This commit addresses a bug introduced in commit bcf654c, which prevented LLDB from parsing the GNU build ID for the main executable from a core file. The fix finds the `p_vaddr` of the first `PT_LOAD` segment as the `base_addr` and subtract this `base_addr` from the virtual address being read. Co-authored-by: George Hu <hyubo@meta.com>
ELF core debugging fix #117070 broke TestLoadUnload.py tests due to GetModuleSpec call, ProcessGDBRemote fetches modules from remote. Revise the original PR, renamed FindBuildId to FindModuleUUID.
DynamicLoader does not use ProcessElfCore NT_FILE entries to get UUID. Use GetModuleSpec to get UUID from Process.
This fixes a functionality gap with GDB, where GDB will properly decode the stop reason and give the address for SIGSEGV. I also added descriptions to all stop reasons, following the same code path that the Native Linux Thread uses.
A previous patch added the ability to load UUID from ELF headers using the program header and finding PT_NOTE entries. The fix would attempt to read the data for the PT_NOTE from memory, but it didn't slide the address so it ended up only working for the main executable if it wasn't moved in memory. This patch slides the address and adds logging. All processes map the ELF header + program headers + some program header contents into memory. The program header for the `PT_NOTE` entries are mapped, but the p_vaddr doesn't get relocated and is relative to the load address of the ELF header. So we take a "p_vaddr" (file address) and convert it into a load address in the process so we can load the correct bytes that contain the `PT_NOTE` contents.
…ror() [NFC]
This patch removes all of the Set.* methods from Status. This cleanup is part of a series of patches that make it harder use the anti-pattern of keeping a long-lives Status object around and updating it while dropping any errors it contains on the floor. This patch is largely NFC, the more interesting next steps this enables is to: 1. remove Status.Clear() 2. assert that Status::operator=() never overwrites an error 3. remove Status::operator=() Note that step (2) will bring 90% of the benefits for users, and step (3) will dramatically clean up the error handling code in various places. In the end my goal is to convert all APIs that are of the form ` ResultTy DoFoo(Status& error) ` to ` llvm::Expected<ResultTy> DoFoo() ` How to read this patch? The interesting changes are in Status.h and Status.cpp, all other changes are mostly ` perl -pi -e 's/\.SetErrorString/ = Status::FromErrorString/g' $(git grep -l SetErrorString lldb/source) ` plus the occasional manual cleanup.
There is no need to clone the content and set extraction properties because `m_auxv` is already in the required form.
As we have debuginfod as symbol locator available in lldb now, we want to make full use of it. In case of post mortem debugging, we don't always have the main executable available. However, the .note.gnu.build-id of the main executable(some other modules too), should be available in the core file, as those binaries are loaded in memory and dumped in the core file. We try to iterate through the NT_FILE entries, read and store the gnu build id if possible. This will be very useful as this id is the unique key which is needed for querying the debuginfod server. Test: Build and run lldb. Breakpoint set to https://github.com/llvm/llvm-project/blob/main/lldb/source/Plugins/SymbolLocator/Debuginfod/SymbolLocatorDebuginfod.cpp#L147 Verified after this commit, module_uuid is the correct gnu build id of the main executable which caused the crash(first in the NT_FILE entry) Previous PR: https://github.com/llvm/llvm-project/pull/92078 was mistakenly merged. This PR is re-opening the commit.
Reverts llvm/llvm-project#92078