https://gcc.gnu.org/g:77fd352a47137d79e6b7a480503ce4368f13c3e5
commit r13-8940-g77fd352a47137d79e6b7a480503ce4368f13c3e5
Author: Peter Bergner <berg...@linux.ibm.com>
Date: Wed Jun 19 16:07:29 2024 -0500
rs6000: ROP - Emit hashst and hashchk insns on Power8 and later [PR114759]
We currently only emit the ROP-protect hash* insns for Power10, where the
insns were added to the architecture. We want to emit them for earlier
cpus (where they operate as NOPs), so that if those older binaries are
ever executed on a Power10, then they'll be protected from ROP attacks.
Binutils accepts hashst and hashchk back to Power8, so change GCC to emit
them for Power8 and later. This matches clang's behavior.
2024-06-19 Peter Bergner <berg...@linux.ibm.com>
gcc/
PR target/114759
* config/rs6000/rs6000-logue.cc (rs6000_stack_info): Use
TARGET_POWER8.
(rs6000_emit_prologue): Likewise.
* config/rs6000/rs6000.md (hashchk): Likewise.
(hashst): Likewise.
Fix whitespace.
gcc/testsuite/
PR target/114759
* gcc.target/powerpc/pr114759-2.c: New test.
* lib/target-supports.exp (rop_ok): Use
check_effective_target_has_arch_pwr8.
(cherry picked from commit a05c3d23d1e1c8d2971b123804fc7a61a3561adb)
Diff:
---
gcc/config/rs6000/rs6000-logue.cc | 6 +++---
gcc/config/rs6000/rs6000.md | 6 +++---
gcc/testsuite/gcc.target/powerpc/pr114759-2.c | 17 +++++++++++++++++
gcc/testsuite/lib/target-supports.exp | 2 +-
4 files changed, 24 insertions(+), 7 deletions(-)
diff --git a/gcc/config/rs6000/rs6000-logue.cc
b/gcc/config/rs6000/rs6000-logue.cc
index d38b90b61070..9e6b4ca5533f 100644
--- a/gcc/config/rs6000/rs6000-logue.cc
+++ b/gcc/config/rs6000/rs6000-logue.cc
@@ -716,7 +716,7 @@ rs6000_stack_info (void)
info->calls_p = (!crtl->is_leaf || cfun->machine->ra_needs_full_frame);
info->rop_hash_size = 0;
- if (TARGET_POWER10
+ if (TARGET_POWER8
&& info->calls_p
&& DEFAULT_ABI == ABI_ELFv2
&& rs6000_rop_protect)
@@ -3275,7 +3275,7 @@ rs6000_emit_prologue (void)
/* NOTE: The hashst isn't needed if we're going to do a sibcall,
but there's no way to know that here. Harmless except for
performance, of course. */
- if (TARGET_POWER10 && rs6000_rop_protect && info->rop_hash_size != 0)
+ if (TARGET_POWER8 && rs6000_rop_protect && info->rop_hash_size != 0)
{
gcc_assert (DEFAULT_ABI == ABI_ELFv2);
rtx stack_ptr = gen_rtx_REG (Pmode, STACK_POINTER_REGNUM);
@@ -5054,7 +5054,7 @@ rs6000_emit_epilogue (enum epilogue_type epilogue_type)
/* The ROP hash check must occur after the stack pointer is restored
(since the hash involves r1), and is not performed for a sibcall. */
- if (TARGET_POWER10
+ if (TARGET_POWER8
&& rs6000_rop_protect
&& info->rop_hash_size != 0
&& epilogue_type != EPILOGUE_TYPE_SIBCALL)
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 8d8118197da7..79aaf490837f 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -15665,9 +15665,9 @@
(define_insn "hashst"
[(set (match_operand:DI 0 "simple_offsettable_mem_operand" "=m")
- (unspec_volatile:DI [(match_operand:DI 1 "int_reg_operand" "r")]
+ (unspec_volatile:DI [(match_operand:DI 1 "int_reg_operand" "r")]
UNSPEC_HASHST))]
- "TARGET_POWER10 && rs6000_rop_protect"
+ "TARGET_POWER8 && rs6000_rop_protect"
{
static char templ[32];
const char *p = rs6000_privileged ? "p" : "";
@@ -15680,7 +15680,7 @@
[(unspec_volatile [(match_operand:DI 0 "int_reg_operand" "r")
(match_operand:DI 1 "simple_offsettable_mem_operand" "m")]
UNSPEC_HASHCHK)]
- "TARGET_POWER10 && rs6000_rop_protect"
+ "TARGET_POWER8 && rs6000_rop_protect"
{
static char templ[32];
const char *p = rs6000_privileged ? "p" : "";
diff --git a/gcc/testsuite/gcc.target/powerpc/pr114759-2.c
b/gcc/testsuite/gcc.target/powerpc/pr114759-2.c
new file mode 100644
index 000000000000..3881ebd416e6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr114759-2.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mdejagnu-cpu=power8 -mrop-protect" } */
+/* { dg-require-effective-target rop_ok } Only enable on supported ABIs. */
+
+/* Verify we generate ROP-protect hash insns when compiling for Power8. */
+
+extern void foo (void);
+
+int
+bar (void)
+{
+ foo ();
+ return 5;
+}
+
+/* { dg-final { scan-assembler-times {\mhashst\M} 1 } } */
+/* { dg-final { scan-assembler-times {\mhashchk\M} 1 } } */
diff --git a/gcc/testsuite/lib/target-supports.exp
b/gcc/testsuite/lib/target-supports.exp
index be8ddc8e0f85..c81313ea7177 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -6919,7 +6919,7 @@ proc check_effective_target_powerpc_elfv2 { } {
# Return 1 if this is a PowerPC target supporting -mrop-protect
proc check_effective_target_rop_ok { } {
- return [check_effective_target_power10_ok] &&
[check_effective_target_powerpc_elfv2]
+ return [check_effective_target_has_arch_pwr8] &&
[check_effective_target_powerpc_elfv2]
}
# The VxWorks SPARC simulator accepts only EM_SPARC executables and
