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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /fs/binfmt_flat.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/binfmt_flat.c')
-rw-r--r-- | fs/binfmt_flat.c | 944 |
1 files changed, 944 insertions, 0 deletions
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c new file mode 100644 index 000000000..c26545d71 --- /dev/null +++ b/fs/binfmt_flat.c @@ -0,0 +1,944 @@ +// SPDX-License-Identifier: GPL-2.0 +/****************************************************************************/ +/* + * linux/fs/binfmt_flat.c + * + * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> + * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> + * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> + * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> + * based heavily on: + * + * linux/fs/binfmt_aout.c: + * Copyright (C) 1991, 1992, 1996 Linus Torvalds + * linux/fs/binfmt_flat.c for 2.0 kernel + * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> + * JAN/99 -- coded full program relocation (gerg@snapgear.com) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/errno.h> +#include <linux/signal.h> +#include <linux/string.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/ptrace.h> +#include <linux/user.h> +#include <linux/slab.h> +#include <linux/binfmts.h> +#include <linux/personality.h> +#include <linux/init.h> +#include <linux/flat.h> +#include <linux/uaccess.h> +#include <linux/vmalloc.h> + +#include <asm/byteorder.h> +#include <asm/unaligned.h> +#include <asm/cacheflush.h> +#include <asm/page.h> +#include <asm/flat.h> + +#ifndef flat_get_relocate_addr +#define flat_get_relocate_addr(rel) (rel) +#endif + +/****************************************************************************/ + +/* + * User data (data section and bss) needs to be aligned. + * We pick 0x20 here because it is the max value elf2flt has always + * used in producing FLAT files, and because it seems to be large + * enough to make all the gcc alignment related tests happy. + */ +#define FLAT_DATA_ALIGN (0x20) + +/* + * User data (stack) also needs to be aligned. + * Here we can be a bit looser than the data sections since this + * needs to only meet arch ABI requirements. + */ +#define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN) + +#define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ +#define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ + +#define MAX_SHARED_LIBS (1) + +#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET +#define DATA_START_OFFSET_WORDS (0) +#else +#define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) +#endif + +struct lib_info { + struct { + unsigned long start_code; /* Start of text segment */ + unsigned long start_data; /* Start of data segment */ + unsigned long start_brk; /* End of data segment */ + unsigned long text_len; /* Length of text segment */ + unsigned long entry; /* Start address for this module */ + unsigned long build_date; /* When this one was compiled */ + bool loaded; /* Has this library been loaded? */ + } lib_list[MAX_SHARED_LIBS]; +}; + +static int load_flat_binary(struct linux_binprm *); + +static struct linux_binfmt flat_format = { + .module = THIS_MODULE, + .load_binary = load_flat_binary, +}; + + +/****************************************************************************/ +/* + * create_flat_tables() parses the env- and arg-strings in new user + * memory and creates the pointer tables from them, and puts their + * addresses on the "stack", recording the new stack pointer value. + */ + +static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start) +{ + char __user *p; + unsigned long __user *sp; + long i, len; + + p = (char __user *)arg_start; + sp = (unsigned long __user *)current->mm->start_stack; + + sp -= bprm->envc + 1; + sp -= bprm->argc + 1; + if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) + sp -= 2; /* argvp + envp */ + sp -= 1; /* &argc */ + + current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN; + sp = (unsigned long __user *)current->mm->start_stack; + + if (put_user(bprm->argc, sp++)) + return -EFAULT; + if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) { + unsigned long argv, envp; + argv = (unsigned long)(sp + 2); + envp = (unsigned long)(sp + 2 + bprm->argc + 1); + if (put_user(argv, sp++) || put_user(envp, sp++)) + return -EFAULT; + } + + current->mm->arg_start = (unsigned long)p; + for (i = bprm->argc; i > 0; i--) { + if (put_user((unsigned long)p, sp++)) + return -EFAULT; + len = strnlen_user(p, MAX_ARG_STRLEN); + if (!len || len > MAX_ARG_STRLEN) + return -EINVAL; + p += len; + } + if (put_user(0, sp++)) + return -EFAULT; + current->mm->arg_end = (unsigned long)p; + + current->mm->env_start = (unsigned long) p; + for (i = bprm->envc; i > 0; i--) { + if (put_user((unsigned long)p, sp++)) + return -EFAULT; + len = strnlen_user(p, MAX_ARG_STRLEN); + if (!len || len > MAX_ARG_STRLEN) + return -EINVAL; + p += len; + } + if (put_user(0, sp++)) + return -EFAULT; + current->mm->env_end = (unsigned long)p; + + return 0; +} + +/****************************************************************************/ + +#ifdef CONFIG_BINFMT_ZFLAT + +#include <linux/zlib.h> + +#define LBUFSIZE 4000 + +/* gzip flag byte */ +#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ +#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ +#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ +#define ORIG_NAME 0x08 /* bit 3 set: original file name present */ +#define COMMENT 0x10 /* bit 4 set: file comment present */ +#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ +#define RESERVED 0xC0 /* bit 6,7: reserved */ + +static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst, + long len, int fd) +{ + unsigned char *buf; + z_stream strm; + int ret, retval; + + pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len); + + memset(&strm, 0, sizeof(strm)); + strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); + if (!strm.workspace) + return -ENOMEM; + + buf = kmalloc(LBUFSIZE, GFP_KERNEL); + if (!buf) { + retval = -ENOMEM; + goto out_free; + } + + /* Read in first chunk of data and parse gzip header. */ + ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos); + + strm.next_in = buf; + strm.avail_in = ret; + strm.total_in = 0; + + retval = -ENOEXEC; + + /* Check minimum size -- gzip header */ + if (ret < 10) { + pr_debug("file too small?\n"); + goto out_free_buf; + } + + /* Check gzip magic number */ + if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { + pr_debug("unknown compression magic?\n"); + goto out_free_buf; + } + + /* Check gzip method */ + if (buf[2] != 8) { + pr_debug("unknown compression method?\n"); + goto out_free_buf; + } + /* Check gzip flags */ + if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || + (buf[3] & RESERVED)) { + pr_debug("unknown flags?\n"); + goto out_free_buf; + } + + ret = 10; + if (buf[3] & EXTRA_FIELD) { + ret += 2 + buf[10] + (buf[11] << 8); + if (unlikely(ret >= LBUFSIZE)) { + pr_debug("buffer overflow (EXTRA)?\n"); + goto out_free_buf; + } + } + if (buf[3] & ORIG_NAME) { + while (ret < LBUFSIZE && buf[ret++] != 0) + ; + if (unlikely(ret == LBUFSIZE)) { + pr_debug("buffer overflow (ORIG_NAME)?\n"); + goto out_free_buf; + } + } + if (buf[3] & COMMENT) { + while (ret < LBUFSIZE && buf[ret++] != 0) + ; + if (unlikely(ret == LBUFSIZE)) { + pr_debug("buffer overflow (COMMENT)?\n"); + goto out_free_buf; + } + } + + strm.next_in += ret; + strm.avail_in -= ret; + + strm.next_out = dst; + strm.avail_out = len; + strm.total_out = 0; + + if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { + pr_debug("zlib init failed?\n"); + goto out_free_buf; + } + + while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { + ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos); + if (ret <= 0) + break; + len -= ret; + + strm.next_in = buf; + strm.avail_in = ret; + strm.total_in = 0; + } + + if (ret < 0) { + pr_debug("decompression failed (%d), %s\n", + ret, strm.msg); + goto out_zlib; + } + + retval = 0; +out_zlib: + zlib_inflateEnd(&strm); +out_free_buf: + kfree(buf); +out_free: + kfree(strm.workspace); + return retval; +} + +#endif /* CONFIG_BINFMT_ZFLAT */ + +/****************************************************************************/ + +static unsigned long +calc_reloc(unsigned long r, struct lib_info *p) +{ + unsigned long addr; + unsigned long start_brk; + unsigned long start_data; + unsigned long text_len; + unsigned long start_code; + + start_brk = p->lib_list[0].start_brk; + start_data = p->lib_list[0].start_data; + start_code = p->lib_list[0].start_code; + text_len = p->lib_list[0].text_len; + + if (r > start_brk - start_data + text_len) { + pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)", + r, start_brk-start_data+text_len, text_len); + goto failed; + } + + if (r < text_len) /* In text segment */ + addr = r + start_code; + else /* In data segment */ + addr = r - text_len + start_data; + + /* Range checked already above so doing the range tests is redundant...*/ + return addr; + +failed: + pr_cont(", killing %s!\n", current->comm); + send_sig(SIGSEGV, current, 0); + + return RELOC_FAILED; +} + +/****************************************************************************/ + +#ifdef CONFIG_BINFMT_FLAT_OLD +static void old_reloc(unsigned long rl) +{ + static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; + flat_v2_reloc_t r; + unsigned long __user *ptr; + unsigned long val; + + r.value = rl; +#if defined(CONFIG_COLDFIRE) + ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset); +#else + ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset); +#endif + get_user(val, ptr); + + pr_debug("Relocation of variable at DATASEG+%x " + "(address %p, currently %lx) into segment %s\n", + r.reloc.offset, ptr, val, segment[r.reloc.type]); + + switch (r.reloc.type) { + case OLD_FLAT_RELOC_TYPE_TEXT: + val += current->mm->start_code; + break; + case OLD_FLAT_RELOC_TYPE_DATA: + val += current->mm->start_data; + break; + case OLD_FLAT_RELOC_TYPE_BSS: + val += current->mm->end_data; + break; + default: + pr_err("Unknown relocation type=%x\n", r.reloc.type); + break; + } + put_user(val, ptr); + + pr_debug("Relocation became %lx\n", val); +} +#endif /* CONFIG_BINFMT_FLAT_OLD */ + +/****************************************************************************/ + +static inline u32 __user *skip_got_header(u32 __user *rp) +{ + if (IS_ENABLED(CONFIG_RISCV)) { + /* + * RISC-V has a 16 byte GOT PLT header for elf64-riscv + * and 8 byte GOT PLT header for elf32-riscv. + * Skip the whole GOT PLT header, since it is reserved + * for the dynamic linker (ld.so). + */ + u32 rp_val0, rp_val1; + + if (get_user(rp_val0, rp)) + return rp; + if (get_user(rp_val1, rp + 1)) + return rp; + + if (rp_val0 == 0xffffffff && rp_val1 == 0xffffffff) + rp += 4; + else if (rp_val0 == 0xffffffff) + rp += 2; + } + return rp; +} + +static int load_flat_file(struct linux_binprm *bprm, + struct lib_info *libinfo, unsigned long *extra_stack) +{ + struct flat_hdr *hdr; + unsigned long textpos, datapos, realdatastart; + u32 text_len, data_len, bss_len, stack_len, full_data, flags; + unsigned long len, memp, memp_size, extra, rlim; + __be32 __user *reloc; + u32 __user *rp; + int i, rev, relocs; + loff_t fpos; + unsigned long start_code, end_code; + ssize_t result; + int ret; + + hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ + + text_len = ntohl(hdr->data_start); + data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); + bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); + stack_len = ntohl(hdr->stack_size); + if (extra_stack) { + stack_len += *extra_stack; + *extra_stack = stack_len; + } + relocs = ntohl(hdr->reloc_count); + flags = ntohl(hdr->flags); + rev = ntohl(hdr->rev); + full_data = data_len + relocs * sizeof(unsigned long); + + if (strncmp(hdr->magic, "bFLT", 4)) { + /* + * Previously, here was a printk to tell people + * "BINFMT_FLAT: bad header magic". + * But for the kernel which also use ELF FD-PIC format, this + * error message is confusing. + * because a lot of people do not manage to produce good + */ + ret = -ENOEXEC; + goto err; + } + + if (flags & FLAT_FLAG_KTRACE) + pr_info("Loading file: %s\n", bprm->filename); + +#ifdef CONFIG_BINFMT_FLAT_OLD + if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { + pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n", + rev, FLAT_VERSION, OLD_FLAT_VERSION); + ret = -ENOEXEC; + goto err; + } + + /* + * fix up the flags for the older format, there were all kinds + * of endian hacks, this only works for the simple cases + */ + if (rev == OLD_FLAT_VERSION && + (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM))) + flags = FLAT_FLAG_RAM; + +#else /* CONFIG_BINFMT_FLAT_OLD */ + if (rev != FLAT_VERSION) { + pr_err("bad flat file version 0x%x (supported 0x%lx)\n", + rev, FLAT_VERSION); + ret = -ENOEXEC; + goto err; + } +#endif /* !CONFIG_BINFMT_FLAT_OLD */ + + /* + * Make sure the header params are sane. + * 28 bits (256 MB) is way more than reasonable in this case. + * If some top bits are set we have probable binary corruption. + */ + if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) { + pr_err("bad header\n"); + ret = -ENOEXEC; + goto err; + } + +#ifndef CONFIG_BINFMT_ZFLAT + if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { + pr_err("Support for ZFLAT executables is not enabled.\n"); + ret = -ENOEXEC; + goto err; + } +#endif + + /* + * Check initial limits. This avoids letting people circumvent + * size limits imposed on them by creating programs with large + * arrays in the data or bss. + */ + rlim = rlimit(RLIMIT_DATA); + if (rlim >= RLIM_INFINITY) + rlim = ~0; + if (data_len + bss_len > rlim) { + ret = -ENOMEM; + goto err; + } + + /* Flush all traces of the currently running executable */ + ret = begin_new_exec(bprm); + if (ret) + goto err; + + /* OK, This is the point of no return */ + set_personality(PER_LINUX_32BIT); + setup_new_exec(bprm); + + /* + * calculate the extra space we need to map in + */ + extra = max_t(unsigned long, bss_len + stack_len, + relocs * sizeof(unsigned long)); + + /* + * there are a couple of cases here, the separate code/data + * case, and then the fully copied to RAM case which lumps + * it all together. + */ + if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { + /* + * this should give us a ROM ptr, but if it doesn't we don't + * really care + */ + pr_debug("ROM mapping of file (we hope)\n"); + + textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, + MAP_PRIVATE, 0); + if (!textpos || IS_ERR_VALUE(textpos)) { + ret = textpos; + if (!textpos) + ret = -ENOMEM; + pr_err("Unable to mmap process text, errno %d\n", ret); + goto err; + } + + len = data_len + extra + + DATA_START_OFFSET_WORDS * sizeof(unsigned long); + len = PAGE_ALIGN(len); + realdatastart = vm_mmap(NULL, 0, len, + PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); + + if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) { + ret = realdatastart; + if (!realdatastart) + ret = -ENOMEM; + pr_err("Unable to allocate RAM for process data, " + "errno %d\n", ret); + vm_munmap(textpos, text_len); + goto err; + } + datapos = ALIGN(realdatastart + + DATA_START_OFFSET_WORDS * sizeof(unsigned long), + FLAT_DATA_ALIGN); + + pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", + data_len + bss_len + stack_len, datapos); + + fpos = ntohl(hdr->data_start); +#ifdef CONFIG_BINFMT_ZFLAT + if (flags & FLAT_FLAG_GZDATA) { + result = decompress_exec(bprm, fpos, (char *)datapos, + full_data, 0); + } else +#endif + { + result = read_code(bprm->file, datapos, fpos, + full_data); + } + if (IS_ERR_VALUE(result)) { + ret = result; + pr_err("Unable to read data+bss, errno %d\n", ret); + vm_munmap(textpos, text_len); + vm_munmap(realdatastart, len); + goto err; + } + + reloc = (__be32 __user *) + (datapos + (ntohl(hdr->reloc_start) - text_len)); + memp = realdatastart; + memp_size = len; + } else { + + len = text_len + data_len + extra + + DATA_START_OFFSET_WORDS * sizeof(u32); + len = PAGE_ALIGN(len); + textpos = vm_mmap(NULL, 0, len, + PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); + + if (!textpos || IS_ERR_VALUE(textpos)) { + ret = textpos; + if (!textpos) + ret = -ENOMEM; + pr_err("Unable to allocate RAM for process text/data, " + "errno %d\n", ret); + goto err; + } + + realdatastart = textpos + ntohl(hdr->data_start); + datapos = ALIGN(realdatastart + + DATA_START_OFFSET_WORDS * sizeof(u32), + FLAT_DATA_ALIGN); + + reloc = (__be32 __user *) + (datapos + (ntohl(hdr->reloc_start) - text_len)); + memp = textpos; + memp_size = len; +#ifdef CONFIG_BINFMT_ZFLAT + /* + * load it all in and treat it like a RAM load from now on + */ + if (flags & FLAT_FLAG_GZIP) { +#ifndef CONFIG_MMU + result = decompress_exec(bprm, sizeof(struct flat_hdr), + (((char *)textpos) + sizeof(struct flat_hdr)), + (text_len + full_data + - sizeof(struct flat_hdr)), + 0); + memmove((void *) datapos, (void *) realdatastart, + full_data); +#else + /* + * This is used on MMU systems mainly for testing. + * Let's use a kernel buffer to simplify things. + */ + long unz_text_len = text_len - sizeof(struct flat_hdr); + long unz_len = unz_text_len + full_data; + char *unz_data = vmalloc(unz_len); + if (!unz_data) { + result = -ENOMEM; + } else { + result = decompress_exec(bprm, sizeof(struct flat_hdr), + unz_data, unz_len, 0); + if (result == 0 && + (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr), + unz_data, unz_text_len) || + copy_to_user((void __user *)datapos, + unz_data + unz_text_len, full_data))) + result = -EFAULT; + vfree(unz_data); + } +#endif + } else if (flags & FLAT_FLAG_GZDATA) { + result = read_code(bprm->file, textpos, 0, text_len); + if (!IS_ERR_VALUE(result)) { +#ifndef CONFIG_MMU + result = decompress_exec(bprm, text_len, (char *) datapos, + full_data, 0); +#else + char *unz_data = vmalloc(full_data); + if (!unz_data) { + result = -ENOMEM; + } else { + result = decompress_exec(bprm, text_len, + unz_data, full_data, 0); + if (result == 0 && + copy_to_user((void __user *)datapos, + unz_data, full_data)) + result = -EFAULT; + vfree(unz_data); + } +#endif + } + } else +#endif /* CONFIG_BINFMT_ZFLAT */ + { + result = read_code(bprm->file, textpos, 0, text_len); + if (!IS_ERR_VALUE(result)) + result = read_code(bprm->file, datapos, + ntohl(hdr->data_start), + full_data); + } + if (IS_ERR_VALUE(result)) { + ret = result; + pr_err("Unable to read code+data+bss, errno %d\n", ret); + vm_munmap(textpos, text_len + data_len + extra + + DATA_START_OFFSET_WORDS * sizeof(u32)); + goto err; + } + } + + start_code = textpos + sizeof(struct flat_hdr); + end_code = textpos + text_len; + text_len -= sizeof(struct flat_hdr); /* the real code len */ + + /* The main program needs a little extra setup in the task structure */ + current->mm->start_code = start_code; + current->mm->end_code = end_code; + current->mm->start_data = datapos; + current->mm->end_data = datapos + data_len; + /* + * set up the brk stuff, uses any slack left in data/bss/stack + * allocation. We put the brk after the bss (between the bss + * and stack) like other platforms. + * Userspace code relies on the stack pointer starting out at + * an address right at the end of a page. + */ + current->mm->start_brk = datapos + data_len + bss_len; + current->mm->brk = (current->mm->start_brk + 3) & ~3; +#ifndef CONFIG_MMU + current->mm->context.end_brk = memp + memp_size - stack_len; +#endif + + if (flags & FLAT_FLAG_KTRACE) { + pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n", + textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); + pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n", + "Load", bprm->filename, + start_code, end_code, datapos, datapos + data_len, + datapos + data_len, (datapos + data_len + bss_len + 3) & ~3); + } + + /* Store the current module values into the global library structure */ + libinfo->lib_list[0].start_code = start_code; + libinfo->lib_list[0].start_data = datapos; + libinfo->lib_list[0].start_brk = datapos + data_len + bss_len; + libinfo->lib_list[0].text_len = text_len; + libinfo->lib_list[0].loaded = 1; + libinfo->lib_list[0].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; + libinfo->lib_list[0].build_date = ntohl(hdr->build_date); + + /* + * We just load the allocations into some temporary memory to + * help simplify all this mumbo jumbo + * + * We've got two different sections of relocation entries. + * The first is the GOT which resides at the beginning of the data segment + * and is terminated with a -1. This one can be relocated in place. + * The second is the extra relocation entries tacked after the image's + * data segment. These require a little more processing as the entry is + * really an offset into the image which contains an offset into the + * image. + */ + if (flags & FLAT_FLAG_GOTPIC) { + rp = skip_got_header((u32 __user *) datapos); + for (; ; rp++) { + u32 addr, rp_val; + if (get_user(rp_val, rp)) + return -EFAULT; + if (rp_val == 0xffffffff) + break; + if (rp_val) { + addr = calc_reloc(rp_val, libinfo); + if (addr == RELOC_FAILED) { + ret = -ENOEXEC; + goto err; + } + if (put_user(addr, rp)) + return -EFAULT; + } + } + } + + /* + * Now run through the relocation entries. + * We've got to be careful here as C++ produces relocatable zero + * entries in the constructor and destructor tables which are then + * tested for being not zero (which will always occur unless we're + * based from address zero). This causes an endless loop as __start + * is at zero. The solution used is to not relocate zero addresses. + * This has the negative side effect of not allowing a global data + * reference to be statically initialised to _stext (I've moved + * __start to address 4 so that is okay). + */ + if (rev > OLD_FLAT_VERSION) { + for (i = 0; i < relocs; i++) { + u32 addr, relval; + __be32 tmp; + + /* + * Get the address of the pointer to be + * relocated (of course, the address has to be + * relocated first). + */ + if (get_user(tmp, reloc + i)) + return -EFAULT; + relval = ntohl(tmp); + addr = flat_get_relocate_addr(relval); + rp = (u32 __user *)calc_reloc(addr, libinfo); + if (rp == (u32 __user *)RELOC_FAILED) { + ret = -ENOEXEC; + goto err; + } + + /* Get the pointer's value. */ + ret = flat_get_addr_from_rp(rp, relval, flags, &addr); + if (unlikely(ret)) + goto err; + + if (addr != 0) { + /* + * Do the relocation. PIC relocs in the data section are + * already in target order + */ + if ((flags & FLAT_FLAG_GOTPIC) == 0) { + /* + * Meh, the same value can have a different + * byte order based on a flag.. + */ + addr = ntohl((__force __be32)addr); + } + addr = calc_reloc(addr, libinfo); + if (addr == RELOC_FAILED) { + ret = -ENOEXEC; + goto err; + } + + /* Write back the relocated pointer. */ + ret = flat_put_addr_at_rp(rp, addr, relval); + if (unlikely(ret)) + goto err; + } + } +#ifdef CONFIG_BINFMT_FLAT_OLD + } else { + for (i = 0; i < relocs; i++) { + __be32 relval; + if (get_user(relval, reloc + i)) + return -EFAULT; + old_reloc(ntohl(relval)); + } +#endif /* CONFIG_BINFMT_FLAT_OLD */ + } + + flush_icache_user_range(start_code, end_code); + + /* zero the BSS, BRK and stack areas */ + if (clear_user((void __user *)(datapos + data_len), bss_len + + (memp + memp_size - stack_len - /* end brk */ + libinfo->lib_list[0].start_brk) + /* start brk */ + stack_len)) + return -EFAULT; + + return 0; +err: + return ret; +} + + +/****************************************************************************/ + +/* + * These are the functions used to load flat style executables and shared + * libraries. There is no binary dependent code anywhere else. + */ + +static int load_flat_binary(struct linux_binprm *bprm) +{ + struct lib_info libinfo; + struct pt_regs *regs = current_pt_regs(); + unsigned long stack_len = 0; + unsigned long start_addr; + int res; + int i, j; + + memset(&libinfo, 0, sizeof(libinfo)); + + /* + * We have to add the size of our arguments to our stack size + * otherwise it's too easy for users to create stack overflows + * by passing in a huge argument list. And yes, we have to be + * pedantic and include space for the argv/envp array as it may have + * a lot of entries. + */ +#ifndef CONFIG_MMU + stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */ +#endif + stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ + stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ + stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN); + + res = load_flat_file(bprm, &libinfo, &stack_len); + if (res < 0) + return res; + + /* Update data segment pointers for all libraries */ + for (i = 0; i < MAX_SHARED_LIBS; i++) { + if (!libinfo.lib_list[i].loaded) + continue; + for (j = 0; j < MAX_SHARED_LIBS; j++) { + unsigned long val = libinfo.lib_list[j].loaded ? + libinfo.lib_list[j].start_data : UNLOADED_LIB; + unsigned long __user *p = (unsigned long __user *) + libinfo.lib_list[i].start_data; + p -= j + 1; + if (put_user(val, p)) + return -EFAULT; + } + } + + set_binfmt(&flat_format); + +#ifdef CONFIG_MMU + res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); + if (!res) + res = create_flat_tables(bprm, bprm->p); +#else + /* Stash our initial stack pointer into the mm structure */ + current->mm->start_stack = + ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; + pr_debug("sp=%lx\n", current->mm->start_stack); + + /* copy the arg pages onto the stack */ + res = transfer_args_to_stack(bprm, ¤t->mm->start_stack); + if (!res) + res = create_flat_tables(bprm, current->mm->start_stack); +#endif + if (res) + return res; + + /* Fake some return addresses to ensure the call chain will + * initialise library in order for us. We are required to call + * lib 1 first, then 2, ... and finally the main program (id 0). + */ + start_addr = libinfo.lib_list[0].entry; + +#ifdef FLAT_PLAT_INIT + FLAT_PLAT_INIT(regs); +#endif + + finalize_exec(bprm); + pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n", + regs, start_addr, current->mm->start_stack); + start_thread(regs, start_addr, current->mm->start_stack); + + return 0; +} + +/****************************************************************************/ + +static int __init init_flat_binfmt(void) +{ + register_binfmt(&flat_format); + return 0; +} +core_initcall(init_flat_binfmt); + +/****************************************************************************/ |