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Detect more ELF symbol kinds (#498)
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This makes 2 changes to `SymbolKind` detection:
- `STT_NOTYPE` is detected as a label, since that's the default type
given to a label in assembly code. This is also used for mapping symbols
that are inserted by the assembler to indicate which addresses contain
code or data.
- `STT_GNU_IFUNC` is detected as a function symbol.
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@Amanieu
Amanieu committed Jan 4, 2023
1 parent d4482ec commit 4c05d01
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Showing 3 changed files with 18 additions and 17 deletions.
4 changes: 2 additions & 2 deletions crates/examples/testfiles/elf/base.o.objdump
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Expand Up @@ -29,8 +29,8 @@ Symbols
7: Symbol { name: "", address: 0, size: 0, kind: Section, section: Section(SectionIndex(8)), scope: Compilation, weak: false, flags: Elf { st_info: 3, st_other: 0 } }
8: Symbol { name: "", address: 0, size: 0, kind: Section, section: Section(SectionIndex(6)), scope: Compilation, weak: false, flags: Elf { st_info: 3, st_other: 0 } }
9: Symbol { name: "main", address: 0, size: 1c, kind: Text, section: Section(SectionIndex(1)), scope: Dynamic, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
10: Symbol { name: "_GLOBAL_OFFSET_TABLE_", address: 0, size: 0, kind: Unknown, section: Undefined, scope: Unknown, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
11: Symbol { name: "printf", address: 0, size: 0, kind: Unknown, section: Undefined, scope: Unknown, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
10: Symbol { name: "_GLOBAL_OFFSET_TABLE_", address: 0, size: 0, kind: Label, section: Undefined, scope: Unknown, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
11: Symbol { name: "printf", address: 0, size: 0, kind: Label, section: Undefined, scope: Unknown, weak: false, flags: Elf { st_info: 10, st_other: 0 } }

.text relocations
(7, Relocation { kind: Relative, encoding: Generic, size: 20, target: Symbol(SymbolIndex(5)), addend: fffffffffffffffc, implicit_addend: false })
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28 changes: 14 additions & 14 deletions crates/examples/testfiles/elf/base.objdump
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Expand Up @@ -78,39 +78,39 @@ Symbols
36: Symbol { name: "crtstuff.c", address: 0, size: 0, kind: File, section: None, scope: Compilation, weak: false, flags: Elf { st_info: 4, st_other: 0 } }
37: Symbol { name: "__FRAME_END__", address: 874, size: 0, kind: Data, section: Section(SectionIndex(13)), scope: Compilation, weak: false, flags: Elf { st_info: 1, st_other: 0 } }
38: Symbol { name: "", address: 0, size: 0, kind: File, section: None, scope: Compilation, weak: false, flags: Elf { st_info: 4, st_other: 0 } }
39: Symbol { name: "__init_array_end", address: 200db0, size: 0, kind: Unknown, section: Section(SectionIndex(14)), scope: Compilation, weak: false, flags: Elf { st_info: 0, st_other: 0 } }
39: Symbol { name: "__init_array_end", address: 200db0, size: 0, kind: Label, section: Section(SectionIndex(14)), scope: Compilation, weak: false, flags: Elf { st_info: 0, st_other: 0 } }
40: Symbol { name: "_DYNAMIC", address: 200db8, size: 0, kind: Data, section: Section(SectionIndex(16)), scope: Compilation, weak: false, flags: Elf { st_info: 1, st_other: 0 } }
41: Symbol { name: "__init_array_start", address: 200da8, size: 0, kind: Unknown, section: Section(SectionIndex(14)), scope: Compilation, weak: false, flags: Elf { st_info: 0, st_other: 0 } }
42: Symbol { name: "__GNU_EH_FRAME_HDR", address: 734, size: 0, kind: Unknown, section: Section(SectionIndex(12)), scope: Compilation, weak: false, flags: Elf { st_info: 0, st_other: 0 } }
41: Symbol { name: "__init_array_start", address: 200da8, size: 0, kind: Label, section: Section(SectionIndex(14)), scope: Compilation, weak: false, flags: Elf { st_info: 0, st_other: 0 } }
42: Symbol { name: "__GNU_EH_FRAME_HDR", address: 734, size: 0, kind: Label, section: Section(SectionIndex(12)), scope: Compilation, weak: false, flags: Elf { st_info: 0, st_other: 0 } }
43: Symbol { name: "_GLOBAL_OFFSET_TABLE_", address: 200fb8, size: 0, kind: Data, section: Section(SectionIndex(17)), scope: Compilation, weak: false, flags: Elf { st_info: 1, st_other: 0 } }
44: Symbol { name: "__libc_csu_fini", address: 710, size: 2, kind: Text, section: Section(SectionIndex(f)), scope: Dynamic, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
45: Symbol { name: "_ITM_deregisterTMCloneTable", address: 0, size: 0, kind: Unknown, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
46: Symbol { name: "data_start", address: 201000, size: 0, kind: Unknown, section: Section(SectionIndex(18)), scope: Dynamic, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
47: Symbol { name: "_edata", address: 201010, size: 0, kind: Unknown, section: Section(SectionIndex(18)), scope: Dynamic, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
45: Symbol { name: "_ITM_deregisterTMCloneTable", address: 0, size: 0, kind: Label, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
46: Symbol { name: "data_start", address: 201000, size: 0, kind: Label, section: Section(SectionIndex(18)), scope: Dynamic, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
47: Symbol { name: "_edata", address: 201010, size: 0, kind: Label, section: Section(SectionIndex(18)), scope: Dynamic, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
48: Symbol { name: "_fini", address: 714, size: 0, kind: Text, section: Section(SectionIndex(10)), scope: Dynamic, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
49: Symbol { name: "printf@@GLIBC_2.2.5", address: 0, size: 0, kind: Text, section: Undefined, scope: Unknown, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
50: Symbol { name: "__libc_start_main@@GLIBC_2.2.5", address: 0, size: 0, kind: Text, section: Undefined, scope: Unknown, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
51: Symbol { name: "__data_start", address: 201000, size: 0, kind: Unknown, section: Section(SectionIndex(18)), scope: Dynamic, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
52: Symbol { name: "__gmon_start__", address: 0, size: 0, kind: Unknown, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
51: Symbol { name: "__data_start", address: 201000, size: 0, kind: Label, section: Section(SectionIndex(18)), scope: Dynamic, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
52: Symbol { name: "__gmon_start__", address: 0, size: 0, kind: Label, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
53: Symbol { name: "__dso_handle", address: 201008, size: 0, kind: Data, section: Section(SectionIndex(18)), scope: Linkage, weak: false, flags: Elf { st_info: 11, st_other: 2 } }
54: Symbol { name: "_IO_stdin_used", address: 720, size: 4, kind: Data, section: Section(SectionIndex(11)), scope: Dynamic, weak: false, flags: Elf { st_info: 11, st_other: 0 } }
55: Symbol { name: "__libc_csu_init", address: 6a0, size: 65, kind: Text, section: Section(SectionIndex(f)), scope: Dynamic, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
56: Symbol { name: "_end", address: 201018, size: 0, kind: Unknown, section: Section(SectionIndex(19)), scope: Dynamic, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
56: Symbol { name: "_end", address: 201018, size: 0, kind: Label, section: Section(SectionIndex(19)), scope: Dynamic, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
57: Symbol { name: "_start", address: 570, size: 2b, kind: Text, section: Section(SectionIndex(f)), scope: Dynamic, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
58: Symbol { name: "__bss_start", address: 201010, size: 0, kind: Unknown, section: Section(SectionIndex(19)), scope: Dynamic, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
58: Symbol { name: "__bss_start", address: 201010, size: 0, kind: Label, section: Section(SectionIndex(19)), scope: Dynamic, weak: false, flags: Elf { st_info: 10, st_other: 0 } }
59: Symbol { name: "main", address: 67a, size: 1c, kind: Text, section: Section(SectionIndex(f)), scope: Dynamic, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
60: Symbol { name: "__TMC_END__", address: 201010, size: 0, kind: Data, section: Section(SectionIndex(18)), scope: Linkage, weak: false, flags: Elf { st_info: 11, st_other: 2 } }
61: Symbol { name: "_ITM_registerTMCloneTable", address: 0, size: 0, kind: Unknown, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
61: Symbol { name: "_ITM_registerTMCloneTable", address: 0, size: 0, kind: Label, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
62: Symbol { name: "__cxa_finalize@@GLIBC_2.2.5", address: 0, size: 0, kind: Text, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 22, st_other: 0 } }
63: Symbol { name: "_init", address: 520, size: 0, kind: Text, section: Section(SectionIndex(c)), scope: Dynamic, weak: false, flags: Elf { st_info: 12, st_other: 0 } }

Dynamic symbols
0: Symbol { name: "", address: 0, size: 0, kind: Null, section: Undefined, scope: Unknown, weak: false, flags: Elf { st_info: 0, st_other: 0 } }
1: Symbol { name: "_ITM_deregisterTMCloneTable", address: 0, size: 0, kind: Unknown, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
1: Symbol { name: "_ITM_deregisterTMCloneTable", address: 0, size: 0, kind: Label, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
2: Symbol { name: "printf", address: 0, size: 0, kind: Text, section: Undefined, scope: Unknown, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
3: Symbol { name: "__libc_start_main", address: 0, size: 0, kind: Text, section: Undefined, scope: Unknown, weak: false, flags: Elf { st_info: 12, st_other: 0 } }
4: Symbol { name: "__gmon_start__", address: 0, size: 0, kind: Unknown, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
5: Symbol { name: "_ITM_registerTMCloneTable", address: 0, size: 0, kind: Unknown, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
4: Symbol { name: "__gmon_start__", address: 0, size: 0, kind: Label, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
5: Symbol { name: "_ITM_registerTMCloneTable", address: 0, size: 0, kind: Label, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 20, st_other: 0 } }
6: Symbol { name: "__cxa_finalize", address: 0, size: 0, kind: Text, section: Undefined, scope: Unknown, weak: true, flags: Elf { st_info: 22, st_other: 0 } }

Dynamic relocations
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3 changes: 2 additions & 1 deletion src/read/elf/symbol.rs
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Expand Up @@ -349,8 +349,9 @@ impl<'data, 'file, Elf: FileHeader, R: ReadRef<'data>> ObjectSymbol<'data>
fn kind(&self) -> SymbolKind {
match self.symbol.st_type() {
elf::STT_NOTYPE if self.index.0 == 0 => SymbolKind::Null,
elf::STT_NOTYPE => SymbolKind::Label,
elf::STT_OBJECT | elf::STT_COMMON => SymbolKind::Data,
elf::STT_FUNC => SymbolKind::Text,
elf::STT_FUNC | elf::STT_GNU_IFUNC => SymbolKind::Text,
elf::STT_SECTION => SymbolKind::Section,
elf::STT_FILE => SymbolKind::File,
elf::STT_TLS => SymbolKind::Tls,
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