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Diffstat (limited to 'gnu/dist/diffutils/lib/c-stack.c')
| -rw-r--r-- | gnu/dist/diffutils/lib/c-stack.c | 239 |
1 files changed, 0 insertions, 239 deletions
diff --git a/gnu/dist/diffutils/lib/c-stack.c b/gnu/dist/diffutils/lib/c-stack.c deleted file mode 100644 index 7826573b0c4..00000000000 --- a/gnu/dist/diffutils/lib/c-stack.c +++ /dev/null @@ -1,239 +0,0 @@ -/* $NetBSD: c-stack.c,v 1.1.1.1 2003/01/26 00:43:15 wiz Exp $ */ - -/* Stack overflow handling. - - Copyright (C) 2002 Free Software Foundation, Inc. - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2, or (at your option) - any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software Foundation, - Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ - -/* Written by Paul Eggert. */ - -/* This module assumes that each stack frame is smaller than a page. - If you use alloca, dynamic arrays, or large local variables, your - program may extend the stack by more than a page at a time. If so, - the code below may incorrectly report a program error, or worse - yet, may not detect the overflow at all. To avoid this problem, - don't use large local arrays. */ - -#if HAVE_CONFIG_H -# include <config.h> -#endif - -#include "gettext.h" -#define _(msgid) gettext (msgid) - -#include <errno.h> -#ifndef ENOTSUP -# define ENOTSUP EINVAL -#endif - -#if HAVE_INTTYPES_H -# include <inttypes.h> -#else -# if HAVE_STDINT_H -# include <stdint.h> -# endif -#endif - -#include <signal.h> -#include <stdlib.h> -#include <string.h> - -#if HAVE_UNISTD_H -# include <unistd.h> -#endif -#ifndef STDERR_FILENO -# define STDERR_FILENO 2 -#endif - -#include "c-stack.h" -#include "exitfail.h" - -extern char *program_name; - -#if HAVE_XSI_STACK_OVERFLOW_HEURISTIC - -# include <ucontext.h> - - -/* Storage for the alternate signal stack. */ -static union -{ - char buffer[SIGSTKSZ]; - - /* These other members are for proper alignment. There's no - standard way to guarantee stack alignment, but this seems enough - in practice. */ - long double ld; - uintmax_t u; - void *p; -} alternate_signal_stack; - - -/* Direction of the C runtime stack. This function is - async-signal-safe. */ - -# if STACK_DIRECTION -# define find_stack_direction(ptr) STACK_DIRECTION -# else -static int -find_stack_direction (char const *addr) -{ - char dummy; - return ! addr ? find_stack_direction (&dummy) : addr < &dummy ? 1 : -1; -} -# endif - -/* The SIGSEGV handler. */ -static void (* volatile segv_action) (int, siginfo_t *, void *); - -/* Handle a segmentation violation and exit. This function is - async-signal-safe. */ - -static void -segv_handler (int signo, siginfo_t *info, void *context) -{ - /* Clear SIGNO if it seems to have been a stack overflow. */ - if (0 < info->si_code) - { - /* If the faulting address is within the stack, or within one - page of the stack end, assume that it is a stack - overflow. */ - ucontext_t const *user_context = context; - char const *stack_min = user_context->uc_stack.ss_sp; - size_t stack_size = user_context->uc_stack.ss_size; - char const *faulting_address = info->si_addr; - size_t s = faulting_address - stack_min; - size_t page_size = sysconf (_SC_PAGESIZE); - if (find_stack_direction (0) < 0) - s += page_size; - if (s < stack_size + page_size) - signo = 0; - } - - segv_action (signo, info, context); -} - -#endif /* HAVE_XSI_STACK_OVERFLOW_HEURISTIC */ - - -/* Translated messages for program errors and stack overflow. Do not - translate them in the signal handler, since gettext is not - async-signal-safe. */ -static char const * volatile program_error_message; -static char const * volatile stack_overflow_message; - -/* Output an error message, then exit with status EXIT_FAILURE if it - appears to have been a stack overflow, or with a core dump - otherwise. This function is async-signal-safe. */ - -void -c_stack_die (int signo, siginfo_t *info, void *context) -{ - char const *message = - signo ? program_error_message : stack_overflow_message; - write (STDERR_FILENO, program_name, strlen (program_name)); - write (STDERR_FILENO, ": ", 2); - write (STDERR_FILENO, message, strlen (message)); - write (STDERR_FILENO, "\n", 1); - if (! signo) - _exit (exit_failure); -#if HAVE_SIGINFO_T - if (context && info && 0 <= info->si_code) - { - /* Re-raise the exception at the same address. */ - char *addr = info->si_addr; - *addr = 0; - } -#endif - kill (getpid (), signo); -} - - -/* Set up ACTION so that it is invoked on C stack overflow. Return -1 - (setting errno) if this cannot be done. - - ACTION must invoke only async-signal-safe functions. ACTION - together with its callees must not require more than SIGSTKSZ bytes - of stack space. */ - -int -c_stack_action (void (*action) (int, siginfo_t *, void *)) -{ -#if ! HAVE_XSI_STACK_OVERFLOW_HEURISTIC - errno = ENOTSUP; - return -1; -#else - struct sigaction act; - stack_t st; - int r; - - st.ss_flags = 0; - st.ss_sp = alternate_signal_stack.buffer; - st.ss_size = sizeof alternate_signal_stack.buffer; - r = sigaltstack (&st, 0); - if (r != 0) - return r; - - program_error_message = _("program error"); - stack_overflow_message = _("stack overflow"); - segv_action = action; - - sigemptyset (&act.sa_mask); - - /* POSIX 1003.1-2001 says SA_RESETHAND implies SA_NODEFER, but this - is not true on Solaris 8 at least. It doesn't hurt to use - SA_NODEFER here, so leave it in. */ - act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO; - - act.sa_sigaction = segv_handler; - return sigaction (SIGSEGV, &act, 0); -#endif -} - -#if DEBUG - -#include <stdio.h> - -int volatile exit_failure; - -static long -recurse (char *p) -{ - char array[500]; - array[0] = 1; - return *p + recurse (array); -} - -char *program_name; - -int -main (int argc, char **argv) -{ - program_name = argv[0]; - c_stack_action (c_stack_die); - return recurse ("\1"); -} - -#endif /* DEBUG */ - -/* -Local Variables: -compile-command: "gcc -D_GNU_SOURCE -DDEBUG \ - -DHAVE_INTTYPES_H -DHAVE_SIGINFO_T \ - -DHAVE_XSI_STACK_OVERFLOW_HEURISTIC -DHAVE_UNISTD_H \ - -Wall -W -g c-stack.c -o c-stack" -End: -*/ |
