[libcxx-commits] [compiler-rt] [libcxxabi] [libunwind] [runtimes][PAC] Harden unwinding when possible (#138571) (PR #143230)

[Anatoly Trosinenko via libcxx-commits]

================
@@ -43,6 +43,130 @@
   #define LIBUNWIND_AVAIL
 #endif
 
+#if __has_extension(ptrauth_qualifier)
+
+  #if __has_include(<ptrauth.h>)
+    #include <ptrauth.h>
+  #endif
+
+  #if __has_extension(ptrauth_restricted_intptr_qualifier)
+    #define __unwind_ptrauth_restricted_intptr(...) \
+      __ptrauth_restricted_intptr(__VA_ARGS__)
+  #else
+    #define __unwind_ptrauth_restricted_intptr(...) \
+      __ptrauth(__VA_ARGS__)
+  #endif
+
+// ptrauth_string_discriminator("unw_proc_info_t::handler") == 0x7405
+  #define __ptrauth_unwind_personality_fn_disc 0x7405
+
+  #define __ptrauth_unwind_personality_fn \
+    __ptrauth(ptrauth_key_function_pointer, 1, __ptrauth_unwind_personality_fn_disc)
+
+  #define __ptrauth_unwind_personality_fn_intptr \
+    __unwind_ptrauth_restricted_intptr(ptrauth_key_function_pointer, 1, __ptrauth_unwind_personality_fn_disc)
+
+// ptrauth_string_discriminator("unw_proc_info_t::start_ip") == 0xCA2C
+  #define __ptrauth_unwind_proc_startip \
+    __unwind_ptrauth_restricted_intptr(ptrauth_key_process_independent_code, 1, 0xCA2C)
+
+// ptrauth_string_discriminator("unw_proc_info_t::end_ip") == 0xE183
+  #define __ptrauth_unwind_proc_endip \
+    __unwind_ptrauth_restricted_intptr(ptrauth_key_process_independent_code, 1, 0xE183)
+
+// ptrauth_string_discriminator("unw_proc_info_t::lsda") == 0x83DE
+  #define __ptrauth_unwind_proc_lsda \
+    __unwind_ptrauth_restricted_intptr(ptrauth_key_process_dependent_data, 1, 0x83DE)
+
+// ptrauth_string_discriminator("unw_proc_info_t::flags") == 0x79A1
+  #define __ptrauth_unwind_proc_flags \
+    __unwind_ptrauth_restricted_intptr(ptrauth_key_process_dependent_data, 1, 0x79A1)
+
+// ptrauth_string_discriminator("unw_proc_info_t::unwind_info") == 0xC20C
+  #define __ptrauth_unwind_proc_info \
+    __unwind_ptrauth_restricted_intptr(ptrauth_key_process_dependent_data, 1, 0xC20C)
+
+// ptrauth_string_discriminator("unw_proc_info_t::extra") == 0x03DF
+  #define __ptrauth_unwind_proc_extra \
+    __unwind_ptrauth_restricted_intptr(ptrauth_key_process_dependent_data, 1, 0x03DF)
+
+// ptrauth_string_discriminator("Registers_arm64::link_reg_t") == 0x8301
+  #define __ptrauth_unwind_arm64_link_reg \
+    __unwind_ptrauth_restricted_intptr(ptrauth_key_process_dependent_code, 1, 0x8301)
+
+// ptrauth_string_discriminator("UnwindInfoSections::dso_base") == 0x4FF5
+  #define __ptrauth_unwind_info_section_dso_base \
+    __unwind_ptrauth_restricted_intptr(ptrauth_key_process_dependent_data, 1, 0x4FF5)
----------------
atrosinenko wrote:

[nit] Other defines below use `__ptrauth_unwind_info_` prefix (without extra `...section_`).

https://github.com/llvm/llvm-project/pull/143230