NetBSD/lib/libpthread/pthread_stack.c

189 lines
5.8 KiB
C

/* $NetBSD: pthread_stack.c,v 1.9 2003/11/27 16:30:54 cl 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 1.9 2003/11/27 16:30:54 cl Exp $");
#include <err.h>
#include <errno.h>
#include <signal.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 pthread_t
pthread__stackid_setup(void *base, size_t size);
#ifndef PT_FIXEDSTACKSIZE_LG
/*
* We have to initialize the pt_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 pt_stacksize_lg = _STACKSIZE_LG;
size_t pt_stacksize = 1 << _STACKSIZE_LG;
vaddr_t pt_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);
*newt = pthread__stackid_setup(addr, PT_STACKSIZE);
return 0;
}
/*
* 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)
{
void *base;
#ifndef PT_FIXEDSTACKSIZE_LG
struct rlimit slimit;
size_t pagesize;
char *value;
int ret;
pagesize = (size_t)sysconf(_SC_PAGESIZE);
pt_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) {
pt_stacksize = atoi(value) * 1024;
if (pt_stacksize > slimit.rlim_cur)
pt_stacksize = (size_t)slimit.rlim_cur;
}
if (pt_stacksize == 0)
pt_stacksize = (size_t)slimit.rlim_cur;
if (pt_stacksize < 4 * pagesize)
errx(1, "Stacksize limit is too low, minimum %zd kbyte.",
4 * pagesize / 1024);
pt_stacksize_lg = -1;
while (pt_stacksize) {
pt_stacksize >>= 1;
pt_stacksize_lg++;
}
pt_stacksize = (1 << pt_stacksize_lg);
pt_stackmask = pt_stacksize - 1;
/*
* XXX The "initial" thread stack can be smaller than
* requested because we don't control the end of the stack.
* On i386 the stack usually ends at 0xbfc00000 and for
* requested sizes >=8MB, we get a 4MB smaller stack.
*/
#endif /* PT_FIXEDSTACKSIZE_LG */
base = (void *) (pthread__sp() & ~PT_STACKMASK);
*newt = pthread__stackid_setup(base, PT_STACKSIZE);
}
static pthread_t
/*ARGSUSED*/
pthread__stackid_setup(void *base, size_t size)
{
pthread_t t;
size_t pagesize;
int ret;
/* Protect the next-to-bottom stack page as a red zone. */
/* XXX assumes that the stack grows down. */
pagesize = (size_t)sysconf(_SC_PAGESIZE);
#ifdef __hppa__
#error "stack does not grow down"
#endif
ret = mprotect((char *)base + pagesize, pagesize, PROT_NONE);
if (ret == -1)
err(2, "Couldn't mprotect() stack redzone at %p\n",
(char *)base + pagesize);
/*
* Put a pointer to the pthread in the bottom (but
* redzone-protected section) of the stack.
*/
t = base;
t->pt_stack.ss_sp = (char *)base + 2 * pagesize;
t->pt_stack.ss_size = PT_STACKSIZE - 2 * pagesize;
/* Set up an initial ucontext pointer to a "safe" area */
t->pt_uc =(ucontext_t *)(void *)((char *)t->pt_stack.ss_sp +
t->pt_stack.ss_size - (pagesize/2));
#ifdef _UC_UCONTEXT_ALIGN
t->pt_uc = (ucontext_t *)((uintptr_t)t->pt_uc & _UC_UCONTEXT_ALIGN);
#endif
return t;
}