llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-lldb Author: aokblast <details> <summary>Changes</summary> A symbol can be a stub that is re-exported to another library. For example, ELF can specify an auxiliary library and emit a zero-sized symbol in the symbol table. This can cause expression evaluation to resolve the stub instead of the actual function. Fix this by resolving re-exported symbols to their actual addressed. --- Full diff: https://github.com/llvm/llvm-project/pull/208998.diff 1 Files Affected: - (modified) lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp (+28-6) ``````````diff diff --git a/lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp b/lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp index 5226b9bbe7c78..f190b589ad704 100644 --- a/lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp +++ b/lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp @@ -33,6 +33,30 @@ using namespace lldb; using namespace lldb_private; +/// Pick a call target from \p sc_list. Re-exported symbols have no code of +/// their own and are resolved through the library that actually defines +/// them, mirroring what the dynamic linker does. +static Address GetCallableAddress(Target &target, + const SymbolContextList &sc_list) { + const uint32_t count = sc_list.GetSize(); + for (uint32_t i = 0; i < count; ++i) { + SymbolContext sc; + if (!sc_list.GetContextAtIndex(i, sc)) + continue; + if (sc.symbol && sc.symbol->GetType() == eSymbolTypeReExported) { + // Pass the containing module so all of its re-exported libraries + // (e.g. an ELF filter library's filtees) are searched in order. + if (Symbol *actual = + sc.symbol->ResolveReExportedSymbol(target, sc.module_sp)) + return actual->GetAddress(); + // Unresolvable re-export: not callable. + continue; + } + return sc.GetFunctionOrSymbolAddress(); + } + return Address(); +} + bool lldb_private::InferiorCallMmap(Process *process, addr_t &allocated_addr, addr_t addr, addr_t length, unsigned prot, unsigned flags, addr_t fd, addr_t offset) { @@ -50,8 +74,7 @@ bool lldb_private::InferiorCallMmap(Process *process, addr_t &allocated_addr, ConstString("mmap"), eFunctionNameTypeFull, function_options, sc_list); const uint32_t count = sc_list.GetSize(); if (count > 0) { - SymbolContext sc; - if (sc_list.GetContextAtIndex(0, sc)) { + { EvaluateExpressionOptions options; options.SetStopOthers(true); options.SetUnwindOnError(true); @@ -74,7 +97,7 @@ bool lldb_private::InferiorCallMmap(Process *process, addr_t &allocated_addr, prot_arg |= PROT_WRITE; } - Address mmap_addr = sc.GetFunctionOrSymbolAddress(); + Address mmap_addr = GetCallableAddress(process->GetTarget(), sc_list); if (mmap_addr.IsValid()) { auto type_system_or_err = process->GetTarget().GetScratchTypeSystemForLanguage( @@ -142,8 +165,7 @@ bool lldb_private::InferiorCallMunmap(Process *process, addr_t addr, ConstString("munmap"), eFunctionNameTypeFull, function_options, sc_list); const uint32_t count = sc_list.GetSize(); if (count > 0) { - SymbolContext sc; - if (sc_list.GetContextAtIndex(0, sc)) { + { EvaluateExpressionOptions options; options.SetStopOthers(true); options.SetUnwindOnError(true); @@ -153,7 +175,7 @@ bool lldb_private::InferiorCallMunmap(Process *process, addr_t addr, options.SetTimeout(process->GetUtilityExpressionTimeout()); options.SetTrapExceptions(false); - Address munmap_addr = sc.GetFunctionOrSymbolAddress(); + Address munmap_addr = GetCallableAddress(process->GetTarget(), sc_list); if (munmap_addr.IsValid()) { lldb::addr_t args[] = {addr, length}; lldb::ThreadPlanSP call_plan_sp(new ThreadPlanCallFunction( `````````` </details> https://github.com/llvm/llvm-project/pull/208998 _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
