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-rw-r--r--fs/read_write.c362
1 files changed, 26 insertions, 336 deletions
diff --git a/fs/read_write.c b/fs/read_write.c
index d3428189f36b..19f5c4bf75aa 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -760,185 +760,6 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter,
return ret;
}
-/**
- * rw_copy_check_uvector() - Copy an array of &struct iovec from userspace
- * into the kernel and check that it is valid.
- *
- * @type: One of %CHECK_IOVEC_ONLY, %READ, or %WRITE.
- * @uvector: Pointer to the userspace array.
- * @nr_segs: Number of elements in userspace array.
- * @fast_segs: Number of elements in @fast_pointer.
- * @fast_pointer: Pointer to (usually small on-stack) kernel array.
- * @ret_pointer: (output parameter) Pointer to a variable that will point to
- * either @fast_pointer, a newly allocated kernel array, or NULL,
- * depending on which array was used.
- *
- * This function copies an array of &struct iovec of @nr_segs from
- * userspace into the kernel and checks that each element is valid (e.g.
- * it does not point to a kernel address or cause overflow by being too
- * large, etc.).
- *
- * As an optimization, the caller may provide a pointer to a small
- * on-stack array in @fast_pointer, typically %UIO_FASTIOV elements long
- * (the size of this array, or 0 if unused, should be given in @fast_segs).
- *
- * @ret_pointer will always point to the array that was used, so the
- * caller must take care not to call kfree() on it e.g. in case the
- * @fast_pointer array was used and it was allocated on the stack.
- *
- * Return: The total number of bytes covered by the iovec array on success
- * or a negative error code on error.
- */
-ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
- unsigned long nr_segs, unsigned long fast_segs,
- struct iovec *fast_pointer,
- struct iovec **ret_pointer)
-{
- unsigned long seg;
- ssize_t ret;
- struct iovec *iov = fast_pointer;
-
- /*
- * 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) {
- ret = 0;
- goto out;
- }
-
- /*
- * First get the "struct iovec" from user memory and
- * verify all the pointers
- */
- if (nr_segs > UIO_MAXIOV) {
- ret = -EINVAL;
- goto out;
- }
- if (nr_segs > fast_segs) {
- iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL);
- if (iov == NULL) {
- ret = -ENOMEM;
- goto out;
- }
- }
- if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
- ret = -EFAULT;
- goto out;
- }
-
- /*
- * According to the Single Unix Specification we should return EINVAL
- * if an element length is < 0 when cast to ssize_t or if the
- * total length would overflow the ssize_t return value of the
- * system call.
- *
- * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
- * overflow case.
- */
- ret = 0;
- for (seg = 0; seg < nr_segs; seg++) {
- void __user *buf = iov[seg].iov_base;
- ssize_t len = (ssize_t)iov[seg].iov_len;
-
- /* see if we we're about to use an invalid len or if
- * it's about to overflow ssize_t */
- if (len < 0) {
- ret = -EINVAL;
- goto out;
- }
- if (type >= 0
- && unlikely(!access_ok(buf, len))) {
- ret = -EFAULT;
- goto out;
- }
- if (len > MAX_RW_COUNT - ret) {
- len = MAX_RW_COUNT - ret;
- iov[seg].iov_len = len;
- }
- ret += len;
- }
-out:
- *ret_pointer = iov;
- 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_array(nr_segs, sizeof(struct iovec), GFP_KERNEL);
- if (iov == NULL)
- goto out;
- }
- *ret_pointer = iov;
-
- ret = -EFAULT;
- if (!access_ok(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(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_iter_read(struct file *file, struct iov_iter *iter,
loff_t *pos, rwf_t flags)
{
@@ -1255,224 +1076,93 @@ SYSCALL_DEFINE6(pwritev2, unsigned long, fd, const struct iovec __user *, vec,
return do_pwritev(fd, vec, vlen, pos, flags);
}
+/*
+ * Various compat syscalls. Note that they all pretend to take a native
+ * iovec - import_iovec will properly treat those as compat_iovecs based on
+ * in_compat_syscall().
+ */
#ifdef CONFIG_COMPAT
-static size_t compat_readv(struct file *file,
- const struct compat_iovec __user *vec,
- unsigned long vlen, loff_t *pos, rwf_t flags)
-{
- struct iovec iovstack[UIO_FASTIOV];
- struct iovec *iov = iovstack;
- struct iov_iter iter;
- ssize_t ret;
-
- ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter);
- if (ret >= 0) {
- ret = do_iter_read(file, &iter, pos, flags);
- kfree(iov);
- }
- if (ret > 0)
- add_rchar(current, ret);
- inc_syscr(current);
- return ret;
-}
-
-static size_t do_compat_readv(compat_ulong_t fd,
- const struct compat_iovec __user *vec,
- compat_ulong_t vlen, rwf_t flags)
-{
- struct fd f = fdget_pos(fd);
- ssize_t ret;
- loff_t pos;
-
- if (!f.file)
- return -EBADF;
- pos = f.file->f_pos;
- ret = compat_readv(f.file, vec, vlen, &pos, flags);
- if (ret >= 0)
- f.file->f_pos = pos;
- fdput_pos(f);
- return ret;
-
-}
-
-COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
- compat_ulong_t, vlen)
-{
- return do_compat_readv(fd, vec, vlen, 0);
-}
-
-static long do_compat_preadv64(unsigned long fd,
- const struct compat_iovec __user *vec,
- unsigned long vlen, loff_t pos, rwf_t flags)
-{
- struct fd f;
- ssize_t ret;
-
- if (pos < 0)
- return -EINVAL;
- f = fdget(fd);
- if (!f.file)
- return -EBADF;
- ret = -ESPIPE;
- if (f.file->f_mode & FMODE_PREAD)
- ret = compat_readv(f.file, vec, vlen, &pos, flags);
- fdput(f);
- return ret;
-}
-
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
unsigned long, vlen, loff_t, pos)
{
- return do_compat_preadv64(fd, vec, vlen, pos, 0);
+ return do_preadv(fd, vec, vlen, pos, 0);
}
#endif
COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
{
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
- return do_compat_preadv64(fd, vec, vlen, pos, 0);
+ return do_preadv(fd, vec, vlen, pos, 0);
}
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
unsigned long, vlen, loff_t, pos, rwf_t, flags)
{
if (pos == -1)
- return do_compat_readv(fd, vec, vlen, flags);
-
- return do_compat_preadv64(fd, vec, vlen, pos, flags);
+ return do_readv(fd, vec, vlen, flags);
+ return do_preadv(fd, vec, vlen, pos, flags);
}
#endif
COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
rwf_t, flags)
{
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
if (pos == -1)
- return do_compat_readv(fd, vec, vlen, flags);
-
- return do_compat_preadv64(fd, vec, vlen, pos, flags);
-}
-
-static size_t compat_writev(struct file *file,
- const struct compat_iovec __user *vec,
- unsigned long vlen, loff_t *pos, rwf_t flags)
-{
- struct iovec iovstack[UIO_FASTIOV];
- struct iovec *iov = iovstack;
- struct iov_iter iter;
- ssize_t ret;
-
- ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter);
- if (ret >= 0) {
- file_start_write(file);
- ret = do_iter_write(file, &iter, pos, flags);
- file_end_write(file);
- kfree(iov);
- }
- if (ret > 0)
- add_wchar(current, ret);
- inc_syscw(current);
- return ret;
-}
-
-static size_t do_compat_writev(compat_ulong_t fd,
- const struct compat_iovec __user* vec,
- compat_ulong_t vlen, rwf_t flags)
-{
- struct fd f = fdget_pos(fd);
- ssize_t ret;
- loff_t pos;
-
- if (!f.file)
- return -EBADF;
- pos = f.file->f_pos;
- ret = compat_writev(f.file, vec, vlen, &pos, flags);
- if (ret >= 0)
- f.file->f_pos = pos;
- fdput_pos(f);
- return ret;
-}
-
-COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
- const struct compat_iovec __user *, vec,
- compat_ulong_t, vlen)
-{
- return do_compat_writev(fd, vec, vlen, 0);
-}
-
-static long do_compat_pwritev64(unsigned long fd,
- const struct compat_iovec __user *vec,
- unsigned long vlen, loff_t pos, rwf_t flags)
-{
- struct fd f;
- ssize_t ret;
-
- if (pos < 0)
- return -EINVAL;
- f = fdget(fd);
- if (!f.file)
- return -EBADF;
- ret = -ESPIPE;
- if (f.file->f_mode & FMODE_PWRITE)
- ret = compat_writev(f.file, vec, vlen, &pos, flags);
- fdput(f);
- return ret;
+ return do_readv(fd, vec, vlen, flags);
+ return do_preadv(fd, vec, vlen, pos, flags);
}
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
unsigned long, vlen, loff_t, pos)
{
- return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+ return do_pwritev(fd, vec, vlen, pos, 0);
}
#endif
COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *,vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
{
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
- return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+ return do_pwritev(fd, vec, vlen, pos, 0);
}
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
unsigned long, vlen, loff_t, pos, rwf_t, flags)
{
if (pos == -1)
- return do_compat_writev(fd, vec, vlen, flags);
-
- return do_compat_pwritev64(fd, vec, vlen, pos, flags);
+ return do_writev(fd, vec, vlen, flags);
+ return do_pwritev(fd, vec, vlen, pos, flags);
}
#endif
COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *,vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags)
{
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
if (pos == -1)
- return do_compat_writev(fd, vec, vlen, flags);
-
- return do_compat_pwritev64(fd, vec, vlen, pos, flags);
+ return do_writev(fd, vec, vlen, flags);
+ return do_pwritev(fd, vec, vlen, pos, flags);
}
-
-#endif
+#endif /* CONFIG_COMPAT */
static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
size_t count, loff_t max)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 07:44:43 +0100