mirror of
https://github.com/jart/cosmopolitan.git
synced 2024-05-17 02:52:40 +00:00
197aa0d465
This change introduces support for Linux-style uc_context manipulation that's fast and works well on all supported OSes and architectures. It also integrates with the Cosmpolitan runtime which can show backtraces comprised of multiple stacks and fibers. See the test and example code for further details. This will be used by Mold once it's been vendored
363 lines
12 KiB
C
363 lines
12 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/assert.h"
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#include "libc/atomic.h"
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#include "libc/calls/calls.h"
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#include "libc/calls/state.internal.h"
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#include "libc/calls/struct/sigaction.h"
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#include "libc/calls/struct/utsname.h"
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#include "libc/calls/syscall-sysv.internal.h"
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#include "libc/dce.h"
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#include "libc/errno.h"
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#include "libc/fmt/itoa.h"
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#include "libc/intrin/asan.internal.h"
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#include "libc/intrin/atomic.h"
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#include "libc/intrin/kmalloc.h"
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#include "libc/intrin/kprintf.h"
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#include "libc/intrin/strace.internal.h"
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#include "libc/intrin/weaken.h"
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#include "libc/log/backtrace.internal.h"
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#include "libc/log/gdb.h"
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#include "libc/log/internal.h"
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#include "libc/log/log.h"
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#include "libc/macros.internal.h"
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#include "libc/nexgen32e/stackframe.h"
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#include "libc/runtime/internal.h"
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#include "libc/runtime/pc.internal.h"
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#include "libc/runtime/runtime.h"
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#include "libc/stdio/stdio.h"
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#include "libc/str/str.h"
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#include "libc/thread/thread.h"
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#include "libc/thread/tls.h"
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#include "third_party/libcxx/math.h"
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#ifdef __x86_64__
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STATIC_YOINK("strerror_wr"); // for kprintf %m
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STATIC_YOINK("strsignal_r"); // for kprintf %G
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static const char kGregOrder[17] forcealign(1) = {
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13, 11, 8, 14, 12, 9, 10, 15, 16, 0, 1, 2, 3, 4, 5, 6, 7,
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};
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static const char kGregNames[17][4] forcealign(1) = {
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"R8", "R9", "R10", "R11", "R12", "R13", "R14", "R15", "RDI",
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"RSI", "RBP", "RBX", "RDX", "RAX", "RCX", "RSP", "RIP",
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};
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static const char kCpuFlags[12] forcealign(1) = "CVPRAKZSTIDO";
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static const char kFpuExceptions[6] forcealign(1) = "IDZOUP";
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relegated static void ShowFunctionCalls(ucontext_t *ctx) {
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struct StackFrame *bp;
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struct StackFrame goodframe;
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if (!ctx->uc_mcontext.rip) {
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kprintf("%s is NULL can't show backtrace\n", "RIP");
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} else {
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goodframe.next = (struct StackFrame *)ctx->uc_mcontext.rbp;
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goodframe.addr = ctx->uc_mcontext.rip;
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bp = &goodframe;
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ShowBacktrace(2, bp);
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}
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}
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relegated static char *AddFlag(char *p, int b, const char *s) {
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if (b) {
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p = stpcpy(p, s);
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} else {
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*p = 0;
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}
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return p;
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}
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relegated static char *DescribeCpuFlags(char *p, int flags, int x87sw,
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int mxcsr) {
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unsigned i;
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for (i = 0; i < ARRAYLEN(kCpuFlags); ++i) {
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if (flags & 1) {
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*p++ = ' ';
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*p++ = kCpuFlags[i];
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*p++ = 'F';
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}
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flags >>= 1;
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}
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for (i = 0; i < ARRAYLEN(kFpuExceptions); ++i) {
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if ((x87sw | mxcsr) & (1 << i)) {
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*p++ = ' ';
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*p++ = kFpuExceptions[i];
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*p++ = 'E';
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}
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}
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p = AddFlag(p, x87sw & FPU_SF, " SF");
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p = AddFlag(p, x87sw & FPU_C0, " C0");
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p = AddFlag(p, x87sw & FPU_C1, " C1");
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p = AddFlag(p, x87sw & FPU_C2, " C2");
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p = AddFlag(p, x87sw & FPU_C3, " C3");
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return p;
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}
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static char *HexCpy(char p[hasatleast 17], uint64_t x, uint8_t k) {
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while (k > 0) *p++ = "0123456789abcdef"[(x >> (k -= 4)) & 15];
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*p = '\0';
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return p;
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}
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relegated static char *ShowGeneralRegisters(char *p, ucontext_t *ctx) {
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int64_t x;
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const char *s;
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size_t i, j, k;
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long double st;
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*p++ = '\n';
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for (i = 0, j = 0, k = 0; i < ARRAYLEN(kGregNames); ++i) {
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if (j > 0) *p++ = ' ';
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if (!(s = kGregNames[(unsigned)kGregOrder[i]])[2]) *p++ = ' ';
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p = stpcpy(p, s), *p++ = ' ';
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p = HexCpy(p, ctx->uc_mcontext.gregs[(unsigned)kGregOrder[i]], 64);
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if (++j == 3) {
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j = 0;
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if (ctx->uc_mcontext.fpregs) {
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memcpy(&st, (char *)&ctx->uc_mcontext.fpregs->st[k], sizeof(st));
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p = stpcpy(p, " ST(");
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p = FormatUint64(p, k++);
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p = stpcpy(p, ") ");
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if (signbit(st)) {
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st = -st;
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*p++ = '-';
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}
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if (isnan(st)) {
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p = stpcpy(p, "nan");
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} else if (isinf(st)) {
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p = stpcpy(p, "inf");
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} else {
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if (st > 999.999) st = 999.999;
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x = st * 1000;
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p = FormatUint64(p, x / 1000), *p++ = '.';
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p = FormatUint64(p, x % 1000);
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}
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}
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*p++ = '\n';
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}
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}
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DescribeCpuFlags(
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p, ctx->uc_mcontext.eflags,
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ctx->uc_mcontext.fpregs ? ctx->uc_mcontext.fpregs->swd : 0,
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ctx->uc_mcontext.fpregs ? ctx->uc_mcontext.fpregs->mxcsr : 0);
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*p++ = '\n';
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return p;
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}
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relegated static char *ShowSseRegisters(char *p, ucontext_t *ctx) {
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size_t i;
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if (ctx->uc_mcontext.fpregs) {
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*p++ = '\n';
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for (i = 0; i < 8; ++i) {
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*p++ = 'X';
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*p++ = 'M';
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*p++ = 'M';
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if (i >= 10) {
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*p++ = i / 10 + '0';
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*p++ = i % 10 + '0';
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} else {
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*p++ = i + '0';
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*p++ = ' ';
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}
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*p++ = ' ';
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p = HexCpy(p, ctx->uc_mcontext.fpregs->xmm[i + 0].u64[1], 64);
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p = HexCpy(p, ctx->uc_mcontext.fpregs->xmm[i + 0].u64[0], 64);
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p = stpcpy(p, " XMM");
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if (i + 8 >= 10) {
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*p++ = (i + 8) / 10 + '0';
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*p++ = (i + 8) % 10 + '0';
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} else {
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*p++ = (i + 8) + '0';
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*p++ = ' ';
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}
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*p++ = ' ';
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p = HexCpy(p, ctx->uc_mcontext.fpregs->xmm[i + 8].u64[1], 64);
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p = HexCpy(p, ctx->uc_mcontext.fpregs->xmm[i + 8].u64[0], 64);
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*p++ = '\n';
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}
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}
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return p;
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}
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void ShowCrashReportHook(int, int, int, struct siginfo *, ucontext_t *);
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relegated void ShowCrashReport(int err, int sig, struct siginfo *si,
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ucontext_t *ctx) {
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int i;
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size_t n;
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char host[64];
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char *p, *buf;
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struct utsname names;
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if (_weaken(ShowCrashReportHook)) {
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ShowCrashReportHook(2, err, sig, si, ctx);
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}
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names.sysname[0] = 0;
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names.release[0] = 0;
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names.version[0] = 0;
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names.nodename[0] = 0;
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stpcpy(host, "unknown");
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gethostname(host, sizeof(host));
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uname(&names);
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errno = err;
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// TODO(jart): Buffer the WHOLE crash report with backtrace for atomic write.
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_npassert((p = buf = kmalloc((n = 1024 * 1024))));
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p += ksnprintf(
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p, n,
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"\n%serror%s: Uncaught %G (%s) on %s pid %d tid %d\n"
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" %s\n"
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" %s\n"
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" %s %s %s %s\n",
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!__nocolor ? "\e[30;101m" : "", !__nocolor ? "\e[0m" : "", sig,
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(ctx && (ctx->uc_mcontext.rsp >= GetStaticStackAddr(0) &&
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ctx->uc_mcontext.rsp <= GetStaticStackAddr(0) + APE_GUARDSIZE))
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? "Stack Overflow"
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: GetSiCodeName(sig, si->si_code),
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host, getpid(), gettid(), program_invocation_name, strerror(err),
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names.sysname, names.version, names.nodename, names.release);
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if (ctx) {
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p = ShowGeneralRegisters(p, ctx);
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p = ShowSseRegisters(p, ctx);
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*p++ = '\n';
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_klog(buf, p - buf);
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ShowFunctionCalls(ctx);
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} else {
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*p++ = '\n';
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_klog(buf, p - buf);
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}
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kprintf("\n");
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if (!IsWindows()) __print_maps();
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/* PrintSystemMappings(2); */
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if (__argv) {
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for (i = 0; i < __argc; ++i) {
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if (!__argv[i]) continue;
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if (IsAsan() && !__asan_is_valid_str(__argv[i])) continue;
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kprintf("%s ", __argv[i]);
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}
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}
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kprintf("\n");
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}
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static wontreturn relegated dontinstrument void __minicrash(int sig,
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struct siginfo *si,
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ucontext_t *ctx,
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const char *kind) {
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kprintf("\n"
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"\n"
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"CRASHED %s WITH %G\n"
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"%s\n"
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"RIP %x\n"
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"RSP %x\n"
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"RBP %x\n"
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"PID %d\n"
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"TID %d\n"
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"\n",
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kind, sig, __argv[0], ctx ? ctx->uc_mcontext.rip : 0,
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ctx ? ctx->uc_mcontext.rsp : 0, ctx ? ctx->uc_mcontext.rbp : 0, __pid,
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__tls_enabled ? __get_tls()->tib_tid : sys_gettid());
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_Exitr(119);
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}
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/**
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* Crashes in a developer-friendly human-centric way.
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*
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* We first try to launch GDB if it's an interactive development
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* session. Otherwise we show a really good crash report, sort of like
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* Python, that includes filenames and line numbers. Many editors, e.g.
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* Emacs, will even recognize its syntax for quick hopping to the
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* failing line. That's only possible if the the .com.dbg file is in the
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* same folder. If the concomitant debug binary can't be found, we
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* simply print addresses which may be cross-referenced using objdump.
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*
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* This function never returns, except for traps w/ human supervision.
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*
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* @threadsafe
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* @vforksafe
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*/
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relegated void __oncrash_amd64(int sig, struct siginfo *si, void *arg) {
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int bZero;
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intptr_t rip;
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int me, owner;
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int gdbpid, err;
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ucontext_t *ctx = arg;
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static atomic_int once;
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static atomic_int once2;
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STRACE("__oncrash rip %x", ctx->uc_mcontext.rip);
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ftrace_enabled(-1);
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strace_enabled(-1);
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owner = 0;
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me = __tls_enabled ? __get_tls()->tib_tid : sys_gettid();
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pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0);
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if (atomic_compare_exchange_strong_explicit(
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&once, &owner, me, memory_order_relaxed, memory_order_relaxed)) {
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if (!__vforked) {
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rip = ctx ? ctx->uc_mcontext.rip : 0;
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err = errno;
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if ((gdbpid = IsDebuggerPresent(true))) {
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DebugBreak();
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} else if (__nocolor || g_isrunningundermake) {
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gdbpid = -1;
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#if 0
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} else if (!IsTiny() && IsLinux() && FindDebugBinary() && !__isworker) {
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// RestoreDefaultCrashSignalHandlers();
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gdbpid = AttachDebugger(
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((sig == SIGTRAP || sig == SIGQUIT) &&
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(rip >= (intptr_t)&__executable_start && rip < (intptr_t)&_etext))
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? rip
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: 0);
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#endif
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}
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if (!(gdbpid > 0 && (sig == SIGTRAP || sig == SIGQUIT))) {
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__restore_tty();
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ShowCrashReport(err, sig, si, ctx);
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_Exitr(128 + sig);
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}
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atomic_store_explicit(&once, 0, memory_order_relaxed);
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} else {
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atomic_store_explicit(&once, 0, memory_order_relaxed);
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__minicrash(sig, si, ctx, "WHILE VFORKED");
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}
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} else if (sig == SIGTRAP) {
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// chances are IsDebuggerPresent() confused strace w/ gdb
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goto ItsATrap;
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} else if (owner == me) {
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// we crashed while generating a crash report
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bZero = false;
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if (atomic_compare_exchange_strong_explicit(
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&once2, &bZero, true, memory_order_relaxed, memory_order_relaxed)) {
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__minicrash(sig, si, ctx, "WHILE CRASHING");
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} else {
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// somehow __minicrash() crashed not possible
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for (;;) {
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abort();
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}
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}
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} else {
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// multiple threads have crashed
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// kill current thread assuming process dies soon
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// TODO(jart): It'd be nice to report on all threads.
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_Exit1(8);
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}
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ItsATrap:
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strace_enabled(+1);
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ftrace_enabled(+1);
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}
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#endif /* __x86_64__ */
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