Date: Fri, 27 Jan 2017 16:53:53 +0000 (UTC) From: Ed Maste <emaste@FreeBSD.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r312891 - projects/clang400-import/contrib/llvm/tools/lld/ELF Message-ID: <201701271653.v0RGrrL3087499@repo.freebsd.org>
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Author: emaste Date: Fri Jan 27 16:53:53 2017 New Revision: 312891 URL: https://svnweb.freebsd.org/changeset/base/312891 Log: lld: do not round up PT_GNU_RELRO p_memsz The change was made to support glibc and believed to be a no-op on FreeBSD, but that is not the case for architectures with multiple page sizes, such as arm64. The relro p_memsz header was rounded up to the default maximum page size (64K). When 4K pages are in use, multiple pages beyond the final PT_LOAD segment had their permissions changed to read-only after application of relocations and copy relocations, which led to a segfault in certain cases. This reverts upstream r290986. I have started a discussion about the upstream fix on the LLVM mailing list. Reported by: andrew Sponsored by: The FreeBSD Foundation Modified: projects/clang400-import/contrib/llvm/tools/lld/ELF/Writer.cpp Modified: projects/clang400-import/contrib/llvm/tools/lld/ELF/Writer.cpp ============================================================================== --- projects/clang400-import/contrib/llvm/tools/lld/ELF/Writer.cpp Fri Jan 27 15:03:51 2017 (r312890) +++ projects/clang400-import/contrib/llvm/tools/lld/ELF/Writer.cpp Fri Jan 27 16:53:53 2017 (r312891) @@ -1461,13 +1461,8 @@ template <class ELFT> void Writer<ELFT>: } if (P.p_type == PT_LOAD) P.p_align = Config->MaxPageSize; - else if (P.p_type == PT_GNU_RELRO) { + else if (P.p_type == PT_GNU_RELRO) P.p_align = 1; - // The glibc dynamic loader rounds the size down, so we need to round up - // to protect the last page. This is a no-op on FreeBSD which always - // rounds up. - P.p_memsz = alignTo(P.p_memsz, Config->MaxPageSize); - } // The TLS pointer goes after PT_TLS. At least glibc will align it, // so round up the size to make sure the offsets are correct.
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