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-rw-r--r--fs/binfmt_flat.c944
1 files changed, 944 insertions, 0 deletions
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
new file mode 100644
index 0000000000..c26545d71d
--- /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, &current->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);
+
+/****************************************************************************/
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 05:13:36 +0000