Author: Jason Molenda Date: 2023-02-06T14:53:50-08:00 New Revision: 701030c3ecba0621ce5d325667fb75b73cf1532b
URL: https://github.com/llvm/llvm-project/commit/701030c3ecba0621ce5d325667fb75b73cf1532b DIFF: https://github.com/llvm/llvm-project/commit/701030c3ecba0621ce5d325667fb75b73cf1532b.diff LOG: In InitializeZerothFrame check for a CFA/AFA or error out There is a failure where we somehow get an invalid register number being used to calculate the canonical frame address, and this ends up with lldb crashing with a null deref because it assumes that it is always able to find information about that register. This patch adds a check for a failure to get a register, and declares the frame invalid in that case, with some additional logging or an assert for debug builds. Differential Revision: https://reviews.llvm.org/D143232 rdar://104428038 Added: Modified: lldb/source/Target/RegisterContextUnwind.cpp Removed: ################################################################################ diff --git a/lldb/source/Target/RegisterContextUnwind.cpp b/lldb/source/Target/RegisterContextUnwind.cpp index 2da40ba2bf61e..bf31ebbd858ae 100644 --- a/lldb/source/Target/RegisterContextUnwind.cpp +++ b/lldb/source/Target/RegisterContextUnwind.cpp @@ -37,6 +37,8 @@ #include "lldb/Utility/RegisterValue.h" #include "lldb/Utility/VASPrintf.h" #include "lldb/lldb-private.h" + +#include <cassert> #include <memory> using namespace lldb; @@ -289,6 +291,13 @@ void RegisterContextUnwind::InitializeZerothFrame() { } else ReadFrameAddress(row_register_kind, active_row->GetAFAValue(), m_afa); + if (m_cfa == LLDB_INVALID_ADDRESS && m_afa == LLDB_INVALID_ADDRESS) { + UnwindLogMsg( + "could not read CFA or AFA values for first frame, not valid."); + m_frame_type = eNotAValidFrame; + return; + } + UnwindLogMsg("initialized frame current pc is 0x%" PRIx64 " cfa is 0x%" PRIx64 " afa is 0x%" PRIx64 " using %s UnwindPlan", (uint64_t)m_current_pc.GetLoadAddress(exe_ctx.GetTargetPtr()), @@ -2116,6 +2125,14 @@ bool RegisterContextUnwind::ReadGPRValue(lldb::RegisterKind register_kind, } const RegisterInfo *reg_info = GetRegisterInfoAtIndex(lldb_regnum); + assert(reg_info); + if (!reg_info) { + UnwindLogMsg( + "Could not find RegisterInfo definition for lldb register number %d", + lldb_regnum); + return false; + } + RegisterValue reg_value; // if this is frame 0 (currently executing frame), get the requested reg // contents from the actual thread registers _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
