commit 3fd917d8860e9bdcabc14c536da4377307906be0
author Joseph Tremoulet <jotrem@microsoft.com> Fri Jul 19 14:05:55 2019 +0000
committer Joseph Tremoulet <jotrem@microsoft.com> Fri Jul 19 14:05:55 2019 +0000
tree 86fceb8a74eaf73a4f2e3c61943131b0dc296e0a
parent 9e6a42a1856468e1408c2e07717b71b9cfe1c86a

Support Linux signal return trampolines in frame initialization

Summary:
Add __kernel_rt_sigreturn to the list of trap handlers for Linux (it's
used as such on aarch64 at least), and __restore_rt as well (used on
x86_64).

Skip decrement-and-recompute for trap handlers in
InitializeNonZerothFrame, as signal dispatch may point the child frame's
return address to the start of the return trampoline.

Parse the 'S' flag for signal handlers from eh_frame augmentation, and
propagate it to the unwind plan.

Reviewers: labath, jankratochvil, compnerd, jfb, jasonmolenda

Reviewed By: jasonmolenda

Subscribers: clayborg, MaskRay, wuzish, nemanjai, kbarton, jrtc27, atanasyan, jsji, javed.absar, kristof.beyls, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D63667

llvm-svn: 366580

lldb/source/Symbol/ArmUnwindInfo.cpp

diff --git a/lldb/source/Symbol/ArmUnwindInfo.cpp b/lldb/source/Symbol/ArmUnwindInfo.cpp
index b9fd84b..fdf4e30 100644
--- a/lldb/source/Symbol/ArmUnwindInfo.cpp
+++ b/lldb/source/Symbol/ArmUnwindInfo.cpp
@@ -344,6 +344,7 @@
   unwind_plan.SetSourceName("ARM.exidx unwind info");
   unwind_plan.SetSourcedFromCompiler(eLazyBoolYes);
   unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
+  unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
   unwind_plan.SetRegisterKind(eRegisterKindDWARF);
 
   return true;

lldb/source/Symbol/CompactUnwindInfo.cpp

diff --git a/lldb/source/Symbol/CompactUnwindInfo.cpp b/lldb/source/Symbol/CompactUnwindInfo.cpp
index 3a2a4d3..1a634f2 100644
--- a/lldb/source/Symbol/CompactUnwindInfo.cpp
+++ b/lldb/source/Symbol/CompactUnwindInfo.cpp
@@ -737,6 +737,7 @@
   unwind_plan.SetSourceName("compact unwind info");
   unwind_plan.SetSourcedFromCompiler(eLazyBoolYes);
   unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
+  unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
   unwind_plan.SetRegisterKind(eRegisterKindEHFrame);
 
   unwind_plan.SetLSDAAddress(function_info.lsda_address);
@@ -1008,6 +1009,7 @@
   unwind_plan.SetSourceName("compact unwind info");
   unwind_plan.SetSourcedFromCompiler(eLazyBoolYes);
   unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
+  unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
   unwind_plan.SetRegisterKind(eRegisterKindEHFrame);
 
   unwind_plan.SetLSDAAddress(function_info.lsda_address);
@@ -1304,6 +1306,7 @@
   unwind_plan.SetSourceName("compact unwind info");
   unwind_plan.SetSourcedFromCompiler(eLazyBoolYes);
   unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
+  unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
   unwind_plan.SetRegisterKind(eRegisterKindEHFrame);
 
   unwind_plan.SetLSDAAddress(function_info.lsda_address);
@@ -1437,6 +1440,7 @@
   unwind_plan.SetSourceName("compact unwind info");
   unwind_plan.SetSourcedFromCompiler(eLazyBoolYes);
   unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolNo);
+  unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
   unwind_plan.SetRegisterKind(eRegisterKindEHFrame);
 
   unwind_plan.SetLSDAAddress(function_info.lsda_address);

lldb/source/Symbol/DWARFCallFrameInfo.cpp

diff --git a/lldb/source/Symbol/DWARFCallFrameInfo.cpp b/lldb/source/Symbol/DWARFCallFrameInfo.cpp
index 0ab9fa4..64bd22b 100644
--- a/lldb/source/Symbol/DWARFCallFrameInfo.cpp
+++ b/lldb/source/Symbol/DWARFCallFrameInfo.cpp
@@ -19,6 +19,7 @@
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/Timer.h"
 #include <list>
+#include <cstring>
 
 using namespace lldb;
 using namespace lldb_private;
@@ -601,6 +602,9 @@
     }
     offset += aug_data_len;
   }
+  unwind_plan.SetUnwindPlanForSignalTrap(
+    strchr(cie->augmentation, 'S') ? eLazyBoolYes : eLazyBoolNo);
+
   Address lsda_data;
   Address personality_function_ptr;