On 10/28/15 at 01:38pm, Dangyi Liu wrote: > logged_chars would be set to 0 by `dmesg -c`, but we want to get the > full dmesg after crash. So instead of using logged_chars directly, we > calculate it by ourselves. > > Now logged_chars is set to the minimum of log_end and log_buf_len, which > is coherent to how crash utility deals with dmesg length. > > Signed-off-by: Dangyi Liu <dliu at redhat.com> > --- > vmcore-dmesg/vmcore-dmesg.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/vmcore-dmesg/vmcore-dmesg.c b/vmcore-dmesg/vmcore-dmesg.c > index f47ee11..ec2570f 100644 > --- a/vmcore-dmesg/vmcore-dmesg.c > +++ b/vmcore-dmesg/vmcore-dmesg.c > @@ -540,6 +540,9 @@ static void dump_dmesg_legacy(int fd) > exit(53); > } > > + // `dmesg -c` would set logged_chars to 0, then we cannot get a full dmesg. Please use /* */ style comment, also it is not a bug because In theroy it is ok for only showing later dmesg after dmesg -c in current code. But crash utils and vmcore-dmesg in new log buf format support dumping all kernel messages which includes the part before dmesg -c. It is not harm to keep same behavior with them. So the comment should be changed to something like below: /* * To collect full dmesg including the part before `dmesg -c` is useful for * later debugging. Use same logic as what crash utility is using. */ > + logged_chars = log_end < log_buf_len ? log_end : log_buf_len; > + > write_to_stdout(buf + (log_buf_len - logged_chars), logged_chars); > } > > -- > 2.4.3 > > > _______________________________________________ > kexec mailing list > kexec at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec > >
