sparc: Fix stack references in return delay slot.

gcc/

	PR target/80968
	* config/sparc/sparc.c (sparc_expand_prologue): Emit frame
	blockage if function uses alloca.

gcc/testsuite/

	* gcc.target/sparc/sparc-ret-3.c: New test.

From-SVN: r248926

gcc/ChangeLog

+2017-06-06  David S. Miller  <davem@davemloft.net>
+
+	PR target/80968
+	* config/sparc/sparc.c (sparc_expand_prologue): Emit frame
+	blockage if function uses alloca.
+
 2017-06-06  Maxim Kuvyrkov  <maxim.kuvyrkov@linaro.org>
 
         * tree-ssa-loop-prefetch.c (struct mem_ref_group, struct mem_ref):

gcc/config/sparc/sparc.c

@@ -5792,6 +5792,9 @@ sparc_expand_epilogue (bool for_eh)
 {
   HOST_WIDE_INT size = sparc_frame_size;
 
+  if (cfun->calls_alloca)
+    emit_insn (gen_frame_blockage ());
+
   if (sparc_n_global_fp_regs > 0)
     emit_save_or_restore_global_fp_regs (sparc_frame_base_reg,
 				         sparc_frame_base_offset

gcc/testsuite/ChangeLog

+2017-06-06  David S. Miller  <davem@davemloft.net>
+
+	* gcc.target/sparc/sparc-ret-3.c: New test.
+
 2017-06-06  Tom de Vries  <tom@codesourcery.com>
 
 	* gcc.c-torture/compile/20000326-2.c: Use dg-require-effective-target

gcc/testsuite/gcc.target/sparc/sparc-ret-3.c

+/* PR target/80968 */
+/* { dg-do compile } */
+/* { dg-skip-if "no register windows" { *-*-* } { "-mflat" } { "" } } */
+/* { dg-require-effective-target ilp32 } */
+/* { dg-options "-mcpu=ultrasparc -O" } */
+
+/* Make sure references to the stack frame do not slip into the delay slot
+   of a return instruction.  */
+
+struct crypto_shash {
+	unsigned int descsize;
+};
+struct crypto_shash *tfm;
+
+struct shash_desc {
+	struct crypto_shash *tfm;
+	unsigned int flags;
+
+	void *__ctx[] __attribute__((aligned(8)));
+};
+
+static inline unsigned int crypto_shash_descsize(struct crypto_shash *tfm)
+{
+	return tfm->descsize;
+}
+
+static inline void *shash_desc_ctx(struct shash_desc *desc)
+{
+	return desc->__ctx;
+}
+
+#define SHASH_DESC_ON_STACK(shash, ctx)				  \
+	char __##shash##_desc[sizeof(struct shash_desc) +	  \
+			      crypto_shash_descsize(ctx)] __attribute__((aligned(8))); \
+	struct shash_desc *shash = (struct shash_desc *)__##shash##_desc
+
+extern int crypto_shash_update(struct shash_desc *, const void *, unsigned int);
+
+unsigned int bug(unsigned int crc, const void *address, unsigned int length)
+{
+	SHASH_DESC_ON_STACK(shash, tfm);
+	unsigned int *ctx = (unsigned int *)shash_desc_ctx(shash);
+	int err;
+
+	shash->tfm = tfm;
+	shash->flags = 0;
+	*ctx = crc;
+
+	err = crypto_shash_update(shash, address, length);
+
+	return *ctx;
+}
+/* { dg-final { scan-assembler "ld\[ \t\]*\\\[%i5\\+8\\\], %i0\n\[^\n\]*return\[ \t\]*%i7\\+8" } } */