From patchwork Mon Apr 5 16:37:06 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 49409 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 03691B7CF6 for ; Tue, 6 Apr 2010 03:56:51 +1000 (EST) Received: from localhost ([127.0.0.1]:44193 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NyqIk-0004BR-ND for incoming@patchwork.ozlabs.org; Mon, 05 Apr 2010 13:41:30 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Nyptf-0005tO-7p for qemu-devel@nongnu.org; Mon, 05 Apr 2010 13:15:35 -0400 Received: from [140.186.70.92] (port=41581 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NyptS-0005oH-SI for qemu-devel@nongnu.org; Mon, 05 Apr 2010 13:15:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1NyptN-0007RJ-8I for qemu-devel@nongnu.org; Mon, 05 Apr 2010 13:15:22 -0400 Received: from are.twiddle.net ([75.149.56.221]:42059) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1NyptL-0007QI-VJ for qemu-devel@nongnu.org; Mon, 05 Apr 2010 13:15:16 -0400 Received: by are.twiddle.net (Postfix, from userid 5000) id 35229DE1; Mon, 5 Apr 2010 10:15:12 -0700 (PDT) Message-Id: <878d3e21b6ae87a80fda3a4653a3a2ba8e1e94bd.1270486025.git.rth@twiddle.net> In-Reply-To: References: From: Richard Henderson Date: Mon, 5 Apr 2010 09:37:06 -0700 To: qemu-devel@nongnu.org X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) Subject: [Qemu-devel] [PATCH 12/14] linux-user: Re-use load_elf_image for the main binary. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This requires moving the PT_INTERP extraction and GUEST_BASE handling into load_elf_image. Key this off a non-null pointer argument to receive the interpreter name. Signed-off-by: Richard Henderson --- linux-user/elfload.c | 269 ++++++++++---------------------------------------- 1 files changed, 53 insertions(+), 216 deletions(-) diff --git a/linux-user/elfload.c b/linux-user/elfload.c index c58387a..100efdc 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -829,9 +829,6 @@ struct exec #define ZMAGIC 0413 #define QMAGIC 0314 -/* max code+data+bss+brk space allocated to ET_DYN executables */ -#define ET_DYN_MAP_SIZE (128 * 1024 * 1024) - /* Necessary parameters */ #define TARGET_ELF_EXEC_PAGESIZE TARGET_PAGE_SIZE #define TARGET_ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(TARGET_ELF_EXEC_PAGESIZE-1)) @@ -1168,7 +1165,7 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc, On return: INFO values will be filled in, as necessary or available. */ static void load_elf_image(const char *image_name, int image_fd, - struct image_info *info, + struct image_info *info, char **pinterp_name, char bprm_buf[BPRM_BUF_SIZE]) { struct elfhdr *ehdr = (struct elfhdr *)bprm_buf; @@ -1228,6 +1225,20 @@ static void load_elf_image(const char *image_name, int image_fd, if (load_addr == -1) { goto exit_perror; } + } else if (pinterp_name != NULL) { + /* This is the main executable. Make sure that the low + address does not conflict with MMAP_MIN_ADDR. */ + /* ??? Ideally, we'd check against more than just the + minimum mmap address, but also against the QEMU program + image itself. I.e. find a range that does not conflict + with PAGE_RESERVED entries. Except that we havn't read + those in yet, since that code uses the guest_base that + we set up here. Blah. */ +#if defined(CONFIG_USE_GUEST_BASE) + if (HOST_PAGE_ALIGN(loaddr) < mmap_min_addr) { + guest_base = HOST_PAGE_ALIGN(mmap_min_addr); + } +#endif } load_bias = load_addr - loaddr; @@ -1289,6 +1300,30 @@ static void load_elf_image(const char *image_name, int image_fd, info->brk = vaddr_em; } } + } else if (eppnt->p_type == PT_INTERP && pinterp_name) { + char *interp_name; + + if (*pinterp_name) { + errmsg = "Multiple PT_INTERP entries"; + goto exit_errmsg; + } + interp_name = malloc(eppnt->p_filesz); + + if (eppnt->p_offset + eppnt->p_filesz <= BPRM_BUF_SIZE) { + memcpy(interp_name, bprm_buf + eppnt->p_offset, + eppnt->p_filesz); + } else { + retval = pread(image_fd, interp_name, eppnt->p_filesz, + eppnt->p_offset); + if (retval != eppnt->p_filesz) { + goto exit_perror; + } + } + if (interp_name[eppnt->p_filesz - 1] != 0) { + errmsg = "Invalid PT_INTERP entry"; + goto exit_errmsg; + } + *pinterp_name = interp_name; } } @@ -1335,7 +1370,7 @@ static void load_elf_interp(const char *filename, struct image_info *info, memset(bprm_buf + retval, 0, BPRM_BUF_SIZE - retval); } - load_elf_image(filename, fd, info, bprm_buf); + load_elf_image(filename, fd, info, NULL, bprm_buf); return; exit_perror: @@ -1479,230 +1514,31 @@ int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs, { struct image_info interp_info; struct elfhdr elf_ex; - abi_ulong load_addr, load_bias; - int load_addr_set = 0; - int i; - struct elf_phdr * elf_ppnt; - struct elf_phdr *elf_phdata; - abi_ulong k, elf_brk; - int retval; char *elf_interpreter = NULL; - abi_ulong elf_entry; - int status; - abi_ulong start_code, end_code, start_data, end_data; - abi_ulong elf_stack; - status = 0; - load_addr = 0; - load_bias = 0; - elf_ex = *((struct elfhdr *) bprm->buf); /* exec-header */ + info->start_mmap = (abi_ulong)ELF_START_MMAP; + info->mmap = 0; + info->rss = 0; + + load_elf_image(bprm->filename, bprm->fd, info, + &elf_interpreter, bprm->buf); - /* First of all, some simple consistency checks */ - if (!elf_check_ident(&elf_ex)) { - return -ENOEXEC; - } - bswap_ehdr(&elf_ex); - if (!elf_check_ehdr(&elf_ex)) { - return -ENOEXEC; - } + /* ??? We need a copy of the elf header for passing to create_elf_tables. + If we do nothing, we'll have overwritten this when we re-use bprm->buf + when we load the interpreter. */ + elf_ex = *(struct elfhdr *)bprm->buf; bprm->p = copy_elf_strings(1, &bprm->filename, bprm->page, bprm->p); bprm->p = copy_elf_strings(bprm->envc,bprm->envp,bprm->page,bprm->p); bprm->p = copy_elf_strings(bprm->argc,bprm->argv,bprm->page,bprm->p); if (!bprm->p) { - retval = -E2BIG; - } - - /* Now read in all of the header information */ - elf_phdata = (struct elf_phdr *) - malloc(elf_ex.e_phnum * sizeof(struct elf_phdr)); - if (elf_phdata == NULL) { - return -ENOMEM; - } - - i = elf_ex.e_phnum * sizeof(struct elf_phdr); - if (elf_ex.e_phoff + i <= BPRM_BUF_SIZE) { - memcpy(elf_phdata, bprm->buf + elf_ex.e_phoff, i); - } else { - retval = pread(bprm->fd, (char *) elf_phdata, i, elf_ex.e_phoff); - if (retval != i) { - perror("load_elf_binary"); - exit(-1); - } - } - bswap_phdr(elf_phdata, elf_ex.e_phnum); - - elf_brk = 0; - elf_stack = ~((abi_ulong)0UL); - start_code = ~((abi_ulong)0UL); - end_code = 0; - start_data = 0; - end_data = 0; - - elf_ppnt = elf_phdata; - for(i=0;i < elf_ex.e_phnum; i++) { - if (elf_ppnt->p_type == PT_INTERP) { - if (elf_ppnt->p_offset + elf_ppnt->p_filesz <= BPRM_BUF_SIZE) { - elf_interpreter = bprm->buf + elf_ppnt->p_offset; - } else { - elf_interpreter = alloca(elf_ppnt->p_filesz); - retval = pread(bprm->fd, elf_interpreter, elf_ppnt->p_filesz, - elf_ppnt->p_offset); - if (retval != elf_ppnt->p_filesz) { - perror("load_elf_binary"); - exit(-1); - } - } - } - elf_ppnt++; - } - - /* OK, This is the point of no return */ - info->end_data = 0; - info->end_code = 0; - info->start_mmap = (abi_ulong)ELF_START_MMAP; - info->mmap = 0; - elf_entry = (abi_ulong) elf_ex.e_entry; - -#if defined(CONFIG_USE_GUEST_BASE) - /* - * In case where user has not explicitly set the guest_base, we - * probe here that should we set it automatically. - */ - if (!have_guest_base) { - /* - * Go through ELF program header table and find out whether - * any of the segments drop below our current mmap_min_addr and - * in that case set guest_base to corresponding address. - */ - for (i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum; - i++, elf_ppnt++) { - if (elf_ppnt->p_type != PT_LOAD) - continue; - if (HOST_PAGE_ALIGN(elf_ppnt->p_vaddr) < mmap_min_addr) { - guest_base = HOST_PAGE_ALIGN(mmap_min_addr); - break; - } - } + fprintf(stderr, "%s: %s\n", bprm->filename, strerror(E2BIG)); + exit(-1); } -#endif /* CONFIG_USE_GUEST_BASE */ /* Do this so that we can load the interpreter, if need be. We will change some of these later */ - info->rss = 0; bprm->p = setup_arg_pages(bprm->p, bprm, info); - info->start_stack = bprm->p; - - /* Now we do a little grungy work by mmaping the ELF image into - * the correct location in memory. At this point, we assume that - * the image should be loaded at fixed address, not at a variable - * address. - */ - - for(i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum; i++, elf_ppnt++) { - int elf_prot = 0; - int elf_flags = 0; - abi_ulong error; - - if (elf_ppnt->p_type != PT_LOAD) - continue; - - if (elf_ppnt->p_flags & PF_R) elf_prot |= PROT_READ; - if (elf_ppnt->p_flags & PF_W) elf_prot |= PROT_WRITE; - if (elf_ppnt->p_flags & PF_X) elf_prot |= PROT_EXEC; - elf_flags = MAP_PRIVATE | MAP_DENYWRITE; - if (elf_ex.e_type == ET_EXEC || load_addr_set) { - elf_flags |= MAP_FIXED; - } else if (elf_ex.e_type == ET_DYN) { - /* Try and get dynamic programs out of the way of the default mmap - base, as well as whatever program they might try to exec. This - is because the brk will follow the loader, and is not movable. */ - /* NOTE: for qemu, we do a big mmap to get enough space - without hardcoding any address */ - error = target_mmap(0, ET_DYN_MAP_SIZE, - PROT_NONE, MAP_PRIVATE | MAP_ANON, - -1, 0); - if (error == -1) { - perror("mmap"); - exit(-1); - } - load_bias = TARGET_ELF_PAGESTART(error - elf_ppnt->p_vaddr); - } - - error = target_mmap(TARGET_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr), - (elf_ppnt->p_filesz + - TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr)), - elf_prot, - (MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE), - bprm->fd, - (elf_ppnt->p_offset - - TARGET_ELF_PAGEOFFSET(elf_ppnt->p_vaddr))); - if (error == -1) { - perror("mmap"); - exit(-1); - } - -#ifdef LOW_ELF_STACK - if (TARGET_ELF_PAGESTART(elf_ppnt->p_vaddr) < elf_stack) - elf_stack = TARGET_ELF_PAGESTART(elf_ppnt->p_vaddr); -#endif - - if (!load_addr_set) { - load_addr_set = 1; - load_addr = elf_ppnt->p_vaddr - elf_ppnt->p_offset; - if (elf_ex.e_type == ET_DYN) { - load_bias += error - - TARGET_ELF_PAGESTART(load_bias + elf_ppnt->p_vaddr); - load_addr += load_bias; - } - } - k = elf_ppnt->p_vaddr; - if (k < start_code) - start_code = k; - if (start_data < k) - start_data = k; - k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; - if ((elf_ppnt->p_flags & PF_X) && end_code < k) - end_code = k; - if (end_data < k) - end_data = k; - k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; - if (k > elf_brk) { - elf_brk = TARGET_PAGE_ALIGN(k); - } - - /* If the load segment requests extra zeros (e.g. bss), map it. */ - if (elf_ppnt->p_filesz < elf_ppnt->p_memsz) { - abi_ulong base = load_bias + elf_ppnt->p_vaddr; - zero_bss(base + elf_ppnt->p_filesz, - base + elf_ppnt->p_memsz, elf_prot); - } - } - - elf_entry += load_bias; - elf_brk += load_bias; - start_code += load_bias; - end_code += load_bias; - start_data += load_bias; - end_data += load_bias; - - info->load_bias = load_bias; - info->load_addr = load_addr; - info->entry = elf_entry; - info->start_brk = info->brk = elf_brk; - info->end_code = end_code; - info->start_code = start_code; - info->start_data = start_data; - info->end_data = end_data; - info->personality = PER_LINUX; - - free(elf_phdata); - - if (qemu_log_enabled()) { - load_symbols(&elf_ex, bprm->fd, load_bias); - } - - close(bprm->fd); if (elf_interpreter) { load_elf_interp(elf_interpreter, &interp_info, bprm->buf); @@ -1734,6 +1570,7 @@ int load_elf_binary(struct linux_binprm * bprm, struct target_pt_regs * regs, if (elf_interpreter) { info->load_addr = interp_info.load_addr; info->entry = interp_info.entry; + free(elf_interpreter); } #ifdef USE_ELF_CORE_DUMP