[libunwind][AIX] Fix the wrong traceback from signal handler (#101069)

xingxue-ibm · web-flow · commit d90fa612604b · 2024-07-30T06:28:59.000-04:00
Patch [#92291](#92291) causes wrong traceback from a signal handler for AIX because the AIX unwinder uses the traceback table at the end of each function instead of FDE/CIE for unwinding. This patch adds a condition to exclude traceback table based unwinding from the code added by the patch.
diff --git a/libunwind/src/UnwindCursor.hpp b/libunwind/src/UnwindCursor.hpp
@@ -2589,7 +2589,8 @@ void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
     --pc;
 #endif
 
-#if !(defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32))
+#if !(defined(_LIBUNWIND_SUPPORT_SEH_UNWIND) && defined(_WIN32)) &&            \
+    !defined(_LIBUNWIND_SUPPORT_TBTAB_UNWIND)
   // In case of this is frame of signal handler, the IP saved in the signal
   // handler points to first non-executed instruction, while FDE/CIE expects IP
   // to be after the first non-executed instruction.
diff --git a/libunwind/test/aix_signal_unwind.pass.sh.S b/libunwind/test/aix_signal_unwind.pass.sh.S
@@ -10,7 +10,7 @@
 // a correct traceback when the function raising the signal does not save
 // the link register or does not store the stack back chain.
 
-// REQUIRES: target=powerpc{{(64)?}}-ibm-aix
+// REQUIRES: target=powerpc{{(64)?}}-ibm-aix{{.*}}
 
 // Test when the function raising the signal does not save the link register
 // RUN: %{cxx} -x c++ %s -o %t.exe -DCXX_CODE %{flags} %{compile_flags}
