================
@@ -597,6 +611,18 @@ _LIBUNWIND_EXPORT uintptr_t _Unwind_GetIP(struct
_Unwind_Context *context) {
unw_cursor_t *cursor = (unw_cursor_t *)context;
unw_word_t result;
__unw_get_reg(cursor, UNW_REG_IP, &result);
+
+#if __has_feature(ptrauth_calls)
+ // If we are in an arm64e frame, then the PC should have been signed with the
+ // sp
+ {
+ unw_word_t sp;
+ __unw_get_reg(cursor, UNW_REG_SP, &sp);
+ result = (unw_word_t)ptrauth_auth_data((void *)result,
+ ptrauth_key_return_address, sp);
+ }
+#endif
----------------
atrosinenko wrote:
Hmm, this `ptrauth_auth_data` call seems to be necessary even if only
`-mbranch-protection=pac-ret` is in effect (that is,
`__has_feature(ptrauth_returns)`). Most of the times, pac-ret protection should
not affect the ABI compatibility, but this doesn't seem to be the case for
exception handling.
@asl I wonder whether the functions whose stack frames can be unwound should be
compiled with the same pac-ret setting as libunwind library itself? Another and
probably better approach would be to take `RA_SIGN_STATE` pseudo register into
account as long as its value can be safely obtained at this point.
https://github.com/llvm/llvm-project/pull/143230
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