e;
size_t i;
sigset_t ss;
struct CrashHandler *ch = arg;
strace_enabled(-1);
sigemptyset(&ss);
sigprocmask(SIG_SETMASK, &ss, NULL);
for (i = 0; i < ARRAYLEN(kCrashSigs); ++i) {
if (kCrashSigs[i]) {
e = errno;
sigaction(kCrashSigs[i], &g_oldcrashacts[i], NULL);
errno = e;
e = errno;
sigaction(ch->sig, &ch->old, NULL);
errno = e;
free(ch);
strace_enabled(+1);
}
static void InstallCrashHandler(int sig, sigaction_f thunk, int extraflags) {
int e;
struct sigaction sa;
struct CrashHandler *ch;
e = errno;
if ((ch = malloc(sizeof(*ch)))) {
ch->sig = sig;
sa.sa_sigaction = thunk;
sigfillset(&sa.sa_mask);
sigdelset(&sa.sa_mask, SIGQUIT);
sigdelset(&sa.sa_mask, SIGFPE);
sigdelset(&sa.sa_mask, SIGILL);
sigdelset(&sa.sa_mask, SIGSEGV);
sigdelset(&sa.sa_mask, SIGTRAP);
sigdelset(&sa.sa_mask, SIGABRT);
sigdelset(&sa.sa_mask, SIGBUS);
sigdelset(&sa.sa_mask, SIGURG);
sa.sa_flags = SA_SIGINFO | SA_NODEFER | extraflags;
if (!sigaction(sig, &sa, &ch->old)) {
__cxa_atexit(RemoveCrashHandler, ch, 0);
}
}
strace_enabled(+1);
errno = e;
}
/**
@ -100,33 +136,25 @@ relegated void RestoreDefaultCrashSignalHandlers(void) {
* useful, for example, if a program is caught in an infinite loop.
*/
void ShowCrashReports(void) {
int ef = 0;
struct sigaltstack ss;
_wantcrashreports = true;
/* <SYNC-LIST>: showcrashreports.c, oncrashthunks.S, oncrash.c */
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. */
kCrashSigs[7] = SIGURG; /* placeholder */
/* </SYNC-LIST>: showcrashreports.c, oncrashthunks.S, oncrash.c */
if (!IsWindows()) {
ef = SA_ONSTACK;
ss.ss_flags = 0;
ss.ss_size = GetStackSize();
// FreeBSD sigaltstack() will EFAULT if we use MAP_STACK here
// OpenBSD sigaltstack() auto-applies MAP_STACK to the memory
_npassert((ss.ss_sp = _mapanon(GetStackSize())));
_npassert(!sigaltstack(&ss, 0));
InstallCrashHandlers(SA_ONSTACK);
} else {
InstallCrashHandlers(0);
}
InstallCrashHandler(SIGQUIT, __got_sigquit, ef); // ctrl+\ aka ctrl+break
InstallCrashHandler(SIGFPE, __got_sigfpe, ef); // 1 / 0
InstallCrashHandler(SIGILL, __got_sigill, ef); // illegal instruction
InstallCrashHandler(SIGSEGV, __got_sigsegv, ef); // bad memory access
InstallCrashHandler(SIGTRAP, __got_sigtrap, ef); // bad system call
InstallCrashHandler(SIGABRT, __got_sigabrt, ef); // abort() called
InstallCrashHandler(SIGBUS, __got_sigbus, ef); // misalign, mmap i/o failed
InstallCrashHandler(SIGURG, __got_sigurg, ef); // placeholder
GetSymbolTable();
}
#else
void ShowCrashReports(void) {
}
#endif /* __x86_64__ */