From 100483b969b816e71cdfadfc591203c77e3e3fc7 Mon Sep 17 00:00:00 2001 From: Pavel Labath Date: Mon, 23 Mar 2020 11:40:25 +0100 Subject: [PATCH] [DWARFDebugLine] Check for (EOF) errors when parsing v5 content descriptors Summary: Without that we could be silently reading zeroes, as that's the default DataExtractor behavior. The entire parse would still most likely fail, but it would do that with a seemingly unrelated/nonsensical error message. Reviewers: dblaikie, probinson, jhenderson Subscribers: hiraditya, MaskRay, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D77554 --- llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp | 14 ++-- .../X86/debug_line_short_prologue.s | 68 +++++++++++++++++++ 2 files changed, 78 insertions(+), 4 deletions(-) create mode 100644 llvm/test/tools/llvm-dwarfdump/X86/debug_line_short_prologue.s diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp index 366f0479c93a..bd1954a73e1d 100644 --- a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp +++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp @@ -219,14 +219,15 @@ parseV2DirFileTables(const DWARFDataExtractor &DebugLineData, static llvm::Expected parseV5EntryFormat(const DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr, DWARFDebugLine::ContentTypeTracker *ContentTypes) { + Error Err = Error::success(); ContentDescriptors Descriptors; - int FormatCount = DebugLineData.getU8(OffsetPtr); + int FormatCount = DebugLineData.getU8(OffsetPtr, &Err); bool HasPath = false; - for (int I = 0; I != FormatCount; ++I) { + for (int I = 0; I != FormatCount && !Err; ++I) { ContentDescriptor Descriptor; Descriptor.Type = - dwarf::LineNumberEntryFormat(DebugLineData.getULEB128(OffsetPtr)); - Descriptor.Form = dwarf::Form(DebugLineData.getULEB128(OffsetPtr)); + dwarf::LineNumberEntryFormat(DebugLineData.getULEB128(OffsetPtr, &Err)); + Descriptor.Form = dwarf::Form(DebugLineData.getULEB128(OffsetPtr, &Err)); if (Descriptor.Type == dwarf::DW_LNCT_path) HasPath = true; if (ContentTypes) @@ -234,6 +235,11 @@ parseV5EntryFormat(const DWARFDataExtractor &DebugLineData, uint64_t *OffsetPtr, Descriptors.push_back(Descriptor); } + if (Err) + return createStringError(errc::invalid_argument, + "failed to parse entry content descriptors: %s", + toString(std::move(Err)).c_str()); + if (!HasPath) return createStringError(errc::invalid_argument, "failed to parse entry content descriptions" diff --git a/llvm/test/tools/llvm-dwarfdump/X86/debug_line_short_prologue.s b/llvm/test/tools/llvm-dwarfdump/X86/debug_line_short_prologue.s new file mode 100644 index 000000000000..0bf4bc90d85d --- /dev/null +++ b/llvm/test/tools/llvm-dwarfdump/X86/debug_line_short_prologue.s @@ -0,0 +1,68 @@ +## Test cases when we run into the end of section while parsing a line table +## prologue. + +# RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj --defsym CASE=0 -o %t0 +# RUN: llvm-dwarfdump -debug-line %t0 2>&1 | FileCheck %s --check-prefixes=ALL,C0 + +# RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj --defsym CASE=1 -o %t1 +# RUN: llvm-dwarfdump -debug-line %t1 2>&1 | FileCheck %s --check-prefixes=ALL,C1 + +# RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj --defsym CASE=2 -o %t2 +# RUN: llvm-dwarfdump -debug-line %t2 2>&1 | FileCheck %s --check-prefixes=ALL,C2 + +# RUN: llvm-mc -triple x86_64-pc-linux %s -filetype=obj --defsym CASE=3 -o %t3 +# RUN: llvm-dwarfdump -debug-line %t3 2>&1 | FileCheck %s --check-prefixes=ALL,OK + +# ALL: debug_line[0x00000000] +# C0-NEXT: warning: parsing line table prologue at 0x00000000 found an invalid directory or file table description at 0x00000027 +# C0-NEXT: warning: failed to parse entry content descriptors: unexpected end of data at offset 0x27 +# C1-NEXT: warning: parsing line table prologue at 0x00000000 found an invalid directory or file table description at 0x0000002a +# C1-NEXT: warning: failed to parse entry content descriptors: malformed uleb128, extends past end +# C2-NEXT: warning: parsing line table prologue at 0x00000000 found an invalid directory or file table description at 0x0000002b +# C2-NEXT: warning: failed to parse entry content descriptors: malformed uleb128, extends past end +# ALL: include_directories[ 0] = "/tmp" +# OK: file_names[ 0]: +# OK-NEXT: name: "foo" +# OK-NEXT: dir_index: 0 + +.section .debug_line,"",@progbits +.long .Lend-.Lstart # Length of Unit +.Lstart: +.short 5 # DWARF version number +.byte 8 # Address Size +.byte 0 # Segment Selector Size +.long .Lprologue_end-.Lprologue_start # Length of Prologue +.Lprologue_start: +.byte 1 # Minimum Instruction Length +.byte 1 # Maximum Operations per Instruction +.byte 1 # Default is_stmt +.byte -5 # Line Base +.byte 14 # Line Range +.byte 13 # Opcode Base +.byte 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1 # Standard Opcode Lengths +# Directory table format +.byte 1 # One element per directory entry +.byte 1 # DW_LNCT_path +.byte 0x08 # DW_FORM_string +# Directory table entries +.byte 1 # 1 directory +.asciz "/tmp" +# File table format +.if CASE >= 1 +.byte 2 # 2 elements per file entry +.byte 1 # DW_LNCT_path +.byte 8 # DW_FORM_string +.if CASE >= 2 +.byte 2 # DW_LNCT_directory_index +.if CASE >= 3 +.byte 11 # DW_FORM_data1 +# File table entries +.byte 1 +.asciz "foo" +.byte 0 +.endif +.endif +.endif + +.Lprologue_end: +.Lend: