https://github.com/simpal01 updated https://github.com/llvm/llvm-project/pull/65966:
>From 7cd4fe122a329d29023f978991baa486266a32f3 Mon Sep 17 00:00:00 2001 From: Simi Pallipurath <simi.pallipur...@arm.com> Date: Mon, 11 Sep 2023 14:42:27 +0100 Subject: [PATCH 1/2] [LLD][AARCH64] lld incorrectly handles .eh_frame when it has a non-zero offset within its output section. When the .eh_frame section is placed at a non-zero offset within its output section, the relocation value within .eh_frame are computed incorrectly. We had similar issue in AArch32 and it has been fixed already in https://reviews.llvm.org/D148033. While applying the relocation using S+A-P, the value of P (the location of the relocation) is getting wrong. P is: P = SecAddr + rel.offset, But SecAddr points to the starting address of the outputsection rather than the starting address of the eh frame section within that output section. --- lld/ELF/Arch/AArch64.cpp | 3 ++ lld/test/ELF/eh-frame-nonzero-offset.s | 55 ++++++++++++++++++++++++++ 2 files changed, 58 insertions(+) create mode 100644 lld/test/ELF/eh-frame-nonzero-offset.s diff --git a/lld/ELF/Arch/AArch64.cpp b/lld/ELF/Arch/AArch64.cpp index 174a0a3624f7765..fd0ef28737042b4 100644 --- a/lld/ELF/Arch/AArch64.cpp +++ b/lld/ELF/Arch/AArch64.cpp @@ -1081,3 +1081,6 @@ void lld::elf::createTaggedSymbols(const SmallVector<ELFFileBase *, 0> &files) { symbol->setIsTagged(true); } } + else if (auto *eh = dyn_cast<EhInputSection>(&sec)) + if (InputSection *isec = eh->getParent()) + secAddr += isec->outSecOff; diff --git a/lld/test/ELF/eh-frame-nonzero-offset.s b/lld/test/ELF/eh-frame-nonzero-offset.s new file mode 100644 index 000000000000000..ef086fcf670d81b --- /dev/null +++ b/lld/test/ELF/eh-frame-nonzero-offset.s @@ -0,0 +1,55 @@ +// REQUIRES: aarch64 +// RUN: rm -rf %t && split-file %s %t + +// RUN: llvm-mc -filetype=obj -triple=aarch64 %t/a.s -o %t/a.o +// RUN: ld.lld %t/a.o -T %t/eh-frame-non-zero-offset.t -o %t/non-zero +// RUN: llvm-readelf --program-headers --unwind --symbols -x .eh_frame %t/non-zero | FileCheck --check-prefix=NONZERO %s +// RUN: ld.lld %t/a.o -T %t/eh-frame-zero-offset.t -o %t/zero +// RUN: llvm-readelf --program-headers --unwind --symbols -x .eh_frame %t/zero | FileCheck --check-prefix=ZERO %s + +// NONZERO: {{[0-9]+}}: 0000000000000080 {{.*}} __eh_frame_start +// NONZERO-NEXT: {{[0-9]+}}: 00000000000000ac {{.*}} __eh_frame_end + +// NONZERO: 0x00000078 00000000 00000000 10000000 00000000 +// NONZERO-NEXT: 0x00000088 017a5200 017c1e01 1b0c1f00 10000000 +// NONZERO-NEXT: 0x00000098 18000000 64ffffff 08000000 00000000 +// NONZERO-NEXT: 0x000000a8 00000000 + +// ZERO: {{[0-9]+}}: 0000000000000080 {{.*}} __eh_frame_start +// ZERO-NEXT: {{[0-9]+}}: 00000000000000ac {{.*}} __eh_frame_end + +// ZERO: 0x00000080 10000000 00000000 017a5200 017c1e01 +// ZERO-NEXT: 0x00000090 1b0c1f00 10000000 18000000 64ffffff +// ZERO-NEXT: 0x000000a0 08000000 00000000 00000000 + +//--- eh-frame-non-zero-offset.t +SECTIONS { + .text : { *(.text .text.*) } + .eh_frame : { + /* Alignment padding within .eh_frame */ + . = ALIGN(128); + __eh_frame_start = .; + *(.eh_frame .eh_frame.*) ; + __eh_frame_end = .; + } +} + +//--- eh-frame-zero-offset.t +SECTIONS { + .text : { *(.text .text.*) } + .eh_frame : ALIGN(128) { + __eh_frame_start = .; + *(.eh_frame .eh_frame.*) ; + __eh_frame_end = .; + } +} + +//--- a.s +.section .text.01, "ax",%progbits +.global f1 +.type f1, %function +f1: +.cfi_startproc + nop + nop +.cfi_endproc >From 31e116847f013c2c9301bb1868fa7a10af9bdf8b Mon Sep 17 00:00:00 2001 From: Simi Pallipurath <simi.pallipur...@arm.com> Date: Mon, 11 Sep 2023 14:42:27 +0100 Subject: [PATCH 2/2] [LLD][AARCH64] lld incorrectly handles .eh_frame when it has a non-zero offset within its output section. When the .eh_frame section is placed at a non-zero offset within its output section, the relocation value within .eh_frame are computed incorrectly. We had similar issue in AArch32 and it has been fixed already in https://reviews.llvm.org/D148033. While applying the relocation using S+A-P, the value of P (the location of the relocation) is getting wrong. P is: P = SecAddr + rel.offset, But SecAddr points to the starting address of the outputsection rather than the starting address of the eh frame section within that output section. --- lld/ELF/Arch/AArch64.cpp | 3 +++ 1 file changed, 3 insertions(+) diff --git a/lld/ELF/Arch/AArch64.cpp b/lld/ELF/Arch/AArch64.cpp index fd0ef28737042b4..411c0a046bd7c58 100644 --- a/lld/ELF/Arch/AArch64.cpp +++ b/lld/ELF/Arch/AArch64.cpp @@ -770,6 +770,9 @@ void AArch64::relocateAlloc(InputSectionBase &sec, uint8_t *buf) const { uint64_t secAddr = sec.getOutputSection()->addr; if (auto *s = dyn_cast<InputSection>(&sec)) secAddr += s->outSecOff; + else if (auto *eh = dyn_cast<EhInputSection>(&sec)) + if (InputSection *isec = eh->getParent()) + secAddr += isec->outSecOff; AArch64Relaxer relaxer(sec.relocs()); for (size_t i = 0, size = sec.relocs().size(); i != size; ++i) { const Relocation &rel = sec.relocs()[i]; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
