Patchwork AArch64: Treat pauth ops as nops on non-pauth systems

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Submitter Alan Hayward
Date May 13, 2019, 2:50 p.m.
Message ID <20190513145017.59728-1-alan.hayward@arm.com>
Download mbox | patch
Permalink /patch/32659/
State New
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Comments

Alan Hayward - May 13, 2019, 2:50 p.m.
Running an address signed binary through GDB on a non pauth system
gives the following error:
Call Frame Instruction op 45 in vendor extension space is not handled on this architecture.

Instead GDB should ignore the op, treating it as a nop.

Add test case for pauth binaries, regardless of whether the target
supports it.

gdb/ChangeLog:

2019-05-13  Alan Hayward  <alan.hayward@arm.com>

	* aarch64-tdep.c (aarch64_execute_dwarf_cfa_vendor_op): Treat
	DW_CFA_AARCH64_negate_ra_state as nop on non pauth targets.

gdb/testsuite/ChangeLog:

2019-05-13  Alan Hayward  <alan.hayward@arm.com>

	* gdb.arch/aarch64-pauth.c: New test.
	* gdb.arch/aarch64-pauth.exp: New file.
---
 gdb/aarch64-tdep.c                       |  6 +++-
 gdb/testsuite/gdb.arch/aarch64-pauth.c   | 36 ++++++++++++++++++++
 gdb/testsuite/gdb.arch/aarch64-pauth.exp | 43 ++++++++++++++++++++++++
 3 files changed, 84 insertions(+), 1 deletion(-)
 create mode 100644 gdb/testsuite/gdb.arch/aarch64-pauth.c
 create mode 100644 gdb/testsuite/gdb.arch/aarch64-pauth.exp

\ No newline at end of file
-- 
2.20.1 (Apple Git-117)
Alan Hayward - May 22, 2019, 1:39 p.m.
Pushed this.
(With the "No newline at end of file" fixed)


> On 13 May 2019, at 15:50, Alan Hayward <Alan.Hayward@arm.com> wrote:
> 
> Running an address signed binary through GDB on a non pauth system
> gives the following error:
> Call Frame Instruction op 45 in vendor extension space is not handled on this architecture.
> 
> Instead GDB should ignore the op, treating it as a nop.
> 
> Add test case for pauth binaries, regardless of whether the target
> supports it.
> 
> gdb/ChangeLog:
> 
> 2019-05-13  Alan Hayward  <alan.hayward@arm.com>
> 
> 	* aarch64-tdep.c (aarch64_execute_dwarf_cfa_vendor_op): Treat
> 	DW_CFA_AARCH64_negate_ra_state as nop on non pauth targets.
> 
> gdb/testsuite/ChangeLog:
> 
> 2019-05-13  Alan Hayward  <alan.hayward@arm.com>
> 
> 	* gdb.arch/aarch64-pauth.c: New test.
> 	* gdb.arch/aarch64-pauth.exp: New file.
> ---
> gdb/aarch64-tdep.c                       |  6 +++-
> gdb/testsuite/gdb.arch/aarch64-pauth.c   | 36 ++++++++++++++++++++
> gdb/testsuite/gdb.arch/aarch64-pauth.exp | 43 ++++++++++++++++++++++++
> 3 files changed, 84 insertions(+), 1 deletion(-)
> create mode 100644 gdb/testsuite/gdb.arch/aarch64-pauth.c
> create mode 100644 gdb/testsuite/gdb.arch/aarch64-pauth.exp
> 
> diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
> index cb185ee337..7368026a7f 100644
> --- a/gdb/aarch64-tdep.c
> +++ b/gdb/aarch64-tdep.c
> @@ -1180,8 +1180,12 @@ aarch64_execute_dwarf_cfa_vendor_op (struct gdbarch *gdbarch, gdb_byte op,
>   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
>   struct dwarf2_frame_state_reg *ra_state;
> 
> -  if (tdep->has_pauth () && op == DW_CFA_AARCH64_negate_ra_state)
> +  if (op == DW_CFA_AARCH64_negate_ra_state)
>     {
> +      /* On systems without pauth, treat as a nop.  */
> +      if (!tdep->has_pauth ())
> +	return true;
> +
>       /* Allocate RA_STATE column if it's not allocated yet.  */
>       fs->regs.alloc_regs (AARCH64_DWARF_PAUTH_RA_STATE + 1);
> 
> diff --git a/gdb/testsuite/gdb.arch/aarch64-pauth.c b/gdb/testsuite/gdb.arch/aarch64-pauth.c
> new file mode 100644
> index 0000000000..af9bbe4a93
> --- /dev/null
> +++ b/gdb/testsuite/gdb.arch/aarch64-pauth.c
> @@ -0,0 +1,36 @@
> +/* This test program is part of GDB, the GNU debugger.
> +
> +   Copyright 2019 Free Software Foundation, Inc.
> +
> +   This program is free software; you can redistribute it and/or modify
> +   it under the terms of the GNU General Public License as published by
> +   the Free Software Foundation; either version 3 of the License, or
> +   (at your option) any later version.
> +
> +   This program is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +   GNU General Public License for more details.
> +
> +   You should have received a copy of the GNU General Public License
> +   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
> +
> +int
> +bar (int b)
> +{
> +  int x = 1; /* break here.  */
> +  return b - x;
> +}
> +
> +int
> +foo (int a)
> +{
> +  int y = bar (9);
> +  return a + y;
> +}
> +
> +int
> +main ()
> +{
> +  foo (5);
> +}
> diff --git a/gdb/testsuite/gdb.arch/aarch64-pauth.exp b/gdb/testsuite/gdb.arch/aarch64-pauth.exp
> new file mode 100644
> index 0000000000..aa4060e88c
> --- /dev/null
> +++ b/gdb/testsuite/gdb.arch/aarch64-pauth.exp
> @@ -0,0 +1,43 @@
> +# Copyright (C) 2019 Free Software Foundation, Inc.
> +
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.
> +
> +# Test a binary with address signing works regardless of whether the target
> +# supports pauth instructions.  On non pauth systems, all pauth instructions
> +# are treated as nops.
> +
> +if {![is_aarch64_target]} {
> +    verbose "Skipping ${gdb_test_file_name}."
> +    return
> +}
> +
> +# Build program with address signing forced on.
> +standard_testfile
> +set compile_flags {debug}
> +lappend compile_flags "additional_flags=-msign-return-address=all"
> +lappend compile_flags "additional_flags=-fno-inline"
> +if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile} ${compile_flags}] } {
> +    return -1
> +}
> +
> +if ![runto_main] {
> +    untested "could not run to main"
> +    return -1
> +}
> +
> +gdb_breakpoint [ gdb_get_line_number "break here" ]
> +gdb_continue_to_breakpoint "break here" ".*break here.*"
> +
> +# Ensure we can get a full backtrace, despite the address signing.
> +gdb_test "bt" "^bt\r\n#0 +bar *\\(b=9\\) +at.*\r\n#1 +0x\[0-9a-f\]* +in +foo \\(a=5\\).*\r\n#2 +0x\[0-9a-f\]* +in +main \\(\\).*" "backtrace"
> \ No newline at end of file
> -- 
> 2.20.1 (Apple Git-117)
>

Patch

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c

index cb185ee337..7368026a7f 100644

--- a/gdb/aarch64-tdep.c

+++ b/gdb/aarch64-tdep.c

@@ -1180,8 +1180,12 @@  aarch64_execute_dwarf_cfa_vendor_op (struct gdbarch *gdbarch, gdb_byte op,

   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
   struct dwarf2_frame_state_reg *ra_state;
 
-  if (tdep->has_pauth () && op == DW_CFA_AARCH64_negate_ra_state)

+  if (op == DW_CFA_AARCH64_negate_ra_state)

     {
+      /* On systems without pauth, treat as a nop.  */

+      if (!tdep->has_pauth ())

+	return true;

+

       /* Allocate RA_STATE column if it's not allocated yet.  */
       fs->regs.alloc_regs (AARCH64_DWARF_PAUTH_RA_STATE + 1);
 
diff --git a/gdb/testsuite/gdb.arch/aarch64-pauth.c b/gdb/testsuite/gdb.arch/aarch64-pauth.c

new file mode 100644
index 0000000000..af9bbe4a93

--- /dev/null

+++ b/gdb/testsuite/gdb.arch/aarch64-pauth.c

@@ -0,0 +1,36 @@ 

+/* This test program is part of GDB, the GNU debugger.

+

+   Copyright 2019 Free Software Foundation, Inc.

+

+   This program is free software; you can redistribute it and/or modify

+   it under the terms of the GNU General Public License as published by

+   the Free Software Foundation; either version 3 of the License, or

+   (at your option) any later version.

+

+   This program is distributed in the hope that it will be useful,

+   but WITHOUT ANY WARRANTY; without even the implied warranty of

+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+   GNU General Public License for more details.

+

+   You should have received a copy of the GNU General Public License

+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

+

+int

+bar (int b)

+{

+  int x = 1; /* break here.  */

+  return b - x;

+}

+

+int

+foo (int a)

+{

+  int y = bar (9);

+  return a + y;

+}

+

+int

+main ()

+{

+  foo (5);

+}

diff --git a/gdb/testsuite/gdb.arch/aarch64-pauth.exp b/gdb/testsuite/gdb.arch/aarch64-pauth.exp

new file mode 100644
index 0000000000..aa4060e88c

--- /dev/null

+++ b/gdb/testsuite/gdb.arch/aarch64-pauth.exp

@@ -0,0 +1,43 @@ 

+# Copyright (C) 2019 Free Software Foundation, Inc.

+

+# This program is free software; you can redistribute it and/or modify

+# it under the terms of the GNU General Public License as published by

+# the Free Software Foundation; either version 3 of the License, or

+# (at your option) any later version.

+#

+# This program is distributed in the hope that it will be useful,

+# but WITHOUT ANY WARRANTY; without even the implied warranty of

+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+# GNU General Public License for more details.

+#

+# You should have received a copy of the GNU General Public License

+# along with this program.  If not, see <http://www.gnu.org/licenses/>.

+

+# Test a binary with address signing works regardless of whether the target

+# supports pauth instructions.  On non pauth systems, all pauth instructions

+# are treated as nops.

+

+if {![is_aarch64_target]} {

+    verbose "Skipping ${gdb_test_file_name}."

+    return

+}

+

+# Build program with address signing forced on.

+standard_testfile

+set compile_flags {debug}

+lappend compile_flags "additional_flags=-msign-return-address=all"

+lappend compile_flags "additional_flags=-fno-inline"

+if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile} ${compile_flags}] } {

+    return -1

+}

+

+if ![runto_main] {

+    untested "could not run to main"

+    return -1

+}

+

+gdb_breakpoint [ gdb_get_line_number "break here" ]

+gdb_continue_to_breakpoint "break here" ".*break here.*"

+

+# Ensure we can get a full backtrace, despite the address signing.

+gdb_test "bt" "^bt\r\n#0 +bar *\\(b=9\\) +at.*\r\n#1 +0x\[0-9a-f\]* +in +foo \\(a=5\\).*\r\n#2 +0x\[0-9a-f\]* +in +main \\(\\).*" "backtrace"