From bf858897b76926b56e948dbe7a1a491b68dccda7 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Tue, 27 Jul 2010 10:25:38 -0700 Subject: linux-user: Re-use load_elf_image for the main binary. 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 Signed-off-by: Edgar E. Iglesias --- linux-user/elfload.c | 380 ++++++++++++++------------------------------------- 1 file changed, 103 insertions(+), 277 deletions(-) (limited to 'linux-user') diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 0a3d0844bb..a53285ae39 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)) @@ -1169,7 +1166,7 @@ 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; @@ -1229,6 +1226,67 @@ 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 or the + QEMU application itself. */ +#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 && !reserved_va) { + unsigned long host_start, real_start, host_size; + + /* Round addresses to page boundaries. */ + loaddr &= qemu_host_page_mask; + hiaddr = HOST_PAGE_ALIGN(hiaddr); + + if (loaddr < mmap_min_addr) { + host_start = HOST_PAGE_ALIGN(mmap_min_addr); + } else { + host_start = loaddr; + if (host_start != loaddr) { + errmsg = "Address overflow loading ELF binary"; + goto exit_errmsg; + } + } + host_size = hiaddr - loaddr; + while (1) { + /* Do not use mmap_find_vma here because that is limited to the + guest address space. We are going to make the + guest address space fit whatever we're given. */ + real_start = (unsigned long) + mmap((void *)host_start, host_size, PROT_NONE, + MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, -1, 0); + if (real_start == (unsigned long)-1) { + goto exit_perror; + } + if (real_start == host_start) { + break; + } + /* That address didn't work. Unmap and try a different one. + The address the host picked because is typically right at + the top of the host address space and leaves the guest with + no usable address space. Resort to a linear search. We + already compensated for mmap_min_addr, so this should not + happen often. Probably means we got unlucky and host + address space randomization put a shared library somewhere + inconvenient. */ + munmap((void *)real_start, host_size); + host_start += qemu_host_page_size; + if (host_start == loaddr) { + /* Theoretically possible if host doesn't have any suitably + aligned areas. Normally the first mmap will fail. */ + errmsg = "Unable to find space for application"; + goto exit_errmsg; + } + } + qemu_log("Relocating guest address space from 0x" + TARGET_ABI_FMT_lx " to 0x%lx\n", loaddr, real_start); + guest_base = real_start - loaddr; + } +#endif } load_bias = load_addr - loaddr; @@ -1290,6 +1348,33 @@ 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 (!interp_name) { + goto exit_perror; + } + + 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; } } @@ -1336,7 +1421,7 @@ 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: @@ -1480,291 +1565,31 @@ 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; - /* 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; - } + load_elf_image(bprm->filename, bprm->fd, info, + &elf_interpreter, bprm->buf); + + /* ??? 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 || reserved_va)) { - /* - * Go through ELF program header table and find the address - * range used by loadable segments. Check that this is available on - * the host, and if not find a suitable value for guest_base. */ - abi_ulong app_start = ~0; - abi_ulong app_end = 0; - abi_ulong addr; - unsigned long host_start; - unsigned long real_start; - unsigned long host_size; - for (i = 0, elf_ppnt = elf_phdata; i < elf_ex.e_phnum; - i++, elf_ppnt++) { - if (elf_ppnt->p_type != PT_LOAD) - continue; - addr = elf_ppnt->p_vaddr; - if (addr < app_start) { - app_start = addr; - } - addr += elf_ppnt->p_memsz; - if (addr > app_end) { - app_end = addr; - } - } - - /* If we don't have any loadable segments then something - is very wrong. */ - assert(app_start < app_end); - - /* Round addresses to page boundaries. */ - app_start = app_start & qemu_host_page_mask; - app_end = HOST_PAGE_ALIGN(app_end); - if (app_start < mmap_min_addr) { - host_start = HOST_PAGE_ALIGN(mmap_min_addr); - } else { - host_start = app_start; - if (host_start != app_start) { - fprintf(stderr, "qemu: Address overflow loading ELF binary\n"); - abort(); - } - } - host_size = app_end - app_start; - while (1) { - /* Do not use mmap_find_vma here because that is limited to the - guest address space. We are going to make the - guest address space fit whatever we're given. */ - real_start = (unsigned long)mmap((void *)host_start, host_size, - PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, -1, 0); - if (real_start == (unsigned long)-1) { - fprintf(stderr, "qemu: Virtual memory exausted\n"); - abort(); - } - if (real_start == host_start) { - break; - } - /* That address didn't work. Unmap and try a different one. - The address the host picked because is typically - right at the top of the host address space and leaves the - guest with no usable address space. Resort to a linear search. - We already compensated for mmap_min_addr, so this should not - happen often. Probably means we got unlucky and host address - space randomization put a shared library somewhere - inconvenient. */ - munmap((void *)real_start, host_size); - host_start += qemu_host_page_size; - if (host_start == app_start) { - /* Theoretically possible if host doesn't have any - suitably aligned areas. Normally the first mmap will - fail. */ - fprintf(stderr, "qemu: Unable to find space for application\n"); - abort(); - } - } - qemu_log("Relocating guest address space from 0x" TARGET_ABI_FMT_lx - " to 0x%lx\n", app_start, real_start); - guest_base = real_start - app_start; + 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); @@ -1796,6 +1621,7 @@ 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 -- cgit v1.2.3