[PATCH] ide-tape: attempt to handle copy_*_user() failures

From: Jesper Juhl
Date: Sun Jan 22 2006 - 16:37:01 EST

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Attempt to handle copy_*_user() failures in
drivers/ide/ide-tape.c::idetape_copy_stage_*_user

drivers/ide/ide-tape.c:2663: warning: ignoring return value of `copy_from_user', declared with attribute warn_unused_result
drivers/ide/ide-tape.c:2690: warning: ignoring return value of `copy_to_user', declared with attribute warn_unused_result

Due to lack of hardware I'm unfortunately not able to test this patch
beyond making sure it compiles.

Signed-off-by: Jesper Juhl <jesper.juhl@xxxxxxxxx>
---

drivers/ide/ide-tape.c | 48 ++++++++++++++++++++++++++++++++----------------
1 files changed, 32 insertions(+), 16 deletions(-)

--- linux-2.6.16-rc1-mm2-orig/drivers/ide/ide-tape.c 2006-01-20 21:50:44.000000000 +0100
+++ linux-2.6.16-rc1-mm2/drivers/ide/ide-tape.c 2006-01-22 22:34:59.000000000 +0100
@@ -2646,21 +2646,23 @@ static idetape_stage_t *idetape_kmalloc_
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 unsigned long 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;
+ unsigned long not_copied;

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 0;
}
#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);
+ not_copied = copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count);
+ count -= not_copied;
n -= count;
atomic_add(count, &bh->b_count);
buf += count;
@@ -2669,26 +2671,30 @@ static void idetape_copy_stage_from_user
if (bh)
atomic_set(&bh->b_count, 0);
}
+ if (not_copied)
+ return not_copied;
}
tape->bh = bh;
+ return 0;
}

-static void idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
+static unsigned long 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;
+ unsigned long not_copied;

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 0;
}
#endif /* IDETAPE_DEBUG_BUGS */
count = min(tape->b_count, n);
- copy_to_user(buf, tape->b_data, count);
- n -= count;
+ not_copied = copy_to_user(buf, tape->b_data, count);
+ n -= count - not_copied;
tape->b_data += count;
tape->b_count -= count;
buf += count;
@@ -2699,7 +2705,10 @@ static void idetape_copy_stage_to_user (
tape->b_count = atomic_read(&bh->b_count);
}
}
+ if (not_copied)
+ return not_copied;
}
+ return 0;
}

static void idetape_init_merge_stage (idetape_tape_t *tape)
@@ -3719,6 +3728,7 @@ static ssize_t idetape_chrdev_read (stru
struct ide_tape_obj *tape = ide_tape_f(file);
ide_drive_t *drive = tape->drive;
ssize_t bytes_read,temp, actually_read = 0, rc;
+ unsigned long not_copied;

#if IDETAPE_DEBUG_LOG
if (tape->debug_level >= 3)
@@ -3737,7 +3747,8 @@ static ssize_t idetape_chrdev_read (stru
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);
+ not_copied = idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read);
+ actually_read -= not_copied;
buf += actually_read;
tape->merge_stage_size -= actually_read;
count -= actually_read;
@@ -3746,7 +3757,8 @@ static ssize_t idetape_chrdev_read (stru
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);
+ not_copied = idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read);
+ bytes_read -= not_copied;
buf += bytes_read;
count -= bytes_read;
actually_read += bytes_read;
@@ -3756,7 +3768,8 @@ static ssize_t idetape_chrdev_read (stru
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);
+ not_copied = idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp);
+ temp -= not_copied;
actually_read += temp;
tape->merge_stage_size = bytes_read-temp;
}
@@ -3778,6 +3791,7 @@ static ssize_t idetape_chrdev_write (str
struct ide_tape_obj *tape = ide_tape_f(file);
ide_drive_t *drive = tape->drive;
ssize_t retval, actually_written = 0;
+ unsigned long not_copied;

/* The drive is write protected. */
if (tape->write_prot)
@@ -3834,7 +3848,8 @@ static ssize_t idetape_chrdev_write (str
}
#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);
+ not_copied = idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written);
+ actually_written -= not_copied;
buf += actually_written;
tape->merge_stage_size += actually_written;
count -= actually_written;
@@ -3847,17 +3862,18 @@ static ssize_t idetape_chrdev_write (str
}
}
while (count >= tape->stage_size) {
- idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size);
- buf += tape->stage_size;
- count -= tape->stage_size;
+ not_copied = idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size);
+ buf += tape->stage_size - not_copied;
+ count -= tape->stage_size - not_copied;
retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
- actually_written += tape->stage_size;
+ actually_written += tape->stage_size - not_copied;
if (retval <= 0)
return (retval);
}
if (count) {
actually_written += count;
- idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count);
+ not_copied = idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count);
+ count -= not_copied;
tape->merge_stage_size += count;
}
return (actually_written);
-
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Next message: Brown, Len: "RE: SMP+nosmp=hang [was: Re: 2.6.15-rc5-mm2]"
Previous message: Sam Ravnborg: "[PATCH] kbuild: support building individual files for external modules"
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