From owner-svn-src-head@freebsd.org Wed Jul 20 16:59:37 2016 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 69CC4B9FE18; Wed, 20 Jul 2016 16:59:37 +0000 (UTC) (envelope-from cem@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 2F30C15AC; Wed, 20 Jul 2016 16:59:37 +0000 (UTC) (envelope-from cem@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u6KGxa89010930; Wed, 20 Jul 2016 16:59:36 GMT (envelope-from cem@FreeBSD.org) Received: (from cem@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u6KGxaNs010929; Wed, 20 Jul 2016 16:59:36 GMT (envelope-from cem@FreeBSD.org) Message-Id: <201607201659.u6KGxaNs010929@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: cem set sender to cem@FreeBSD.org using -f From: "Conrad E. Meyer" Date: Wed, 20 Jul 2016 16:59:36 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r303099 - head/sys/kern X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Jul 2016 16:59:37 -0000 Author: cem Date: Wed Jul 20 16:59:36 2016 New Revision: 303099 URL: https://svnweb.freebsd.org/changeset/base/303099 Log: Extend ELF coredump to support more than 65535 segments The ELF e_phnum field is only 16 bits wide. To support more than 65535 segments (program headers), Sun's "Linker and Libraries Guide" table 7-7 (or 12-7, depending on document version) prescribes a special first section header where sh_info represents the real number of program headers. Test code to follow, when it is ready. Reference: http://docs.oracle.com/cd/E18752_01/pdf/817-1984.pdf Reviewed by: emaste, markj Sponsored by: EMC / Isilon Storage Division Differential Revision: https://reviews.freebsd.org/D7255 Modified: head/sys/kern/imgact_elf.c Modified: head/sys/kern/imgact_elf.c ============================================================================== --- head/sys/kern/imgact_elf.c Wed Jul 20 16:48:25 2016 (r303098) +++ head/sys/kern/imgact_elf.c Wed Jul 20 16:59:36 2016 (r303099) @@ -1323,6 +1323,8 @@ __elfN(coredump)(struct thread *td, stru * Collect info about the core file header area. */ hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count); + if (seginfo.count + 1 >= PN_XNUM) + hdrsize += sizeof(Elf_Shdr); __elfN(prepare_notes)(td, ¬elst, ¬esz); coresize = round_page(hdrsize + notesz) + seginfo.size; @@ -1618,10 +1620,10 @@ __elfN(puthdr)(struct thread *td, void * { Elf_Ehdr *ehdr; Elf_Phdr *phdr; + Elf_Shdr *shdr; struct phdr_closure phc; ehdr = (Elf_Ehdr *)hdr; - phdr = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)); ehdr->e_ident[EI_MAG0] = ELFMAG0; ehdr->e_ident[EI_MAG1] = ELFMAG1; @@ -1645,14 +1647,43 @@ __elfN(puthdr)(struct thread *td, void * ehdr->e_flags = 0; ehdr->e_ehsize = sizeof(Elf_Ehdr); ehdr->e_phentsize = sizeof(Elf_Phdr); - ehdr->e_phnum = numsegs + 1; ehdr->e_shentsize = sizeof(Elf_Shdr); - ehdr->e_shnum = 0; ehdr->e_shstrndx = SHN_UNDEF; + if (numsegs + 1 < PN_XNUM) { + ehdr->e_phnum = numsegs + 1; + ehdr->e_shnum = 0; + } else { + ehdr->e_phnum = PN_XNUM; + ehdr->e_shnum = 1; + + ehdr->e_shoff = ehdr->e_phoff + + (numsegs + 1) * ehdr->e_phentsize; + KASSERT(ehdr->e_shoff == hdrsize - sizeof(Elf_Shdr), + ("e_shoff: %zu, hdrsize - shdr: %zu", + ehdr->e_shoff, hdrsize - sizeof(Elf_Shdr))); + + shdr = (Elf_Shdr *)((char *)hdr + ehdr->e_shoff); + memset(shdr, 0, sizeof(*shdr)); + /* + * A special first section is used to hold large segment and + * section counts. This was proposed by Sun Microsystems in + * Solaris and has been adopted by Linux; the standard ELF + * tools are already familiar with the technique. + * + * See table 7-7 of the Solaris "Linker and Libraries Guide" + * (or 12-7 depending on the version of the document) for more + * details. + */ + shdr->sh_type = SHT_NULL; + shdr->sh_size = ehdr->e_shnum; + shdr->sh_link = ehdr->e_shstrndx; + shdr->sh_info = numsegs + 1; + } /* * Fill in the program header entries. */ + phdr = (Elf_Phdr *)((char *)hdr + ehdr->e_phoff); /* The note segement. */ phdr->p_type = PT_NOTE;