[Lldb-commits] [lldb] [LLDB][Minidump] Extend the minidump x86_64 registers to include fs_base and gs_base (PR #106767)
Jacob Lalonde via lldb-commits
lldb-commits at lists.llvm.org
Fri Aug 30 10:37:05 PDT 2024
https://github.com/Jlalond created https://github.com/llvm/llvm-project/pull/106767
A follow up to #106473 Minidump wasn't collecting fs or gs_base. This patch extends the x86_64 register context and gated reading it behind an lldb specific flag. Additionally these registers are explicitly checked in the tests.
>From ceb20d62d9cef3090e34e8b9fc0bc620a7d9da3d Mon Sep 17 00:00:00 2001
From: Jacob Lalonde <jalalonde at fb.com>
Date: Fri, 30 Aug 2024 10:33:08 -0700
Subject: [PATCH 1/2] Extend the minidump x86_64 registers to include fs_base
and gs_base
---
.../Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp | 5 ++++-
.../Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp | 2 +-
.../Process/minidump/RegisterContextMinidump_x86_64.cpp | 7 +++++++
.../Process/minidump/RegisterContextMinidump_x86_64.h | 7 ++++++-
.../TestProcessSaveCoreMinidump.py | 7 +++++++
5 files changed, 25 insertions(+), 3 deletions(-)
diff --git a/lldb/source/Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp b/lldb/source/Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp
index 13355afb58dbd1..5c9ba223ad143e 100644
--- a/lldb/source/Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp
+++ b/lldb/source/Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp
@@ -473,7 +473,8 @@ GetThreadContext_x86_64(RegisterContext *reg_ctx) {
lldb_private::minidump::MinidumpContext_x86_64_Flags::x86_64_Flag |
lldb_private::minidump::MinidumpContext_x86_64_Flags::Control |
lldb_private::minidump::MinidumpContext_x86_64_Flags::Segments |
- lldb_private::minidump::MinidumpContext_x86_64_Flags::Integer);
+ lldb_private::minidump::MinidumpContext_x86_64_Flags::Integer |
+ lldb_private::minidump::MinidumpContext_x86_64_Flags::LLDBSpecific);
thread_context.rax = read_register_u64(reg_ctx, "rax");
thread_context.rbx = read_register_u64(reg_ctx, "rbx");
thread_context.rcx = read_register_u64(reg_ctx, "rcx");
@@ -499,6 +500,8 @@ GetThreadContext_x86_64(RegisterContext *reg_ctx) {
thread_context.gs = read_register_u64(reg_ctx, "gs");
thread_context.ss = read_register_u64(reg_ctx, "ss");
thread_context.ds = read_register_u64(reg_ctx, "ds");
+ thread_context.fs_base = read_register_u64(reg_ctx, "fs_base");
+ thread_context.gs_base = read_register_u64(reg_ctx, "gs_base");
return thread_context;
}
diff --git a/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp b/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp
index 845312f4c1eddc..f60757a52c6310 100644
--- a/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp
+++ b/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp
@@ -21,7 +21,7 @@ RegisterContextCorePOSIX_x86_64::RegisterContextCorePOSIX_x86_64(
size = GetGPRSize();
m_gpregset.reset(new uint8_t[size]);
- len =
+ len =
gpregset.ExtractBytes(0, size, lldb::eByteOrderLittle, m_gpregset.get());
if (len != size)
m_gpregset.reset();
diff --git a/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.cpp b/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.cpp
index 917140cab29767..4db049ff7e64e7 100644
--- a/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.cpp
+++ b/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.cpp
@@ -67,6 +67,7 @@ lldb::DataBufferSP lldb_private::minidump::ConvertMinidumpContext_x86_64(
auto ControlFlag = MinidumpContext_x86_64_Flags::Control;
auto IntegerFlag = MinidumpContext_x86_64_Flags::Integer;
auto SegmentsFlag = MinidumpContext_x86_64_Flags::Segments;
+ auto LLDBSpecificFlag = MinidumpContext_x86_64_Flags::LLDBSpecific;
if ((context_flags & x86_64_Flag) != x86_64_Flag)
return nullptr;
@@ -104,6 +105,12 @@ lldb::DataBufferSP lldb_private::minidump::ConvertMinidumpContext_x86_64(
writeRegister(&context->r15, result_base, reg_info[lldb_r15_x86_64]);
}
+ if ((context_flags & LLDBSpecificFlag) == LLDBSpecificFlag) {
+ writeRegister(&context->fs_base, result_base, reg_info[x86_64_with_base::lldb_fs_base]);
+ writeRegister(&context->gs_base, result_base,
+ reg_info[x86_64_with_base::lldb_gs_base]);
+ }
+
// TODO parse the floating point registers
return result_context_buf;
diff --git a/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.h b/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.h
index d920ea9d823f4f..f214e04a315a8e 100644
--- a/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.h
+++ b/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.h
@@ -153,6 +153,10 @@ struct MinidumpContext_x86_64 {
llvm::support::ulittle64_t last_branch_from_rip;
llvm::support::ulittle64_t last_exception_to_rip;
llvm::support::ulittle64_t last_exception_from_rip;
+
+ // These registers are LLDB specific.
+ llvm::support::ulittle64_t fs_base;
+ llvm::support::ulittle64_t gs_base;
};
// For context_flags. These values indicate the type of
@@ -168,9 +172,10 @@ enum class MinidumpContext_x86_64_Flags : uint32_t {
FloatingPoint = x86_64_Flag | 0x00000008,
DebugRegisters = x86_64_Flag | 0x00000010,
XState = x86_64_Flag | 0x00000040,
+ LLDBSpecific = x86_64_Flag | 0x80000000,
Full = Control | Integer | FloatingPoint,
- All = Full | Segments | DebugRegisters,
+ All = Full | Segments | DebugRegisters | LLDBSpecific,
LLVM_MARK_AS_BITMASK_ENUM(/* LargestValue = */ All)
};
diff --git a/lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump.py b/lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump.py
index ea59aef004aff5..482d000081e1d7 100644
--- a/lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump.py
+++ b/lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump.py
@@ -67,6 +67,13 @@ def verify_core_file(
self.assertIn(thread_id, stacks_to_registers_map)
register_val_list = stacks_to_registers_map[thread_id]
frame_register_list = frame.GetRegisters()
+ # explicitly verify we collected fs and gs base for x86_64
+ explicit_registers = ["fs_base", "gs_base"]
+ for reg in explicit_registers:
+ register = frame_register_list.GetFirstValueByName(reg)
+ self.assertNotEqual(None, register)
+ self.assertEqual(register.GetValueAsUnsigned(), stacks_to_registers_map[thread_id].GetFirstValueByName("fs_base").GetValueAsUnsigned())
+
for x in register_val_list:
self.assertEqual(
x.GetValueAsUnsigned(),
>From 7b4cf905ece3409633dd9d96838497723409aa04 Mon Sep 17 00:00:00 2001
From: Jacob Lalonde <jalalonde at fb.com>
Date: Fri, 30 Aug 2024 10:35:38 -0700
Subject: [PATCH 2/2] Rebase and format
---
.../Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp | 2 +-
.../Process/minidump/RegisterContextMinidump_x86_64.cpp | 3 ++-
.../TestProcessSaveCoreMinidump.py | 7 ++++++-
3 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp b/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp
index f60757a52c6310..845312f4c1eddc 100644
--- a/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp
+++ b/lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_x86_64.cpp
@@ -21,7 +21,7 @@ RegisterContextCorePOSIX_x86_64::RegisterContextCorePOSIX_x86_64(
size = GetGPRSize();
m_gpregset.reset(new uint8_t[size]);
- len =
+ len =
gpregset.ExtractBytes(0, size, lldb::eByteOrderLittle, m_gpregset.get());
if (len != size)
m_gpregset.reset();
diff --git a/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.cpp b/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.cpp
index 4db049ff7e64e7..e879c493156593 100644
--- a/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.cpp
+++ b/lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.cpp
@@ -106,7 +106,8 @@ lldb::DataBufferSP lldb_private::minidump::ConvertMinidumpContext_x86_64(
}
if ((context_flags & LLDBSpecificFlag) == LLDBSpecificFlag) {
- writeRegister(&context->fs_base, result_base, reg_info[x86_64_with_base::lldb_fs_base]);
+ writeRegister(&context->fs_base, result_base,
+ reg_info[x86_64_with_base::lldb_fs_base]);
writeRegister(&context->gs_base, result_base,
reg_info[x86_64_with_base::lldb_gs_base]);
}
diff --git a/lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump.py b/lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump.py
index 482d000081e1d7..ed15793b527fc9 100644
--- a/lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump.py
+++ b/lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump.py
@@ -72,7 +72,12 @@ def verify_core_file(
for reg in explicit_registers:
register = frame_register_list.GetFirstValueByName(reg)
self.assertNotEqual(None, register)
- self.assertEqual(register.GetValueAsUnsigned(), stacks_to_registers_map[thread_id].GetFirstValueByName("fs_base").GetValueAsUnsigned())
+ self.assertEqual(
+ register.GetValueAsUnsigned(),
+ stacks_to_registers_map[thread_id]
+ .GetFirstValueByName("fs_base")
+ .GetValueAsUnsigned(),
+ )
for x in register_val_list:
self.assertEqual(
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