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4631d34d0d
It's now possible to use sigaltstack() to recover from stack overflows on Windows. Several bugs in sigaltstack() have been fixed, for all our supported platforms. There's a newer better example showing how to use this, along with three independent unit tests just to further showcase the various techniques.
96 lines
4.3 KiB
C
96 lines
4.3 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/calls/struct/sigaction.h"
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#include "libc/calls/struct/sigaltstack.h"
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#include "libc/calls/struct/sigset.h"
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#include "libc/intrin/leaky.internal.h"
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#include "libc/log/internal.h"
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#include "libc/mem/mem.h"
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#include "libc/runtime/runtime.h"
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#include "libc/runtime/symbols.internal.h"
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#include "libc/sysv/consts/sa.h"
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#include "libc/sysv/consts/sig.h"
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#ifndef TINY
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__static_yoink("zipos"); // for symtab
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__static_yoink("__die"); // for backtracing
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__static_yoink("ShowBacktrace"); // for backtracing
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__static_yoink("GetSymbolTable"); // for backtracing
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__static_yoink("PrintBacktraceUsingSymbols"); // for backtracing
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__static_yoink("malloc_inspect_all"); // for asan memory origin
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__static_yoink("GetSymbolByAddr"); // for asan memory origin
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#endif
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static void InstallCrashHandler(int sig, int flags) {
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struct sigaction sa;
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sigemptyset(&sa.sa_mask);
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sigaddset(&sa.sa_mask, SIGQUIT);
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sigaddset(&sa.sa_mask, SIGFPE);
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sigaddset(&sa.sa_mask, SIGILL);
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sigaddset(&sa.sa_mask, SIGSEGV);
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sigaddset(&sa.sa_mask, SIGTRAP);
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sigaddset(&sa.sa_mask, SIGBUS);
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sigaddset(&sa.sa_mask, SIGABRT);
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sa.sa_flags = SA_SIGINFO | flags;
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#ifdef TINY
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sa.sa_sigaction = __minicrash;
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#else
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GetSymbolTable();
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sa.sa_sigaction = __oncrash;
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#endif
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unassert(!sigaction(sig, &sa, 0));
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}
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/**
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* Installs crash signal handlers.
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*
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* Normally, only functions calling die() will print backtraces. This
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* function may be called at program startup to install handlers that
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* will display similar information, for most types of crashes.
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*
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* - Backtraces
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* - CPU state printout
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* - Automatic debugger attachment
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*
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* Another trick this function enables, is you can press CTRL+\ to open
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* the debugger GUI at any point while the program is running. It can be
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* useful, for example, if a program is caught in an infinite loop.
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*/
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void ShowCrashReports(void) {
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struct sigaltstack ss;
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static char crashstack[65536];
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ss.ss_flags = 0;
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ss.ss_size = sizeof(crashstack);
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ss.ss_sp = crashstack;
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unassert(!sigaltstack(&ss, 0));
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InstallCrashHandler(SIGQUIT, 0);
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#ifdef __x86_64__
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InstallCrashHandler(SIGTRAP, 0);
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#else
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InstallCrashHandler(SIGTRAP, SA_RESETHAND);
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#endif
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InstallCrashHandler(SIGFPE, SA_RESETHAND);
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InstallCrashHandler(SIGILL, SA_RESETHAND);
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InstallCrashHandler(SIGBUS, SA_RESETHAND);
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InstallCrashHandler(SIGABRT, SA_RESETHAND);
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InstallCrashHandler(SIGSEGV, SA_RESETHAND | SA_ONSTACK);
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}
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IGNORE_LEAKS(ShowCrashReports)
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