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Diffstat (limited to 'src/grep/m4/sigaltstack.m4')
| -rw-r--r-- | src/grep/m4/sigaltstack.m4 | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/src/grep/m4/sigaltstack.m4 b/src/grep/m4/sigaltstack.m4 new file mode 100644 index 0000000..6dbd677 --- /dev/null +++ b/src/grep/m4/sigaltstack.m4 @@ -0,0 +1,197 @@ +# sigaltstack.m4 serial 15 +dnl Copyright (C) 2002-2021 Free Software Foundation, Inc. +dnl This file is free software, distributed under the terms of the GNU +dnl General Public License. As a special exception to the GNU General +dnl Public License, this file may be distributed as part of a program +dnl that contains a configuration script generated by Autoconf, under +dnl the same distribution terms as the rest of that program. + +dnl Written by Bruno Haible and Eric Blake. + +AC_DEFUN([SV_SIGALTSTACK], +[ + AC_REQUIRE([AC_PROG_CC]) + AC_REQUIRE([AC_CANONICAL_HOST]) + + AC_CHECK_FUNCS_ONCE([sigaltstack setrlimit]) + + if test "$ac_cv_func_sigaltstack" = yes; then + AC_CHECK_TYPE([stack_t], , + [AC_DEFINE(stack_t, [struct sigaltstack], + [Define to 'struct sigaltstack' if that's the type of the argument to sigaltstack]) + ], + [ +#include <signal.h> +#if HAVE_SYS_SIGNAL_H +# include <sys/signal.h> +#endif + ]) + fi + + AC_CACHE_CHECK([for working sigaltstack], [sv_cv_sigaltstack], [ + if test "$ac_cv_func_sigaltstack" = yes; then + case "$host_os" in + macos* | darwin[[6-9]]* | darwin[[1-9]][[0-9]]*) + # On MacOS X 10.2 or newer, just assume that if it compiles, it will + # work. If we were to perform the real test, 1 Crash Report dialog + # window would pop up. + AC_LINK_IFELSE([ + AC_LANG_PROGRAM([[#include <signal.h>]], + [[int x = SA_ONSTACK; stack_t ss; sigaltstack ((stack_t*)0, &ss);]])], + [sv_cv_sigaltstack="guessing yes"], + [sv_cv_sigaltstack=no]) + ;; + *) + AC_RUN_IFELSE([ + AC_LANG_SOURCE([[ +#include <stdlib.h> +#include <signal.h> +#if HAVE_SYS_SIGNAL_H +# include <sys/signal.h> +#endif +#if HAVE_SETRLIMIT +# include <sys/types.h> +# include <sys/time.h> +# include <sys/resource.h> +#endif +void stackoverflow_handler (int sig) +{ + /* If we get here, the stack overflow was caught. */ + exit (0); +} +volatile int * recurse_1 (volatile int n, volatile int *p) +{ + if (n >= 0) + *recurse_1 (n + 1, p) += n; + return p; +} +int recurse (volatile int n) +{ + int sum = 0; + return *recurse_1 (n, &sum); +} +char mystack[2 * (1 << 24)]; +int main () +{ + stack_t altstack; + struct sigaction action; +#if defined HAVE_SETRLIMIT && defined RLIMIT_STACK + /* Before starting the endless recursion, try to be friendly to the user's + machine. On some Linux 2.2.x systems, there is no stack limit for user + processes at all. We don't want to kill such systems. */ + struct rlimit rl; + rl.rlim_cur = rl.rlim_max = 0x100000; /* 1 MB */ + setrlimit (RLIMIT_STACK, &rl); +#endif + /* Install the alternate stack. Use the midpoint of mystack, to guard + against a buggy interpretation of ss_sp on IRIX. */ +#ifdef SIGSTKSZ + if (sizeof mystack / 2 < SIGSTKSZ) + exit (3); +#endif + altstack.ss_sp = mystack + sizeof mystack / 2; + altstack.ss_size = sizeof mystack / 2; + altstack.ss_flags = 0; /* no SS_DISABLE */ + if (sigaltstack (&altstack, NULL) < 0) + exit (1); + /* Install the SIGSEGV handler. */ + sigemptyset (&action.sa_mask); + action.sa_handler = &stackoverflow_handler; + action.sa_flags = SA_ONSTACK; + sigaction (SIGSEGV, &action, (struct sigaction *) NULL); + sigaction (SIGBUS, &action, (struct sigaction *) NULL); + /* Provoke a stack overflow. */ + recurse (0); + exit (2); +}]])], + [sv_cv_sigaltstack=yes], + [sv_cv_sigaltstack=no], + [ + dnl FIXME: Put in some more known values here. + case "$host_os" in + *) + AC_LINK_IFELSE([ + AC_LANG_PROGRAM([[#include <signal.h>]], + [[int x = SA_ONSTACK; stack_t ss; sigaltstack ((stack_t*)0, &ss);]])], + [sv_cv_sigaltstack="guessing yes"], + [sv_cv_sigaltstack=no]) + ;; + esac + ]) + ;; + esac + else + sv_cv_sigaltstack=no + fi + ]) + if test "$sv_cv_sigaltstack" != no; then + AC_DEFINE([HAVE_WORKING_SIGALTSTACK], [1], + [Define if you have the sigaltstack() function and it works.]) + + dnl The ss_sp field of a stack_t is, according to POSIX, the lowest address + dnl of the memory block designated as an alternate stack. But IRIX 5.3 + dnl interprets it as the highest address! + AC_CACHE_CHECK([for correct stack_t interpretation], + [sv_cv_sigaltstack_low_base], [ + AC_RUN_IFELSE([ + AC_LANG_SOURCE([[ +#include <stdlib.h> +#include <signal.h> +#if HAVE_SYS_SIGNAL_H +# include <sys/signal.h> +#endif +volatile char *stack_lower_bound; +volatile char *stack_upper_bound; +static void check_stack_location (volatile char *addr) +{ + if (addr >= stack_lower_bound && addr <= stack_upper_bound) + exit (0); + else + exit (1); +} +static void stackoverflow_handler (int sig) +{ + char dummy; + check_stack_location (&dummy); +} +char mystack[2 * (1 << 24)]; +int main () +{ + stack_t altstack; + struct sigaction action; + /* Install the alternate stack. */ + altstack.ss_sp = mystack + sizeof mystack / 2; + altstack.ss_size = sizeof mystack / 2; + stack_lower_bound = (char *) altstack.ss_sp; + stack_upper_bound = (char *) altstack.ss_sp + altstack.ss_size - 1; + altstack.ss_flags = 0; /* no SS_DISABLE */ + if (sigaltstack (&altstack, NULL) < 0) + exit (2); + /* Install the SIGSEGV handler. */ + sigemptyset (&action.sa_mask); + action.sa_handler = &stackoverflow_handler; + action.sa_flags = SA_ONSTACK; + if (sigaction (SIGSEGV, &action, (struct sigaction *) NULL) < 0) + exit(3); + /* Provoke a SIGSEGV. */ + raise (SIGSEGV); + exit (3); +}]])], + [sv_cv_sigaltstack_low_base=yes], + [sv_cv_sigaltstack_low_base=no], + [ + dnl FIXME: Put in some more known values here. + case "$host_os" in + irix5*) sv_cv_sigaltstack_low_base="no" ;; + *) sv_cv_sigaltstack_low_base="guessing yes" ;; + esac + ]) + ]) + if test "$sv_cv_sigaltstack_low_base" = no; then + AC_DEFINE([SIGALTSTACK_SS_REVERSED], [1], + [Define if sigaltstack() interprets the stack_t.ss_sp field incorrectly, + as the highest address of the alternate stack range rather than as the + lowest address.]) + fi + fi +]) |