[PATCH 13/17] gadget/f_mass_storage: stop messing with the address limit

From: Christoph Hellwig
Date: Fri Sep 01 2017 - 11:40:19 EST


Instead use kernel_read/write consistently, which also makes sparse
happy.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/usb/gadget/function/f_mass_storage.c | 21 ++++++---------------
1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
index f95bddd6513f..d6bd0244b008 100644
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -686,9 +686,8 @@ static int do_read(struct fsg_common *common)

/* Perform the read */
file_offset_tmp = file_offset;
- nread = vfs_read(curlun->filp,
- (char __user *)bh->buf,
- amount, &file_offset_tmp);
+ nread = kernel_read(curlun->filp, bh->buf, amount,
+ &file_offset_tmp);
VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
(unsigned long long)file_offset, (int)nread);
if (signal_pending(current))
@@ -883,8 +882,8 @@ static int do_write(struct fsg_common *common)

/* Perform the write */
file_offset_tmp = file_offset;
- nwritten = vfs_write(curlun->filp, (char __user *)bh->buf,
- amount, &file_offset_tmp);
+ nwritten = kernel_write(curlun->filp, bh->buf, amount,
+ &file_offset_tmp);
VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
(unsigned long long)file_offset, (int)nwritten);
if (signal_pending(current))
@@ -1021,9 +1020,8 @@ static int do_verify(struct fsg_common *common)

/* Perform the read */
file_offset_tmp = file_offset;
- nread = vfs_read(curlun->filp,
- (char __user *) bh->buf,
- amount, &file_offset_tmp);
+ nread = kernel_read(curlun->filp, bh->buf, amount,
+ &file_offset_tmp);
VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
(unsigned long long) file_offset,
(int) nread);
@@ -2453,13 +2451,6 @@ static int fsg_main_thread(void *common_)
/* Allow the thread to be frozen */
set_freezable();

- /*
- * Arrange for userspace references to be interpreted as kernel
- * pointers. That way we can pass a kernel pointer to a routine
- * that expects a __user pointer and it will work okay.
- */
- set_fs(get_ds());
-
/* The main loop */
while (common->state != FSG_STATE_TERMINATED) {
if (exception_in_progress(common) || signal_pending(current)) {
--
2.11.0