X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fc-stack.c;h=9bf19ff56d9a2a80e4947eaf5872cc7b09f12603;hb=28d9a006c64dcc3e831f8a5149eed0739a89df12;hp=095f890e514209ddcc3f4b1e4d270c55b4d2c09c;hpb=19434ee9fb81a65f28fd994e7ee4f99c23cf26e5;p=gnulib.git
diff --git a/lib/c-stack.c b/lib/c-stack.c
index 095f890e5..9bf19ff56 100644
--- a/lib/c-stack.c
+++ b/lib/c-stack.c
@@ -1,11 +1,11 @@
/* Stack overflow handling.
- Copyright (C) 2002 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2004, 2006 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ 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.
+ the Free Software Foundation; either version 3 of the License, 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
@@ -13,8 +13,7 @@
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. */
+ along with this program. If not, see . */
/* Written by Paul Eggert. */
@@ -32,15 +31,9 @@
(e.g., with malloc). Yes, this is a pain, but we don't know of any
better solution that is portable.
- No attempt has been made to deal with multithreaded applications.
+ No attempt has been made to deal with multithreaded applications. */
- If ! HAVE_XSI_STACK_OVERFLOW_HEURISTIC, the current implementation
- assumes that, if the RLIMIT_STACK limit changes during execution,
- then c_stack_action is invoked immediately afterwards. */
-
-#if HAVE_CONFIG_H
-# include
-#endif
+#include
#ifndef __attribute__
# if __GNUC__ < 3 || __STRICT_ANSI__
@@ -68,6 +61,12 @@ typedef struct sigaltstack stack_t;
#include
#if HAVE_SYS_RESOURCE_H
+/* Include sys/time.h here, because...
+ SunOS-4.1.x fails to include .
+ This gives "incomplete type" errors for ru_utime and tu_stime. */
+# if HAVE_SYS_TIME_H
+# include
+# endif
# include
#endif
@@ -75,9 +74,7 @@ typedef struct sigaltstack stack_t;
# include
#endif
-#if HAVE_UNISTD_H
-# include
-#endif
+#include
#ifndef STDERR_FILENO
# define STDERR_FILENO 2
#endif
@@ -89,6 +86,13 @@ typedef struct sigaltstack stack_t;
#include "c-stack.h"
#include "exitfail.h"
+#if (HAVE_STRUCT_SIGACTION_SA_SIGACTION && defined SA_NODEFER \
+ && defined SA_ONSTACK && defined SA_RESETHAND && defined SA_SIGINFO)
+# define SIGACTION_WORKS 1
+#else
+# define SIGACTION_WORKS 0
+#endif
+
extern char *program_name;
/* The user-specified action to take when a SEGV-related program error
@@ -109,9 +113,9 @@ static void die (int) __attribute__ ((noreturn));
static void
die (int signo)
{
- char const *message =
- signo ? program_error_message : stack_overflow_message;
+ char const *message;
segv_action (signo);
+ 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));
@@ -138,132 +142,6 @@ find_stack_direction (char const *addr)
}
# endif
-# if HAVE_XSI_STACK_OVERFLOW_HEURISTIC
-# define get_stack_location(argv) 0
-# else
-
-# if defined RLIMIT_STACK && defined _SC_PAGESIZE
-
-/* Return the minimum machine address deducible from ARGV. This
- includes the addresses of all the strings that ARGV points at, as
- well as the address of ARGV itself. */
-
-static char const *
-min_address_from_argv (char * const *argv)
-{
- char const *min = (char const *) argv;
- char const *p;
- while ((p = *argv++))
- if (p < min)
- min = p;
- return min;
-}
-
-/* Return the maximum machine address deducible from ARGV. */
-
-static char const *
-max_address_from_argv (char * const *argv)
-{
- char const *max = *argv;
- char const *max1;
- char const *p;
- while ((p = *argv++))
- if (max < p)
- max = p;
- max1 = (char const *) (argv + 1);
- return max && max1 < max ? max + strlen (max) + 1 : max1;
-}
-# endif
-
-/* The base and size of the stack, determined at startup. */
-static char const * volatile stack_base;
-static size_t volatile stack_size;
-
-/* Store the base and size of the stack into the static variables
- STACK_BASE and STACK_SIZE. The base is the numerically lowest
- address in the stack. Return -1 (setting errno) if this cannot be
- done. */
-
-static int
-get_stack_location (char * const *argv)
-{
-# if ! (defined RLIMIT_STACK && defined _SC_PAGESIZE)
-
- errno = ENOTSUP;
- return -1;
-
-# else
-
- struct rlimit rlimit;
- int r = getrlimit (RLIMIT_STACK, &rlimit);
- if (r == 0)
- {
- char const *base;
- size_t size = rlimit.rlim_cur;
- extern char **environ;
- size_t page_size = sysconf (_SC_PAGESIZE);
- int stack_direction = find_stack_direction (0);
-
-# if HAVE_GETCONTEXT && HAVE_DECL_GETCONTEXT
- ucontext_t context;
- if (getcontext (&context) == 0)
- {
- base = context.uc_stack.ss_sp;
- if (stack_direction < 0)
- base -= size - context.uc_stack.ss_size;
- }
- else
-# endif
- {
- if (stack_direction < 0)
- {
- char const *a = max_address_from_argv (argv);
- char const *b = max_address_from_argv (environ);
- base = (a < b ? b : a) - size;
- base += - (size_t) base % page_size;
- }
- else
- {
- char const *a = min_address_from_argv (argv);
- char const *b = min_address_from_argv (environ);
- base = a < b ? a : b;
- base -= (size_t) base % page_size;
- }
- }
-
- if (size != rlimit.rlim_cur
- || rlimit.rlim_cur < 0
- || base + size < base
-# ifdef RLIM_SAVED_CUR
- || rlimit.rlim_cur == RLIM_SAVED_CUR
-# endif
-# ifdef RLIM_SAVED_MAX
- || rlimit.rlim_cur == RLIM_SAVED_MAX
-# endif
-# ifdef RLIM_INFINITY
- || rlimit.rlim_cur == RLIM_INFINITY
-# endif
- )
- {
- errno = EOVERFLOW;
- return -1;
- }
-
- stack_base = base;
- stack_size = size;
-
-# if DEBUG
- fprintf (stderr, "get_stack_location base=%p size=%lx\n",
- base, (unsigned long) size);
-# endif
- }
-
- return r;
-
-# endif
-}
-# endif
-
/* Storage for the alternate signal stack. */
static union
{
@@ -277,7 +155,7 @@ static union
void *p;
} alternate_signal_stack;
-# if defined SA_ONSTACK && defined SA_SIGINFO && defined _SC_PAGESIZE
+# if SIGACTION_WORKS
/* Handle a segmentation violation and exit. This function is
async-signal-safe. */
@@ -290,14 +168,18 @@ segv_handler (int signo, siginfo_t *info,
/* Clear SIGNO if it seems to have been a stack overflow. */
if (0 < info->si_code)
{
+# if ! HAVE_XSI_STACK_OVERFLOW_HEURISTIC
+ /* We can't easily determine whether it is a stack overflow; so
+ assume that the rest of our program is perfect (!) and that
+ this segmentation violation is a stack overflow. */
+ signo = 0;
+# else
/* If the faulting address is within the stack, or within one
page of the stack end, assume that it is a stack
overflow. */
-# if HAVE_XSI_STACK_OVERFLOW_HEURISTIC
ucontext_t const *user_context = context;
char const *stack_base = user_context->uc_stack.ss_sp;
size_t stack_size = user_context->uc_stack.ss_size;
-# endif
char const *faulting_address = info->si_addr;
size_t s = faulting_address - stack_base;
size_t page_size = sysconf (_SC_PAGESIZE);
@@ -306,7 +188,7 @@ segv_handler (int signo, siginfo_t *info,
if (s < stack_size + page_size)
signo = 0;
-# if DEBUG
+# if DEBUG
{
char buf[1024];
sprintf (buf,
@@ -315,6 +197,7 @@ segv_handler (int signo, siginfo_t *info,
(unsigned long) page_size, signo);
write (STDERR_FILENO, buf, strlen (buf));
}
+# endif
# endif
}
@@ -327,13 +210,13 @@ null_action (int signo __attribute__ ((unused)))
{
}
-/* Assuming ARGV is the argument vector of `main', set up ACTION so
- that it is invoked on C stack overflow. Return -1 (setting errno)
- if this cannot be done.
+/* Set up ACTION so that it is invoked on C stack overflow. Return -1
+ (setting errno) if this cannot be done.
When ACTION is called, it is passed an argument equal to SIGSEGV
for a segmentation violation that does not appear related to stack
- overflow, and is passed zero otherwise.
+ overflow, and is passed zero otherwise. On many platforms it is
+ hard to tell; when in doubt, zero is passed.
A null ACTION acts like an action that does nothing.
@@ -341,31 +224,23 @@ null_action (int signo __attribute__ ((unused)))
must not require more than SIGSTKSZ bytes of stack space. */
int
-c_stack_action (char * const *argv __attribute__ ((unused)),
- void (*action) (int))
+c_stack_action (void (*action) (int))
{
- int r = get_stack_location (argv);
+ int r;
+ stack_t st;
+ 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;
- {
- stack_t st;
- 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;
- }
-
segv_action = action ? action : null_action;
program_error_message = _("program error");
stack_overflow_message = _("stack overflow");
{
-# if ! (defined SA_ONSTACK && defined SA_SIGINFO && defined _SC_PAGESIZE)
- return signal (SIGSEGV, die) == SIG_ERR ? -1 : 0;
-# else
+# if SIGACTION_WORKS
struct sigaction act;
sigemptyset (&act.sa_mask);
@@ -377,6 +252,8 @@ c_stack_action (char * const *argv __attribute__ ((unused)),
act.sa_sigaction = segv_handler;
return sigaction (SIGSEGV, &act, 0);
+# else
+ return signal (SIGSEGV, die) == SIG_ERR ? -1 : 0;
# endif
}
}
@@ -384,8 +261,7 @@ c_stack_action (char * const *argv __attribute__ ((unused)),
#else /* ! (HAVE_SIGALTSTACK && HAVE_DECL_SIGALTSTACK) */
int
-c_stack_action (char * const *argv __attribute__ ((unused)),
- void (*action) (int) __attribute__ ((unused)))
+c_stack_action (void (*action) (int) __attribute__ ((unused)))
{
errno = ENOTSUP;
return -1;
@@ -413,8 +289,9 @@ int
main (int argc __attribute__ ((unused)), char **argv)
{
program_name = argv[0];
- fprintf (stderr, "The last line of output should be \"stack overflow\".\n");
- if (c_stack_action (argv, 0) == 0)
+ fprintf (stderr,
+ "The last output line should contain \"stack overflow\".\n");
+ if (c_stack_action (0) == 0)
return recurse ("\1");
perror ("c_stack_action");
return 1;
@@ -424,6 +301,6 @@ main (int argc __attribute__ ((unused)), char **argv)
/*
Local Variables:
-compile-command: "gcc -DDEBUG -DHAVE_CONFIG_H -I.. -g -O -Wall -W c-stack.c"
+compile-command: "gcc -DDEBUG -g -O -Wall -W c-stack.c"
End:
*/