[Lldb-commits] [lldb] [lldb][FreeBSDKernel] Support cross-architecture FreeBSD kernel cores (PR #223593)
Minsoo Choo via lldb-commits
lldb-commits at lists.llvm.org
Tue Sep 15 06:50:42 PDT 2026
https://github.com/mchoo7 updated https://github.com/llvm/llvm-project/pull/223593
>From 2418f233bc0e548a6cf9aac7f88c024caebe3a1e Mon Sep 17 00:00:00 2001
From: Minsoo Choo <minsoo at minsoo.io>
Date: Mon, 14 Sep 2026 22:29:33 -0400
Subject: [PATCH 1/2] [lldb] Support cross-architecture FreeBSD kernel cores
---
.../ProcessFreeBSDKernelCore.cpp | 42 ++++++++++++++++---
1 file changed, 37 insertions(+), 5 deletions(-)
diff --git a/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.cpp b/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.cpp
index 22e574c6e2624..7072677af67d2 100644
--- a/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.cpp
+++ b/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.cpp
@@ -18,6 +18,7 @@
#include "lldb/Utility/StreamString.h"
#include "llvm/Support/Error.h"
+#include "llvm/Support/SaveAndRestore.h"
#include "Plugins/DynamicLoader/FreeBSD-Kernel/DynamicLoaderFreeBSDKernel.h"
#include "ProcessFreeBSDKernelCore.h"
@@ -59,6 +60,38 @@ class PluginProperties : public Properties {
} // namespace
+namespace {
+
+thread_local Module *g_kvm_kernel_module;
+
+int ResolveKVMSymbol(const char *name, kvaddr_t *value) {
+ if (!g_kvm_kernel_module)
+ return 1;
+
+ const Symbol *symbol =
+ g_kvm_kernel_module->FindFirstSymbolWithNameAndType(ConstString(name));
+ if (!symbol)
+ return 1;
+
+ lldb::addr_t address = symbol->GetFileAddress();
+ if (address == LLDB_INVALID_ADDRESS)
+ return 1;
+
+ *value = address;
+ return 0;
+}
+
+kvm_t *OpenKVM(const ModuleSP &kernel_module, const FileSpec &core_file,
+ int flags, char *errbuf) {
+ llvm::SaveAndRestore resolver_module(g_kvm_kernel_module,
+ kernel_module.get());
+ return kvm_open2(kernel_module->GetFileSpec().GetPath().c_str(),
+ core_file.GetPath().c_str(), flags, errbuf,
+ ResolveKVMSymbol);
+}
+
+} // namespace
+
static PluginProperties &GetGlobalPluginProperties() {
static PluginProperties g_settings;
return g_settings;
@@ -134,9 +167,7 @@ lldb::ProcessSP ProcessFreeBSDKernelCore::CreateInstance(
ModuleSP executable = target_sp->GetExecutableModule();
if (crash_file && !can_connect && executable) {
char errbuf[_POSIX2_LINE_MAX];
- kvm_t *kvm =
- kvm_open2(executable->GetFileSpec().GetPath().c_str(),
- crash_file->GetPath().c_str(), O_RDONLY, errbuf, nullptr);
+ kvm_t *kvm = OpenKVM(executable, *crash_file, O_RDONLY, errbuf);
if (kvm) {
kvm_close(kvm);
return std::make_shared<ProcessFreeBSDKernelCore>(target_sp, listener_sp,
@@ -196,8 +227,9 @@ Status ProcessFreeBSDKernelCore::DoLoadCore() {
"ProcessFreeBSDKernelCore: no executable module set on target");
char errbuf[_POSIX2_LINE_MAX];
- m_kvm = kvm_open2(executable->GetFileSpec().GetPath().c_str(),
- GetCoreFile().GetPath().c_str(), O_RDWR, errbuf, nullptr);
+ const int flags =
+ GetGlobalPluginProperties().GetReadOnly() ? O_RDONLY : O_RDWR;
+ m_kvm = OpenKVM(executable, GetCoreFile(), flags, errbuf);
if (!m_kvm) {
LLDB_LOGF(GetLog(LLDBLog::Process), "FreeBSD-Kernel-Core: %s", errbuf);
>From b6e70e7c757e4fe328435ea11401faed2f3f7198 Mon Sep 17 00:00:00 2001
From: Minsoo Choo <minsoo at minsoo.io>
Date: Tue, 15 Sep 2026 09:43:27 -0400
Subject: [PATCH 2/2] fixup! [lldb] Support cross-architecture FreeBSD kernel
cores
---
.../ProcessFreeBSDKernelCore.cpp | 60 +++++++++----------
.../ProcessFreeBSDKernelCore.h | 10 ++++
2 files changed, 38 insertions(+), 32 deletions(-)
diff --git a/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.cpp b/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.cpp
index 7072677af67d2..7fa2dd95a6de1 100644
--- a/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.cpp
+++ b/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.cpp
@@ -60,38 +60,6 @@ class PluginProperties : public Properties {
} // namespace
-namespace {
-
-thread_local Module *g_kvm_kernel_module;
-
-int ResolveKVMSymbol(const char *name, kvaddr_t *value) {
- if (!g_kvm_kernel_module)
- return 1;
-
- const Symbol *symbol =
- g_kvm_kernel_module->FindFirstSymbolWithNameAndType(ConstString(name));
- if (!symbol)
- return 1;
-
- lldb::addr_t address = symbol->GetFileAddress();
- if (address == LLDB_INVALID_ADDRESS)
- return 1;
-
- *value = address;
- return 0;
-}
-
-kvm_t *OpenKVM(const ModuleSP &kernel_module, const FileSpec &core_file,
- int flags, char *errbuf) {
- llvm::SaveAndRestore resolver_module(g_kvm_kernel_module,
- kernel_module.get());
- return kvm_open2(kernel_module->GetFileSpec().GetPath().c_str(),
- core_file.GetPath().c_str(), flags, errbuf,
- ResolveKVMSymbol);
-}
-
-} // namespace
-
static PluginProperties &GetGlobalPluginProperties() {
static PluginProperties g_settings;
return g_settings;
@@ -569,6 +537,34 @@ lldb::addr_t ProcessFreeBSDKernelCore::FindSymbol(const char *name) {
return sym ? sym->GetLoadAddress(&GetTarget()) : LLDB_INVALID_ADDRESS;
}
+int ProcessFreeBSDKernelCore::ResolveKVMSymbol(const char *name,
+ kvaddr_t *value) {
+ if (!g_kvm_kernel_module)
+ return 1;
+
+ const Symbol *symbol =
+ g_kvm_kernel_module->FindFirstSymbolWithNameAndType(ConstString(name));
+ if (!symbol)
+ return 1;
+
+ lldb::addr_t address = symbol->GetFileAddress();
+ if (address == LLDB_INVALID_ADDRESS)
+ return 1;
+
+ *value = address;
+ return 0;
+}
+
+kvm_t *ProcessFreeBSDKernelCore::OpenKVM(const ModuleSP &kernel_module,
+ const FileSpec &core_file, int flags,
+ char *errbuf) {
+ llvm::SaveAndRestore resolver_module(g_kvm_kernel_module,
+ kernel_module.get());
+ return kvm_open2(kernel_module->GetFileSpec().GetPath().c_str(),
+ core_file.GetPath().c_str(), flags, errbuf,
+ ResolveKVMSymbol);
+}
+
void ProcessFreeBSDKernelCore::SetKernelDisplacement() {
kssize_t displacement = kvm_kerndisp(m_kvm);
diff --git a/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.h b/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.h
index 477ae77791e51..3105b01a42eec 100644
--- a/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.h
+++ b/lldb/source/Plugins/Process/FreeBSD-Kernel-Core/ProcessFreeBSDKernelCore.h
@@ -10,6 +10,7 @@
#define LLDB_SOURCE_PLUGINS_PROCESS_FREEBSDKERNEL_PROCESSFREEBSDKERNELCORE_H
#include "lldb/Core/Debugger.h"
+#include "lldb/Core/Module.h"
#include "lldb/Target/PostMortemProcess.h"
#include <kvm.h>
@@ -68,6 +69,15 @@ class ProcessFreeBSDKernelCore : public lldb_private::PostMortemProcess {
lldb::addr_t FindSymbol(const char *name);
private:
+ static inline thread_local lldb_private::Module *g_kvm_kernel_module =
+ nullptr;
+
+ static int ResolveKVMSymbol(const char *name, kvaddr_t *value);
+
+ static kvm_t *OpenKVM(const lldb::ModuleSP &kernel_module,
+ const lldb_private::FileSpec &core_file, int flags,
+ char *errbuf);
+
void SetKernelDisplacement();
void PrintUnreadMessage();
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