* [PATCH] sys_sendmsg() alignment bug fix
@ 2005-09-26 20:02 Alex Williamson
2005-09-26 20:36 ` Andrew Morton
2005-09-27 3:40 ` Coywolf Qi Hunt
0 siblings, 2 replies; 6+ messages in thread
From: Alex Williamson @ 2005-09-26 20:02 UTC (permalink / raw)
To: akpm; +Cc: linux-kernel, netdev
The patch below adds an alignment attribute to the buffer used in
sys_sendmsg(). This eliminates an unaligned access warning on ia64.
Signed-off-by: Alex Williamson <alex.williamson@hp.com>
diff -r db9b9552a2b4 net/socket.c
--- a/net/socket.c Sat Sep 24 23:56:08 2005
+++ b/net/socket.c Mon Sep 26 13:44:09 2005
@@ -1700,7 +1700,9 @@
struct socket *sock;
char address[MAX_SOCK_ADDR];
struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
- unsigned char ctl[sizeof(struct cmsghdr) + 20]; /* 20 is size of ipv6_pktinfo */
+ unsigned char ctl[sizeof(struct cmsghdr) + 20]
+ __attribute__ ((aligned (sizeof(__kernel_size_t))));
+ /* 20 is size of ipv6_pktinfo */
unsigned char *ctl_buf = ctl;
struct msghdr msg_sys;
int err, ctl_len, iov_size, total_len;
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] sys_sendmsg() alignment bug fix
2005-09-26 20:02 [PATCH] sys_sendmsg() alignment bug fix Alex Williamson
@ 2005-09-26 20:36 ` Andrew Morton
2005-09-26 21:28 ` David S. Miller
2005-09-27 3:40 ` Coywolf Qi Hunt
1 sibling, 1 reply; 6+ messages in thread
From: Andrew Morton @ 2005-09-26 20:36 UTC (permalink / raw)
To: Alex Williamson; +Cc: linux-kernel, netdev, David S. Miller
Alex Williamson <alex.williamson@hp.com> wrote:
>
> The patch below adds an alignment attribute to the buffer used in
> sys_sendmsg(). This eliminates an unaligned access warning on ia64.
>
Vaguely surprised that the compiler cannot be taught to do this.
>
> diff -r db9b9552a2b4 net/socket.c
> --- a/net/socket.c Sat Sep 24 23:56:08 2005
> +++ b/net/socket.c Mon Sep 26 13:44:09 2005
> @@ -1700,7 +1700,9 @@
> struct socket *sock;
> char address[MAX_SOCK_ADDR];
> struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
> - unsigned char ctl[sizeof(struct cmsghdr) + 20]; /* 20 is size of ipv6_pktinfo */
> + unsigned char ctl[sizeof(struct cmsghdr) + 20]
> + __attribute__ ((aligned (sizeof(__kernel_size_t))));
> + /* 20 is size of ipv6_pktinfo */
> unsigned char *ctl_buf = ctl;
> struct msghdr msg_sys;
> int err, ctl_len, iov_size, total_len;
OK, thanks - I'll send this on to davem. It seems odd to be using
__kernel_size_t rather than size_t, but that's what struct cmshdr does
(also oddly).
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] sys_sendmsg() alignment bug fix
2005-09-26 20:02 [PATCH] sys_sendmsg() alignment bug fix Alex Williamson
2005-09-26 20:36 ` Andrew Morton
@ 2005-09-27 3:40 ` Coywolf Qi Hunt
2005-09-27 3:59 ` Alex Williamson
2005-09-27 4:50 ` David S. Miller
1 sibling, 2 replies; 6+ messages in thread
From: Coywolf Qi Hunt @ 2005-09-27 3:40 UTC (permalink / raw)
To: Alex Williamson; +Cc: akpm, linux-kernel, netdev
On 9/27/05, Alex Williamson <alex.williamson@hp.com> wrote:
> The patch below adds an alignment attribute to the buffer used in
> sys_sendmsg(). This eliminates an unaligned access warning on ia64.
Is this a warning fix or bug fix?
--
Coywolf Qi Hunt
http://sosdg.org/~coywolf/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] sys_sendmsg() alignment bug fix
2005-09-27 3:40 ` Coywolf Qi Hunt
@ 2005-09-27 3:59 ` Alex Williamson
2005-09-27 4:50 ` David S. Miller
1 sibling, 0 replies; 6+ messages in thread
From: Alex Williamson @ 2005-09-27 3:59 UTC (permalink / raw)
To: Coywolf Qi Hunt; +Cc: akpm, linux-kernel, netdev
On Tue, 2005-09-27 at 11:40 +0800, Coywolf Qi Hunt wrote:
> On 9/27/05, Alex Williamson <alex.williamson@hp.com> wrote:
> > The patch below adds an alignment attribute to the buffer used in
> > sys_sendmsg(). This eliminates an unaligned access warning on ia64.
>
> Is this a warning fix or bug fix?
Guess I'd have to classify it as a warning fix. ia64 is fairly
verbose about unaligned accesses by default, so the warning is printed
out runtime.
Alex
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] sys_sendmsg() alignment bug fix
2005-09-27 3:40 ` Coywolf Qi Hunt
2005-09-27 3:59 ` Alex Williamson
@ 2005-09-27 4:50 ` David S. Miller
1 sibling, 0 replies; 6+ messages in thread
From: David S. Miller @ 2005-09-27 4:50 UTC (permalink / raw)
To: coywolf; +Cc: alex.williamson, akpm, linux-kernel, netdev
From: Coywolf Qi Hunt <coywolf@gmail.com>
Date: Tue, 27 Sep 2005 11:40:38 +0800
> On 9/27/05, Alex Williamson <alex.williamson@hp.com> wrote:
> > The patch below adds an alignment attribute to the buffer used in
> > sys_sendmsg(). This eliminates an unaligned access warning on ia64.
>
> Is this a warning fix or bug fix?
It doesn't generate a warning, but it does generate totally
unnecessary unaligned access traps on RISC systems.
^ permalink raw reply [flat|nested] 6+ messages in thread
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2005-09-26 20:02 [PATCH] sys_sendmsg() alignment bug fix Alex Williamson
2005-09-26 20:36 ` Andrew Morton
2005-09-26 21:28 ` David S. Miller
2005-09-27 3:40 ` Coywolf Qi Hunt
2005-09-27 3:59 ` Alex Williamson
2005-09-27 4:50 ` David S. Miller
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