Fixed signal stack handling on Linux when sigaltstack is available.

configure

@@ -5930,87 +5930,13 @@ EOF
 fi
 
 
-echo $ac_n "checking "for working sigaltstack"""... $ac_c" 1>&6
-echo "configure:5935: checking "for working sigaltstack"" >&5
-if eval "test \"`echo '$''{'ac_cv_c_working_sigaltstack'+set}'`\" = set"; then
-  echo $ac_n "(cached) $ac_c" 1>&6
-else
-  if test "$cross_compiling" = yes; then
-  ac_cv_c_working_sigaltstack="no"
-
-else
-  cat > conftest.$ac_ext <<EOF
-#line 5944 "configure"
-#include "confdefs.h"
-
-	#include <stdio.h>
-	#include <time.h> /* <sys/time.h> ? bad magic without end */
-	#include <sys/types.h>
-	#include <sys/signal.h>
-	#ifdef HAVE_SYS_PARAM_H
-	# include <sys/param.h>
-	#endif
-	#ifdef HAVE_SYSCALL_H
-	# include <syscall.h>
-	#else
-	# ifdef HAVE_SYS_SYSCALL_H
-	#  include <sys/syscall.h>
-	# endif
-	#endif
-	
-	unsigned char *xaltstack;
-
-	int
-	main(int argc,char **argv) {
-	    struct sigaltstack	ss;
-
-	    xaltstack = malloc(16384);
-	    ss.ss_sp    = xaltstack;
-	    ss.ss_size  = 16384;
-	    ss.ss_flags = 0;
-	    if (sigaltstack(&ss, NULL) < 0) {
-	    	/* this catches the glibc case */
-		perror("sigaltstack");
-	    	return (1); /* aka exit(1) aka fail */
-	    }
-	    /* assume it works. */
-	    return 0; /* OK */
-	}
-	
-EOF
-if { (eval echo configure:5982: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext} && (./conftest; exit) 2>/dev/null
-then
-  ac_cv_c_working_sigaltstack="yes"
-else
-  echo "configure: failed program was:" >&5
-  cat conftest.$ac_ext >&5
-  rm -fr conftest*
-  ac_cv_c_working_sigaltstack="no"
-fi
-rm -fr conftest*
-fi
-
-fi
-
-echo "$ac_t""$ac_cv_c_working_sigaltstack" 1>&6
-
-if test "$ac_cv_c_working_sigaltstack" = "yes"
-then
-    cat >> confdefs.h <<\EOF
-#define HAVE_WORKING_SIGALTSTACK 1
-EOF
-
-fi
-
-
-
 echo $ac_n "checking "for msg_accrights in struct msghdr"""... $ac_c" 1>&6
-echo "configure:6009: checking "for msg_accrights in struct msghdr"" >&5
+echo "configure:5935: checking "for msg_accrights in struct msghdr"" >&5
 if eval "test \"`echo '$''{'ac_cv_c_msg_accrights'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 6014 "configure"
+#line 5940 "configure"
 #include "confdefs.h"
 #include <sys/types.h>
 #include <sys/socket.h>
@@ -6018,7 +5944,7 @@ int main() {
 struct msghdr hdr; hdr.msg_accrights=0
 ; return 0; }
 EOF
-if { (eval echo configure:6022: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
+if { (eval echo configure:5948: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
   rm -rf conftest*
   ac_cv_c_msg_accrights="yes"
 else
@@ -6041,12 +5967,12 @@ fi
 
 
 echo $ac_n "checking "for sun_len in struct sockaddr_un"""... $ac_c" 1>&6
-echo "configure:6045: checking "for sun_len in struct sockaddr_un"" >&5
+echo "configure:5971: checking "for sun_len in struct sockaddr_un"" >&5
 if eval "test \"`echo '$''{'ac_cv_c_sun_len'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 6050 "configure"
+#line 5976 "configure"
 #include "confdefs.h"
 #include <sys/types.h>
 #include <sys/socket.h>
@@ -6055,7 +5981,7 @@ int main() {
 static struct sockaddr_un addr; addr.sun_len = 1
 ; return 0; }
 EOF
-if { (eval echo configure:6059: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
+if { (eval echo configure:5985: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
   rm -rf conftest*
   ac_cv_c_sun_len="yes"
 else
@@ -6078,12 +6004,12 @@ fi
 
 
 echo $ac_n "checking "whether we need to define __i386__"""... $ac_c" 1>&6
-echo "configure:6082: checking "whether we need to define __i386__"" >&5
+echo "configure:6008: checking "whether we need to define __i386__"" >&5
 if eval "test \"`echo '$''{'ac_cv_cpp_def_i386'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 6087 "configure"
+#line 6013 "configure"
 #include "confdefs.h"
 #if (defined(i386) || defined(__i386)) && !defined(__i386__)
 yes

configure.in

@@ -867,57 +867,6 @@ then
   AC_DEFINE(STATFS_HAS_BAVAIL)
 fi
 
-dnl *** check for working sigaltstack
-dnl glibc 2.0x defines it, but it always fails... so it is useless for us.
-
-AC_CACHE_CHECK("for working sigaltstack",
-	ac_cv_c_working_sigaltstack,
-	AC_TRY_RUN([
-	#include <stdio.h>
-	#include <time.h> /* <sys/time.h> ? bad magic without end */
-	#include <sys/types.h>
-	#include <sys/signal.h>
-	#ifdef HAVE_SYS_PARAM_H
-	# include <sys/param.h>
-	#endif
-	#ifdef HAVE_SYSCALL_H
-	# include <syscall.h>
-	#else
-	# ifdef HAVE_SYS_SYSCALL_H
-	#  include <sys/syscall.h>
-	# endif
-	#endif
-	
-	unsigned char *xaltstack;
-
-	int
-	main(int argc,char **argv) {
-	    struct sigaltstack	ss;
-
-	    xaltstack = malloc(16384);
-	    ss.ss_sp    = xaltstack;
-	    ss.ss_size  = 16384;
-	    ss.ss_flags = 0;
-	    if (sigaltstack(&ss, NULL) < 0) {
-	    	/* this catches the glibc case */
-		perror("sigaltstack");
-	    	return (1); /* aka exit(1) aka fail */
-	    }
-	    /* assume it works. */
-	    return 0; /* OK */
-	}
-	],
-	ac_cv_c_working_sigaltstack="yes",
-	ac_cv_c_working_sigaltstack="no",
-	ac_cv_c_working_sigaltstack="no"
-))
-
-if test "$ac_cv_c_working_sigaltstack" = "yes"
-then
-    AC_DEFINE(HAVE_WORKING_SIGALTSTACK)
-fi
-
-
 dnl *** check for file descriptor passing with msg_accrights
 
 AC_CACHE_CHECK("for msg_accrights in struct msghdr", ac_cv_c_msg_accrights,

dlls/ntdll/signal_i386.c

@@ -62,13 +62,12 @@ typedef struct
 #define HANDLER_CONTEXT (&__context)
 
 /* this is the sigaction structure from the Linux 2.1.20 kernel.  */
-#undef sa_handler
 struct kernel_sigaction
 {
-    void (*sa_handler)();
-    unsigned long sa_mask;
-    unsigned long sa_flags;
-    void *sa_restorer;
+    void (*ksa_handler)();
+    unsigned long ksa_mask;
+    unsigned long ksa_flags;
+    void *ksa_restorer;
 };
 
 /* Similar to the sigaction function in libc, except it leaves alone the
@@ -87,6 +86,24 @@ static inline int wine_sigaction( int sig, struct kernel_sigaction *new,
     return -1;
 }
 
+#ifdef HAVE_SIGALTSTACK
+/* direct syscall for sigaltstack to work around glibc 2.0 brain-damage */
+static inline int wine_sigaltstack( const struct sigaltstack *new,
+                                    struct sigaltstack *old )
+{
+    int ret;
+    __asm__ __volatile__( "pushl %%ebx\n\t"
+                          "movl %2,%%ebx\n\t"
+                          "int $0x80\n\t"
+                          "popl %%ebx"
+                          : "=a" (ret)
+                          : "0" (SYS_sigaltstack), "r" (new), "c" (old) );
+    if (ret >= 0) return 0;
+    errno = -ret;
+    return -1;
+}
+#endif
+
 #endif  /* linux */
 
 #ifdef BSDI
@@ -660,32 +677,37 @@ static HANDLER_DEF(int_handler)
  *
  * Set a signal handler
  */
-static int set_handler( int sig, void (*func)() )
+static int set_handler( int sig, int have_sigaltstack, void (*func)() )
 {
-#ifdef linux
-    struct kernel_sigaction sig_act;
-    sig_act.sa_handler = func;
-    sig_act.sa_flags   = SA_RESTART | SA_NOMASK;
-    sig_act.sa_mask    = 0;
-    /* point to the top of the stack */
-    sig_act.sa_restorer = (char *)NtCurrentTeb()->signal_stack + SIGNAL_STACK_SIZE;
-    return wine_sigaction( sig, &sig_act, NULL );
-#else  /* linux */
     struct sigaction sig_act;
+
+#ifdef linux
+    if (!have_sigaltstack && NtCurrentTeb()->signal_stack)
+    {
+        struct kernel_sigaction sig_act;
+        sig_act.ksa_handler = func;
+        sig_act.ksa_flags   = SA_RESTART | SA_NOMASK;
+        sig_act.ksa_mask    = 0;
+        /* point to the top of the stack */
+        sig_act.ksa_restorer = (char *)NtCurrentTeb()->signal_stack + SIGNAL_STACK_SIZE;
+        return wine_sigaction( sig, &sig_act, NULL );
+    }
+#endif  /* linux */
     sig_act.sa_handler = func;
     sigemptyset( &sig_act.sa_mask );
 
-# if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__)
-    sig_act.sa_flags = SA_ONSTACK;
-# elif defined (__svr4__) || defined(_SCO_DS)
-    sig_act.sa_flags = SA_SIGINFO | SA_ONSTACK | SA_RESTART;
-# elif defined(__EMX__)
-    sig_act.sa_flags = 0; /* FIXME: EMX has only SA_ACK and SA_SYSV */
-# else
+#ifdef linux
+    sig_act.sa_flags = SA_RESTART | SA_NOMASK;
+#elif defined (__svr4__) || defined(_SCO_DS)
+    sig_act.sa_flags = SA_SIGINFO | SA_RESTART;
+#else
     sig_act.sa_flags = 0;
-# endif
+#endif
+
+#ifdef SA_ONSTACK
+    if (have_sigaltstack) sig_act.sa_flags |= SA_ONSTACK;
+#endif
     return sigaction( sig, &sig_act, NULL );
-#endif  /* linux */
 }
 
 
@@ -694,17 +716,21 @@ static int set_handler( int sig, void (*func)() )
  */
 BOOL SIGNAL_Init(void)
 {
-#ifdef HAVE_WORKING_SIGALTSTACK
+    int have_sigaltstack = 0;
+
+#ifdef HAVE_SIGALTSTACK
     struct sigaltstack ss;
     if ((ss.ss_sp = NtCurrentTeb()->signal_stack))
     {
         ss.ss_size  = SIGNAL_STACK_SIZE;
         ss.ss_flags = 0;
-        if (sigaltstack(&ss, NULL) < 0)
-        {
-            perror("sigaltstack");
-            /* fall through on error and try it differently */
-        }
+        if (!sigaltstack(&ss, NULL)) have_sigaltstack = 1;
+#ifdef linux
+        /* sigaltstack may fail because the kernel is too old, or
+           because glibc is brain-dead. In the latter case a
+           direct system call should succeed. */
+        else if (!wine_sigaltstack(&ss, NULL)) have_sigaltstack = 1;
+#endif  /* linux */
     }
 #endif  /* HAVE_SIGALTSTACK */
     
@@ -713,15 +739,15 @@ BOOL SIGNAL_Init(void)
     /* automatic child reaping to avoid zombies */
     signal( SIGCHLD, SIG_IGN );
 
-    if (set_handler( SIGINT,  (void (*)())int_handler ) == -1) goto error;
-    if (set_handler( SIGFPE,  (void (*)())fpe_handler ) == -1) goto error;
-    if (set_handler( SIGSEGV, (void (*)())segv_handler ) == -1) goto error;
-    if (set_handler( SIGILL,  (void (*)())segv_handler ) == -1) goto error;
+    if (set_handler( SIGINT,  have_sigaltstack, (void (*)())int_handler ) == -1) goto error;
+    if (set_handler( SIGFPE,  have_sigaltstack, (void (*)())fpe_handler ) == -1) goto error;
+    if (set_handler( SIGSEGV, have_sigaltstack, (void (*)())segv_handler ) == -1) goto error;
+    if (set_handler( SIGILL,  have_sigaltstack, (void (*)())segv_handler ) == -1) goto error;
 #ifdef SIGBUS
-    if (set_handler( SIGBUS,  (void (*)())segv_handler ) == -1) goto error;
+    if (set_handler( SIGBUS,  have_sigaltstack, (void (*)())segv_handler ) == -1) goto error;
 #endif
 #ifdef SIGTRAP
-    if (set_handler( SIGTRAP, (void (*)())trap_handler ) == -1) goto error;
+    if (set_handler( SIGTRAP, have_sigaltstack, (void (*)())trap_handler ) == -1) goto error;
 #endif
     return TRUE;
 

include/acconfig.h

@@ -66,9 +66,6 @@
 /* Define if the struct statfs has the member bfree */
 #undef STATFS_HAS_BFREE
 
-/* Define if we have a working sigaltstack */
-#undef HAVE_WORKING_SIGALTSTACK
-
 /* Define if the struct statfs is defined by <sys/vfs.h> */
 #undef STATFS_DEFINED_BY_SYS_VFS
 

include/config.h.in

@@ -107,9 +107,6 @@
 /* Define if the struct statfs has the member bfree */
 #undef STATFS_HAS_BFREE
 
-/* Define if we have a working sigaltstack */
-#undef HAVE_WORKING_SIGALTSTACK
-
 /* Define if the struct statfs is defined by <sys/vfs.h> */
 #undef STATFS_DEFINED_BY_SYS_VFS