diff mbox series

[v2] rs6000: ROP - Do not disable shrink-wrapping for leaf functions [PR114759]

Message ID 1e003d78-3b2e-4263-830a-7c00a3e9db54@linux.ibm.com
State New
Headers
Series [v2] rs6000: ROP - Do not disable shrink-wrapping for leaf functions [PR114759] |

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Commit Message

Peter Bergner June 18, 2024, 10:59 p.m. UTC 
  Updated patch.  This passed bootstrap and regtesting on powerpc64le-linux
with no regressions.  Ok for trunk?

Changes from v1:
    1. Moved the disabling of shrink-wrapping to rs6000_emit_prologue
       and beefed up comment.  Used a more accurate test.
    2. Added comment to the test case on why rop_ok is needed.

Peter


rs6000: ROP - Do not disable shrink-wrapping for leaf functions [PR114759]

Only disable shrink-wrapping when using -mrop-protect when we know we
will be emitting the ROP-protect hash instructions (ie, non-leaf functions).

2024-06-17  Peter Bergner  <bergner@linux.ibm.com>

gcc/
	PR target/114759
	* config/rs6000/rs6000.cc (rs6000_override_options_after_change): Move
	the disabling of shrink-wrapping from here....
	* config/rs6000/rs6000-logue.cc (rs6000_emit_prologue): ...to here.

gcc/testsuite/
	PR target/114759
	* gcc.target/powerpc/pr114759-1.c: New test.
---
 gcc/config/rs6000/rs6000-logue.cc             |  5 +++++
 gcc/config/rs6000/rs6000.cc                   |  4 ----
 gcc/testsuite/gcc.target/powerpc/pr114759-1.c | 16 ++++++++++++++++
 3 files changed, 21 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/powerpc/pr114759-1.c

Comments

Peter Bergner June 24, 2024, 9:21 p.m. UTC | #1 
Ping.   [Message-ID: <1e003d78-3b2e-4263-830a-7c00a3e9db54@linux.ibm.com>]

Peter


On 6/18/24 5:59 PM, Peter Bergner wrote:
> Updated patch.  This passed bootstrap and regtesting on powerpc64le-linux
> with no regressions.  Ok for trunk?
> 
> Changes from v1:
>     1. Moved the disabling of shrink-wrapping to rs6000_emit_prologue
>        and beefed up comment.  Used a more accurate test.
>     2. Added comment to the test case on why rop_ok is needed.
> 
> Peter
> 
> 
> rs6000: ROP - Do not disable shrink-wrapping for leaf functions [PR114759]
> 
> Only disable shrink-wrapping when using -mrop-protect when we know we
> will be emitting the ROP-protect hash instructions (ie, non-leaf functions).
> 
> 2024-06-17  Peter Bergner  <bergner@linux.ibm.com>
> 
> gcc/
> 	PR target/114759
> 	* config/rs6000/rs6000.cc (rs6000_override_options_after_change): Move
> 	the disabling of shrink-wrapping from here....
> 	* config/rs6000/rs6000-logue.cc (rs6000_emit_prologue): ...to here.
> 
> gcc/testsuite/
> 	PR target/114759
> 	* gcc.target/powerpc/pr114759-1.c: New test.
> ---
>  gcc/config/rs6000/rs6000-logue.cc             |  5 +++++
>  gcc/config/rs6000/rs6000.cc                   |  4 ----
>  gcc/testsuite/gcc.target/powerpc/pr114759-1.c | 16 ++++++++++++++++
>  3 files changed, 21 insertions(+), 4 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.target/powerpc/pr114759-1.c
> 
> diff --git a/gcc/config/rs6000/rs6000-logue.cc b/gcc/config/rs6000/rs6000-logue.cc
> index 193e2122c0f..c384e48e378 100644
> --- a/gcc/config/rs6000/rs6000-logue.cc
> +++ b/gcc/config/rs6000/rs6000-logue.cc
> @@ -3018,6 +3018,11 @@ rs6000_emit_prologue (void)
>                             && (lookup_attribute ("no_split_stack",
>                                                   DECL_ATTRIBUTES (cfun->decl))
>                                 == NULL));
> +  /* If we are inserting ROP-protect hash instructions, disable shrink-wrap
> +     until the bug where the hashst insn is emitted in the wrong location
> +     is fixed.  See PR101324 for details.  */
> +  if (info->rop_hash_size)
> +    flag_shrink_wrap = 0;
>  
>    frame_pointer_needed_indeed
>      = frame_pointer_needed && df_regs_ever_live_p (HARD_FRAME_POINTER_REGNUM);
> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
> index e4dc629ddcc..fd6e013c346 100644
> --- a/gcc/config/rs6000/rs6000.cc
> +++ b/gcc/config/rs6000/rs6000.cc
> @@ -3427,10 +3427,6 @@ rs6000_override_options_after_change (void)
>      }
>    else if (!OPTION_SET_P (flag_cunroll_grow_size))
>      flag_cunroll_grow_size = flag_peel_loops || optimize >= 3;
> -
> -  /* If we are inserting ROP-protect instructions, disable shrink wrap.  */
> -  if (rs6000_rop_protect)
> -    flag_shrink_wrap = 0;
>  }
>  
>  #ifdef TARGET_USES_LINUX64_OPT
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr114759-1.c b/gcc/testsuite/gcc.target/powerpc/pr114759-1.c
> new file mode 100644
> index 00000000000..579e08e920f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pr114759-1.c
> @@ -0,0 +1,16 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mdejagnu-cpu=power10 -mrop-protect -fdump-rtl-pro_and_epilogue" } */
> +/* { dg-require-effective-target rop_ok } Only enable on supported ABIs. */
> +
> +/* Verify we still attempt shrink-wrapping when using -mrop-protect
> +   and there are no function calls.  */
> +
> +long
> +foo (long arg)
> +{
> +  if (arg)
> +    asm ("" ::: "r20");
> +  return 0;
> +}
> +
> +/* { dg-final { scan-rtl-dump-times "Performing shrink-wrapping" 1 "pro_and_epilogue" } } */
diff mbox series

Patch

diff --git a/gcc/config/rs6000/rs6000-logue.cc b/gcc/config/rs6000/rs6000-logue.cc
index 193e2122c0f..c384e48e378 100644
--- a/gcc/config/rs6000/rs6000-logue.cc
+++ b/gcc/config/rs6000/rs6000-logue.cc
@@ -3018,6 +3018,11 @@  rs6000_emit_prologue (void)
                            && (lookup_attribute ("no_split_stack",
                                                  DECL_ATTRIBUTES (cfun->decl))
                                == NULL));
+  /* If we are inserting ROP-protect hash instructions, disable shrink-wrap
+     until the bug where the hashst insn is emitted in the wrong location
+     is fixed.  See PR101324 for details.  */
+  if (info->rop_hash_size)
+    flag_shrink_wrap = 0;
 
   frame_pointer_needed_indeed
     = frame_pointer_needed && df_regs_ever_live_p (HARD_FRAME_POINTER_REGNUM);
diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index e4dc629ddcc..fd6e013c346 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -3427,10 +3427,6 @@  rs6000_override_options_after_change (void)
     }
   else if (!OPTION_SET_P (flag_cunroll_grow_size))
     flag_cunroll_grow_size = flag_peel_loops || optimize >= 3;
-
-  /* If we are inserting ROP-protect instructions, disable shrink wrap.  */
-  if (rs6000_rop_protect)
-    flag_shrink_wrap = 0;
 }
 
 #ifdef TARGET_USES_LINUX64_OPT
diff --git a/gcc/testsuite/gcc.target/powerpc/pr114759-1.c b/gcc/testsuite/gcc.target/powerpc/pr114759-1.c
new file mode 100644
index 00000000000..579e08e920f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr114759-1.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mdejagnu-cpu=power10 -mrop-protect -fdump-rtl-pro_and_epilogue" } */
+/* { dg-require-effective-target rop_ok } Only enable on supported ABIs. */
+
+/* Verify we still attempt shrink-wrapping when using -mrop-protect
+   and there are no function calls.  */
+
+long
+foo (long arg)
+{
+  if (arg)
+    asm ("" ::: "r20");
+  return 0;
+}
+
+/* { dg-final { scan-rtl-dump-times "Performing shrink-wrapping" 1 "pro_and_epilogue" } } */