c49f83b6e9
removeEmptyPTLoad() removes empty (p_memsz=0) PT_LOAD segments. In assignFileOffsets(), setFileOffset() unnecessarily advances file offsets for containing empty sections. This is exposed by arm Linux kernel's multi_v5_defconfig (see https://bugs.llvm.org/show_bug.cgi?id=45632) ``` ld.lld (max-page-size=65536): [34] .init.data PROGBITS c0c24000 c34000 0128ac 00 WA 0 0 4096 [35] .text_itcm PROGBITS fffe0000 c50000 000000 00 WA 0 0 1 [36] .data_dtcm PROGBITS fffe8000 c58000 000000 00 WA 0 0 1 [37] .data PROGBITS c0c38000 c58000 0647a0 00 WA 0 0 32 arm-linux-gnueabi-ld (max-page-size=65536): [23] .init.data PROGBITS c0c12000 c22000 0128ac 00 WA 0 0 4096 [24] .text_itcm PROGBITS fffe0000 ca2558 000000 00 W 0 0 1 [25] .data_dtcm PROGBITS fffe8000 ca2558 000000 00 W 0 0 1 [26] .data PROGBITS c0c26000 c36000 0647a0 00 WA 0 0 32 ``` This patch clears OutputSection::ptLoad if ptLoad is removed by removeEmptyPTLoad(). Conceptually this removes "dangling" references. Reviewed By: psmith Differential Revision: https://reviews.llvm.org/D79254
31 lines
1.1 KiB
Plaintext
31 lines
1.1 KiB
Plaintext
# REQUIRES: x86
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# RUN: echo ".text; nop; .data; .byte 0" \
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# RUN: | llvm-mc -filetype=obj -triple=x86_64-pc-linux - -o %t.o
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# RUN: ld.lld -o %t --script %s %t.o
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# RUN: llvm-readelf -S -l %t | FileCheck %s
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## Check we do not remove the empty output sections used in LOADADDR/ADDR
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## expressions and hence can evaluate the correct addresses.
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# CHECK: Name Type Address Off Size
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# CHECK-NEXT: NULL 0000000000000000 000000 000000
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# CHECK-NEXT: .empty PROGBITS 0000000000080000 000158 000000
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# CHECK-NEXT: .text PROGBITS 0000000000080000 001000 000001
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# CHECK-NEXT: .data PROGBITS 0000000000080001 001001 000001
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# CHECK: Program Headers:
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# CHECK-NEXT: Type Offset VirtAddr PhysAddr
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# CHECK-NEXT: LOAD 0x001000 0x0000000000080000 0x0000000000080000
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# CHECK-NEXT: LOAD 0x001001 0x0000000000080001 0x0000000000082000
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# CHECK: Section to Segment mapping:
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# CHECK: 00 .text {{$}}
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# CHECK-NEXT: 01 .data {{$}}
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SECTIONS {
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. = 0x00080000;
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.empty : { *(.empty ) }
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.text : AT(LOADADDR(.empty) + SIZEOF(.empty)) { *(.text) }
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.data : AT(ADDR(.empty) + 0x2000) { *(.data) }
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}
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