netbsd.h (NETBSD_ENABLE_EXECUTE_STACK): Define __enable_execute_stack function.

* config/netbsd.h (NETBSD_ENABLE_EXECUTE_STACK): Define
__enable_execute_stack function.
* config/alpha/netbsd.h (TRANSFER_FROM_TRAMPOLINE): Define
as NETBSD_ENABLE_EXECUTE_STACK.
* config/i386/netbsd-elf.h (TRANSFER_FROM_TRAMPOLINE): Ditto.
* config/i386/netbsd.h (TRANSFER_FROM_TRAMPOLINE): Ditto.
* config/i386/netbsd64.h (TRANSFER_FROM_TRAMPOLINE): Ditto.
* config/sparc/netbsd-elf.h (TRANSFER_FROM_TRAMPOLINE): Ditto.
* config/sparc/netbsd.h (TRANSFER_FROM_TRAMPOLINE): Ditto.

From-SVN: r58292

gcc/ChangeLog

 2002-10-18  Jason Thorpe  <thorpej@wasabisystems.com>
 
+	* config/netbsd.h (NETBSD_ENABLE_EXECUTE_STACK): Define 
+	__enable_execute_stack function. 
+	* config/alpha/netbsd.h (TRANSFER_FROM_TRAMPOLINE): Define
+	as NETBSD_ENABLE_EXECUTE_STACK.
+	* config/i386/netbsd-elf.h (TRANSFER_FROM_TRAMPOLINE): Ditto.
+	* config/i386/netbsd.h (TRANSFER_FROM_TRAMPOLINE): Ditto.
+	* config/i386/netbsd64.h (TRANSFER_FROM_TRAMPOLINE): Ditto.
+	* config/sparc/netbsd-elf.h (TRANSFER_FROM_TRAMPOLINE): Ditto.
+	* config/sparc/netbsd.h (TRANSFER_FROM_TRAMPOLINE): Ditto.
+
+2002-10-18  Jason Thorpe  <thorpej@wasabisystems.com>
+
 	* config/i386/i386.c (x86_initialize_trampoline): Emit a call
 	to __enable_execute_stack with the address of the trampoline
 	if TRANSFER_FROM_TRAMPOLINE is defined.

gcc/config/alpha/netbsd.h

@@ -75,5 +75,10 @@ Boston, MA 02111-1307, USA.  */
    %{!shared:crtend%O%s} %{shared:crtendS%O%s}"
 
 
+/* Attempt to enable execute permissions on the stack.  */
+
+#define TRANSFER_FROM_TRAMPOLINE NETBSD_ENABLE_EXECUTE_STACK
+
+
 #undef TARGET_VERSION
 #define TARGET_VERSION fprintf (stderr, " (NetBSD/alpha ELF)");

gcc/config/i386/netbsd-elf.h

@@ -121,4 +121,7 @@ Boston, MA 02111-1307, USA.  */
    we don't care about compatibility with older gcc versions.  */
 #define DEFAULT_PCC_STRUCT_RETURN 1
 
+/* Attempt to enable execute permissions on the stack.  */
+#define TRANSFER_FROM_TRAMPOLINE NETBSD_ENABLE_EXECUTE_STACK
+
 #define TARGET_VERSION fprintf (stderr, " (NetBSD/i386 ELF)");

gcc/config/i386/netbsd.h

@@ -67,3 +67,6 @@
    prefix is added.  */
 #undef GOT_SYMBOL_NAME
 #define GOT_SYMBOL_NAME "GLOBAL_OFFSET_TABLE_"
+
+/* Attempt to enable execute permissions on the stack.  */
+#define TRANSFER_FROM_TRAMPOLINE NETBSD_ENABLE_EXECUTE_STACK

gcc/config/i386/netbsd64.h

@@ -69,5 +69,7 @@ Boston, MA 02111-1307, USA.  */
     fprintf (FILE, "\tcall __mcount\n");				\
 }
 
+/* Attempt to enable execute permissions on the stack.  */
+#define TRANSFER_FROM_TRAMPOLINE NETBSD_ENABLE_EXECUTE_STACK
 
 #define TARGET_VERSION fprintf (stderr, " (NetBSD/x86_64 ELF)");

gcc/config/netbsd.h

@@ -161,3 +161,51 @@ Boston, MA 02111-1307, USA.  */
 
 #undef WINT_TYPE
 #define WINT_TYPE "int"
+
+
+/* Attempt to turn on execute permission for the stack.  This may be
+   used by TRANSFER_FROM_TRAMPOLINE of the target needs it (that is,
+   if the target machine can change execute permissions on a page).
+
+   There is no way to query the execute permission of the stack, so
+   we always issue the mprotect() call.
+
+   Note that we go out of our way to use namespace-non-invasive calls
+   here.  Unfortunately, there is no libc-internal name for mprotect().
+
+   Also note that no errors should be emitted by this code; it is considered
+   dangerous for library calls to send messages to stdout/stderr.  */
+
+#define NETBSD_ENABLE_EXECUTE_STACK					\
+extern void __enable_execute_stack (void *);				\
+void									\
+__enable_execute_stack (addr)						\
+     void *addr;							\
+{									\
+  extern int mprotect (void *, size_t, int);				\
+  extern int __sysctl (int *, unsigned int, void *, size_t *,		\
+		       void *, size_t);					\
+									\
+  static int size;							\
+  static long mask;							\
+									\
+  char *page, *end;							\
+									\
+  if (size == 0)							\
+    {									\
+      int mib[2];							\
+      size_t len;							\
+									\
+      mib[0] = 6; /* CTL_HW */						\
+      mib[1] = 7; /* HW_PAGESIZE */					\
+      len = sizeof (size);						\
+      (void) __sysctl (mib, 2, &size, &len, NULL, 0);			\
+      mask = ~((long) size - 1);					\
+    }									\
+									\
+  page = (char *) (((long) addr) & mask);				\
+  end  = (char *) ((((long) (addr + TRAMPOLINE_SIZE)) & mask) + size);	\
+									\
+  /* 7 == PROT_READ | PROT_WRITE | PROT_EXEC */				\
+  (void) mprotect (page, end - page, 7);				\
+}

gcc/config/sparc/netbsd-elf.h

@@ -102,6 +102,9 @@ Boston, MA 02111-1307, USA.  */
 
 #undef STDC_0_IN_SYSTEM_HEADERS
 
+/* Attempt to enable execute permissions on the stack.  */
+#define TRANSFER_FROM_TRAMPOLINE NETBSD_ENABLE_EXECUTE_STACK
+
 #undef TARGET_VERSION
 #define TARGET_VERSION fprintf (stderr, " (%s)", TARGET_NAME);
 

gcc/config/sparc/netbsd.h

@@ -44,3 +44,6 @@
 /* Until they use ELF or something that handles dwarf2 unwinds
    and initialization stuff better.  */
 #define DWARF2_UNWIND_INFO 0
+
+/* Attempt to enable execute permissions on the stack.  */
+#define TRANSFER_FROM_TRAMPOLINE NETBSD_ENABLE_EXECUTE_STACK