* [dpdk-stable] [PATCH 16.11] vhost-user: fix false negative in handling user messages
@ 2018-11-28 16:20 ` Luca Boccassi
2018-11-29 7:58 ` Ilya Maximets
2018-11-29 8:49 ` Maxime Coquelin
0 siblings, 2 replies; 4+ messages in thread
From: Luca Boccassi @ 2018-11-28 16:20 UTC (permalink / raw)
To: stable; +Cc: i.maximets, maxime.coquelin
vhost_user_msg_handler checks an accumulated return code before
returning, and prints an error and returns -1 if it's non-zero.
But some of the possible user messages cannot fail and thus do not
set the variable, which might retain a previously set and unrelated
value, causing unnecessary failures and error messages.
Reset the return code before use.
Fixes: 0ce9e73d1e8d ("vhost-user: drop connection on message handling failures")
Signed-off-by: Luca Boccassi <bluca@debian.org>
---
Found this issue when testing with the Vyatta stuff, "ret" is set at
the beginning of the function and never reset when the message is for example
VHOST_USER_GET_FEATURES so there's a flurry of errors.
lib/librte_vhost/vhost_user.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 00872c868..618d413fe 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1087,6 +1087,7 @@ vhost_user_msg_handler(int vid, int fd)
}
+ ret = 0;
switch (msg.request) {
case VHOST_USER_GET_FEATURES:
msg.payload.u64 = vhost_user_get_features();
--
2.19.2
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dpdk-stable] [PATCH 16.11] vhost-user: fix false negative in handling user messages
2018-11-28 16:20 ` [dpdk-stable] [PATCH 16.11] vhost-user: fix false negative in handling user messages Luca Boccassi
@ 2018-11-29 7:58 ` Ilya Maximets
2018-11-29 10:45 ` Luca Boccassi
2018-11-29 8:49 ` Maxime Coquelin
1 sibling, 1 reply; 4+ messages in thread
From: Ilya Maximets @ 2018-11-29 7:58 UTC (permalink / raw)
To: Luca Boccassi, stable; +Cc: maxime.coquelin
On 28.11.2018 19:20, Luca Boccassi wrote:
> vhost_user_msg_handler checks an accumulated return code before
> returning, and prints an error and returns -1 if it's non-zero.
> But some of the possible user messages cannot fail and thus do not
> set the variable, which might retain a previously set and unrelated
> value, causing unnecessary failures and error messages.
>
> Reset the return code before use.
>
> Fixes: 0ce9e73d1e8d ("vhost-user: drop connection on message handling failures")
>
> Signed-off-by: Luca Boccassi <bluca@debian.org>
> ---
> Found this issue when testing with the Vyatta stuff, "ret" is set at
> the beginning of the function and never reset when the message is for example
> VHOST_USER_GET_FEATURES so there's a flurry of errors.
Hmm. Yes, current implementation in 16.11 branch doesn't work at all.
I think that it's a kind of an issue in the original patch 0d7853a4d.
But it uncovered only after backporting. On master we had additional
call 'ret = vhost_user_check_and_alloc_queue_pair()' before the main
handling switch and this function could only return 0 or -1. So, the
'ret' was always zero if we reached the handling switch.
LGTM,
Acked-by: Ilya Maximets <i.maximets@samsung.com>
>
> lib/librte_vhost/vhost_user.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 00872c868..618d413fe 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1087,6 +1087,7 @@ vhost_user_msg_handler(int vid, int fd)
>
> }
>
> + ret = 0;
> switch (msg.request) {
> case VHOST_USER_GET_FEATURES:
> msg.payload.u64 = vhost_user_get_features();
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dpdk-stable] [PATCH 16.11] vhost-user: fix false negative in handling user messages
2018-11-28 16:20 ` [dpdk-stable] [PATCH 16.11] vhost-user: fix false negative in handling user messages Luca Boccassi
2018-11-29 7:58 ` Ilya Maximets
@ 2018-11-29 8:49 ` Maxime Coquelin
1 sibling, 0 replies; 4+ messages in thread
From: Maxime Coquelin @ 2018-11-29 8:49 UTC (permalink / raw)
To: Luca Boccassi, stable; +Cc: i.maximets
On 11/28/18 5:20 PM, Luca Boccassi wrote:
> vhost_user_msg_handler checks an accumulated return code before
> returning, and prints an error and returns -1 if it's non-zero.
> But some of the possible user messages cannot fail and thus do not
> set the variable, which might retain a previously set and unrelated
> value, causing unnecessary failures and error messages.
>
> Reset the return code before use.
>
> Fixes: 0ce9e73d1e8d ("vhost-user: drop connection on message handling failures")
>
> Signed-off-by: Luca Boccassi <bluca@debian.org>
> ---
> Found this issue when testing with the Vyatta stuff, "ret" is set at
> the beginning of the function and never reset when the message is for example
> VHOST_USER_GET_FEATURES so there's a flurry of errors.
>
> lib/librte_vhost/vhost_user.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 00872c868..618d413fe 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1087,6 +1087,7 @@ vhost_user_msg_handler(int vid, int fd)
>
> }
>
> + ret = 0;
> switch (msg.request) {
> case VHOST_USER_GET_FEATURES:
> msg.payload.u64 = vhost_user_get_features();
>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks!
Maxime
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dpdk-stable] [PATCH 16.11] vhost-user: fix false negative in handling user messages
2018-11-29 7:58 ` Ilya Maximets
@ 2018-11-29 10:45 ` Luca Boccassi
0 siblings, 0 replies; 4+ messages in thread
From: Luca Boccassi @ 2018-11-29 10:45 UTC (permalink / raw)
To: Ilya Maximets, stable; +Cc: maxime.coquelin
On Thu, 2018-11-29 at 10:58 +0300, Ilya Maximets wrote:
> On 28.11.2018 19:20, Luca Boccassi wrote:
> > vhost_user_msg_handler checks an accumulated return code before
> > returning, and prints an error and returns -1 if it's non-zero.
> > But some of the possible user messages cannot fail and thus do not
> > set the variable, which might retain a previously set and unrelated
> > value, causing unnecessary failures and error messages.
> >
> > Reset the return code before use.
> >
> > Fixes: 0ce9e73d1e8d ("vhost-user: drop connection on message
> > handling failures")
> >
> > Signed-off-by: Luca Boccassi <bluca@debian.org>
> > ---
> > Found this issue when testing with the Vyatta stuff, "ret" is set
> > at
> > the beginning of the function and never reset when the message is
> > for example
> > VHOST_USER_GET_FEATURES so there's a flurry of errors.
>
> Hmm. Yes, current implementation in 16.11 branch doesn't work at all.
> I think that it's a kind of an issue in the original patch 0d7853a4d.
> But it uncovered only after backporting. On master we had additional
> call 'ret = vhost_user_check_and_alloc_queue_pair()' before the main
> handling switch and this function could only return 0 or -1. So, the
> 'ret' was always zero if we reached the handling switch.
>
> LGTM,
> Acked-by: Ilya Maximets <i.maximets@samsung.com>
I see. Thank you both for the reviews, applied and pushed.
--
Kind regards,
Luca Boccassi
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-11-28 16:20 ` [dpdk-stable] [PATCH 16.11] vhost-user: fix false negative in handling user messages Luca Boccassi
2018-11-29 7:58 ` Ilya Maximets
2018-11-29 10:45 ` Luca Boccassi
2018-11-29 8:49 ` Maxime Coquelin
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