[Lldb-commits] [lldb] [lldb][DynamicLoader] Fix lldb unable to stop at _dl_debug_state if user set it before the process launched. (PR #88792)
Zequan Wu via lldb-commits
lldb-commits at lists.llvm.org
Mon Apr 15 13:43:10 PDT 2024
https://github.com/ZequanWu created https://github.com/llvm/llvm-project/pull/88792
If user sets a breakpoint at `_dl_debug_state` before the process launched, the breakpoint is not resolved yet. When lldb loads dynamic loader module, it's created with `Target::GetOrCreateModule` which notifies any pending breakpoint to resolve. However, the module's sections are not loaded at this time. They are loaded after returned from [Target::GetOrCreateModule](https://github.com/llvm/llvm-project/blob/0287a5cc4e2a5ded1ae2e4079f91052e6a6b8d9b/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp#L574-L577). This change fixes it by manually resolving breakpoints after creating dynamic loader module.
>From 26528cd679478448edf446e0e82e5f207ffd6113 Mon Sep 17 00:00:00 2001
From: Zequan Wu <zequanwu at google.com>
Date: Mon, 15 Apr 2024 16:30:38 -0400
Subject: [PATCH] [lldb][DynamicLoader] Fix lldb unable to stop at
_dl_debug_state if user set it before the process launched.
---
lldb/include/lldb/Target/Target.h | 3 +++
.../POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp | 5 +++++
lldb/source/Target/Target.cpp | 17 ++++++++++-------
.../breakpoint_command/TestBreakpointCommand.py | 17 +++++++++++++++++
4 files changed, 35 insertions(+), 7 deletions(-)
diff --git a/lldb/include/lldb/Target/Target.h b/lldb/include/lldb/Target/Target.h
index 2c2e6b2831ccee..3554ef0ea5a140 100644
--- a/lldb/include/lldb/Target/Target.h
+++ b/lldb/include/lldb/Target/Target.h
@@ -878,6 +878,9 @@ class Target : public std::enable_shared_from_this<Target>,
// the address of its previous instruction and return that address.
lldb::addr_t GetBreakableLoadAddress(lldb::addr_t addr);
+ void UpdateBreakpoints(ModuleList &module_list, bool added,
+ bool delete_locations);
+
void ModulesDidLoad(ModuleList &module_list);
void ModulesDidUnload(ModuleList &module_list, bool delete_locations);
diff --git a/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp b/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp
index 9baf86da4dc799..901fa53682da8e 100644
--- a/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp
+++ b/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp
@@ -576,6 +576,11 @@ ModuleSP DynamicLoaderPOSIXDYLD::LoadInterpreterModule() {
UpdateLoadedSections(module_sp, LLDB_INVALID_ADDRESS, m_interpreter_base,
false);
m_interpreter_module = module_sp;
+ // Manually update breakpoints after updating loaded sections, because they
+ // cannot be resolve at the time when creating this module.
+ ModuleList module_list;
+ module_list.Append(module_sp);
+ m_process->GetTarget().UpdateBreakpoints(module_list, true, false);
return module_sp;
}
return nullptr;
diff --git a/lldb/source/Target/Target.cpp b/lldb/source/Target/Target.cpp
index 09b0ac42631d1a..ec2dea5cc238d3 100644
--- a/lldb/source/Target/Target.cpp
+++ b/lldb/source/Target/Target.cpp
@@ -1687,6 +1687,13 @@ void Target::NotifyModulesRemoved(lldb_private::ModuleList &module_list) {
ModulesDidUnload(module_list, false);
}
+void Target::UpdateBreakpoints(ModuleList &module_list, bool added,
+ bool delete_locations) {
+ m_breakpoint_list.UpdateBreakpoints(module_list, added, delete_locations);
+ m_internal_breakpoint_list.UpdateBreakpoints(module_list, added,
+ delete_locations);
+}
+
void Target::ModulesDidLoad(ModuleList &module_list) {
const size_t num_images = module_list.GetSize();
if (m_valid && num_images) {
@@ -1694,8 +1701,7 @@ void Target::ModulesDidLoad(ModuleList &module_list) {
ModuleSP module_sp(module_list.GetModuleAtIndex(idx));
LoadScriptingResourceForModule(module_sp, this);
}
- m_breakpoint_list.UpdateBreakpoints(module_list, true, false);
- m_internal_breakpoint_list.UpdateBreakpoints(module_list, true, false);
+ UpdateBreakpoints(module_list, true, false);
if (m_process_sp) {
m_process_sp->ModulesDidLoad(module_list);
}
@@ -1713,8 +1719,7 @@ void Target::SymbolsDidLoad(ModuleList &module_list) {
}
}
- m_breakpoint_list.UpdateBreakpoints(module_list, true, false);
- m_internal_breakpoint_list.UpdateBreakpoints(module_list, true, false);
+ UpdateBreakpoints(module_list, true, false);
auto data_sp =
std::make_shared<TargetEventData>(shared_from_this(), module_list);
BroadcastEvent(eBroadcastBitSymbolsLoaded, data_sp);
@@ -1727,9 +1732,7 @@ void Target::ModulesDidUnload(ModuleList &module_list, bool delete_locations) {
auto data_sp =
std::make_shared<TargetEventData>(shared_from_this(), module_list);
BroadcastEvent(eBroadcastBitModulesUnloaded, data_sp);
- m_breakpoint_list.UpdateBreakpoints(module_list, false, delete_locations);
- m_internal_breakpoint_list.UpdateBreakpoints(module_list, false,
- delete_locations);
+ UpdateBreakpoints(module_list, false, delete_locations);
// If a module was torn down it will have torn down the 'TypeSystemClang's
// that we used as source 'ASTContext's for the persistent variables in
diff --git a/lldb/test/API/functionalities/breakpoint/breakpoint_command/TestBreakpointCommand.py b/lldb/test/API/functionalities/breakpoint/breakpoint_command/TestBreakpointCommand.py
index ea242952e409ec..a7e23fae14a21f 100644
--- a/lldb/test/API/functionalities/breakpoint/breakpoint_command/TestBreakpointCommand.py
+++ b/lldb/test/API/functionalities/breakpoint/breakpoint_command/TestBreakpointCommand.py
@@ -671,3 +671,20 @@ def test_breakpoint_statistics_hitcount(self):
self.assertNotEqual(breakpoints_stats, None)
for breakpoint_stats in breakpoints_stats:
self.assertIn("hitCount", breakpoint_stats)
+
+ @skipIf(oslist=no_match(["linux"]))
+ def test_break_at__dl_debug_state(self):
+ """
+ Test lldb is able to stop at _dl_debug_state if it is set before the
+ process is launched.
+ """
+ self.build()
+ exe = self.getBuildArtifact("a.out")
+ self.runCmd("target create %s" % exe)
+ bpid = lldbutil.run_break_set_by_symbol(self, "_dl_debug_state",
+ num_expected_locations=0)
+ self.runCmd("run")
+ self.assertIsNotNone(
+ lldbutil.get_one_thread_stopped_at_breakpoint_id(self.process(),
+ bpid)
+ )
More information about the lldb-commits
mailing list