d64efe42eb
When `-fixup_chains`/`-init_offsets` is used, a different section, `__init_offsets` is synthesized from `__mod_init_func`. If there are any symbols defined inside `__mod_init_func`, they are added to the symbol table unconditionally while processing the input files. Later, when querying these symbols' addresses (when constructing the symtab or exports trie), we crash with a null deref, as there is no output section assigned to them. Just making the symbols point to `__init_offsets` is a bad idea, as the new section stores 32-bit integers instead of 64-bit pointers; accessing the symbols would not do what the programmer intended. We should entirely omit them from the output. This is what ld64 and ld-prime do. This patch uses the same mechanism as dead-stripping to mark these symbols as not needed in the output. There might be nicer fixes than the workaround, this is discussed in #97155. Fixes https://github.com/llvm/llvm-project/pull/79894#issuecomment-1944092892 Fixes #94716
78 lines
2.6 KiB
ArmAsm
78 lines
2.6 KiB
ArmAsm
# REQUIRES: x86
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# RUN: rm -rf %t; split-file %s %t
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# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/first.s -o %t/first.o
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# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/second.s -o %t/second.o
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# RUN: %lld -lSystem -init_offsets -undefined dynamic_lookup %t/first.o %t/second.o -o %t/out
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# RUN: llvm-otool -lv %t/out | FileCheck --check-prefix=FLAGS --implicit-check-not=__mod_init_func %s
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# RUN: llvm-otool -l %t/out > %t/dump.txt
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# RUN: llvm-objdump --macho --print-imm-hex --section=__TEXT,__stubs %t/out >> %t/dump.txt
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# RUN: llvm-objdump --macho --syms %t/out >> %t/dump.txt
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# RUN: llvm-objcopy --dump-section=__TEXT,__init_offsets=%t/section.bin %t/out
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# RUN: echo "__TEXT,__init_offsets contents:" >> %t/dump.txt
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# RUN: od -An -txI %t/section.bin >> %t/dump.txt
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# RUN: FileCheck --check-prefix=CONTENT --implicit-check-not=_init_ptr %s < %t/dump.txt
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## This test checks that:
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## - __mod_init_func is replaced by __init_offsets.
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## - __mod_init_func has type S_INIT_FUNC_OFFSETS.
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## - initializers show up in the order their parent objects are specified on the
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## command line, and in the order they show up within __mod_init_func.
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## - for undefined and dylib symbols, stubs are created, and the offsets point to those.
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## - offsets are relative to __TEXT's address, they aren't an absolute virtual address.
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## - symbols defined within __mod_init_func are ignored.
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# FLAGS: sectname __init_offsets
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# FLAGS-NEXT: segname __TEXT
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# FLAGS-NEXT: addr
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# FLAGS-NEXT: size 0x0000000000000010
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# FLAGS-NEXT: offset
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# FLAGS-NEXT: align 2^2 (4)
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# FLAGS-NEXT: reloff 0
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# FLAGS-NEXT: nreloc 0
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# FLAGS-NEXT: type S_INIT_FUNC_OFFSETS
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# CONTENT: segname __TEXT
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# CONTENT-NEXT: 0x[[#%x, TEXT:]]
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# CONTENT: Contents of (__TEXT,__stubs) section
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# CONTENT-NEXT: [[#%x, ISNAN:]]: {{.*}} ## literal pool symbol address: ___isnan
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# CONTENT-NEXT: [[#%x, UNDEF:]]: {{.*}} ## literal pool symbol address: _undefined
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# CONTENT: SYMBOL TABLE:
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# CONTENT: [[#%x, FIRST:]] g F __TEXT,__text _first_init
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# CONTENT: [[#%x, SECOND:]] g F __TEXT,__text _second_init
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# CONTENT: __TEXT,__init_offsets contents:
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# CONTENT: [[#%.8x, FIRST - TEXT]] [[#%.8x, ISNAN - TEXT]] [[#%.8x, UNDEF - TEXT]] [[#%.8x, SECOND - TEXT]]
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#--- first.s
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.globl _first_init, ___isnan, _main
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.globl _init_ptr_1
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.text
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_first_init:
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ret
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_main:
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ret
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.section __DATA,__mod_init_func,mod_init_funcs
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_init_ptr_1:
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.quad _first_init
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.quad ___isnan
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.subsections_via_symbols
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#--- second.s
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.globl _second_init, _undefined
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.text
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_second_init:
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ret
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.section __DATA,__mod_init_func,mod_init_funcs
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.quad _undefined
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_init_ptr_2:
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.quad _second_init
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.subsections_via_symbols
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