From bf7225888a99f49afac0b95a8996d0a942b6b0e3 Mon Sep 17 00:00:00 2001 From: Jan Kratochvil Date: Mon, 13 Jan 2020 12:03:14 +0100 Subject: [PATCH] [lldb] Fix lookup of symbols with the same address range but different binding This fixes a failing testcase on Fedora 30 x86_64 (regression Fedora 29->30): PASS: ./bin/lldb ./lldb-test-build.noindex/functionalities/unwind/noreturn/TestNoreturnUnwind.test_dwarf/a.out -o 'settings set symbols.enable-external-lookup false' -o r -o bt -o quit * frame #0: 0x00007ffff7aa6e75 libc.so.6`__GI_raise + 325 frame #1: 0x00007ffff7a91895 libc.so.6`__GI_abort + 295 frame #2: 0x0000000000401140 a.out`func_c at main.c:12:2 frame #3: 0x000000000040113a a.out`func_b at main.c:18:2 frame #4: 0x0000000000401134 a.out`func_a at main.c:26:2 frame #5: 0x000000000040112e a.out`main(argc=, argv=) at main.c:32:2 frame #6: 0x00007ffff7a92f33 libc.so.6`__libc_start_main + 243 frame #7: 0x000000000040106e a.out`_start + 46 vs. FAIL - unrecognized abort() function: ./bin/lldb ./lldb-test-build.noindex/functionalities/unwind/noreturn/TestNoreturnUnwind.test_dwarf/a.out -o 'settings set symbols.enable-external-lookup false' -o r -o bt -o quit * frame #0: 0x00007ffff7aa6e75 libc.so.6`.annobin_raise.c + 325 frame #1: 0x00007ffff7a91895 libc.so.6`.annobin_loadmsgcat.c_end.unlikely + 295 frame #2: 0x0000000000401140 a.out`func_c at main.c:12:2 frame #3: 0x000000000040113a a.out`func_b at main.c:18:2 frame #4: 0x0000000000401134 a.out`func_a at main.c:26:2 frame #5: 0x000000000040112e a.out`main(argc=, argv=) at main.c:32:2 frame #6: 0x00007ffff7a92f33 libc.so.6`.annobin_libc_start.c + 243 frame #7: 0x000000000040106e a.out`.annobin_init.c.hot + 46 The extra ELF symbols are there due to Annobin (I did not investigate why this problem happened specifically since F-30 and not since F-28). It is due to: Symbol table '.dynsym' contains 2361 entries: Valu e Size Type Bind Vis Name 0000000000022769 5 FUNC LOCAL DEFAULT _nl_load_domain.cold 000000000002276e 0 NOTYPE LOCAL HIDDEN .annobin_abort.c.unlikely ... 000000000002276e 0 NOTYPE LOCAL HIDDEN .annobin_loadmsgcat.c_end.unlikely ... 000000000002276e 0 NOTYPE LOCAL HIDDEN .annobin_textdomain.c_end.unlikely 000000000002276e 548 FUNC GLOBAL DEFAULT abort 000000000002276e 548 FUNC GLOBAL DEFAULT abort@@GLIBC_2.2.5 000000000002276e 548 FUNC LOCAL DEFAULT __GI_abort 0000000000022992 0 NOTYPE LOCAL HIDDEN .annobin_abort.c_end.unlikely GDB has some more complicated preferences between overlapping and/or sharing address symbols, I have made here so far the most simple fix for this case. Differential revision: https://reviews.llvm.org/D63540 --- lldb/include/lldb/Symbol/Symtab.h | 24 ++++++++++++++++++- .../Plugins/ObjectFile/ELF/ObjectFileELF.cpp | 2 ++ lldb/source/Symbol/Symtab.cpp | 2 +- .../Shell/SymbolFile/Inputs/symbol-binding.s | 22 +++++++++++++++++ .../test/Shell/SymbolFile/symbol-binding.test | 22 +++++++++++++++++ 5 files changed, 70 insertions(+), 2 deletions(-) create mode 100644 lldb/test/Shell/SymbolFile/Inputs/symbol-binding.s create mode 100644 lldb/test/Shell/SymbolFile/symbol-binding.test diff --git a/lldb/include/lldb/Symbol/Symtab.h b/lldb/include/lldb/Symbol/Symtab.h index e42261ef11da55..f121bef1bfbe41 100644 --- a/lldb/include/lldb/Symbol/Symtab.h +++ b/lldb/include/lldb/Symbol/Symtab.h @@ -143,7 +143,29 @@ class Symtab { typedef std::vector collection; typedef collection::iterator iterator; typedef collection::const_iterator const_iterator; - typedef RangeDataVector + class FileRangeToIndexMapCompare { + public: + FileRangeToIndexMapCompare(const Symtab &symtab) : m_symtab(symtab) {} + bool operator()(const uint32_t a_data, const uint32_t b_data) const { + return rank(a_data) > rank(b_data); + } + + private: + // How much preferred is this symbol? + int rank(const uint32_t data) const { + const Symbol &symbol = *m_symtab.SymbolAtIndex(data); + if (symbol.IsExternal()) + return 3; + if (symbol.IsWeak()) + return 2; + if (symbol.IsDebug()) + return 0; + return 1; + } + const Symtab &m_symtab; + }; + typedef RangeDataVector FileRangeToIndexMap; void InitNameIndexes(); void InitAddressIndexes(); diff --git a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp index 8eadaf1323d555..893d294c0faed7 100644 --- a/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp +++ b/lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp @@ -2258,6 +2258,8 @@ unsigned ObjectFileELF::ParseSymbols(Symtab *symtab, user_id_t start_id, symbol_size_valid, // Symbol size is valid has_suffix, // Contains linker annotations? flags); // Symbol flags. + if (symbol.getBinding() == STB_WEAK) + dc_symbol.SetIsWeak(true); symtab->AddSymbol(dc_symbol); } return i; diff --git a/lldb/source/Symbol/Symtab.cpp b/lldb/source/Symbol/Symtab.cpp index c7a6bf2145267b..f5bd22ee5ee275 100644 --- a/lldb/source/Symbol/Symtab.cpp +++ b/lldb/source/Symbol/Symtab.cpp @@ -28,7 +28,7 @@ using namespace lldb; using namespace lldb_private; Symtab::Symtab(ObjectFile *objfile) - : m_objfile(objfile), m_symbols(), m_file_addr_to_index(), + : m_objfile(objfile), m_symbols(), m_file_addr_to_index(*this), m_name_to_index(), m_mutex(), m_file_addr_to_index_computed(false), m_name_indexes_computed(false) {} diff --git a/lldb/test/Shell/SymbolFile/Inputs/symbol-binding.s b/lldb/test/Shell/SymbolFile/Inputs/symbol-binding.s new file mode 100644 index 00000000000000..b7976849241fa9 --- /dev/null +++ b/lldb/test/Shell/SymbolFile/Inputs/symbol-binding.s @@ -0,0 +1,22 @@ + .text + .byte 0 +sizeless: +sizeful: + .byte 0 + .byte 0 +sizeend: + .size sizeful, sizeend - sizeful + .byte 0 +case1_local: +case1_global: + .globl case1_global + .byte 0 +case2_local: +case2_weak: + .weak case2_weak + .byte 0 +case3_weak: + .weak case3_weak +case3_global: + .globl case3_global + .byte 0 diff --git a/lldb/test/Shell/SymbolFile/symbol-binding.test b/lldb/test/Shell/SymbolFile/symbol-binding.test new file mode 100644 index 00000000000000..ce8a5af4c880fd --- /dev/null +++ b/lldb/test/Shell/SymbolFile/symbol-binding.test @@ -0,0 +1,22 @@ +# Some targets do not have the .size directive. +# RUN: %clang -target x86_64-unknown-unknown-elf %S/Inputs/symbol-binding.s -c -o %t.o +# RUN: %lldb %t.o -s %s -o quit | FileCheck %s + +image lookup --address 4 +# CHECK: Summary: symbol-binding.test.tmp.o`case1_global +image lookup --address 5 +# CHECK: Summary: symbol-binding.test.tmp.o`case2_weak +image lookup --address 6 +# CHECK: Summary: symbol-binding.test.tmp.o`case3_global +image dump symtab +# CHECK: Index UserID DSX Type File Address/Value Load Address Size Flags Name +# CHECK-NEXT:------- ------ --- --------------- ------------------ ------------------ ------------------ ---------- ---------------------------------- +# CHECK-NEXT:[ 0] 1 Code 0x0000000000000004 0x0000000000000001 0x00000000 case1_local +# CHECK-NEXT:[ 1] 2 Code 0x0000000000000005 0x0000000000000001 0x00000000 case2_local +# CHECK-NEXT:[ 2] 3 Code 0x0000000000000003 0x0000000000000001 0x00000000 sizeend +# CHECK-NEXT:[ 3] 4 Code 0x0000000000000001 0x0000000000000002 0x00000000 sizeful +# CHECK-NEXT:[ 4] 5 Code 0x0000000000000001 0x0000000000000002 0x00000000 sizeless +# CHECK-NEXT:[ 5] 6 X Code 0x0000000000000004 0x0000000000000001 0x00000010 case1_global +# CHECK-NEXT:[ 6] 7 Code 0x0000000000000005 0x0000000000000001 0x00000020 case2_weak +# CHECK-NEXT:[ 7] 8 X Code 0x0000000000000006 0x0000000000000001 0x00000010 case3_global +# CHECK-NEXT:[ 8] 9 Code 0x0000000000000006 0x0000000000000001 0x00000020 case3_weak