re PR target/65408 (powerpc64 function argument passing may access invalid memory)

	PR target/65408
	PR target/58744
	PR middle-end/36043
	* calls.c (load_register_parameters): Don't load past end of
	mem unless suitably aligned.

From-SVN: r222115

gcc/ChangeLog

+2015-04-15  Alan Modra  <amodra@gmail.com>
+
+	PR target/65408
+	PR target/58744
+	PR middle-end/36043
+	* calls.c (load_register_parameters): Don't load past end of
+	mem unless suitably aligned.
+
 2015-04-15  Nick Clifton  <nickc@redhat.com>
 
 	* config/rl78/rl78.c (rl78_expand_prologue): Mark large stack

gcc/calls.c

@@ -2099,6 +2099,26 @@ load_register_parameters (struct arg_data *args, int num_actuals,
 					   (XEXP (args[i].value, 0), size)))
 		*sibcall_failure = 1;
 
+	      if (size % UNITS_PER_WORD == 0
+		  || MEM_ALIGN (mem) % BITS_PER_WORD == 0)
+		move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
+	      else
+		{
+		  if (nregs > 1)
+		    move_block_to_reg (REGNO (reg), mem, nregs - 1,
+				       args[i].mode);
+		  rtx dest = gen_rtx_REG (word_mode, REGNO (reg) + nregs - 1);
+		  unsigned int bitoff = (nregs - 1) * BITS_PER_WORD;
+		  unsigned int bitsize = size * BITS_PER_UNIT - bitoff;
+		  rtx x = extract_bit_field (mem, bitsize, bitoff, 1,
+					     dest, word_mode, word_mode);
+		  if (BYTES_BIG_ENDIAN)
+		    x = expand_shift (LSHIFT_EXPR, word_mode, x,
+				      BITS_PER_WORD - bitsize, dest, 1);
+		  if (x != dest)
+		    emit_move_insn (dest, x);
+		}
+
 	      /* Handle a BLKmode that needs shifting.  */
 	      if (nregs == 1 && size < UNITS_PER_WORD
 #ifdef BLOCK_REG_PADDING
@@ -2106,22 +2126,18 @@ load_register_parameters (struct arg_data *args, int num_actuals,
 #else
 		  && BYTES_BIG_ENDIAN
 #endif
-		 )
+		  )
 		{
-		  rtx tem = operand_subword_force (mem, 0, args[i].mode);
-		  rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
-		  rtx x = gen_reg_rtx (word_mode);
+		  rtx dest = gen_rtx_REG (word_mode, REGNO (reg));
 		  int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
-		  enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
-							: LSHIFT_EXPR;
+		  enum tree_code dir = (BYTES_BIG_ENDIAN
+					? RSHIFT_EXPR : LSHIFT_EXPR);
+		  rtx x;
 
-		  emit_move_insn (x, tem);
-		  x = expand_shift (dir, word_mode, x, shift, ri, 1);
-		  if (x != ri)
-		    emit_move_insn (ri, x);
+		  x = expand_shift (dir, word_mode, dest, shift, dest, 1);
+		  if (x != dest)
+		    emit_move_insn (dest, x);
 		}
-	      else
-		move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
 	    }
 
 	  /* When a parameter is a block, and perhaps in other cases, it is

gcc/testsuite/ChangeLog

+2015-04-15  Alan Modra  <amodra@gmail.com>
+
+	* gcc.dg/pr65408.c: New.
+
 2015-04-14  Yvan Roux  <yvan.roux@linaro.org>
 
 	PR target/65729

gcc/testsuite/gcc.dg/pr65408.c

+/* PR middle-end/36043 target/58744 target/65408 */
+/* { dg-do run { target mmap } } */
+/* { dg-options "-O2" } */
+
+#include <sys/mman.h>
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+#ifndef MAP_ANON
+#define MAP_ANON 0
+#endif
+#ifndef MAP_FAILED
+#define MAP_FAILED ((void *)-1)
+#endif
+
+typedef struct
+{
+  unsigned char r;
+  unsigned char g;
+  unsigned char b;
+} __attribute__((packed)) pr58744;
+
+typedef struct
+{
+  unsigned short r;
+  unsigned short g;
+  unsigned short b;
+} pr36043;
+
+typedef struct
+{
+  int r;
+  int g;
+  int b;
+} pr65408;
+
+__attribute__ ((noinline, noclone))
+void
+f1a (pr58744 x)
+{
+  if (x.r != 1 || x.g != 2 || x.b != 3)
+    __builtin_abort();
+}
+
+__attribute__ ((noinline, noclone))
+void
+f1 (pr58744 *x)
+{
+  f1a (*x);
+}
+
+__attribute__ ((noinline, noclone))
+void
+f2a (pr36043 x)
+{
+  if (x.r != 1 || x.g != 2 || x.b != 3)
+    __builtin_abort();
+}
+
+__attribute__ ((noinline, noclone))
+void
+f2 (pr36043 *x)
+{
+  f2a (*x);
+}
+
+__attribute__ ((noinline, noclone))
+void
+f3a (pr65408 x)
+{
+  if (x.r != 1 || x.g != 2 || x.b != 3)
+    __builtin_abort();
+}
+
+__attribute__ ((noinline, noclone))
+void
+f3 (pr65408 *x)
+{
+  f3a (*x);
+}
+
+int
+main ()
+{
+  char *p = mmap ((void *) 0, 131072, PROT_READ | PROT_WRITE,
+		  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+  if (p == MAP_FAILED)
+    return 0;
+  char *endp = p + 65536;
+  if (munmap (endp, 65536) < 0)
+    return 0;
+
+  pr58744 *s1 = (pr58744 *) endp - 1;
+  s1->r = 1;
+  s1->g = 2;
+  s1->b = 3;
+  f1 (s1);
+
+  pr36043 *s2 = (pr36043 *) endp - 1;
+  s2->r = 1;
+  s2->g = 2;
+  s2->b = 3;
+  f2 (s2);
+
+  pr65408 *s3 = (pr65408 *) endp - 1;
+  s3->r = 1;
+  s3->g = 2;
+  s3->b = 3;
+  f3 (s3);
+
+  return 0;
+}