https://github.com/jasonmolenda updated
https://github.com/llvm/llvm-project/pull/146460
>From a9b23cc16ca7b3a20ccc7c63e64f840fcbf7da9d Mon Sep 17 00:00:00 2001
From: Jason Molenda <jmole...@apple.com>
Date: Mon, 30 Jun 2025 20:26:40 -0700
Subject: [PATCH 1/2] [lldb][Mach-O] Fix several bugs in x86_64 Mach-O corefile
reading, and one bug in the new RegisterContextUnifiedCore class.
The PR I landed a few days ago to allow Mach-O corefiles to
augment their registers with additional per-thread registers
in metadata exposed a few bugs in the x86_64 corefile reader
when running under different CI environments. It also showed
a bug in my RegisterContextUnifiedCore class where I wasn't
properly handling lookups of unknown registers (e.g.
the LLDB_GENERIC_RA when debugging an intel target).
The Mach-O x86_64 corefile support would say that it had fpu & exc
registers available in every corefile, regardless of whether they
were actually present. It would only read the bytes for the first
register flavor in the LC_THREAD, the GPRs, but it read them
incorrectly, so sometimes you got more register context than you'd
expect. The LC_THREAD register context specifies a flavor and the
number of uint32_t words; the ObjectFileMachO method would read
that number of uint64_t's, exceeding the GPR register space, but
it was followed by FPU and then EXC register space so it didn't
crash. If you had a corefile with GPR and EXC register bytes,
it would be written into the GPR and then FPU register areas,
with zeroes filling out the rest of the context.
---
.../ObjectFile/Mach-O/ObjectFileMachO.cpp | 66 ++++++++-----------
.../mach-core/RegisterContextUnifiedCore.cpp | 8 ++-
2 files changed, 32 insertions(+), 42 deletions(-)
diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index 4394caf7f31e9..ddb662c374edb 100644
--- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -184,46 +184,32 @@ class RegisterContextDarwin_x86_64_Mach : public
RegisterContextDarwin_x86_64 {
SetError(GPRRegSet, Read, -1);
SetError(FPURegSet, Read, -1);
SetError(EXCRegSet, Read, -1);
- bool done = false;
- while (!done) {
+ while (offset < data.GetByteSize()) {
int flavor = data.GetU32(&offset);
if (flavor == 0)
- done = true;
- else {
- uint32_t i;
- uint32_t count = data.GetU32(&offset);
- switch (flavor) {
- case GPRRegSet:
- for (i = 0; i < count; ++i)
- (&gpr.rax)[i] = data.GetU64(&offset);
- SetError(GPRRegSet, Read, 0);
- done = true;
-
- break;
- case FPURegSet:
- // TODO: fill in FPU regs....
- // SetError (FPURegSet, Read, -1);
- done = true;
-
- break;
- case EXCRegSet:
- exc.trapno = data.GetU32(&offset);
- exc.err = data.GetU32(&offset);
- exc.faultvaddr = data.GetU64(&offset);
- SetError(EXCRegSet, Read, 0);
- done = true;
- break;
- case 7:
- case 8:
- case 9:
- // fancy flavors that encapsulate of the above flavors...
- break;
-
- default:
- done = true;
- break;
- }
+ break;
+ uint32_t count = data.GetU32(&offset);
+ switch (flavor) {
+ case GPRRegSet: {
+ uint32_t *gpr_data = reinterpret_cast<uint32_t *>(&gpr.rax);
+ for (uint32_t i = 0; i < count; ++i)
+ gpr_data[i] = data.GetU32(&offset);
+ SetError(GPRRegSet, Read, 0);
+ } break;
+ case FPURegSet:
+ // TODO: fill in FPU regs....
+ SetError(FPURegSet, Read, -1);
+ break;
+ case EXCRegSet:
+ exc.trapno = data.GetU32(&offset);
+ exc.err = data.GetU32(&offset);
+ exc.faultvaddr = data.GetU64(&offset);
+ SetError(EXCRegSet, Read, 0);
+ break;
+ default:
+ offset += count * 4;
+ break;
}
}
}
@@ -353,11 +339,11 @@ class RegisterContextDarwin_x86_64_Mach : public
RegisterContextDarwin_x86_64 {
}
protected:
- int DoReadGPR(lldb::tid_t tid, int flavor, GPR &gpr) override { return 0; }
+ int DoReadGPR(lldb::tid_t tid, int flavor, GPR &gpr) override { return -1; }
- int DoReadFPU(lldb::tid_t tid, int flavor, FPU &fpu) override { return 0; }
+ int DoReadFPU(lldb::tid_t tid, int flavor, FPU &fpu) override { return -1; }
- int DoReadEXC(lldb::tid_t tid, int flavor, EXC &exc) override { return 0; }
+ int DoReadEXC(lldb::tid_t tid, int flavor, EXC &exc) override { return -1; }
int DoWriteGPR(lldb::tid_t tid, int flavor, const GPR &gpr) override {
return 0;
diff --git
a/lldb/source/Plugins/Process/mach-core/RegisterContextUnifiedCore.cpp
b/lldb/source/Plugins/Process/mach-core/RegisterContextUnifiedCore.cpp
index 16568f788c202..449f85bc3f52a 100644
--- a/lldb/source/Plugins/Process/mach-core/RegisterContextUnifiedCore.cpp
+++ b/lldb/source/Plugins/Process/mach-core/RegisterContextUnifiedCore.cpp
@@ -262,7 +262,9 @@ size_t RegisterContextUnifiedCore::GetRegisterCount() {
const RegisterInfo *
RegisterContextUnifiedCore::GetRegisterInfoAtIndex(size_t reg) {
- return &m_register_infos[reg];
+ if (reg < m_register_infos.size())
+ return &m_register_infos[reg];
+ return nullptr;
}
size_t RegisterContextUnifiedCore::GetRegisterSetCount() {
@@ -270,7 +272,9 @@ size_t RegisterContextUnifiedCore::GetRegisterSetCount() {
}
const RegisterSet *RegisterContextUnifiedCore::GetRegisterSet(size_t set) {
- return &m_register_sets[set];
+ if (set < m_register_sets.size())
+ return &m_register_sets[set];
+ return nullptr;
}
bool RegisterContextUnifiedCore::ReadRegister(
>From e4958d5723e5aefbb89b6ccc82826e20a9a1f07c Mon Sep 17 00:00:00 2001
From: Jason Molenda <github-m...@molenda.com>
Date: Mon, 30 Jun 2025 21:23:53 -0700
Subject: [PATCH 2/2] Update
lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
Co-authored-by: Jonas Devlieghere <jo...@devlieghere.com>
---
lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
index ddb662c374edb..70f954cd5413f 100644
--- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
+++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp
@@ -193,7 +193,7 @@ class RegisterContextDarwin_x86_64_Mach : public
RegisterContextDarwin_x86_64 {
switch (flavor) {
case GPRRegSet: {
uint32_t *gpr_data = reinterpret_cast<uint32_t *>(&gpr.rax);
- for (uint32_t i = 0; i < count; ++i)
+ for (uint32_t i = 0; i < count && offset < data.GetByteSize(); ++i)
gpr_data[i] = data.GetU32(&offset);
SetError(GPRRegSet, Read, 0);
} break;
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