On 2024-08-06 15:28, Jakub Jelinek wrote:
On Tue, Aug 06, 2024 at 03:07:44PM +0100, Matthieu Longo wrote:
On AArch64, the RA state informs the unwinder whether the return address
is mangled and how, or not. This information is encoded in a boolean in
the CFI row. This binary approach prevents from expressing more complex
configuration, as it is the case with PAuth_LR introduced in Armv9.5-A.
This patch addresses this limitation by replacing the boolean by an enum.
Formatting nits.
gcc/ChangeLog:
* dwarf2cfi.cc
(struct dw_cfi_row): Declare a new enum type to replace ra_mangled.
(cfi_row_equal_p): Use ra_state instead of ra_mangled.
(dwarf2out_frame_debug_cfa_negate_ra_state): Same.
(change_cfi_row): Same.
---
gcc/dwarf2cfi.cc | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/gcc/dwarf2cfi.cc b/gcc/dwarf2cfi.cc
index 6c80e0b17bd..023f61fb712 100644
--- a/gcc/dwarf2cfi.cc
+++ b/gcc/dwarf2cfi.cc
@@ -57,6 +57,15 @@ along with GCC; see the file COPYING3. If not see
#define DEFAULT_INCOMING_FRAME_SP_OFFSET INCOMING_FRAME_SP_OFFSET
#endif
+
+/* Signing method used for return address authentication.
+ (AArch64 extension)*/
Dot and two spaces missing before */
+typedef enum
+{
+ RA_no_signing = 0x0,
+ RA_signing_SP = 0x1,
+} RA_signing_method_t;
I think it should be ra_* and *_sp
@@ -1556,8 +1565,11 @@ dwarf2out_frame_debug_cfa_negate_ra_state (void)
{
dw_cfi_ref cfi = new_cfi ();
cfi->dw_cfi_opc = DW_CFA_AARCH64_negate_ra_state;
+ cur_row->ra_state =
+ (cur_row->ra_state == RA_no_signing)
+ ? RA_signing_SP
+ : RA_no_signing;
This is wrongly formatted. = shouldn't be at the end of line.
Better
cur_row->ra_state
= (cur_row->ra_state == ra_no_signing
? ra_signing_sp : ra_no_signing);
Jakub
The comments are addressed in the next revision.
Thanks,
Matthieu.
