From owner-svn-src-stable@FreeBSD.ORG Tue Dec 22 14:13:13 2009 Return-Path: Delivered-To: svn-src-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 55FA7106568D; Tue, 22 Dec 2009 14:13:13 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id 441B38FC29; Tue, 22 Dec 2009 14:13:13 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id nBMEDDnG066248; Tue, 22 Dec 2009 14:13:13 GMT (envelope-from kib@svn.freebsd.org) Received: (from kib@localhost) by svn.freebsd.org (8.14.3/8.14.3/Submit) id nBMEDDrp066246; Tue, 22 Dec 2009 14:13:13 GMT (envelope-from kib@svn.freebsd.org) Message-Id: <200912221413.nBMEDDrp066246@svn.freebsd.org> From: Konstantin Belousov Date: Tue, 22 Dec 2009 14:13:13 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-7@freebsd.org X-SVN-Group: stable-7 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r200839 - stable/7/libexec/rtld-elf X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Dec 2009 14:13:13 -0000 Author: kib Date: Tue Dec 22 14:13:13 2009 New Revision: 200839 URL: http://svn.freebsd.org/changeset/base/200839 Log: MFC r190883: Update comment, fix spacing. MFC r190885: Change the way the mapping of the ELF objects is constructed, by first mapping PROT_NONE anonymous memory over the whole range, and then mapping the segments of the object over it. MFC r195743: Only perform .bss mapping and cleaning operations when segment file size is not equal to its memory size. Tested by: Mykola Dzham Modified: stable/7/libexec/rtld-elf/map_object.c Directory Properties: stable/7/libexec/rtld-elf/ (props changed) Modified: stable/7/libexec/rtld-elf/map_object.c ============================================================================== --- stable/7/libexec/rtld-elf/map_object.c Tue Dec 22 13:53:34 2009 (r200838) +++ stable/7/libexec/rtld-elf/map_object.c Tue Dec 22 14:13:13 2009 (r200839) @@ -91,8 +91,7 @@ map_object(int fd, const char *path, con /* * Scan the program header entries, and save key information. * - * We rely on there being exactly two load segments, text and data, - * in that order. + * We expect that the loadable segments are ordered by load address. */ phdr = (Elf_Phdr *) ((char *)hdr + hdr->e_phoff); phsize = hdr->e_phnum * sizeof (phdr[0]); @@ -153,8 +152,8 @@ map_object(int fd, const char *path, con mapsize = base_vlimit - base_vaddr; base_addr = hdr->e_type == ET_EXEC ? (caddr_t) base_vaddr : NULL; - mapbase = mmap(base_addr, mapsize, convert_prot(segs[0]->p_flags), - convert_flags(segs[0]->p_flags), fd, base_offset); + mapbase = mmap(base_addr, mapsize, PROT_NONE, MAP_ANON | MAP_PRIVATE | + MAP_NOCORE, -1, 0); if (mapbase == (caddr_t) -1) { _rtld_error("%s: mmap of entire address space failed: %s", path, strerror(errno)); @@ -167,7 +166,7 @@ map_object(int fd, const char *path, con return NULL; } - for (i = 0; i <= nsegs; i++) { + for (i = 0; i <= nsegs; i++) { /* Overlay the segment onto the proper region. */ data_offset = trunc_page(segs[i]->p_offset); data_vaddr = trunc_page(segs[i]->p_vaddr); @@ -175,45 +174,49 @@ map_object(int fd, const char *path, con data_addr = mapbase + (data_vaddr - base_vaddr); data_prot = convert_prot(segs[i]->p_flags); data_flags = convert_flags(segs[i]->p_flags) | MAP_FIXED; - /* Do not call mmap on the first segment - this is redundant */ - if (i && mmap(data_addr, data_vlimit - data_vaddr, data_prot, + if (mmap(data_addr, data_vlimit - data_vaddr, data_prot, data_flags, fd, data_offset) == (caddr_t) -1) { _rtld_error("%s: mmap of data failed: %s", path, strerror(errno)); return NULL; } - /* Clear any BSS in the last page of the segment. */ - clear_vaddr = segs[i]->p_vaddr + segs[i]->p_filesz; - clear_addr = mapbase + (clear_vaddr - base_vaddr); - clear_page = mapbase + (trunc_page(clear_vaddr) - base_vaddr); - if ((nclear = data_vlimit - clear_vaddr) > 0) { - /* Make sure the end of the segment is writable */ - if ((data_prot & PROT_WRITE) == 0 && - -1 == mprotect(clear_page, PAGE_SIZE, data_prot|PROT_WRITE)) { + /* Do BSS setup */ + if (segs[i]->p_filesz != segs[i]->p_memsz) { + + /* Clear any BSS in the last page of the segment. */ + clear_vaddr = segs[i]->p_vaddr + segs[i]->p_filesz; + clear_addr = mapbase + (clear_vaddr - base_vaddr); + clear_page = mapbase + (trunc_page(clear_vaddr) - base_vaddr); + + if ((nclear = data_vlimit - clear_vaddr) > 0) { + /* Make sure the end of the segment is writable */ + if ((data_prot & PROT_WRITE) == 0 && -1 == + mprotect(clear_page, PAGE_SIZE, data_prot|PROT_WRITE)) { _rtld_error("%s: mprotect failed: %s", path, strerror(errno)); return NULL; - } + } - memset(clear_addr, 0, nclear); + memset(clear_addr, 0, nclear); - /* Reset the data protection back */ - if ((data_prot & PROT_WRITE) == 0) - mprotect(clear_page, PAGE_SIZE, data_prot); - } + /* Reset the data protection back */ + if ((data_prot & PROT_WRITE) == 0) + mprotect(clear_page, PAGE_SIZE, data_prot); + } - /* Overlay the BSS segment onto the proper region. */ - bss_vaddr = data_vlimit; - bss_vlimit = round_page(segs[i]->p_vaddr + segs[i]->p_memsz); - bss_addr = mapbase + (bss_vaddr - base_vaddr); - if (bss_vlimit > bss_vaddr) { /* There is something to do */ - if (mmap(bss_addr, bss_vlimit - bss_vaddr, data_prot, - MAP_PRIVATE|MAP_FIXED|MAP_ANON, -1, 0) == (caddr_t) -1) { - _rtld_error("%s: mmap of bss failed: %s", path, + /* Overlay the BSS segment onto the proper region. */ + bss_vaddr = data_vlimit; + bss_vlimit = round_page(segs[i]->p_vaddr + segs[i]->p_memsz); + bss_addr = mapbase + (bss_vaddr - base_vaddr); + if (bss_vlimit > bss_vaddr) { /* There is something to do */ + if (mprotect(bss_addr, bss_vlimit - bss_vaddr, data_prot) == -1) { + _rtld_error("%s: mprotect of bss failed: %s", path, strerror(errno)); - return NULL; + return NULL; + } } } + if (phdr_vaddr == 0 && data_offset <= hdr->e_phoff && (data_vlimit - data_vaddr + data_offset) >= (hdr->e_phoff + hdr->e_phnum * sizeof (Elf_Phdr))) {