From: Daniel Walker Date: Sun, 25 Jun 2006 12:47:37 +0000 (-0700) Subject: [PATCH] idetape gcc 4.1 warning fix X-Git-Tag: v2.6.18-rc1~1002 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=dcd96379613a3cbe87c30e1c20122ecdcdf3a4b8;p=linux-2.6-omap-h63xx.git [PATCH] idetape gcc 4.1 warning fix 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 Cc: Alan Cox Cc: Bartlomiej Zolnierkiewicz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c index f04791a58df..09f3a7dab28 100644 --- a/drivers/ide/ide-tape.c +++ b/drivers/ide/ide-tape.c @@ -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; @@ -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; @@ -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) @@ -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) @@ -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; @@ -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; @@ -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; } @@ -3769,7 +3779,8 @@ finish: 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, @@ -3777,7 +3788,8 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf, { 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) @@ -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; @@ -3834,12 +3846,14 @@ 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) @@ -3847,7 +3861,9 @@ static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf, } } 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); @@ -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)