Re: [PATCH] ide-cd: fix endianity for the error message incdrom_read_capacity

From: Borislav Petkov
Date: Wed Jul 30 2008 - 15:27:22 EST


... and here the rediffed one for 2.6.25.y:

---
From: Petr Tesarik <ptesarik@xxxxxxx>

Aesthetic regards aside, commit e8e7b9eb11c34ee18bde8b7011af41938d1ad667
still leaves a bug in the error message, because it uses the unconverted
big-endian value for printk.

Fix this by using a local variable in machine byte order. The result is
correct, more readable, and also produces slightly shorter code on i386.

Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Signed-off-by: Petr Tesarik <ptesarik@xxxxxxx>
Acked-by: Borislav Petkov <petkovbb@xxxxxxxxx>
---
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index e54da02..3b388ca 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1411,6 +1411,7 @@ static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,

int stat;
struct request req;
+ __u32 blocklen;

ide_cd_init_rq(drive, &req);

@@ -1427,23 +1428,24 @@ static int cdrom_read_capacity(ide_drive_t *drive, unsigned long *capacity,
/*
* Sanity check the given block size
*/
- switch (capbuf.blocklen) {
- case __constant_cpu_to_be32(512):
- case __constant_cpu_to_be32(1024):
- case __constant_cpu_to_be32(2048):
- case __constant_cpu_to_be32(4096):
+ blocklen = be32_to_cpu(capbuf.blocklen);
+ switch (blocklen) {
+ case 512:
+ case 1024:
+ case 2048:
+ case 4096:
break;
default:
printk(KERN_ERR "%s: weird block size %u\n",
- drive->name, capbuf.blocklen);
+ drive->name, blocklen);
printk(KERN_ERR "%s: default to 2kb block size\n",
drive->name);
- capbuf.blocklen = __constant_cpu_to_be32(2048);
+ blocklen = 2048;
break;
}

*capacity = 1 + be32_to_cpu(capbuf.lba);
- *sectors_per_frame = be32_to_cpu(capbuf.blocklen) >> SECTOR_BITS;
+ *sectors_per_frame = blocklen >> SECTOR_BITS;
return 0;
}


--
Regards/Gruß,
Boris.
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