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/*
* Copyright (C) 2001 Jason Evans <jasone@freebsd.org>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice(s), this list of conditions and the following disclaimer
* unmodified other than the allowable addition of one or more
* copyright notices.
* 2. Redistributions in binary form must reproduce the above copyright
* notice(s), this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*
* Test thread stack guard functionality.
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <limits.h>
#include <pthread.h>
#define FRAME_SIZE 1024
#define FRAME_OVERHEAD 40
struct args
{
void *top; /* Top of thread's initial stack frame. */
int cur; /* Recursion depth. */
int max; /* Maximum recursion depth. */
};
void *
recurse(void *args)
{
int top;
struct args *parms = (struct args *)args;
char filler[FRAME_SIZE - FRAME_OVERHEAD];
/* Touch the memory in this stack frame. */
top = 0xa5;
memset(filler, 0xa5, sizeof(filler));
if (parms->top == NULL) {
/* Initial stack frame. */
parms->top = (void*)⊤
}
/*
* Make sure frame size is what we expect. Getting this right involves
* hand tweaking, so just print a warning rather than aborting.
*/
if (parms->top - (void *)&top != FRAME_SIZE * parms->cur) {
fprintf(stderr, "Stack size (%d) != expected (%d), frame %d\n",
parms->top - (void *)&top, FRAME_SIZE * parms->cur,
parms->cur);
}
parms->cur++;
if (parms->cur < parms->max)
recurse(args);
return NULL;
}
int
main(int argc, char **argv)
{
size_t def_stacksize, def_guardsize;
size_t stacksize, guardsize;
pthread_t thread;
pthread_attr_t attr;
struct args args;
if (argc != 3) {
fprintf(stderr, "usage: guard_b <stacksize> <guardsize>\n");
exit(1);
}
fprintf(stderr, "Test begin\n");
stacksize = strtoul(argv[1], NULL, 10);
guardsize = strtoul(argv[2], NULL, 10);
assert(pthread_attr_init(&attr) == 0);
/*
* Exercise the attribute APIs more thoroughly than is strictly
* necessary for the meat of this test program.
*/
assert(pthread_attr_getstacksize(&attr, &def_stacksize) == 0);
assert(pthread_attr_getguardsize(&attr, &def_guardsize) == 0);
if (def_stacksize != stacksize) {
assert(pthread_attr_setstacksize(&attr, stacksize) == 0);
assert(pthread_attr_getstacksize(&attr, &def_stacksize) == 0);
assert(def_stacksize == stacksize);
}
if (def_guardsize != guardsize) {
assert(pthread_attr_setguardsize(&attr, guardsize) == 0);
assert(pthread_attr_getguardsize(&attr, &def_guardsize) == 0);
assert(def_guardsize >= guardsize);
}
/*
* Create a thread that will come just short of overflowing the thread
* stack. We need to leave a bit of breathing room in case the thread
* is context switched, and we also have to take care not to call any
* functions in the deepest stack frame.
*/
args.top = NULL;
args.cur = 0;
args.max = (stacksize / FRAME_SIZE) - 1;
fprintf(stderr, "No overflow:\n");
assert(pthread_create(&thread, &attr, recurse, &args) == 0);
assert(pthread_join(thread, NULL) == 0);
/*
* Create a thread that will barely of overflow the thread stack. This
* should cause a segfault.
*/
args.top = NULL;
args.cur = 0;
args.max = (stacksize / FRAME_SIZE) + 1;
fprintf(stderr, "Overflow:\n");
assert(pthread_create(&thread, &attr, recurse, &args) == 0);
assert(pthread_join(thread, NULL) == 0);
/* Not reached. */
fprintf(stderr, "Unexpected success\n");
abort();
return 0;
}
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