Re: Re: [PATCH] usb-storage: don't call utsname()

From: Steve French (smfltc)
Date: Wed May 21 2008 - 17:01:24 EST


Greg KH wrote:
On Wed, May 21, 2008 at 02:52:51PM -0400, Christoph Hellwig wrote:
On Wed, May 21, 2008 at 11:09:57AM -0700, Greg KH wrote:
Why? With this change, if you change the version number, the file will
have to be rebuilt. Without the change, the file will not need to be
rebuilt, right?
Because thanks to the container patches it utsname fields other than
hostname can actually change at runtime now and you'll get races looking
at them. And probably not the output you want if someone in your
container changes the kernel version to trick applications.

So, do we now go and rip out all usages of utsname()->release and put
back the #define just because of the loonacy of containers?

No kernel should have to change it's version number to trick an
application, why would an application care about the version number to
The version number (of the OS not just of the SMB/CIFS implementation, both of which are exchanged by client and server) has sometimes been useful in debugging problems that I and others and the Samba team look at (you can see it in wireshark/tcpdump traces, and it can be logged easily on either end as well).

If containers are crazy enough to change the version number, not just the hostname, why don't we simply define a three line macro for retrieving this which is safe and put it in utsname.h?
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