[lldb] Fix uninitialized memory access. #150544
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lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump64b.py fails under msan with uninitialized memory access errors. The problem is that a few structs are written to the dump without having been fully initialized. This change makes them default-initialized so dumping the fields that aren't explicitly written to won't trigger UB.
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@llvm/pr-subscribers-lldb Author: Jorge Gorbe Moya (slackito) Changeslldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump64b.py fails under msan with uninitialized memory access errors. The problem is that a few structs are written to the dump without having been fully initialized. This change makes them default-initialized so dumping the fields that aren't explicitly written to won't trigger UB. Full diff: https://github.com/llvm/llvm-project/pull/150544.diff 1 Files Affected:
diff --git a/lldb/source/Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp b/lldb/source/Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp
index fe28213c49740..25e98882c20c9 100644
--- a/lldb/source/Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp
+++ b/lldb/source/Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp
@@ -201,7 +201,7 @@ Status MinidumpFileBuilder::AddSystemInfo() {
return error;
};
- llvm::minidump::SystemInfo sys_info;
+ llvm::minidump::SystemInfo sys_info{};
sys_info.ProcessorArch =
static_cast<llvm::support::little_t<ProcessorArchitecture>>(arch);
// Global offset to beginning of a csd_string in a data section
@@ -378,7 +378,7 @@ Status MinidumpFileBuilder::AddModuleList() {
helper_data.AppendData(&signature, sizeof(llvm::support::ulittle32_t));
helper_data.AppendData(uuid.begin(), uuid.size());
- llvm::minidump::Module m;
+ llvm::minidump::Module m{};
m.BaseOfImage = static_cast<llvm::support::ulittle64_t>(
mod->GetObjectFile()->GetBaseAddress().GetLoadAddress(&target));
m.SizeOfImage = static_cast<llvm::support::ulittle32_t>(mod_size);
@@ -745,7 +745,7 @@ lldb_private::Status MinidumpFileBuilder::AddMiscInfo() {
if (error.Fail())
return error;
- lldb_private::minidump::MinidumpMiscInfo misc_info;
+ lldb_private::minidump::MinidumpMiscInfo misc_info{};
misc_info.size = static_cast<llvm::support::ulittle32_t>(
sizeof(lldb_private::minidump::MinidumpMiscInfo));
// Default set flags1 to 0, in case that we will not be able to
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Jlalond
approved these changes
Jul 25, 2025
Collaborator
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/11/builds/20338 Here is the relevant piece of the build log for the reference |
mahesh-attarde
pushed a commit
to mahesh-attarde/llvm-project
that referenced
this pull request
Jul 28, 2025
lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump64b.py fails under msan with uninitialized memory access errors. The problem is that a few structs are written to the dump without having been fully initialized. This change makes them default-initialized so dumping the fields that aren't explicitly written to won't trigger UB.
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lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump64b.py fails under msan with uninitialized memory access errors. The problem is that a few structs are written to the dump without having been fully initialized. This change makes them default-initialized so dumping the fields that aren't explicitly written to won't trigger UB.