diff options
Diffstat (limited to 'fs/readdir.c')
| -rw-r--r-- | fs/readdir.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/fs/readdir.c b/fs/readdir.c index 0e8a7f355f7a..89659549c09d 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -18,6 +18,7 @@ #include <linux/security.h> #include <linux/syscalls.h> #include <linux/unistd.h> +#include <linux/compat.h> #include <linux/uaccess.h> @@ -324,3 +325,167 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd, fdput_pos(f); return error; } + +#ifdef CONFIG_COMPAT +struct compat_old_linux_dirent { + compat_ulong_t d_ino; + compat_ulong_t d_offset; + unsigned short d_namlen; + char d_name[1]; +}; + +struct compat_readdir_callback { + struct dir_context ctx; + struct compat_old_linux_dirent __user *dirent; + int result; +}; + +static int compat_fillonedir(struct dir_context *ctx, const char *name, + int namlen, loff_t offset, u64 ino, + unsigned int d_type) +{ + struct compat_readdir_callback *buf = + container_of(ctx, struct compat_readdir_callback, ctx); + struct compat_old_linux_dirent __user *dirent; + compat_ulong_t d_ino; + + if (buf->result) + return -EINVAL; + d_ino = ino; + if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { + buf->result = -EOVERFLOW; + return -EOVERFLOW; + } + buf->result++; + dirent = buf->dirent; + if (!access_ok(VERIFY_WRITE, dirent, + (unsigned long)(dirent->d_name + namlen + 1) - + (unsigned long)dirent)) + goto efault; + if ( __put_user(d_ino, &dirent->d_ino) || + __put_user(offset, &dirent->d_offset) || + __put_user(namlen, &dirent->d_namlen) || + __copy_to_user(dirent->d_name, name, namlen) || + __put_user(0, dirent->d_name + namlen)) + goto efault; + return 0; +efault: + buf->result = -EFAULT; + return -EFAULT; +} + +COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd, + struct compat_old_linux_dirent __user *, dirent, unsigned int, count) +{ + int error; + struct fd f = fdget_pos(fd); + struct compat_readdir_callback buf = { + .ctx.actor = compat_fillonedir, + .dirent = dirent + }; + + if (!f.file) + return -EBADF; + + error = iterate_dir(f.file, &buf.ctx); + if (buf.result) + error = buf.result; + + fdput_pos(f); + return error; +} + +struct compat_linux_dirent { + compat_ulong_t d_ino; + compat_ulong_t d_off; + unsigned short d_reclen; + char d_name[1]; +}; + +struct compat_getdents_callback { + struct dir_context ctx; + struct compat_linux_dirent __user *current_dir; + struct compat_linux_dirent __user *previous; + int count; + int error; +}; + +static int compat_filldir(struct dir_context *ctx, const char *name, int namlen, + loff_t offset, u64 ino, unsigned int d_type) +{ + struct compat_linux_dirent __user * dirent; + struct compat_getdents_callback *buf = + container_of(ctx, struct compat_getdents_callback, ctx); + compat_ulong_t d_ino; + int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) + + namlen + 2, sizeof(compat_long_t)); + + buf->error = -EINVAL; /* only used if we fail.. */ + if (reclen > buf->count) + return -EINVAL; + d_ino = ino; + if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { + buf->error = -EOVERFLOW; + return -EOVERFLOW; + } + dirent = buf->previous; + if (dirent) { + if (signal_pending(current)) + return -EINTR; + if (__put_user(offset, &dirent->d_off)) + goto efault; + } + dirent = buf->current_dir; + if (__put_user(d_ino, &dirent->d_ino)) + goto efault; + if (__put_user(reclen, &dirent->d_reclen)) + goto efault; + if (copy_to_user(dirent->d_name, name, namlen)) + goto efault; + if (__put_user(0, dirent->d_name + namlen)) + goto efault; + if (__put_user(d_type, (char __user *) dirent + reclen - 1)) + goto efault; + buf->previous = dirent; + dirent = (void __user *)dirent + reclen; + buf->current_dir = dirent; + buf->count -= reclen; + return 0; +efault: + buf->error = -EFAULT; + return -EFAULT; +} + +COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd, + struct compat_linux_dirent __user *, dirent, unsigned int, count) +{ + struct fd f; + struct compat_linux_dirent __user * lastdirent; + struct compat_getdents_callback buf = { + .ctx.actor = compat_filldir, + .current_dir = dirent, + .count = count + }; + int error; + + if (!access_ok(VERIFY_WRITE, dirent, count)) + return -EFAULT; + + f = fdget_pos(fd); + if (!f.file) + return -EBADF; + + error = iterate_dir(f.file, &buf.ctx); + if (error >= 0) + error = buf.error; + lastdirent = buf.previous; + if (lastdirent) { + if (put_user(buf.ctx.pos, &lastdirent->d_off)) + error = -EFAULT; + else + error = count - buf.count; + } + fdput_pos(f); + return error; +} +#endif |