Hello, A few days ago I filed a kernel regression report concerning a change in /proc/kmsg behaviour with short reads:
https://bugzilla.kernel.org/show_bug.cgi?id=44211 The comments suggest that this is probably intentional, but that it would be best make sure that the current semantics wrt short reads are as intended. The problem appears on a Debian (unstable) system that drains /proc/kmsg into a separate fifo read by klogd(8): /bin/dd bs=1 if=/proc/kmsg of=/var/run/klogd/kmsg With the recent kernel logging changes this /bin/dd exits immediately, as 1-byte reads are shorter than any log message could possibly be and read() returns 0. No dd feeding the fifo results in no logging and a rather unhappy klogd on the reading end of /var/run/klogd/kmsg. I suppose a safe solution is to only do reads that are big enough for any single kernel message, but this is still a change that affects user space being shipped, so some might find it surprising. I don't know what other distros do. Is it just Debian being the odd one out? -J -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
