Author: Jez Ng Date: 2020-12-15T15:58:26-05:00 New Revision: 31845199094418173a3beadb786767b860bfda03
URL: https://github.com/llvm/llvm-project/commit/31845199094418173a3beadb786767b860bfda03 DIFF: https://github.com/llvm/llvm-project/commit/31845199094418173a3beadb786767b860bfda03.diff LOG: [lld-macho] Don't emit rebase opcodes for relocs in TLV sections Their addresses are already encoded as section-relative offsets, so there's no need to rebase them at runtime. {D85080} has some context on the weirdness of TLV sections. Fixes llvm.org/PR48491. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D93257 Added: Modified: lld/MachO/Arch/X86_64.cpp lld/test/MachO/tlv-dylib.s lld/test/MachO/tlv.s Removed: ################################################################################ diff --git a/lld/MachO/Arch/X86_64.cpp b/lld/MachO/Arch/X86_64.cpp index 7f4024cc998dd..c776e21d6f5f5 100644 --- a/lld/MachO/Arch/X86_64.cpp +++ b/lld/MachO/Arch/X86_64.cpp @@ -248,7 +248,11 @@ void X86_64::prepareSymbolRelocation(lld::macho::Symbol *sym, return; } } - addNonLazyBindingEntries(sym, isec, r.offset, r.addend); + // References from thread-local variable sections are treated as offsets + // relative to the start of the referent section, and therefore have no + // need of rebase opcodes. + if (!(isThreadLocalVariables(isec->flags) && isa<Defined>(sym))) + addNonLazyBindingEntries(sym, isec, r.offset, r.addend); break; } case X86_64_RELOC_SIGNED: diff --git a/lld/test/MachO/tlv-dylib.s b/lld/test/MachO/tlv-dylib.s index c6f9b9add3a0a..74e27e9e24d1b 100644 --- a/lld/test/MachO/tlv-dylib.s +++ b/lld/test/MachO/tlv-dylib.s @@ -4,9 +4,14 @@ # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/libtlv.s -o %t/libtlv.o # RUN: %lld -dylib -install_name @executable_path/libtlv.dylib \ # RUN: -lSystem -o %t/libtlv.dylib %t/libtlv.o -# RUN: llvm-objdump --exports-trie -d --no-show-raw-insn %t/libtlv.dylib | FileCheck %s --check-prefix=DYLIB +# RUN: llvm-objdump --macho --exports-trie --rebase %t/libtlv.dylib | \ +# RUN: FileCheck %s --check-prefix=DYLIB # DYLIB-DAG: _foo [per-thread] # DYLIB-DAG: _bar [per-thread] +## Make sure we don't emit rebase opcodes for relocations in __thread_vars. +# DYLIB: Rebase table: +# DYLIB-NEXT: segment section address type +# DYLIB-EMPTY: # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/test.s -o %t/test.o # RUN: %lld -lSystem -L%t -ltlv %t/test.o -o %t/test diff --git a/lld/test/MachO/tlv.s b/lld/test/MachO/tlv.s index bf0dfcd02b565..d8d0a950d794c 100644 --- a/lld/test/MachO/tlv.s +++ b/lld/test/MachO/tlv.s @@ -1,9 +1,14 @@ # REQUIRES: x86 # RUN: mkdir -p %t # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t/test.o + # RUN: %lld -lSystem -o %t/test %t/test.o # RUN: llvm-readobj --file-headers %t/test | FileCheck %s --check-prefix=HEADER -# RUN: llvm-objdump -D %t/test | FileCheck %s +# RUN: llvm-objdump -D --bind --rebase %t/test | FileCheck %s + +# RUN: %lld -lSystem -pie -o %t/test %t/test.o +# RUN: llvm-readobj --file-headers %t/test | FileCheck %s --check-prefix=HEADER +# RUN: llvm-objdump -D --bind --rebase %t/test | FileCheck %s # HEADER: MH_HAS_TLV_DESCRIPTORS @@ -36,6 +41,13 @@ # CHECK-NEXT: 00 00 # CHECK-NEXT: 00 00 +## Make sure we don't emit rebase opcodes for relocations in __thread_vars. +# CHECK: Rebase table: +# CHECK-NEXT: segment section address type +# CHECK-NEXT: Bind table: +# CHECK: __DATA __thread_vars 0x{{[0-9a-f]*}} pointer 0 libSystem __tlv_bootstrap +# CHECK: __DATA __thread_vars 0x{{[0-9a-f]*}} pointer 0 libSystem __tlv_bootstrap + .globl _main _main: mov _foo@TLVP(%rip), %rax _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
