Skip to content

Commit

Permalink
[PATCH] idetape gcc 4.1 warning fix
Browse files Browse the repository at this point in the history 
In both the read and write cases it will return an error if
copy_{from/to}_user faults.  However, I let the driver try to read/write as
much as it can just as it normally would , then finally it returns an error
if there was one.  This was the most straight forward way to handle the
error , since there isn't a clear way to clean up the buffers on error .

I moved retval in idetape_chrdev_write() down into the actual code blocks
since it's really once used there, and it conflicted with my ret variable.

Fixes the following warning,

drivers/ide/ide-tape.c: In function �idetape_copy_stage_from_user�:
drivers/ide/ide-tape.c:2662: warning: ignoring return value of �copy_from_user�, declared with attribute warn_unused_result
drivers/ide/ide-tape.c: In function �idetape_copy_stage_to_user�:
drivers/ide/ide-tape.c:2689: warning: ignoring return value of �copy_to_user�, declared with attribute warn_unused_result

Signed-off-by: Daniel Walker <dwalker@mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
  • Loading branch information
Daniel Walker authored and Linus Torvalds committed Jun 25, 2006
1 parent a04ee14 commit dcd9637
Showing 1 changed file with 33 additions and 16 deletions.
49 changes: 33 additions & 16 deletions drivers/ide/ide-tape.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2646,21 +2646,23 @@ static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape)
return __idetape_kmalloc_stage(tape, 0, 0);
}

static void idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
{
struct idetape_bh *bh = tape->bh;
int count;
int ret = 0;

while (n) {
#if IDETAPE_DEBUG_BUGS
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_copy_stage_from_user\n");
return;
return 1;
}
#endif /* IDETAPE_DEBUG_BUGS */
count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count);
if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count))
ret = 1;
n -= count;
atomic_add(count, &bh->b_count);
buf += count;
Expand All @@ -2671,23 +2673,26 @@ static void idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t
}
}
tape->bh = bh;
return ret;
}

static void idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
static int idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
{
struct idetape_bh *bh = tape->bh;
int count;
int ret = 0;

while (n) {
#if IDETAPE_DEBUG_BUGS
if (bh == NULL) {
printk(KERN_ERR "ide-tape: bh == NULL in "
"idetape_copy_stage_to_user\n");
return;
return 1;
}
#endif /* IDETAPE_DEBUG_BUGS */
count = min(tape->b_count, n);
copy_to_user(buf, tape->b_data, count);
if (copy_to_user(buf, tape->b_data, count))
ret = 1;
n -= count;
tape->b_data += count;
tape->b_count -= count;
Expand All @@ -2700,6 +2705,7 @@ static void idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf,
}
}
}
return ret;
}

static void idetape_init_merge_stage (idetape_tape_t *tape)
Expand Down Expand Up @@ -3719,6 +3725,7 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
struct ide_tape_obj *tape = ide_tape_f(file);
ide_drive_t *drive = tape->drive;
ssize_t bytes_read,temp, actually_read = 0, rc;
ssize_t ret = 0;

#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 3)
Expand All @@ -3737,7 +3744,8 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
return (0);
if (tape->merge_stage_size) {
actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count);
idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read);
if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read))
ret = -EFAULT;
buf += actually_read;
tape->merge_stage_size -= actually_read;
count -= actually_read;
Expand All @@ -3746,7 +3754,8 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl);
if (bytes_read <= 0)
goto finish;
idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read);
if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read))
ret = -EFAULT;
buf += bytes_read;
count -= bytes_read;
actually_read += bytes_read;
Expand All @@ -3756,7 +3765,8 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
if (bytes_read <= 0)
goto finish;
temp = min((unsigned long)count, (unsigned long)bytes_read);
idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp);
if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp))
ret = -EFAULT;
actually_read += temp;
tape->merge_stage_size = bytes_read-temp;
}
Expand All @@ -3769,15 +3779,17 @@ static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
idetape_space_over_filemarks(drive, MTFSF, 1);
return 0;
}
return actually_read;

return (ret) ? ret : actually_read;
}

static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct ide_tape_obj *tape = ide_tape_f(file);
ide_drive_t *drive = tape->drive;
ssize_t retval, actually_written = 0;
ssize_t actually_written = 0;
ssize_t ret = 0;

/* The drive is write protected. */
if (tape->write_prot)
Expand Down Expand Up @@ -3813,7 +3825,7 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
* some drives (Seagate STT3401A) will return an error.
*/
if (drive->dsc_overlap) {
retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
ssize_t retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
if (retval < 0) {
__idetape_kfree_stage(tape->merge_stage);
tape->merge_stage = NULL;
Expand All @@ -3834,20 +3846,24 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
}
#endif /* IDETAPE_DEBUG_BUGS */
actually_written = min((unsigned int)(tape->stage_size - tape->merge_stage_size), (unsigned int)count);
idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written);
if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written))
ret = -EFAULT;
buf += actually_written;
tape->merge_stage_size += actually_written;
count -= actually_written;

if (tape->merge_stage_size == tape->stage_size) {
ssize_t retval;
tape->merge_stage_size = 0;
retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
if (retval <= 0)
return (retval);
}
}
while (count >= tape->stage_size) {
idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size);
ssize_t retval;
if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size))
ret = -EFAULT;
buf += tape->stage_size;
count -= tape->stage_size;
retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
Expand All @@ -3857,10 +3873,11 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
}
if (count) {
actually_written += count;
idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count);
if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count))
ret = -EFAULT;
tape->merge_stage_size += count;
}
return (actually_written);
return (ret) ? ret : actually_written;
}

static int idetape_write_filemark (ide_drive_t *drive)
Expand Down

0 comments on commit dcd9637

Please sign in to comment.