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Changes to m4/src/stackovf.c,v
From: |
Eric Blake |
Subject: |
Changes to m4/src/stackovf.c,v |
Date: |
Sat, 22 Jul 2006 22:38:15 +0000 |
CVSROOT: /sources/m4
Module name: m4
Changes by: Eric Blake <ericb> 06/07/22 22:38:14
Index: src/stackovf.c
===================================================================
RCS file: /sources/m4/m4/src/stackovf.c,v
retrieving revision 1.18
retrieving revision 1.19
diff -u -b -r1.18 -r1.19
--- src/stackovf.c 22 Jul 2006 19:23:04 -0000 1.18
+++ src/stackovf.c 22 Jul 2006 22:38:14 -0000 1.19
@@ -91,6 +91,13 @@
# include <siginfo.h>
#endif
+#ifndef SA_RESETHAND
+# define SA_RESETHAND 0
+#endif
+#ifndef SA_SIGINFO
+# define SA_SIGINFO 0
+#endif
+
#ifndef SIGSTKSZ
# define SIGSTKSZ 8192
#endif
@@ -108,7 +115,6 @@
# define STACKOVF_DETECT 16384
#endif
-/* Giving a hand to ansi2knr... */
typedef void (*handler_t) (void);
#if defined(__ultrix) && defined(__vax)
@@ -147,21 +153,22 @@
message and abort with a core dump. This only occurs on systems which
provide no information, but is better than nothing. */
-#define PARAM_STACKOVF ((const char *) 1)
-#define PARAM_NOSTACKOVF ((const char *) 2)
+#define PARAM_STACKOVF ((const char *) (1 + STACKOVF_DETECT))
+#define PARAM_NOSTACKOVF ((const char *) (2 + STACKOVF_DETECT))
static void
process_sigsegv (int signo, const char *p)
{
- long diff;
+ ptrdiff_t diff;
diff = (p - stackend);
#ifdef DEBUG_STKOVF
{
- char buf[140];
+ char buf[200];
- sprintf (buf, "process_sigsegv: p=%#lx stackend=%#lx diff=%ld bot=%#lx\n",
- (long) p, (long) stackend, (long) diff, (long) stackbot);
+ sprintf (buf,
+ "process_sigsegv: p=%p stackend=%p diff=%" PRIdPTR "bot=%p\n",
+ p, stackend, diff, stackbot);
write (2, buf, strlen (buf));
}
#endif
@@ -170,11 +177,18 @@
{
if ((long) sbrk (8192) == (long) -1)
{
+ const char *cp;
/* sbrk failed. Assume the RLIMIT_VMEM prevents expansion even
if the stack limit has not been reached. */
- write (2, _("VMEM limit exceeded?\n"), 21);
+ /* FIXME - calling gettext inside a signal handler is
+ dangerous, since it can call malloc, which is not signal
+ safe. We can sort of justify it by the fact that this
+ handler is designed to exit() the program, but it could
+ really use a better fix. */
+ cp = _("VMEM limit exceeded?\n");
+ write (2, cp, strlen (cp));
p = PARAM_STACKOVF;
}
if (diff >= -STACKOVF_DETECT && diff <= STACKOVF_DETECT)
@@ -196,6 +210,8 @@
{
const char *cp;
+ /* FIXME - calling gettext inside a signal handler is dangerous,
+ since it can call malloc, which is not signal safe. */
cp = _("\
Memory bounds violation detected (SIGSEGV). Either a stack overflow\n\
occurred, or there is a bug in ");
@@ -211,20 +227,31 @@
signal (signo, SIG_DFL);
}
-#if HAVE_SIGINFO_H || HAVE_SIGINFO_T
+#if HAVE_STRUCT_SIGACTION_SA_SIGACTION
+
+/* POSIX. */
+
+static void
+sigsegv_handler (int signo, siginfo_t *ip, void *context)
+{
+ process_sigsegv
+ (signo, (ip != NULL
+ && ip->si_signo == SIGSEGV ? (char *) ip->si_addr : NULL));
+}
+
+#elif HAVE_SIGINFO_T
/* SVR4. */
static void
-sigsegv_handler (int signo, siginfo_t * ip)
+sigsegv_handler (int signo, siginfo_t *ip)
{
process_sigsegv
- (signo, (ip != (siginfo_t *) 0
+ (signo, (ip != NULL
&& ip->si_signo == SIGSEGV ? (char *) ip->si_addr : NULL));
}
-#else /* not HAVE_SIGINFO_H */
-#if HAVE_SIGCONTEXT
+#elif HAVE_SIGCONTEXT
/* SunOS 4.x (and BSD?). (not tested) */
@@ -245,7 +272,6 @@
}
#endif /* not HAVE_SIGCONTEXT */
-#endif /* not HAVE_SIGINFO && not HAVE_SIGINFO_T */
/* Arrange to trap a stack-overflow and call a specified handler. The
call is on a dedicated signal stack.
@@ -270,20 +296,23 @@
int grows_upward;
register char *const *v;
register char *p;
-#if HAVE_SIGACTION && defined(SA_ONSTACK)
+#if HAVE_SIGACTION && defined SA_ONSTACK
struct sigaction act;
-#else
+#elif HAVE_SIGVEC && defined SV_ONSTACK
struct sigvec vec;
+#else
+
+Error - Do not know how to set up stack-ovf trap handler...
+
#endif
- grows_upward = ((char *) argv < (char *) &stack_len);
arg0 = argv[0];
stackovf_handler = handler;
/* Calculate the approximate expected addr for a stack-ovf trap. */
if (getrlimit (RLIMIT_STACK, &rl) < 0)
- error (1, errno, "getrlimit");
+ error (EXIT_FAILURE, errno, "getrlimit");
stack_len = (rl.rlim_cur < rl.rlim_max ? rl.rlim_cur : rl.rlim_max);
stackbot = (char *) argv;
grows_upward = ((char *) &stack_len > stackbot);
@@ -292,14 +321,14 @@
/* Grows toward increasing addresses. */
- for (v = argv; (p = (char *) *v) != (char *) 0; v++)
+ for (v = argv; (p = (char *) *v) != NULL; v++)
{
if (p < stackbot)
stackbot = p;
}
if ((char *) envp < stackbot)
stackbot = (char *) envp;
- for (v = envp; (p = (char *) *v) != (char *) 0; v++)
+ for (v = envp; (p = (char *) *v) != NULL; v++)
{
if (p < stackbot)
stackbot = p;
@@ -311,14 +340,14 @@
/* The stack grows "downward" (toward decreasing addresses). */
- for (v = argv; (p = (char *) *v) != (char *) 0; v++)
+ for (v = argv; (p = (char *) *v) != NULL; v++)
{
if (p > stackbot)
stackbot = p;
}
if ((char *) envp > stackbot)
stackbot = (char *) envp;
- for (v = envp; (p = (char *) *v) != (char *) 0; v++)
+ for (v = envp; (p = (char *) *v) != NULL; v++)
{
if (p > stackbot)
stackbot = p;
@@ -328,9 +357,9 @@
/* Allocate a separate signal-handler stack. */
-#if HAVE_SIGALTSTACK && (HAVE_SIGINFO_H || HAVE_SIGINFO_T || !HAVE_SIGSTACK)
+#if HAVE_SIGALTSTACK && (HAVE_SIGINFO_T || ! HAVE_SIGSTACK)
- /* Use sigaltstack only if siginfo is available, unless there is no
+ /* Use sigaltstack only if siginfo_t is available, unless there is no
choice. */
{
@@ -341,15 +370,14 @@
ss.ss_size = SIGSTKSZ;
ss.ss_sp = (void *) stackbuf;
ss.ss_flags = 0;
- if (sigaltstack (&ss, (stack_t *) 0) < 0)
+ if (sigaltstack (&ss, NULL) < 0)
{
free ((void *) stackbuf);
- error (1, errno, "sigaltstack");
+ error (EXIT_FAILURE, errno, "sigaltstack");
}
}
-#else /* not HAVE_SIGALTSTACK || not HAVE_SIGINFO_H && not HAVE_SIGINFO_T &&
HAVE_SIGSTACK */
-#if HAVE_SIGSTACK
+#elif HAVE_SIGSTACK
{
struct sigstack ss;
@@ -359,8 +387,8 @@
ss.ss_onstack = 0;
if (sigstack (&ss, NULL) < 0)
{
- free (stackbuf);
- error (1, errno, "sigstack");
+ free ((void *) stackbuf);
+ error (EXIT_FAILURE, errno, "sigstack");
}
}
@@ -369,45 +397,31 @@
Error - Do not know how to set up stack-ovf trap handler...
#endif /* not HAVE_SIGSTACK */
-#endif /* not HAVE_SIGALTSTACK || not HAVE_SIGINFO_H && HAVE_SIGSTACK */
/* Arm the SIGSEGV signal handler. */
-#if HAVE_SIGACTION && defined(SA_ONSTACK)
+#if HAVE_SIGACTION && defined SA_ONSTACK
sigaction (SIGSEGV, NULL, &act);
+# if HAVE_STRUCT_SIGACTION_SA_SIGACTION
+ act.sa_sigaction = sigsegv_handler;
+# else /* ! HAVE_STRUCT_SIGACTION_SA_SIGACTION */
act.sa_handler = (RETSIGTYPE (*) (int)) sigsegv_handler;
+# endif /* ! HAVE_STRUCT_SIGACTION_SA_SIGACTION */
sigemptyset (&act.sa_mask);
- act.sa_flags = (SA_ONSTACK
-#ifdef SA_RESETHAND
- | SA_RESETHAND
-#endif
-#ifdef SA_SIGINFO
- | SA_SIGINFO
-#endif
- );
+ act.sa_flags = (SA_ONSTACK | SA_RESETHAND | SA_SIGINFO);
if (sigaction (SIGSEGV, &act, NULL) < 0)
- error (1, errno, "sigaction");
+ error (EXIT_FAILURE, errno, "sigaction");
-#else /* not HAVE_SIGACTION */
-#if HAVE_SIGVEC && defined(SV_ONSTACK)
+#else /* ! HAVE_SIGACTION */
vec.sv_handler = (RETSIGTYPE (*) (int)) sigsegv_handler;
vec.sv_mask = 0;
- vec.sv_flags = (SV_ONSTACK
-#ifdef SV_RESETHAND
- | SV_RESETHAND
-#endif
- );
+ vec.sv_flags = (SV_ONSTACK | SV_RESETHAND);
if (sigvec (SIGSEGV, &vec, NULL) < 0)
- error (1, errno, "sigvec");
-
-#else /* not HAVE_SIGVEC && defined(SV_ONSTACK) */
-
-Error - Do not know how to catch signals on an alternate stack...
+ error (EXIT_FAILURE, errno, "sigvec");
-#endif /* HAVE_SIGVEC && defined(SV_ONSTACK) */
-#endif /* HAVE_SIGALTSTACK && defined(SA_ONSTACK) */
+#endif /* ! HAVE_SIGACTION */
}