diff --git a/linux-user/elfload.c b/linux-user/elfload.c index d5af354a78..d763cb855a 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -3102,10 +3102,9 @@ static bool parse_elf_property(const uint32_t *data, int *off, int datasz, } /* Process NT_GNU_PROPERTY_TYPE_0. */ -static bool parse_elf_properties(int image_fd, +static bool parse_elf_properties(const ImageSource *src, struct image_info *info, const struct elf_phdr *phdr, - char bprm_buf[BPRM_BUF_SIZE], Error **errp) { union { @@ -3133,14 +3132,8 @@ static bool parse_elf_properties(int image_fd, return false; } - if (phdr->p_offset + n <= BPRM_BUF_SIZE) { - memcpy(¬e, bprm_buf + phdr->p_offset, n); - } else { - ssize_t len = pread(image_fd, ¬e, n, phdr->p_offset); - if (len != n) { - error_setg_errno(errp, errno, "Error reading file header"); - return false; - } + if (!imgsrc_read(¬e, phdr->p_offset, n, src, errp)) { + return false; } /* @@ -3186,30 +3179,34 @@ static bool parse_elf_properties(int image_fd, } } -/* Load an ELF image into the address space. +/** + * load_elf_image: Load an ELF image into the address space. + * @image_name: the filename of the image, to use in error messages. + * @src: the ImageSource from which to read. + * @info: info collected from the loaded image. + * @ehdr: the ELF header, not yet bswapped. + * @pinterp_name: record any PT_INTERP string found. + * + * On return: @info values will be filled in, as necessary or available. + */ - IMAGE_NAME is the filename of the image, to use in error messages. - IMAGE_FD is the open file descriptor for the image. - - BPRM_BUF is a copy of the beginning of the file; this of course - contains the elf file header at offset 0. It is assumed that this - buffer is sufficiently aligned to present no problems to the host - in accessing data at aligned offsets within the buffer. - - On return: INFO values will be filled in, as necessary or available. */ - -static void load_elf_image(const char *image_name, int image_fd, +static void load_elf_image(const char *image_name, const ImageSource *src, struct image_info *info, struct elfhdr *ehdr, - char **pinterp_name, - char bprm_buf[BPRM_BUF_SIZE]) + char **pinterp_name) { - struct elf_phdr *phdr; + g_autofree struct elf_phdr *phdr = NULL; abi_ulong load_addr, load_bias, loaddr, hiaddr, error; - int i, retval, prot_exec; + int i, prot_exec; Error *err = NULL; - /* First of all, some simple consistency checks */ - memcpy(ehdr, bprm_buf, sizeof(*ehdr)); + /* + * First of all, some simple consistency checks. + * Note that we rely on the bswapped ehdr staying in bprm_buf, + * for later use by load_elf_binary and create_elf_tables. + */ + if (!imgsrc_read(ehdr, 0, sizeof(*ehdr), src, &err)) { + goto exit_errmsg; + } if (!elf_check_ident(ehdr)) { error_setg(&err, "Invalid ELF image for this architecture"); goto exit_errmsg; @@ -3220,15 +3217,11 @@ static void load_elf_image(const char *image_name, int image_fd, goto exit_errmsg; } - i = ehdr->e_phnum * sizeof(struct elf_phdr); - if (ehdr->e_phoff + i <= BPRM_BUF_SIZE) { - phdr = (struct elf_phdr *)(bprm_buf + ehdr->e_phoff); - } else { - phdr = (struct elf_phdr *) alloca(i); - retval = pread(image_fd, phdr, i, ehdr->e_phoff); - if (retval != i) { - goto exit_read; - } + phdr = imgsrc_read_alloc(ehdr->e_phoff, + ehdr->e_phnum * sizeof(struct elf_phdr), + src, &err); + if (phdr == NULL) { + goto exit_errmsg; } bswap_phdr(phdr, ehdr->e_phnum); @@ -3265,17 +3258,10 @@ static void load_elf_image(const char *image_name, int image_fd, goto exit_errmsg; } - interp_name = g_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_read; - } + interp_name = imgsrc_read_alloc(eppnt->p_offset, eppnt->p_filesz, + src, &err); + if (interp_name == NULL) { + goto exit_errmsg; } if (interp_name[eppnt->p_filesz - 1] != 0) { error_setg(&err, "Invalid PT_INTERP entry"); @@ -3283,7 +3269,7 @@ static void load_elf_image(const char *image_name, int image_fd, } *pinterp_name = g_steal_pointer(&interp_name); } else if (eppnt->p_type == PT_GNU_PROPERTY) { - if (!parse_elf_properties(image_fd, info, eppnt, bprm_buf, &err)) { + if (!parse_elf_properties(src, info, eppnt, &err)) { goto exit_errmsg; } } else if (eppnt->p_type == PT_GNU_STACK) { @@ -3436,9 +3422,9 @@ static void load_elf_image(const char *image_name, int image_fd, * but no backing file segment. */ if (eppnt->p_filesz != 0) { - error = target_mmap(vaddr_ps, eppnt->p_filesz + vaddr_po, + error = imgsrc_mmap(vaddr_ps, eppnt->p_filesz + vaddr_po, elf_prot, MAP_PRIVATE | MAP_FIXED, - image_fd, eppnt->p_offset - vaddr_po); + src, eppnt->p_offset - vaddr_po); if (error == -1) { goto exit_mmap; } @@ -3470,20 +3456,11 @@ static void load_elf_image(const char *image_name, int image_fd, #ifdef TARGET_MIPS } else if (eppnt->p_type == PT_MIPS_ABIFLAGS) { Mips_elf_abiflags_v0 abiflags; - if (eppnt->p_filesz < sizeof(Mips_elf_abiflags_v0)) { - error_setg(&err, "Invalid PT_MIPS_ABIFLAGS entry"); + + if (!imgsrc_read(&abiflags, eppnt->p_offset, sizeof(abiflags), + src, &err)) { goto exit_errmsg; } - if (eppnt->p_offset + eppnt->p_filesz <= BPRM_BUF_SIZE) { - memcpy(&abiflags, bprm_buf + eppnt->p_offset, - sizeof(Mips_elf_abiflags_v0)); - } else { - retval = pread(image_fd, &abiflags, sizeof(Mips_elf_abiflags_v0), - eppnt->p_offset); - if (retval != sizeof(Mips_elf_abiflags_v0)) { - goto exit_read; - } - } bswap_mips_abiflags(&abiflags); info->fp_abi = abiflags.fp_abi; #endif @@ -3496,23 +3473,16 @@ static void load_elf_image(const char *image_name, int image_fd, } if (qemu_log_enabled()) { - load_symbols(ehdr, image_fd, load_bias); + load_symbols(ehdr, src->fd, load_bias); } - debuginfo_report_elf(image_name, image_fd, load_bias); + debuginfo_report_elf(image_name, src->fd, load_bias); mmap_unlock(); - close(image_fd); + close(src->fd); return; - exit_read: - if (retval >= 0) { - error_setg(&err, "Incomplete read of file header"); - } else { - error_setg_errno(&err, errno, "Error reading file header"); - } - goto exit_errmsg; exit_mmap: error_setg_errno(&err, errno, "Error mapping file"); goto exit_errmsg; @@ -3525,6 +3495,7 @@ static void load_elf_interp(const char *filename, struct image_info *info, char bprm_buf[BPRM_BUF_SIZE]) { struct elfhdr ehdr; + ImageSource src; int fd, retval; Error *err = NULL; @@ -3542,11 +3513,11 @@ static void load_elf_interp(const char *filename, struct image_info *info, exit(-1); } - if (retval < BPRM_BUF_SIZE) { - memset(bprm_buf + retval, 0, BPRM_BUF_SIZE - retval); - } + src.fd = fd; + src.cache = bprm_buf; + src.cache_size = retval; - load_elf_image(filename, fd, info, &ehdr, NULL, bprm_buf); + load_elf_image(filename, &src, info, &ehdr, NULL); } static int symfind(const void *s0, const void *s1) @@ -3755,8 +3726,7 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info) interp_info.fp_abi = MIPS_ABI_FP_UNKNOWN; #endif - load_elf_image(bprm->filename, bprm->fd, info, - &ehdr, &elf_interpreter, bprm->buf); + load_elf_image(bprm->filename, &bprm->src, info, &ehdr, &elf_interpreter); /* Do this so that we can load the interpreter, if need be. We will change some of these later */