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113 lines
2.9 KiB
C
113 lines
2.9 KiB
C
/* Run with a larger (mmap'd) stack.
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Copyright (C) 2003 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* Written by Jim Meyering. */
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#if HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <stdio.h>
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#include <assert.h>
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#include <unistd.h>
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#include <stdarg.h>
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#if HAVE_SYS_MMAN_H
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# include <sys/mman.h>
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#endif
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#if HAVE_UCONTEXT_H
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# include <ucontext.h>
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#endif
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#include "mmap-stack.h"
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#ifndef MAP_ANONYMOUS
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# ifdef MAP_ANON
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# define MAP_ANONYMOUS MAP_ANON
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# else
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# define MAP_ANONYMOUS 0
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# endif
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#endif
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/* Set up context, *CTX, so that it may be used via makecontext,
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using a block of SIZE bytes of mmap'd memory for its stack.
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Return nonzero upon error. */
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static int
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get_context (ucontext_t *ctx, size_t size)
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{
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void *stack;
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int fd = -1; /* This must be -1 in order for Solaris' MAP_ANON to work. */
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if (getcontext (ctx))
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return 1;
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/* use tmpfile if MAP_ANONYMOUS is not useful. */
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#if MAP_ANONYMOUS == 0
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{
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FILE *fp = tmpfile ();
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if (!fp)
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return 1;
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fd = fileno (fp);
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}
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#endif
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stack = mmap (NULL, size,
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PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
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if (stack == MAP_FAILED)
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return 1;
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ctx->uc_stack.ss_sp = stack;
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ctx->uc_stack.ss_size = size;
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ctx->uc_link = NULL;
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return 0;
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}
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/* Yep, this is arbitrary. tough :-) */
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#define ARGC_MAX 6
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/* Set up a context without conventional stack limitations,
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then call function FUNC with the specified number (ARGC) of arguments.
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If get_context and setcontext succeed, this function does not return,
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so FUNC must be sure to exit appropriately. Otherwise, this function
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does return, and the caller should diagnose the failure. */
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void
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run_on_mmaped_stack (void (*func) (void), size_t argc, ...)
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{
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ucontext_t ctx;
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size_t size = 1024 * 1024 * 1024;
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long bs_argv[ARGC_MAX];
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unsigned i;
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va_list ap;
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assert (argc <= ARGC_MAX);
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va_start (ap, argc);
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for (i = 0; i < argc; i++)
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bs_argv[i] = va_arg (ap, long);
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va_end (ap);
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if (get_context (&ctx, size) == 0)
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{
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makecontext (&ctx, func, argc,
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bs_argv[0], bs_argv[1], bs_argv[2],
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bs_argv[3], bs_argv[4], bs_argv[5]);
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setcontext (&ctx);
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}
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/* get_context or setcontext failed;
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Resort to using the conventional stack. */
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}
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