re PR target/12865 (`mprotect' call to make trampoline executable may fail)

	PR target/12865
	* config/sparc/sparc.c (sparc_initialize_trampoline): Call
	__enable_execute_stack only after writing onto the stack.
	(sparc64_initialize_trampoline): Likewise.

From-SVN: r73402

4 files changed, 79 insertions, 11 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8603eb5..268e61f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2003-11-10  Waldek Hebisch  <hebisch@math.uni.wroc.pl>
+
+	PR target/12865
+	* config/sparc/sparc.c (sparc_initialize_trampoline): Call
+	__enable_execute_stack only after writing onto the stack.
+	(sparc64_initialize_trampoline): Likewise.
+
 2003-11-09  Roger Sayle  <roger@eyesopen.com>
 
 	* loop.c (check_dbra_loop): Try swapping the comparison operands
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index 1454fd9..f821a5a 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -7087,7 +7087,7 @@ sparc_type_code (register tree type)
 void
 sparc_initialize_trampoline (rtx tramp, rtx fnaddr, rtx cxt)
 {
-  /* SPARC 32 bit trampoline:
+  /* SPARC 32-bit trampoline:
 
  	sethi	%hi(fn), %g1
  	sethi	%hi(static), %g2
@@ -7097,10 +7097,6 @@ sparc_initialize_trampoline (rtx tramp, rtx fnaddr, rtx cxt)
     SETHI i,r  = 00rr rrr1 00ii iiii iiii iiii iiii iiii
     JMPL r+i,d = 10dd ddd1 1100 0rrr rr1i iiii iiii iiii
    */
-#ifdef TRANSFER_FROM_TRAMPOLINE
-  emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__enable_execute_stack"),
-                     LCT_NORMAL, VOIDmode, 1, tramp, Pmode);
-#endif
 
   emit_move_insn
     (gen_rtx_MEM (SImode, plus_constant (tramp, 0)),
@@ -7139,21 +7135,25 @@ sparc_initialize_trampoline (rtx tramp, rtx fnaddr, rtx cxt)
       && sparc_cpu != PROCESSOR_ULTRASPARC3)
     emit_insn (gen_flush (validize_mem (gen_rtx_MEM (SImode,
 						     plus_constant (tramp, 8)))));
+
+  /* Call __enable_execute_stack after writing onto the stack to make sure
+     the stack address is accessible.  */
+#ifdef TRANSFER_FROM_TRAMPOLINE
+  emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__enable_execute_stack"),
+                     LCT_NORMAL, VOIDmode, 1, tramp, Pmode);
+#endif
+
 }
 
-/* The 64 bit version is simpler because it makes more sense to load the
+/* The 64-bit version is simpler because it makes more sense to load the
    values as "immediate" data out of the trampoline.  It's also easier since
    we can read the PC without clobbering a register.  */
 
 void
 sparc64_initialize_trampoline (rtx tramp, rtx fnaddr, rtx cxt)
 {
-#ifdef TRANSFER_FROM_TRAMPOLINE
-  emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__enable_execute_stack"),
-                     LCT_NORMAL, VOIDmode, 1, tramp, Pmode);
-#endif
+  /* SPARC 64-bit trampoline:
 
-  /*
 	rd	%pc, %g1
 	ldx	[%g1+24], %g5
 	jmp	%g5
@@ -7176,6 +7176,13 @@ sparc64_initialize_trampoline (rtx tramp, rtx fnaddr, rtx cxt)
   if (sparc_cpu != PROCESSOR_ULTRASPARC
       && sparc_cpu != PROCESSOR_ULTRASPARC3)
     emit_insn (gen_flushdi (validize_mem (gen_rtx_MEM (DImode, plus_constant (tramp, 8)))));
+
+  /* Call __enable_execute_stack after writing onto the stack to make sure
+     the stack address is accessible.  */
+#ifdef TRANSFER_FROM_TRAMPOLINE
+  emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__enable_execute_stack"),
+                     LCT_NORMAL, VOIDmode, 1, tramp, Pmode);
+#endif
 }
 
 /* Subroutines to support a flat (single) register window calling
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9359954..f69b0d6 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2003-11-10  Waldek Hebisch  <hebisch@math.uni.wroc.pl>
+
+	* gcc.dg/trampoline-1.c: New test.
+
 2003-11-09  Andrew Pinski  <pinskia@physics.uc.edu>
 
 	* gcc.c-torture/compile/200031109-1.c: New test.
diff --git a/gcc/testsuite/gcc.dg/trampoline-1.c b/gcc/testsuite/gcc.dg/trampoline-1.c
new file mode 100644
index 0000000..dbbd850
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/trampoline-1.c
@@ -0,0 +1,50 @@
+/* PR target/12865 */
+/* Origin: Waldek Hebisch <hebisch@math.uni.wroc.pl> */
+
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+/* This used to fail on various versions of Solaris 2 because the
+   trampoline couldn't be made executable.  */
+
+extern void abort(void);
+
+void foo (void)
+{
+  const int correct[1100] = {1, 0, -2, 0, 1, 0, 1, -1, -10, -30, -67};
+  int i;
+
+  double x1 (void) {return 1; }
+  double x2 (void) {return -1;}
+  double x3 (void) {return -1;}
+  double x4 (void) {return 1; }
+  double x5 (void) {return 0; }
+
+  typedef double pfun(void);
+
+  double a (int k, pfun x1, pfun x2, pfun x3, pfun x4, pfun x5)
+  {
+    double b (void)
+    {
+      k = k - 1;
+      return a (k, b, x1, x2, x3, x4 );
+    }
+
+    if (k <= 0)
+      return x4 () + x5 ();
+    else
+      return b ();
+  }
+
+  for (i=0; i<=10; i++)
+  {
+    if (fabs(a( i, x1, x2, x3, x4, x5 ) - correct [i]) > 0.1)
+      abort();
+  }
+}
+
+int main (void)
+{
+  foo ();
+  return 0;
+}