2000-11-30 21:16:50

by Richard Pries

Subject: [PATCH] Replace wrong structure type in mmc_ioctl() in cdrom.c

Jens,

Please consider the following patch for the wrong type of structure
in mmc_ioctl() in cdrom.c.

Currently, mmc_ioctl() in cdrom.c is passed a cdrom_msf structure
when ioctl() is called with CDROMREADRAW, CDROMREADMODE1, or
CDROMREADMODE2 as its second argument. This structure does not
provide the required buffer for reading the data, and it does not
correspond to the structure that cdrom.h says to use with these
ioctl() calls. This patch replaces the cdrom_msf structure with a
cdrom_read structure (as specified in cdrom.h). Preliminary tests
indicate that this patch works for both IDE and SCSI drives.


--- linux-2.2.17/drivers/cdrom/cdrom.c Mon Sep 4 10:39:17 2000
+++ linux-2.2.17rap/drivers/cdrom/cdrom.c Thu Nov 30 09:01:54 2000
@@ -1432,7 +1432,7 @@
cgc->cmd[7] = (nblocks >> 8) & 0xff;
cgc->cmd[8] = nblocks & 0xff;
cgc->buflen = blksize * nblocks;
-
+
/* set the header info returned */
switch (blksize) {
case CD_FRAMESIZE_RAW0 : cgc->cmd[9] = 0x58; break;
@@ -1863,8 +1863,10 @@
case CDROMREADRAW:
case CDROMREADMODE1:
case CDROMREADMODE2: {
- struct cdrom_msf msf;
+
+ struct cdrom_read cdr;
int blocksize = 0, format = 0, lba;
+ int nframes;

switch (cmd) {
case CDROMREADRAW:
@@ -1878,15 +1880,17 @@
blocksize = CD_FRAMESIZE_RAW0;
break;
}
- IOCTL_IN(arg, struct cdrom_msf, msf);
- lba = msf_to_lba(msf.cdmsf_min0,msf.cdmsf_sec0,msf.cdmsf_frame0);
+ IOCTL_IN(arg, struct cdrom_read, cdr);
+ lba = cdr.cdread_lba;
+ nframes = cdr.cdread_buflen/blocksize;
/* FIXME: we need upper bound checking, too!! */
- if (lba < 0)
+ if (lba < 0)
return -EINVAL;
- cgc.buffer = (char *) kmalloc(blocksize, GFP_KERNEL);
+ cgc.buffer = (char *) kmalloc(blocksize*nframes, GFP_KERNEL);
if (cgc.buffer == NULL)
return -ENOMEM;
- ret = cdrom_read_block(cdi, &cgc, lba, 1, format, blocksize);
+ ret = cdrom_read_block(cdi, &cgc, lba, nframes, format,
+ blocksize);
if (ret) {
/*
* SCSI-II devices are not required to support
@@ -1897,10 +1901,11 @@
kfree(cgc.buffer);
return ret;
}
- ret = cdrom_read_cd(cdi, &cgc, lba, blocksize, 1);
+ ret = cdrom_read_cd(cdi, &cgc, lba, blocksize, nframes);
ret |= cdrom_switch_blocksize(cdi, blocksize);
}
- if (!ret && copy_to_user((char *)arg, cgc.buffer, blocksize))
+ if (!ret && copy_to_user(cdr.cdread_bufaddr, cgc.buffer,
+ blocksize*nframes))
ret = -EFAULT;
kfree(cgc.buffer);
return ret;

2000-11-30 21:52:56

by Jens Axboe

Subject: Re: [PATCH] Replace wrong structure type in mmc_ioctl() in cdrom.c

On Thu, Nov 30 2000, Richard Pries wrote:
> Jens,
>
> Please consider the following patch for the wrong type of structure
> in mmc_ioctl() in cdrom.c.
>
> Currently, mmc_ioctl() in cdrom.c is passed a cdrom_msf structure
> when ioctl() is called with CDROMREADRAW, CDROMREADMODE1, or
> CDROMREADMODE2 as its second argument. This structure does not
> provide the required buffer for reading the data, and it does not
> correspond to the structure that cdrom.h says to use with these
> ioctl() calls. This patch replaces the cdrom_msf structure with a
> cdrom_read structure (as specified in cdrom.h). Preliminary tests
> indicate that this patch works for both IDE and SCSI drives.

Sure I bet it works, but you just broke all the programs that currently
use any of the above ioctls. I've known about this for years... You
can do all that you want with cdrom_msf, it's just more hassle. For
2.5 I'll introduce newer variants of the above ioctls and keep them as-is
for compatability, tossing them out is not an option.

I will take a patch that corrects the comment though!

--
* Jens Axboe <[email protected]>
* SuSE Labs