NetBSD/lib/libpthread/pthread_stack.c
yamt 9f9e6a32dd - do PTHREAD_MLOCK_KLUDGE in pthread__stackid_setup, rather than callers,
so that the main thread is not different from others.
  as a side effect, fix memory leak in pthread_create on error.
- make pthread__stackid_setup return a error rather than calling err(2).
2006-02-12 11:41:53 +00:00

234 lines
6.8 KiB
C

/* $NetBSD: pthread_stack.c,v 1.17 2006/02/12 11:41:53 yamt Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nathan J. Williams.
*
* 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, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: pthread_stack.c,v 1.17 2006/02/12 11:41:53 yamt Exp $");
#define __EXPOSE_STACK 1
#include <sys/param.h>
#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <ucontext.h>
#include <unistd.h>
#include <sys/queue.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sched.h>
#include "pthread.h"
#include "pthread_int.h"
static int pthread__stackid_setup(void *, size_t, pthread_t *);
#ifndef PT_FIXEDSTACKSIZE_LG
/*
* We have to initialize the pthread_stack* variables here because
* mutexes are used before pthread_init() and thus pthread__initmain()
* are called. Since mutexes only save the stack pointer and not a
* pointer to the thread data, it is safe to change the mapping from
* stack pointer to thread data afterwards.
*/
#define _STACKSIZE_LG 18
int pthread_stacksize_lg = _STACKSIZE_LG;
size_t pthread_stacksize = 1 << _STACKSIZE_LG;
vaddr_t pthread_stackmask = (1 << _STACKSIZE_LG) - 1;
#undef _STACKSIZE_LG
#endif /* !PT_FIXEDSTACKSIZE_LG */
/*
* Allocate a stack for a thread, and set it up. It needs to be aligned, so
* that a thread can find itself by its stack pointer.
*/
int
pthread__stackalloc(pthread_t *newt)
{
void *addr;
addr = mmap(NULL, PT_STACKSIZE, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE | MAP_ALIGNED(PT_STACKSIZE_LG), -1, (off_t)0);
if (addr == MAP_FAILED)
return ENOMEM;
pthread__assert(((intptr_t)addr & PT_STACKMASK) == 0);
return pthread__stackid_setup(addr, PT_STACKSIZE, newt);
}
/*
* Set up the slightly special stack for the "initial" thread, which
* runs on the normal system stack, and thus gets slightly different
* treatment.
*/
void
pthread__initmain(pthread_t *newt)
{
pthread_t t;
void *base;
size_t size;
int error;
#ifndef PT_FIXEDSTACKSIZE_LG
struct rlimit slimit;
size_t pagesize;
char *value;
int ret;
pagesize = (size_t)sysconf(_SC_PAGESIZE);
pthread_stacksize = 0;
ret = getrlimit(RLIMIT_STACK, &slimit);
if (ret == -1)
err(1, "Couldn't get stack resource consumption limits");
value = getenv("PTHREAD_STACKSIZE");
if (value) {
pthread_stacksize = atoi(value) * 1024;
if (pthread_stacksize > slimit.rlim_cur)
pthread_stacksize = (size_t)slimit.rlim_cur;
}
if (pthread_stacksize == 0)
pthread_stacksize = (size_t)slimit.rlim_cur;
if (pthread_stacksize < 4 * pagesize)
errx(1, "Stacksize limit is too low, minimum %zd kbyte.",
4 * pagesize / 1024);
pthread_stacksize_lg = -1;
while (pthread_stacksize) {
pthread_stacksize >>= 1;
pthread_stacksize_lg++;
}
pthread_stacksize = (1 << pthread_stacksize_lg);
pthread_stackmask = pthread_stacksize - 1;
#endif /* PT_FIXEDSTACKSIZE_LG */
base = (void *)(pthread__sp() & ~PT_STACKMASK);
size = PT_STACKSIZE;
error = pthread__stackid_setup(base, size, &t);
if (error) {
/* XXX */
errx(2, "failed to setup main thread: error=%d", error);
}
/*
* The "safe" area chosen below isn't safe for the initial thread stack
* because we don't control the end of the stack.
* For example, on i386 the stack usually ends at 0xbfc00000,
* so for requested sizes >=8MB, the last 4MB of stack isn't available.
* Also, we don't want to clobber the argv, environment, etc.
* Reset the initial pt_uc pointer to be safe for the initial thread.
*/
#ifdef __MACHINE_STACK_GROWS_UP
t->pt_uc = (ucontext_t *)
((char *)t->pt_stack.ss_sp + t->pt_stack.ss_size -
sizeof (ucontext_t));
#else
t->pt_uc = (ucontext_t *)t->pt_stack.ss_sp;
#endif
*newt = t;
}
static int
/*ARGSUSED*/
pthread__stackid_setup(void *base, size_t size, pthread_t *tp)
{
pthread_t t;
void *redaddr;
size_t pagesize;
caddr_t sp;
int ret;
t = base;
pagesize = (size_t)sysconf(_SC_PAGESIZE);
/*
* Put a pointer to the pthread in the bottom (but
* redzone-protected section) of the stack.
*/
redaddr = STACK_SHRINK(STACK_MAX(base, size), pagesize);
t->pt_stack.ss_size = size - 2 * pagesize;
#ifdef __MACHINE_STACK_GROWS_UP
t->pt_stack.ss_sp = (char *)base + pagesize;
sp = t->pt_stack.ss_sp;
#else
t->pt_stack.ss_sp = (char *)base + 2 * pagesize;
sp = (caddr_t)t->pt_stack.ss_sp + t->pt_stack.ss_size;
#endif
/* Set up an initial ucontext pointer to a "safe" area */
t->pt_uc = (ucontext_t *)
STACK_ALIGN(STACK_GROW(sp, pagesize / 2), ~_UC_UCONTEXT_ALIGN);
/* Protect the next-to-bottom stack page as a red zone. */
ret = mprotect(redaddr, pagesize, PROT_NONE);
if (ret == -1) {
return errno;
}
#ifdef PTHREAD_MLOCK_KLUDGE
ret = mlock(t, sizeof(struct __pthread_st));
if (ret < 0) {
return errno;
}
#endif
*tp = t;
return 0;
}
ssize_t
pthread__stackinfo_offset()
{
size_t pagesize;
pagesize = (size_t)sysconf(_SC_PAGESIZE);
#ifdef __MACHINE_STACK_GROWS_UP
return (-pagesize + offsetof(struct __pthread_st, pt_stackinfo));
#else
return (-(2 * pagesize) + offsetof(struct __pthread_st, pt_stackinfo));
#endif
}