| Message ID | 1401196563-6999-1-git-send-email-mschmidt@redhat.com |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
Le 27/05/2014 15:16, Michal Schmidt a écrit : > Any process is able to send netlink messages with leftover bytes, so > downgrade the warning message to pr_debug in order to avoid possible > kernel log spam. Yes, but that's not a normal case. I think that the level warning is good, there is something wrong with this kind of messages. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/28/2014 09:42 AM, Nicolas Dichtel wrote: > Le 27/05/2014 15:16, Michal Schmidt a écrit : >> Any process is able to send netlink messages with leftover bytes, so >> downgrade the warning message to pr_debug in order to avoid possible >> kernel log spam. > Yes, but that's not a normal case. I think that the level warning is good, > there is something wrong with this kind of messages. As an alternative we could at least guard it with net_ratelimit(). But still, the message indicates a userspace bug. It can be useful for a developer of a netlink library, but not for many more. I think it's odd to let unprivileged userspace spam the dmesg, even if rate-limited. The kernel does not emit warning messages when userspace is buggy in other ways, like calling syscalls with invalid arguments. Regards, Michal -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Le 28/05/2014 11:18, Michal Schmidt a écrit : > On 05/28/2014 09:42 AM, Nicolas Dichtel wrote: >> Le 27/05/2014 15:16, Michal Schmidt a écrit : >>> Any process is able to send netlink messages with leftover bytes, so >>> downgrade the warning message to pr_debug in order to avoid possible >>> kernel log spam. >> Yes, but that's not a normal case. I think that the level warning is good, >> there is something wrong with this kind of messages. > > As an alternative we could at least guard it with net_ratelimit(). I would prefer this solution. > > But still, the message indicates a userspace bug. It can be useful > for a developer of a netlink library, but not for many more. Or to let you know why a userspace tool does not work ;-) > I think it's odd to let unprivileged userspace spam the dmesg, > even if rate-limited. The kernel does not emit warning messages when > userspace is buggy in other ways, like calling syscalls with invalid > arguments. If it's really a problem (this message is here since 2.6.15 and nobody complains), maybe a level between warning and debug may be acceptable. Regards, Nicolas -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/lib/nlattr.c b/lib/nlattr.c index fc67547..fbadde6 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -201,8 +201,8 @@ int nla_parse(struct nlattr **tb, int maxtype, const struct nlattr *head, } if (unlikely(rem > 0)) - printk(KERN_WARNING "netlink: %d bytes leftover after parsing " - "attributes.\n", rem); + pr_debug("netlink: %d bytes leftover after parsing attributes.\n", + rem); err = 0; errout:
Any process is able to send netlink messages with leftover bytes, so downgrade the warning message to pr_debug in order to avoid possible kernel log spam. Signed-off-by: Michal Schmidt <mschmidt@redhat.com> --- lib/nlattr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)