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Improve multithreading

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Justine Tunney 2024-07-21 06:41:30 -07:00
parent d3167126aa
commit 30afd6ddbb
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38 changed files with 752 additions and 174 deletions
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test/libc/calls/stackoverflow5_test.c Normal file
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et 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 <cosmo.h>
#include <limits.h>
#include <pthread.h>
#include <signal.h>
#include <unistd.h>
/**
* stack overflow recovery technique #5
* use the cosmo posix threads extensions
*/
sig_atomic_t smashed_stack;
void CrashHandler(int sig) {
smashed_stack = true;
pthread_exit(0);
}
int StackOverflow(int f(), int n) {
if (n < INT_MAX) {
return f(f, n + 1) - 1;
} else {
return INT_MAX;
}
}
int (*pStackOverflow)(int (*)(), int) = StackOverflow;
void *MyPosixThread(void *arg) {
exit(pStackOverflow(pStackOverflow, 0));
return 0;
}
int main() {
// choose the most dangerously small size possible
size_t sigstacksize = sysconf(_SC_MINSIGSTKSZ) + 2048;
// setup signal handler
struct sigaction sa;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_ONSTACK;
sa.sa_handler = CrashHandler;
if (sigaction(SIGBUS, &sa, 0))
return 1;
if (sigaction(SIGSEGV, &sa, 0))
return 2;
// create thread with signal stack
pthread_t id;
pthread_attr_t attr;
if (pthread_attr_init(&attr))
return 3;
if (pthread_attr_setguardsize(&attr, getpagesize()))
return 4;
if (pthread_attr_setsigaltstacksize_np(&attr, sigstacksize))
return 5;
if (pthread_create(&id, &attr, MyPosixThread, 0))
return 6;
if (pthread_attr_destroy(&attr))
return 7;
if (pthread_join(id, 0))
return 8;
if (!smashed_stack)
return 9;
CheckForMemoryLeaks();
}