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Diffstat (limited to 'source/Plugins/Process/Utility/UnwindLLDB.cpp')
-rw-r--r--source/Plugins/Process/Utility/UnwindLLDB.cpp86
1 files changed, 85 insertions, 1 deletions
diff --git a/source/Plugins/Process/Utility/UnwindLLDB.cpp b/source/Plugins/Process/Utility/UnwindLLDB.cpp
index 1cdae9011673b..9be09c478a0ee 100644
--- a/source/Plugins/Process/Utility/UnwindLLDB.cpp
+++ b/source/Plugins/Process/Utility/UnwindLLDB.cpp
@@ -86,6 +86,9 @@ UnwindLLDB::AddFirstFrame ()
if (m_frames.size() > 0)
return true;
+ ProcessSP process_sp (m_thread.GetProcess());
+ ABI *abi = process_sp ? process_sp->GetABI().get() : NULL;
+
// First, set up the 0th (initial) frame
CursorSP first_cursor_sp(new Cursor ());
RegisterContextLLDBSP reg_ctx_sp (new RegisterContextLLDB (m_thread,
@@ -108,6 +111,10 @@ UnwindLLDB::AddFirstFrame ()
// cursor own it in its shared pointer
first_cursor_sp->reg_ctx_lldb_sp = reg_ctx_sp;
m_frames.push_back (first_cursor_sp);
+
+ // Update the Full Unwind Plan for this frame if not valid
+ UpdateUnwindPlanForFirstFrameIfInvalid(abi);
+
return true;
unwind_done:
@@ -161,7 +168,14 @@ UnwindLLDB::GetOneMoreFrame (ABI* abi)
// If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to that and return
// true. Subsequent calls to TryFallbackUnwindPlan() will return false.
if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan())
+ {
+ // TryFallbackUnwindPlan for prev_frame succeeded and updated reg_ctx_lldb_sp field of
+ // prev_frame. However, cfa field of prev_frame still needs to be updated. Hence updating it.
+ if ( !(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
+ return nullptr;
+
return GetOneMoreFrame (abi);
+ }
if (log)
log->Printf ("%*sFrame %d did not get a RegisterContext, stopping.",
@@ -175,7 +189,14 @@ UnwindLLDB::GetOneMoreFrame (ABI* abi)
// See if the regctx below this on the stack has a fallback unwind plan it can use.
// Subsequent calls to TryFallbackUnwindPlan() will return false.
if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan())
+ {
+ // TryFallbackUnwindPlan for prev_frame succeeded and updated reg_ctx_lldb_sp field of
+ // prev_frame. However, cfa field of prev_frame still needs to be updated. Hence updating it.
+ if ( !(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
+ return nullptr;
+
return GetOneMoreFrame (abi);
+ }
if (log)
log->Printf("%*sFrame %d invalid RegisterContext for this frame, stopping stack walk",
@@ -187,7 +208,14 @@ UnwindLLDB::GetOneMoreFrame (ABI* abi)
// If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to that and return
// true. Subsequent calls to TryFallbackUnwindPlan() will return false.
if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan())
+ {
+ // TryFallbackUnwindPlan for prev_frame succeeded and updated reg_ctx_lldb_sp field of
+ // prev_frame. However, cfa field of prev_frame still needs to be updated. Hence updating it.
+ if ( !(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
+ return nullptr;
+
return GetOneMoreFrame (abi);
+ }
if (log)
log->Printf("%*sFrame %d did not get CFA for this frame, stopping stack walk",
@@ -212,7 +240,14 @@ UnwindLLDB::GetOneMoreFrame (ABI* abi)
|| abi->CallFrameAddressIsValid(cursor_sp->cfa) == false)
{
if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan())
+ {
+ // TryFallbackUnwindPlan for prev_frame succeeded and updated reg_ctx_lldb_sp field of
+ // prev_frame. However, cfa field of prev_frame still needs to be updated. Hence updating it.
+ if ( !(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
+ return nullptr;
+
return GetOneMoreFrame (abi);
+ }
if (log)
log->Printf("%*sFrame %d did not get a valid CFA for this frame, stopping stack walk",
@@ -232,7 +267,14 @@ UnwindLLDB::GetOneMoreFrame (ABI* abi)
// If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to that and return
// true. Subsequent calls to TryFallbackUnwindPlan() will return false.
if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan())
+ {
+ // TryFallbackUnwindPlan for prev_frame succeeded and updated reg_ctx_lldb_sp field of
+ // prev_frame. However, cfa field of prev_frame still needs to be updated. Hence updating it.
+ if ( !(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
+ return nullptr;
+
return GetOneMoreFrame (abi);
+ }
if (log)
log->Printf("%*sFrame %d did not get PC for this frame, stopping stack walk",
@@ -244,7 +286,14 @@ UnwindLLDB::GetOneMoreFrame (ABI* abi)
// If the RegisterContextLLDB has a fallback UnwindPlan, it will switch to that and return
// true. Subsequent calls to TryFallbackUnwindPlan() will return false.
if (prev_frame->reg_ctx_lldb_sp->TryFallbackUnwindPlan())
+ {
+ // TryFallbackUnwindPlan for prev_frame succeeded and updated reg_ctx_lldb_sp field of
+ // prev_frame. However, cfa field of prev_frame still needs to be updated. Hence updating it.
+ if ( !(prev_frame->reg_ctx_lldb_sp->GetCFA(prev_frame->cfa)))
+ return nullptr;
+
return GetOneMoreFrame (abi);
+ }
if (log)
log->Printf("%*sFrame %d did not get a valid PC, stopping stack walk",
@@ -263,6 +312,33 @@ UnwindLLDB::GetOneMoreFrame (ABI* abi)
return cursor_sp;
}
+void
+UnwindLLDB::UpdateUnwindPlanForFirstFrameIfInvalid (ABI *abi)
+{
+ // This function is called for First Frame only.
+ assert (m_frames.size() == 1 && "No. of cursor frames are not 1");
+
+ bool old_m_unwind_complete = m_unwind_complete;
+ CursorSP old_m_candidate_frame = m_candidate_frame;
+
+ // Try to unwind 2 more frames using the Unwinder. It uses Full UnwindPlan
+ // and if Full UnwindPlan fails, then uses FallBack UnwindPlan. Also
+ // update the cfa of Frame 0 (if required).
+ AddOneMoreFrame(abi);
+
+ // Remove all the frames added by above function as the purpose of
+ // using above function was just to check whether Unwinder of Frame 0
+ // works or not.
+ for(uint32_t i=1; i<m_frames.size(); i++)
+ m_frames.pop_back();
+
+ // Restore status after calling AddOneMoreFrame
+ m_unwind_complete = old_m_unwind_complete;
+ m_candidate_frame = old_m_candidate_frame;
+ return;
+}
+
+
bool
UnwindLLDB::AddOneMoreFrame (ABI *abi)
{
@@ -321,9 +397,17 @@ UnwindLLDB::AddOneMoreFrame (ABI *abi)
m_frames.push_back(new_frame_v2);
m_candidate_frame = GetOneMoreFrame(abi);
if (m_candidate_frame)
+ {
+ // If control reached here then TryFallbackUnwindPlan had succeeded for Cursor::m_frames[m_frames.size() - 2].
+ // It also succeeded to Unwind next 2 frames i.e. m_frames[m_frames.size() - 1] and a frame after that.
+ // For Cursor::m_frames[m_frames.size() - 2], reg_ctx_lldb_sp field was already updated during TryFallbackUnwindPlan
+ // call above. However, cfa field still needs to be updated. Hence updating it here and then returning.
+ if ( !(m_frames[m_frames.size() - 2]->reg_ctx_lldb_sp->GetCFA(m_frames[m_frames.size() - 2]->cfa)))
+ return false;
return true;
+ }
- // The new frame isn't helped in unwinding. Fall back to the original one as the default unwind
+ // The new frame hasn't helped in unwinding. Fall back to the original one as the default unwind
// plan is usually more reliable then the fallback one.
m_frames.pop_back();
m_frames.push_back(new_frame);
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-31 12:15:12 +0000