diff options
Diffstat (limited to 'fs/compat.c')
| -rw-r--r-- | fs/compat.c | 235 |
1 files changed, 0 insertions, 235 deletions
diff --git a/fs/compat.c b/fs/compat.c index 72fe6cd..0ea00832 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1306,241 +1306,6 @@ compat_sys_openat(unsigned int dfd, const char __user *filename, int flags, int return do_sys_open(dfd, filename, flags, mode); } -/* - * compat_count() counts the number of arguments/envelopes. It is basically - * a copy of count() from fs/exec.c, except that it works with 32 bit argv - * and envp pointers. - */ -static int compat_count(compat_uptr_t __user *argv, int max) -{ - int i = 0; - - if (argv != NULL) { - for (;;) { - compat_uptr_t p; - - if (get_user(p, argv)) - return -EFAULT; - if (!p) - break; - argv++; - if (i++ >= max) - return -E2BIG; - - if (fatal_signal_pending(current)) - return -ERESTARTNOHAND; - cond_resched(); - } - } - return i; -} - -/* - * compat_copy_strings() is basically a copy of copy_strings() from fs/exec.c - * except that it works with 32 bit argv and envp pointers. - */ -static int compat_copy_strings(int argc, compat_uptr_t __user *argv, - struct linux_binprm *bprm) -{ - struct page *kmapped_page = NULL; - char *kaddr = NULL; - unsigned long kpos = 0; - int ret; - - while (argc-- > 0) { - compat_uptr_t str; - int len; - unsigned long pos; - - if (get_user(str, argv+argc) || - !(len = strnlen_user(compat_ptr(str), MAX_ARG_STRLEN))) { - ret = -EFAULT; - goto out; - } - - if (len > MAX_ARG_STRLEN) { - ret = -E2BIG; - goto out; - } - - /* We're going to work our way backwords. */ - pos = bprm->p; - str += len; - bprm->p -= len; - - while (len > 0) { - int offset, bytes_to_copy; - - if (fatal_signal_pending(current)) { - ret = -ERESTARTNOHAND; - goto out; - } - cond_resched(); - - offset = pos % PAGE_SIZE; - if (offset == 0) - offset = PAGE_SIZE; - - bytes_to_copy = offset; - if (bytes_to_copy > len) - bytes_to_copy = len; - - offset -= bytes_to_copy; - pos -= bytes_to_copy; - str -= bytes_to_copy; - len -= bytes_to_copy; - - if (!kmapped_page || kpos != (pos & PAGE_MASK)) { - struct page *page; - - page = get_arg_page(bprm, pos, 1); - if (!page) { - ret = -E2BIG; - goto out; - } - - if (kmapped_page) { - flush_kernel_dcache_page(kmapped_page); - kunmap(kmapped_page); - put_page(kmapped_page); - } - kmapped_page = page; - kaddr = kmap(kmapped_page); - kpos = pos & PAGE_MASK; - flush_cache_page(bprm->vma, kpos, - page_to_pfn(kmapped_page)); - } - if (copy_from_user(kaddr+offset, compat_ptr(str), - bytes_to_copy)) { - ret = -EFAULT; - goto out; - } - } - } - ret = 0; -out: - if (kmapped_page) { - flush_kernel_dcache_page(kmapped_page); - kunmap(kmapped_page); - put_page(kmapped_page); - } - return ret; -} - -/* - * compat_do_execve() is mostly a copy of do_execve(), with the exception - * that it processes 32 bit argv and envp pointers. - */ -int compat_do_execve(char * filename, - compat_uptr_t __user *argv, - compat_uptr_t __user *envp, - struct pt_regs * regs) -{ - struct linux_binprm *bprm; - struct file *file; - struct files_struct *displaced; - bool clear_in_exec; - int retval; - - retval = unshare_files(&displaced); - if (retval) - goto out_ret; - - retval = -ENOMEM; - bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); - if (!bprm) - goto out_files; - - retval = prepare_bprm_creds(bprm); - if (retval) - goto out_free; - - retval = check_unsafe_exec(bprm); - if (retval < 0) - goto out_free; - clear_in_exec = retval; - current->in_execve = 1; - - file = open_exec(filename); - retval = PTR_ERR(file); - if (IS_ERR(file)) - goto out_unmark; - - sched_exec(); - - bprm->file = file; - bprm->filename = filename; - bprm->interp = filename; - - retval = bprm_mm_init(bprm); - if (retval) - goto out_file; - - bprm->argc = compat_count(argv, MAX_ARG_STRINGS); - if ((retval = bprm->argc) < 0) - goto out; - - bprm->envc = compat_count(envp, MAX_ARG_STRINGS); - if ((retval = bprm->envc) < 0) - goto out; - - retval = prepare_binprm(bprm); - if (retval < 0) - goto out; - - retval = copy_strings_kernel(1, &bprm->filename, bprm); - if (retval < 0) - goto out; - - bprm->exec = bprm->p; - retval = compat_copy_strings(bprm->envc, envp, bprm); - if (retval < 0) - goto out; - - retval = compat_copy_strings(bprm->argc, argv, bprm); - if (retval < 0) - goto out; - - retval = search_binary_handler(bprm, regs); - if (retval < 0) - goto out; - - /* execve succeeded */ - current->fs->in_exec = 0; - current->in_execve = 0; - acct_update_integrals(current); - free_bprm(bprm); - if (displaced) - put_files_struct(displaced); - return retval; - -out: - if (bprm->mm) { - acct_arg_size(bprm, 0); - mmput(bprm->mm); - } - -out_file: - if (bprm->file) { - allow_write_access(bprm->file); - fput(bprm->file); - } - -out_unmark: - if (clear_in_exec) - current->fs->in_exec = 0; - current->in_execve = 0; - -out_free: - free_bprm(bprm); - -out_files: - if (displaced) - reset_files_struct(displaced); -out_ret: - return retval; -} - #define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t)) static int poll_select_copy_remaining(struct timespec *end_time, void __user *p, |
