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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-02 11:54:26 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-02 11:54:26 -0700 |
commit | 204f144c9fcac355843412b6ba1150086488a208 (patch) | |
tree | 7c06bcb63f2caf961855d2cea968d9fd94b325d7 /fs/read_write.c | |
parent | da7b66ffb2815800440d9e1649282a27c805304f (diff) | |
parent | 801b25f104647d44dc5b5cce2c72e2283b3757de (diff) |
Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fs/compat.c cleanups from Al Viro:
"More moving of compat syscalls from fs/compat.c to fs/*.c where the
native counterparts live.
And death to compat_sys_getdents64() - the only architecture that used
to need it was ia64, and _that_ has lost biarch support quite a few
years ago"
* 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs/compat.c: trim unused includes
move compat_rw_copy_check_uvector() over to fs/read_write.c
fhandle: move compat syscalls from compat.c
open: move compat syscalls from compat.c
stat: move compat syscalls from compat.c
fcntl: move compat syscalls from compat.c
readdir: move compat syscalls from compat.c
statfs: move compat syscalls from compat.c
utimes: move compat syscalls from compat.c
move compat select-related syscalls to fs/select.c
Remove compat_sys_getdents64()
Diffstat (limited to 'fs/read_write.c')
-rw-r--r-- | fs/read_write.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index c4f88afbc67f..47c1d4484df9 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -841,6 +841,81 @@ out: return ret; } +#ifdef CONFIG_COMPAT +ssize_t compat_rw_copy_check_uvector(int type, + const struct compat_iovec __user *uvector, unsigned long nr_segs, + unsigned long fast_segs, struct iovec *fast_pointer, + struct iovec **ret_pointer) +{ + compat_ssize_t tot_len; + struct iovec *iov = *ret_pointer = fast_pointer; + ssize_t ret = 0; + int seg; + + /* + * SuS says "The readv() function *may* fail if the iovcnt argument + * was less than or equal to 0, or greater than {IOV_MAX}. Linux has + * traditionally returned zero for zero segments, so... + */ + if (nr_segs == 0) + goto out; + + ret = -EINVAL; + if (nr_segs > UIO_MAXIOV) + goto out; + if (nr_segs > fast_segs) { + ret = -ENOMEM; + iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL); + if (iov == NULL) + goto out; + } + *ret_pointer = iov; + + ret = -EFAULT; + if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector))) + goto out; + + /* + * Single unix specification: + * We should -EINVAL if an element length is not >= 0 and fitting an + * ssize_t. + * + * In Linux, the total length is limited to MAX_RW_COUNT, there is + * no overflow possibility. + */ + tot_len = 0; + ret = -EINVAL; + for (seg = 0; seg < nr_segs; seg++) { + compat_uptr_t buf; + compat_ssize_t len; + + if (__get_user(len, &uvector->iov_len) || + __get_user(buf, &uvector->iov_base)) { + ret = -EFAULT; + goto out; + } + if (len < 0) /* size_t not fitting in compat_ssize_t .. */ + goto out; + if (type >= 0 && + !access_ok(vrfy_dir(type), compat_ptr(buf), len)) { + ret = -EFAULT; + goto out; + } + if (len > MAX_RW_COUNT - tot_len) + len = MAX_RW_COUNT - tot_len; + tot_len += len; + iov->iov_base = compat_ptr(buf); + iov->iov_len = (compat_size_t) len; + uvector++; + iov++; + } + ret = tot_len; + +out: + return ret; +} +#endif + static ssize_t __do_readv_writev(int type, struct file *file, struct iov_iter *iter, loff_t *pos, int flags) { |