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|
|
@ -0,0 +1,686 @@
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|
diff --git a/gnulib-tests/Makefile.in b/gnulib-tests/Makefile.in
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|
|
index aa979f4..194cc7d 100644
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|
|
--- a/gnulib-tests/Makefile.in
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|
|
|
+++ b/gnulib-tests/Makefile.in
|
|
|
|
|
@@ -3100,7 +3100,7 @@ test_argmatch_LDADD = $(LDADD) @LIBINTL@ $(LIB_MBRTOWC)
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|
|
|
test_bind_LDADD = $(LDADD) @LIBSOCKET@ $(INET_PTON_LIB)
|
|
|
|
|
test_btowc_LDADD = $(LDADD) $(LIB_SETLOCALE)
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|
|
|
test_c_ctype_LDADD = $(LDADD) $(LIB_SETLOCALE)
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|
-test_c_stack_LDADD = $(LDADD) $(LIBCSTACK) @LIBINTL@
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|
|
+test_c_stack_LDADD = $(LDADD) -lsigsegv @LIBINTL@
|
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|
|
test_c_strcasecmp_LDADD = $(LDADD) $(LIB_SETLOCALE)
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|
|
test_c_strncasecmp_LDADD = $(LDADD) $(LIB_SETLOCALE)
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|
|
|
test_connect_LDADD = $(LDADD) @LIBSOCKET@ $(INET_PTON_LIB)
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|
|
diff --git a/gnulib-tests/gnulib.mk b/gnulib-tests/gnulib.mk
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|
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index b1dc6f9..ba0594e 100644
|
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|
--- a/gnulib-tests/gnulib.mk
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|
|
+++ b/gnulib-tests/gnulib.mk
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|
|
@@ -209,7 +209,7 @@ EXTRA_DIST += test-c-ctype.c macros.h
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|
|
TESTS += test-c-stack.sh test-c-stack2.sh
|
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|
|
|
TESTS_ENVIRONMENT += LIBSIGSEGV='@LIBSIGSEGV@'
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|
|
check_PROGRAMS += test-c-stack
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|
|
-test_c_stack_LDADD = $(LDADD) $(LIBCSTACK) @LIBINTL@
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|
+test_c_stack_LDADD = $(LDADD) -lsigsegv @LIBINTL@
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|
|
MOSTLYCLEANFILES += t-c-stack.tmp t-c-stack2.tmp
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|
|
|
EXTRA_DIST += test-c-stack.c test-c-stack.sh test-c-stack2.sh macros.h
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|
|
|
|
|
|
diff --git a/lib/c-stack.c b/lib/c-stack.c
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|
|
index 3aea16a..b0e5cb1 100644
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|
|
--- a/lib/c-stack.c
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|
+++ b/lib/c-stack.c
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|
|
@@ -1,6 +1,6 @@
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|
|
/* Stack overflow handling.
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|
- Copyright (C) 2002, 2004, 2006, 2008-2020 Free Software Foundation, Inc.
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+ Copyright (C) 2002, 2004, 2006, 2008-2021 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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@@ -37,54 +37,28 @@
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|
|
#include "c-stack.h"
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|
|
-#include "gettext.h"
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|
|
-#define _(msgid) gettext (msgid)
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|
|
-
|
|
|
|
|
#include <errno.h>
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|
|
#include <inttypes.h>
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|
-
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|
#include <signal.h>
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|
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-#if ! HAVE_STACK_T && ! defined stack_t
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|
-typedef struct sigaltstack stack_t;
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-#endif
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-
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|
|
-#include <stdbool.h>
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|
|
#include <stddef.h>
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|
|
#include <stdlib.h>
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|
|
#include <string.h>
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|
|
|
-
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|
|
-/* Pre-2008 POSIX declared ucontext_t in ucontext.h instead of signal.h. */
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|
|
-#if HAVE_UCONTEXT_H
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|
|
|
-# include <ucontext.h>
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|
|
-#endif
|
|
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|
|
-
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|
|
#include <unistd.h>
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|
|
|
|
#if DEBUG
|
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|
|
|
# include <stdio.h>
|
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|
#endif
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-/* Use libsigsegv only if needed; kernels like Solaris can detect
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|
|
- stack overflow without the overhead of an external library. */
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|
-#define USE_LIBSIGSEGV (!HAVE_XSI_STACK_OVERFLOW_HEURISTIC && HAVE_LIBSIGSEGV)
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-
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|
-#if USE_LIBSIGSEGV
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|
|
-# include <sigsegv.h>
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|
-#endif
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|
+#include <sigsegv.h>
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|
#include "exitfail.h"
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|
-#include "ignore-value.h"
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|
-#include "intprops.h"
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|
#include "getprogname.h"
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|
+#include "ignore-value.h"
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|
|
-#if defined SA_ONSTACK && defined SA_SIGINFO
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|
|
-# define SIGINFO_WORKS 1
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|
|
-#else
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|
|
-# define SIGINFO_WORKS 0
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|
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-# ifndef SA_ONSTACK
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-# define SA_ONSTACK 0
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|
|
-# endif
|
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|
-#endif
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|
+#include "gettext.h"
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+#define _(msgid) gettext (msgid)
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+
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|
+#if HAVE_STACK_OVERFLOW_RECOVERY
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|
|
/* Storage for the alternate signal stack.
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|
64 KiB is not too large for Gnulib-using apps, and is large enough
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@@ -106,9 +80,6 @@ static _GL_ASYNC_SAFE void (* volatile segv_action) (int);
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static char const * volatile program_error_message;
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static char const * volatile stack_overflow_message;
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-#if (USE_LIBSIGSEGV \
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|
- || (HAVE_DECL_SIGALTSTACK && HAVE_STACK_OVERFLOW_HANDLING))
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-
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|
/* Output an error message, then exit with status EXIT_FAILURE if it
|
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|
|
appears to have been a stack overflow, or with a core dump
|
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|
otherwise. This function is async-signal-safe. */
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@@ -118,12 +89,6 @@ static char const * volatile progname;
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static _GL_ASYNC_SAFE _Noreturn void
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die (int signo)
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{
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-# if !SIGINFO_WORKS && !USE_LIBSIGSEGV
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- /* We can't easily determine whether it is a stack overflow; so
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|
- assume that the rest of our program is perfect (!) and that
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- this segmentation violation is a stack overflow. */
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- signo = 0;
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|
-# endif
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segv_action (signo);
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char const *message = signo ? program_error_message : stack_overflow_message;
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@@ -164,12 +129,8 @@ null_action (int signo _GL_UNUSED)
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{
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}
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-#endif /* SIGALTSTACK || LIBSIGSEGV */
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-
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|
-#if USE_LIBSIGSEGV
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-
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/* Pacify GCC 9.3.1, which otherwise would complain about segv_handler. */
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-# if __GNUC_PREREQ (4, 6)
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+# if 4 < __GNUC__ + (6 <= __GNUC_MINOR__)
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# pragma GCC diagnostic ignored "-Wsuggest-attribute=pure"
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# endif
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@@ -240,132 +201,7 @@ c_stack_action (_GL_ASYNC_SAFE void (*action) (int))
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return 0;
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}
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-#elif HAVE_DECL_SIGALTSTACK && HAVE_STACK_OVERFLOW_HANDLING
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-
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-# if SIGINFO_WORKS
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-
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|
-static size_t volatile page_size;
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-
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-/* Handle a segmentation violation and exit. This function is
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|
- async-signal-safe. */
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-
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|
-static _GL_ASYNC_SAFE _Noreturn void
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-segv_handler (int signo, siginfo_t *info, void *context _GL_UNUSED)
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-{
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- /* Clear SIGNO if it seems to have been a stack overflow. */
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-
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|
- /* If si_code is nonpositive, something like raise (SIGSEGV) occurred
|
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|
- so it cannot be a stack overflow. */
|
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|
|
- bool cannot_be_stack_overflow = info->si_code <= 0;
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-
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|
- /* An unaligned address cannot be a stack overflow. */
|
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|
|
-# if FAULT_YIELDS_SIGBUS
|
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|
|
- cannot_be_stack_overflow |= signo == SIGBUS && info->si_code == BUS_ADRALN;
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|
|
-# endif
|
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|
-
|
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|
|
- /* If we can't easily determine that it is not a stack overflow,
|
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|
|
|
- assume that the rest of our program is perfect (!) and that
|
|
|
|
|
- this segmentation violation is a stack overflow.
|
|
|
|
|
-
|
|
|
|
|
- Note that although both Linux and Solaris provide
|
|
|
|
|
- sigaltstack, SA_ONSTACK, and SA_SIGINFO, currently only
|
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|
|
- Solaris satisfies the XSI heuristic. This is because
|
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|
|
|
- Solaris populates uc_stack with the details of the
|
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|
- interrupted stack, while Linux populates it with the details
|
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|
- of the current stack. */
|
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|
|
|
- if (!cannot_be_stack_overflow)
|
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|
|
- {
|
|
|
|
|
- /* If the faulting address is within the stack, or within one
|
|
|
|
|
- page of the stack, assume that it is a stack overflow. */
|
|
|
|
|
- uintptr_t faulting_address = (uintptr_t) info->si_addr;
|
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|
|
|
-
|
|
|
|
|
- /* On all platforms we know of, the first page is not in the
|
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|
|
|
- stack to catch null pointer dereferening. However, all other
|
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|
|
|
- pages might be in the stack. */
|
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|
|
|
- void *stack_base = (void *) (uintptr_t) page_size;
|
|
|
|
|
- uintptr_t stack_size = 0; stack_size -= page_size;
|
|
|
|
|
-# if HAVE_XSI_STACK_OVERFLOW_HEURISTIC
|
|
|
|
|
- /* Tighten the stack bounds via the XSI heuristic. */
|
|
|
|
|
- ucontext_t const *user_context = context;
|
|
|
|
|
- stack_base = user_context->uc_stack.ss_sp;
|
|
|
|
|
- stack_size = user_context->uc_stack.ss_size;
|
|
|
|
|
-# endif
|
|
|
|
|
- uintptr_t base = (uintptr_t) stack_base,
|
|
|
|
|
- lo = (INT_SUBTRACT_WRAPV (base, page_size, &lo) || lo < page_size
|
|
|
|
|
- ? page_size : lo),
|
|
|
|
|
- hi = ((INT_ADD_WRAPV (base, stack_size, &hi)
|
|
|
|
|
- || INT_ADD_WRAPV (hi, page_size - 1, &hi))
|
|
|
|
|
- ? UINTPTR_MAX : hi);
|
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|
|
|
- if (lo <= faulting_address && faulting_address <= hi)
|
|
|
|
|
- signo = 0;
|
|
|
|
|
-
|
|
|
|
|
-# if DEBUG
|
|
|
|
|
- {
|
|
|
|
|
- char buf[1024];
|
|
|
|
|
- ignore_value (write (STDERR_FILENO, buf,
|
|
|
|
|
- sprintf (buf,
|
|
|
|
|
- ("segv_handler code=%d fault=%p base=%p"
|
|
|
|
|
- " size=0x%zx page=0x%zx signo=%d\n"),
|
|
|
|
|
- info->si_code, info->si_addr, stack_base,
|
|
|
|
|
- stack_size, page_size, signo)));
|
|
|
|
|
- }
|
|
|
|
|
-# endif
|
|
|
|
|
- }
|
|
|
|
|
-
|
|
|
|
|
- die (signo);
|
|
|
|
|
-}
|
|
|
|
|
-# endif
|
|
|
|
|
-
|
|
|
|
|
-int
|
|
|
|
|
-c_stack_action (_GL_ASYNC_SAFE void (*action) (int))
|
|
|
|
|
-{
|
|
|
|
|
- stack_t st;
|
|
|
|
|
- st.ss_flags = 0;
|
|
|
|
|
- st.ss_sp = alternate_signal_stack;
|
|
|
|
|
- st.ss_size = sizeof alternate_signal_stack;
|
|
|
|
|
-# if SIGALTSTACK_SS_REVERSED
|
|
|
|
|
- /* Irix mistakenly treats ss_sp as the upper bound, rather than
|
|
|
|
|
- lower bound, of the alternate stack. */
|
|
|
|
|
- st.ss_size -= sizeof (void *);
|
|
|
|
|
- char *ss_sp = st.ss_sp;
|
|
|
|
|
- st.ss_sp = ss_sp + st.ss_size;
|
|
|
|
|
-# endif
|
|
|
|
|
- int r = sigaltstack (&st, NULL);
|
|
|
|
|
- if (r != 0)
|
|
|
|
|
- return r;
|
|
|
|
|
-
|
|
|
|
|
- segv_action = action ? action : null_action;
|
|
|
|
|
- program_error_message = _("program error");
|
|
|
|
|
- stack_overflow_message = _("stack overflow");
|
|
|
|
|
- progname = getprogname ();
|
|
|
|
|
-
|
|
|
|
|
-# if SIGINFO_WORKS
|
|
|
|
|
- page_size = sysconf (_SC_PAGESIZE);
|
|
|
|
|
-# endif
|
|
|
|
|
-
|
|
|
|
|
- struct sigaction act;
|
|
|
|
|
- sigemptyset (&act.sa_mask);
|
|
|
|
|
-
|
|
|
|
|
-# if SIGINFO_WORKS
|
|
|
|
|
- /* 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;
|
|
|
|
|
-# else
|
|
|
|
|
- act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
|
|
|
|
|
- act.sa_handler = die;
|
|
|
|
|
-# endif
|
|
|
|
|
-
|
|
|
|
|
-# if FAULT_YIELDS_SIGBUS
|
|
|
|
|
- if (sigaction (SIGBUS, &act, NULL) < 0)
|
|
|
|
|
- return -1;
|
|
|
|
|
-# endif
|
|
|
|
|
- return sigaction (SIGSEGV, &act, NULL);
|
|
|
|
|
-}
|
|
|
|
|
-
|
|
|
|
|
-#else /* ! (USE_LIBSIGSEGV
|
|
|
|
|
- || (HAVE_DECL_SIGALTSTACK && HAVE_STACK_OVERFLOW_HANDLING)) */
|
|
|
|
|
+#else /* !HAVE_STACK_OVERFLOW_RECOVERY */
|
|
|
|
|
|
|
|
|
|
int
|
|
|
|
|
c_stack_action (_GL_ASYNC_SAFE void (*action) (int) _GL_UNUSED)
|
|
|
|
|
diff --git a/m4/c-stack.m4 b/m4/c-stack.m4
|
|
|
|
|
index 85107f4..7cccb06 100644
|
|
|
|
|
--- a/m4/c-stack.m4
|
|
|
|
|
+++ b/m4/c-stack.m4
|
|
|
|
|
@@ -1,376 +1,21 @@
|
|
|
|
|
# Check prerequisites for compiling lib/c-stack.c.
|
|
|
|
|
|
|
|
|
|
-# Copyright (C) 2002-2004, 2008-2020 Free Software Foundation, Inc.
|
|
|
|
|
+# Copyright (C) 2002-2004, 2008-2021 Free Software Foundation, Inc.
|
|
|
|
|
# This file is free software; the Free Software Foundation
|
|
|
|
|
# gives unlimited permission to copy and/or distribute it,
|
|
|
|
|
# with or without modifications, as long as this notice is preserved.
|
|
|
|
|
|
|
|
|
|
# Written by Paul Eggert.
|
|
|
|
|
|
|
|
|
|
-# serial 20
|
|
|
|
|
-
|
|
|
|
|
-AC_DEFUN([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC],
|
|
|
|
|
- [
|
|
|
|
|
- AC_REQUIRE([AC_CANONICAL_HOST])
|
|
|
|
|
- AC_CHECK_FUNCS_ONCE([setrlimit])
|
|
|
|
|
- AC_CHECK_HEADERS_ONCE([ucontext.h])
|
|
|
|
|
-
|
|
|
|
|
- dnl List of signals that are sent when an invalid virtual memory address
|
|
|
|
|
- dnl is accessed, or when the stack overflows.
|
|
|
|
|
- dnl Either { SIGSEGV } or { SIGSEGV, SIGBUS }.
|
|
|
|
|
- case "$host_os" in
|
|
|
|
|
- sunos4* | freebsd* | dragonfly* | openbsd* | mirbsd* | netbsd* | kfreebsd* | knetbsd*) # BSD systems
|
|
|
|
|
- FAULT_YIELDS_SIGBUS=1 ;;
|
|
|
|
|
- hpux*) # HP-UX
|
|
|
|
|
- FAULT_YIELDS_SIGBUS=1 ;;
|
|
|
|
|
- macos* | darwin*) # Mac OS X
|
|
|
|
|
- FAULT_YIELDS_SIGBUS=1 ;;
|
|
|
|
|
- gnu*) # Hurd
|
|
|
|
|
- FAULT_YIELDS_SIGBUS=1 ;;
|
|
|
|
|
- *)
|
|
|
|
|
- FAULT_YIELDS_SIGBUS=0 ;;
|
|
|
|
|
- esac
|
|
|
|
|
- AC_DEFINE_UNQUOTED([FAULT_YIELDS_SIGBUS], [$FAULT_YIELDS_SIGBUS],
|
|
|
|
|
- [Define to 1 if an invalid memory address access may yield a SIGBUS.])
|
|
|
|
|
-
|
|
|
|
|
- AC_CACHE_CHECK([for working C stack overflow detection],
|
|
|
|
|
- [gl_cv_sys_stack_overflow_works],
|
|
|
|
|
- [AC_RUN_IFELSE([AC_LANG_SOURCE(
|
|
|
|
|
- [[
|
|
|
|
|
- #include <unistd.h>
|
|
|
|
|
- #include <signal.h>
|
|
|
|
|
- #if HAVE_SETRLIMIT
|
|
|
|
|
- # include <sys/types.h>
|
|
|
|
|
- # include <sys/time.h>
|
|
|
|
|
- # include <sys/resource.h>
|
|
|
|
|
- #endif
|
|
|
|
|
- #ifndef SIGSTKSZ
|
|
|
|
|
- # define SIGSTKSZ 16384
|
|
|
|
|
- #endif
|
|
|
|
|
-
|
|
|
|
|
- static union
|
|
|
|
|
- {
|
|
|
|
|
- char buffer[2 * SIGSTKSZ];
|
|
|
|
|
- long double ld;
|
|
|
|
|
- long u;
|
|
|
|
|
- void *p;
|
|
|
|
|
- } alternate_signal_stack;
|
|
|
|
|
-
|
|
|
|
|
- static void
|
|
|
|
|
- segv_handler (int signo)
|
|
|
|
|
- {
|
|
|
|
|
- _exit (0);
|
|
|
|
|
- }
|
|
|
|
|
-
|
|
|
|
|
- static int
|
|
|
|
|
- c_stack_action ()
|
|
|
|
|
- {
|
|
|
|
|
- stack_t st;
|
|
|
|
|
- struct sigaction act;
|
|
|
|
|
- int r;
|
|
|
|
|
-
|
|
|
|
|
- st.ss_flags = 0;
|
|
|
|
|
- /* Use the midpoint to avoid Irix sigaltstack bug. */
|
|
|
|
|
- st.ss_sp = alternate_signal_stack.buffer + SIGSTKSZ;
|
|
|
|
|
- st.ss_size = SIGSTKSZ;
|
|
|
|
|
- r = sigaltstack (&st, 0);
|
|
|
|
|
- if (r != 0)
|
|
|
|
|
- return 1;
|
|
|
|
|
-
|
|
|
|
|
- sigemptyset (&act.sa_mask);
|
|
|
|
|
- act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
|
|
|
|
|
- act.sa_handler = segv_handler;
|
|
|
|
|
- #if FAULT_YIELDS_SIGBUS
|
|
|
|
|
- if (sigaction (SIGBUS, &act, 0) < 0)
|
|
|
|
|
- return 2;
|
|
|
|
|
- #endif
|
|
|
|
|
- if (sigaction (SIGSEGV, &act, 0) < 0)
|
|
|
|
|
- return 3;
|
|
|
|
|
- return 0;
|
|
|
|
|
- }
|
|
|
|
|
- static volatile int *
|
|
|
|
|
- recurse_1 (volatile int n, volatile int *p)
|
|
|
|
|
- {
|
|
|
|
|
- if (n >= 0)
|
|
|
|
|
- *recurse_1 (n + 1, p) += n;
|
|
|
|
|
- return p;
|
|
|
|
|
- }
|
|
|
|
|
- static int
|
|
|
|
|
- recurse (volatile int n)
|
|
|
|
|
- {
|
|
|
|
|
- int sum = 0;
|
|
|
|
|
- return *recurse_1 (n, &sum);
|
|
|
|
|
- }
|
|
|
|
|
- int
|
|
|
|
|
- main ()
|
|
|
|
|
- {
|
|
|
|
|
- int result;
|
|
|
|
|
- #if 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
|
|
|
|
|
-
|
|
|
|
|
- result = c_stack_action ();
|
|
|
|
|
- if (result != 0)
|
|
|
|
|
- return result;
|
|
|
|
|
- return recurse (0);
|
|
|
|
|
- }
|
|
|
|
|
- ]])],
|
|
|
|
|
- [gl_cv_sys_stack_overflow_works=yes],
|
|
|
|
|
- [gl_cv_sys_stack_overflow_works=no],
|
|
|
|
|
- [case "$host_os" in
|
|
|
|
|
- # Guess no on native Windows.
|
|
|
|
|
- mingw*) gl_cv_sys_stack_overflow_works="guessing no" ;;
|
|
|
|
|
- *) gl_cv_sys_stack_overflow_works=cross-compiling ;;
|
|
|
|
|
- esac
|
|
|
|
|
- ])
|
|
|
|
|
- ])
|
|
|
|
|
-
|
|
|
|
|
- if test "$gl_cv_sys_stack_overflow_works" = yes; then
|
|
|
|
|
- AC_DEFINE([HAVE_STACK_OVERFLOW_HANDLING], [1],
|
|
|
|
|
- [Define to 1 if extending the stack slightly past the limit causes
|
|
|
|
|
- a SIGSEGV which can be handled on an alternate stack established
|
|
|
|
|
- with sigaltstack.])
|
|
|
|
|
-
|
|
|
|
|
- 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],
|
|
|
|
|
- [gl_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
|
|
|
|
|
-#ifndef SIGSTKSZ
|
|
|
|
|
-# define SIGSTKSZ 16384
|
|
|
|
|
-#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);
|
|
|
|
|
-}
|
|
|
|
|
-int main ()
|
|
|
|
|
-{
|
|
|
|
|
- char mystack[2 * SIGSTKSZ];
|
|
|
|
|
- stack_t altstack;
|
|
|
|
|
- struct sigaction action;
|
|
|
|
|
- /* Install the alternate stack. */
|
|
|
|
|
- altstack.ss_sp = mystack + SIGSTKSZ;
|
|
|
|
|
- altstack.ss_size = SIGSTKSZ;
|
|
|
|
|
- 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 (4);
|
|
|
|
|
-}]])],
|
|
|
|
|
- [gl_cv_sigaltstack_low_base=yes],
|
|
|
|
|
- [gl_cv_sigaltstack_low_base=no],
|
|
|
|
|
- [gl_cv_sigaltstack_low_base=cross-compiling])])
|
|
|
|
|
- if test "$gl_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
|
|
|
|
|
-
|
|
|
|
|
- AC_CACHE_CHECK([for precise C stack overflow detection],
|
|
|
|
|
- [gl_cv_sys_xsi_stack_overflow_heuristic],
|
|
|
|
|
- [dnl On Linux/sparc64 (both in 32-bit and 64-bit mode), it would be wrong
|
|
|
|
|
- dnl to set HAVE_XSI_STACK_OVERFLOW_HEURISTIC to 1, because the third
|
|
|
|
|
- dnl argument passed to the segv_handler is a 'struct sigcontext *', not
|
|
|
|
|
- dnl an 'ucontext_t *'. It would lead to a failure of test-c-stack2.sh.
|
|
|
|
|
- case "${host_os}--${host_cpu}" in
|
|
|
|
|
- linux*--sparc*)
|
|
|
|
|
- gl_cv_sys_xsi_stack_overflow_heuristic=no
|
|
|
|
|
- ;;
|
|
|
|
|
- *)
|
|
|
|
|
- AC_RUN_IFELSE(
|
|
|
|
|
- [AC_LANG_SOURCE(
|
|
|
|
|
- [[
|
|
|
|
|
- #include <unistd.h>
|
|
|
|
|
- #include <signal.h>
|
|
|
|
|
- #if HAVE_UCONTEXT_H
|
|
|
|
|
- # include <ucontext.h>
|
|
|
|
|
- #endif
|
|
|
|
|
- #if HAVE_SETRLIMIT
|
|
|
|
|
- # include <sys/types.h>
|
|
|
|
|
- # include <sys/time.h>
|
|
|
|
|
- # include <sys/resource.h>
|
|
|
|
|
- #endif
|
|
|
|
|
- #ifndef SIGSTKSZ
|
|
|
|
|
- # define SIGSTKSZ 16384
|
|
|
|
|
- #endif
|
|
|
|
|
-
|
|
|
|
|
- static union
|
|
|
|
|
- {
|
|
|
|
|
- char buffer[2 * SIGSTKSZ];
|
|
|
|
|
- long double ld;
|
|
|
|
|
- long u;
|
|
|
|
|
- void *p;
|
|
|
|
|
- } alternate_signal_stack;
|
|
|
|
|
-
|
|
|
|
|
- #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
|
|
|
|
|
-
|
|
|
|
|
- static void
|
|
|
|
|
- segv_handler (int signo, siginfo_t *info, void *context)
|
|
|
|
|
- {
|
|
|
|
|
- if (0 < info->si_code)
|
|
|
|
|
- {
|
|
|
|
|
- /* For XSI heuristics to work, we need uc_stack to
|
|
|
|
|
- describe the interrupted stack (as on Solaris), and
|
|
|
|
|
- not the currently executing stack (as on Linux). */
|
|
|
|
|
- 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)
|
|
|
|
|
- _exit (0);
|
|
|
|
|
- _exit (4);
|
|
|
|
|
- }
|
|
|
|
|
- _exit (5);
|
|
|
|
|
- }
|
|
|
|
|
-
|
|
|
|
|
- static int
|
|
|
|
|
- c_stack_action ()
|
|
|
|
|
- {
|
|
|
|
|
- stack_t st;
|
|
|
|
|
- struct sigaction act;
|
|
|
|
|
- int r;
|
|
|
|
|
-
|
|
|
|
|
- st.ss_flags = 0;
|
|
|
|
|
- /* Use the midpoint to avoid Irix sigaltstack bug. */
|
|
|
|
|
- st.ss_sp = alternate_signal_stack.buffer + SIGSTKSZ;
|
|
|
|
|
- st.ss_size = SIGSTKSZ;
|
|
|
|
|
- r = sigaltstack (&st, 0);
|
|
|
|
|
- if (r != 0)
|
|
|
|
|
- return 1;
|
|
|
|
|
-
|
|
|
|
|
- sigemptyset (&act.sa_mask);
|
|
|
|
|
- act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO;
|
|
|
|
|
- act.sa_sigaction = segv_handler;
|
|
|
|
|
- #if FAULT_YIELDS_SIGBUS
|
|
|
|
|
- if (sigaction (SIGBUS, &act, 0) < 0)
|
|
|
|
|
- return 2;
|
|
|
|
|
- #endif
|
|
|
|
|
- if (sigaction (SIGSEGV, &act, 0) < 0)
|
|
|
|
|
- return 3;
|
|
|
|
|
- return 0;
|
|
|
|
|
- }
|
|
|
|
|
- static volatile int *
|
|
|
|
|
- recurse_1 (volatile int n, volatile int *p)
|
|
|
|
|
- {
|
|
|
|
|
- if (n >= 0)
|
|
|
|
|
- *recurse_1 (n + 1, p) += n;
|
|
|
|
|
- return p;
|
|
|
|
|
- }
|
|
|
|
|
- static int
|
|
|
|
|
- recurse (volatile int n)
|
|
|
|
|
- {
|
|
|
|
|
- int sum = 0;
|
|
|
|
|
- return *recurse_1 (n, &sum);
|
|
|
|
|
- }
|
|
|
|
|
- int
|
|
|
|
|
- main ()
|
|
|
|
|
- {
|
|
|
|
|
- int result;
|
|
|
|
|
- #if 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
|
|
|
|
|
-
|
|
|
|
|
- result = c_stack_action ();
|
|
|
|
|
- if (result != 0)
|
|
|
|
|
- return result;
|
|
|
|
|
- return recurse (0);
|
|
|
|
|
- }
|
|
|
|
|
- ]])],
|
|
|
|
|
- [gl_cv_sys_xsi_stack_overflow_heuristic=yes],
|
|
|
|
|
- [gl_cv_sys_xsi_stack_overflow_heuristic=no],
|
|
|
|
|
- [gl_cv_sys_xsi_stack_overflow_heuristic=cross-compiling])
|
|
|
|
|
- ;;
|
|
|
|
|
- esac
|
|
|
|
|
- ])
|
|
|
|
|
-
|
|
|
|
|
- if test "$gl_cv_sys_xsi_stack_overflow_heuristic" = yes; then
|
|
|
|
|
- AC_DEFINE([HAVE_XSI_STACK_OVERFLOW_HEURISTIC], [1],
|
|
|
|
|
- [Define to 1 if extending the stack slightly past the limit causes
|
|
|
|
|
- a SIGSEGV, and an alternate stack can be established with sigaltstack,
|
|
|
|
|
- and the signal handler is passed a context that specifies the
|
|
|
|
|
- run time stack. This behavior is defined by POSIX 1003.1-2001
|
|
|
|
|
- with the X/Open System Interface (XSI) option
|
|
|
|
|
- and is a standardized way to implement a SEGV-based stack
|
|
|
|
|
- overflow detection heuristic.])
|
|
|
|
|
- fi
|
|
|
|
|
- fi])
|
|
|
|
|
-
|
|
|
|
|
-
|
|
|
|
|
-AC_DEFUN([gl_PREREQ_C_STACK],
|
|
|
|
|
- [AC_REQUIRE([AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC])
|
|
|
|
|
-
|
|
|
|
|
- AC_CHECK_FUNCS_ONCE([sigaltstack])
|
|
|
|
|
- AC_CHECK_DECLS([sigaltstack], , , [[#include <signal.h>]])
|
|
|
|
|
-
|
|
|
|
|
- AC_CHECK_HEADERS_ONCE([ucontext.h])
|
|
|
|
|
-
|
|
|
|
|
- AC_CHECK_TYPES([stack_t], , , [[#include <signal.h>]])
|
|
|
|
|
-
|
|
|
|
|
- dnl c-stack does not need -lsigsegv if the system has XSI heuristics.
|
|
|
|
|
- if test "$gl_cv_sys_xsi_stack_overflow_heuristic" != yes; then
|
|
|
|
|
- gl_LIBSIGSEGV
|
|
|
|
|
- if test "$gl_cv_lib_sigsegv" = yes; then
|
|
|
|
|
- AC_SUBST([LIBCSTACK], [$LIBSIGSEGV])
|
|
|
|
|
- AC_SUBST([LTLIBCSTACK], [$LTLIBSIGSEGV])
|
|
|
|
|
- fi
|
|
|
|
|
- fi
|
|
|
|
|
-])
|
|
|
|
|
+# serial 23
|
|
|
|
|
|
|
|
|
|
AC_DEFUN([gl_C_STACK],
|
|
|
|
|
[
|
|
|
|
|
- dnl Prerequisites of lib/c-stack.c.
|
|
|
|
|
- gl_PREREQ_C_STACK
|
|
|
|
|
+ dnl 'c-stack' needs -lsigsegv if and only if the 'sigsegv' module needs it.
|
|
|
|
|
+ if test "$with_libsigsegv" = yes; then
|
|
|
|
|
+ if test "$gl_cv_lib_sigsegv" = yes; then
|
|
|
|
|
+ AC_SUBST([LIBCSTACK], [$LIBSIGSEGV])
|
|
|
|
|
+ AC_SUBST([LTLIBCSTACK], [$LTLIBSIGSEGV])
|
|
|
|
|
+ fi
|
|
|
|
|
+ fi
|
|
|
|
|
])
|
|
|
|
|
diff --git a/src/Makefile.am b/src/Makefile.am
|
|
|
|
|
index 1aebcf7..055ee17 100644
|
|
|
|
|
--- a/src/Makefile.am
|
|
|
|
|
+++ b/src/Makefile.am
|
|
|
|
|
@@ -45,7 +45,7 @@ LDADD = \
|
|
|
|
|
../lib/libgreputils.a $(LIBINTL) ../lib/libgreputils.a $(LIBICONV) \
|
|
|
|
|
$(LIBTHREAD)
|
|
|
|
|
|
|
|
|
|
-grep_LDADD = $(LDADD) $(PCRE_LIBS) $(LIBCSTACK)
|
|
|
|
|
+grep_LDADD = $(LDADD) $(PCRE_LIBS) -lsigsegv
|
|
|
|
|
localedir = $(datadir)/locale
|
|
|
|
|
AM_CPPFLAGS = -I$(top_builddir)/lib -I$(top_srcdir)/lib
|
|
|
|
|
|
|
|
|
|
diff --git a/src/Makefile.in b/src/Makefile.in
|
|
|
|
|
index 20c43b5..a276db8 100644
|
|
|
|
|
--- a/src/Makefile.in
|
|
|
|
|
+++ b/src/Makefile.in
|
|
|
|
|
@@ -1541,7 +1541,7 @@ LDADD = \
|
|
|
|
|
../lib/libgreputils.a $(LIBINTL) ../lib/libgreputils.a $(LIBICONV) \
|
|
|
|
|
$(LIBTHREAD)
|
|
|
|
|
|
|
|
|
|
-grep_LDADD = $(LDADD) $(PCRE_LIBS) $(LIBCSTACK)
|
|
|
|
|
+grep_LDADD = $(LDADD) $(PCRE_LIBS) -lsigsegv
|
|
|
|
|
AM_CPPFLAGS = -I$(top_builddir)/lib -I$(top_srcdir)/lib
|
|
|
|
|
EXTRA_DIST = egrep.sh
|
|
|
|
|
CLEANFILES = egrep fgrep *-t
|
