lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Wed, 2 May 2007 02:54:40 +0200
From:	Segher Boessenkool <>
To:	Scott Wood <>
Subject: Re: [PATCH] gianfar: Add I/O barriers when touching buffer descriptor ownership.

> The hardware must not see that is given ownership of a buffer until it 
> is
> completely written, and when the driver receives ownership of a buffer,
> it must ensure that any other reads to the buffer reflect its final
> state.  Thus, I/O barriers are added where required.
> Without this patch, I have observed GCC reordering the setting of
> bdp->length and bdp->status in gfar_new_skb.

The :::"memory" in the barriers you used prevent GCC
from reordering accesses around the barriers.

AFAICS you need stronger barriers though; {w,r,}mb(),
to prevent _any_ reordering of those memory accesses,
not just the compiler-generated ones.


To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists