Author: James Henderson Date: 2019-11-07T17:42:06-08:00 New Revision: 2c69f98463a2cae9ea1f42285f6ac89b02dc8ec9
URL: https://github.com/llvm/llvm-project/commit/2c69f98463a2cae9ea1f42285f6ac89b02dc8ec9 DIFF: https://github.com/llvm/llvm-project/commit/2c69f98463a2cae9ea1f42285f6ac89b02dc8ec9.diff LOG: [llvm-objcopy] Preserve .ARM.attributes section when stripping files This works around a bug in Debian's patchset for glibc. The bug is described in detail in the upstream debian bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=943798, but the short version of it is that glibc on any Debian based distro don't load libraries unless it has a .ARM.attribute section. Reviewed by: jhenderson, rupprecht, MaskRay, jakehehrlich Differential Revision: https://reviews.llvm.org/D69188 Patch by Tobias Hieta. (cherry picked from commit fb4a55010ee9bd03720609c8542f770775576fc8) Added: llvm/test/tools/llvm-objcopy/ELF/strip-preserve-arm-attributes.test Modified: llvm/docs/CommandGuide/llvm-objcopy.rst llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp llvm/tools/llvm-objcopy/ObjcopyOpts.td llvm/tools/llvm-objcopy/StripOpts.td Removed: ################################################################################ diff --git a/llvm/docs/CommandGuide/llvm-objcopy.rst b/llvm/docs/CommandGuide/llvm-objcopy.rst index e113a82b6eea..bc589ae188fd 100644 --- a/llvm/docs/CommandGuide/llvm-objcopy.rst +++ b/llvm/docs/CommandGuide/llvm-objcopy.rst @@ -79,7 +79,8 @@ multiple file formats. .. option:: --strip-all, -S For ELF objects, remove from the output all symbols and non-alloc sections not - within segments, except for .gnu.warning sections and the section name table. + within segments, except for .gnu.warning, .ARM.attribute sections and the + section name table. For COFF objects, remove all symbols, debug sections, and relocations from the output. diff --git a/llvm/test/tools/llvm-objcopy/ELF/strip-preserve-arm-attributes.test b/llvm/test/tools/llvm-objcopy/ELF/strip-preserve-arm-attributes.test new file mode 100644 index 000000000000..2dcca66df1a6 --- /dev/null +++ b/llvm/test/tools/llvm-objcopy/ELF/strip-preserve-arm-attributes.test @@ -0,0 +1,25 @@ +## This test makes sure that --strip-all and --strip-all-gnu preserve +## .ARM.attributes sections in ELF files. This is needed to maintain +## compatibility for Ubuntu/Debian distributions on ARM. + +# RUN: yaml2obj %s > %t +# RUN: llvm-objcopy --strip-all %t %t2 +# RUN: llvm-readobj --sections %t2 | FileCheck %s +# RUN: llvm-objcopy --strip-all-gnu %t %t3 +# RUN: llvm-readobj --sections %t3 | FileCheck %s +# RUN: llvm-strip %t -o %t4 +# RUN: cmp %t4 %t2 +# RUN: llvm-strip --strip-all-gnu %t -o %t5 +# RUN: cmp %t5 %t3 + +!ELF +FileHeader: + Class: ELFCLASS32 + Data: ELFDATA2LSB + Type: ET_DYN + Machine: EM_ARM +Sections: + - Name: .ARM.attributes + Type: SHT_ARM_ATTRIBUTES + +# CHECK: Name: .ARM.attributes diff --git a/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp b/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp index b366c6e55987..2e25a47dde01 100644 --- a/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp +++ b/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp @@ -504,6 +504,12 @@ static Error replaceAndRemoveSections(const CopyConfig &Config, Object &Obj) { return false; if (StringRef(Sec.Name).startswith(".gnu.warning")) return false; + // We keep the .ARM.attribute section to maintain compatibility + // with Debian derived distributions. This is a bug in their + // patchset as documented here: + // https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=943798 + if (Sec.Type == SHT_ARM_ATTRIBUTES) + return false; if (Sec.ParentSegment != nullptr) return false; return (Sec.Flags & SHF_ALLOC) == 0; diff --git a/llvm/tools/llvm-objcopy/ObjcopyOpts.td b/llvm/tools/llvm-objcopy/ObjcopyOpts.td index 5fce4fbde539..757d7e97958d 100644 --- a/llvm/tools/llvm-objcopy/ObjcopyOpts.td +++ b/llvm/tools/llvm-objcopy/ObjcopyOpts.td @@ -112,7 +112,8 @@ defm set_section_flags def strip_all : Flag<["--"], "strip-all">, HelpText<"Remove non-allocated sections outside segments. " - ".gnu.warning* sections are not removed">; + ".gnu.warning* and .ARM.attribute sections are not " + "removed">; def S : Flag<["-"], "S">, Alias<strip_all>; def strip_all_gnu : Flag<["--"], "strip-all-gnu">, HelpText<"Compatible with GNU objcopy's --strip-all">; diff --git a/llvm/tools/llvm-objcopy/StripOpts.td b/llvm/tools/llvm-objcopy/StripOpts.td index 1d06bb3dfb38..a80a91e744a9 100644 --- a/llvm/tools/llvm-objcopy/StripOpts.td +++ b/llvm/tools/llvm-objcopy/StripOpts.td @@ -40,7 +40,8 @@ def p : Flag<["-"], "p">, Alias<preserve_dates>; def strip_all : Flag<["--"], "strip-all">, HelpText<"Remove non-allocated sections outside segments. " - ".gnu.warning* sections are not removed">; + ".gnu.warning* and .ARM.attribute sections are not " + "removed">; def s : Flag<["-"], "s">, Alias<strip_all>; def no_strip_all : Flag<["--"], "no-strip-all">, HelpText<"Disable --strip-all">; _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
