Date: Fri, 30 Mar 2001 04:52:27 -0800 (PST) From: sonnet@teatime.org To: freebsd-gnats-submit@FreeBSD.org Subject: i386/26216: alloca() couldn't detect thread stack limit Message-ID: <200103301252.f2UCqR831862@freefall.freebsd.org>
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>Number: 26216
>Category: i386
>Synopsis: alloca() couldn't detect thread stack limit
>Confidential: no
>Severity: serious
>Priority: high
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Fri Mar 30 05:00:01 PST 2001
>Closed-Date:
>Last-Modified:
>Originator: Soonmyung Hong
>Release: 3-Stable/4-Stable
>Organization:
Innovay Inc
>Environment:
FreeBSD alfheim.innovay.com 3.5-STABLE FreeBSD 3.5-STABLE #3: Wed Jul 26 19:37:39 KST 2000 root@alfheim.innovay.com:/usr/src/sys/compile/ALFHEIM i386
FreeBSD hel.innovay.com 4.2-STABLE FreeBSD 4.2-STABLE #2: Wed Feb 28 17:22:54 KST 2001 root@hel.innovay.com:/usr/src/sys/compile/HEL i386
>Description:
On pthread environment, each thread has their own stack limit.
when user requested larger than current thread's stack size to alloca(),
alloca() return invalid pointer.
It must be NULL pointer.
>How-To-Repeat:
gcc -ansi -pedantic -g -Wall -pthread -o test test.c
./test
./test <stacksize>
--
/* test.c */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <pthread.h>
/* the stderr time ticker thread */
static void *ticker(void *_arg)
{
int kb = (int)_arg;
char *ptr;
if (NULL != (ptr = alloca(kb * 1024))) {
printf("alloca(%dKB) return %p\n", kb, ptr);
memset(ptr, 0xdf, kb * 1024);
}
else {
printf("alloca(%dKB) return NULL\n", kb);
}
return NULL;
}
int main(int argc, char *argv[])
{
pthread_attr_t thread_attr;
pthread_t ticker_thread;
size_t stacksize;
int i;
signal(SIGPIPE, SIG_IGN);
pthread_attr_init(&thread_attr);
pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);
if (2 == argc) {
stacksize = (size_t) strtoul(argv[1], (char **)NULL, 10);
if (!pthread_attr_setstacksize(&thread_attr, stacksize*1024)) {
printf("set stacksize = %dKB\n", stacksize);
}
}
if (!pthread_attr_getstacksize(&thread_attr, &stacksize)) {
printf("stack size = %dKB\n", stacksize/1024);
}
for (i = 4; i < 65536 ; i += 8) {
pthread_create(&ticker_thread, &thread_attr, ticker, (void *)i);
sleep(1);
}
return 0;
}
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:
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