Re: [PATCH][RFC] 2.5.42: remove capable(CAP_SYS_RAWIO) check from open_kmem

[Olaf Dietsche <olaf.dietsche#list.linux-kernel@t-online.de>]

Olaf Dietsche <olaf.dietsche#list.linux-kernel@t-online.de> writes:

> In drivers/char/mem.c there's open_port(), which is used as open_mem()
> and open_kmem() as well. I don't see the benefit of this, since
> /dev/mem and /dev/kmem are already protected by filesystem
> permissions.
>
> mem.c, line 526:
> static int open_port(struct inode * inode, struct file * filp)
> {
> 	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
> }
>
> If anyone knows, why this is done this way, please let me
> know. Otherwise, I suggest the patch below.

I haven't got a convincing answer against this patch, so far. The
patch applies to 2.5.43 as well.
Linus, please apply.

Regards, Olaf.

--- a/drivers/char/mem.c	Sat Oct  5 18:44:55 2002
+++ b/drivers/char/mem.c	Sun Oct 13 13:59:25 2002
@@ -533,15 +533,12 @@
 #define full_lseek      null_lseek
 #define write_zero	write_null
 #define read_full       read_zero
-#define open_mem	open_port
-#define open_kmem	open_mem
 
 static struct file_operations mem_fops = {
 	llseek:		memory_lseek,
 	read:		read_mem,
 	write:		write_mem,
 	mmap:		mmap_mem,
-	open:		open_mem,
 };
 
 static struct file_operations kmem_fops = {
@@ -549,7 +546,6 @@
 	read:		read_kmem,
 	write:		write_kmem,
 	mmap:		mmap_kmem,
-	open:		open_kmem,
 };
 
 static struct file_operations null_fops = {