Re: [Crash-utility] Crash-utility Digest, Vol 179, Issue 4

Hi Lianbo, > -----Original Message----- > 在 2020年08月07日 00:00, crash-utility-request(a)redhat.com 写道: >> Message: 5 >> Date: Thu, 6 Aug 2020 09:30:22 -0400 >> From: Dave Wysochanski <dwysocha(a)redhat.com&gt; >> To: crash-utility(a)redhat.com >> Subject: [Crash-utility] [PATCH v3] Fix "log" command when crash is >> started with "--minimal" option >> Message-ID: <20200806133022.2127538-1-dwysocha(a)redhat.com&gt; >> >> Commit c86250bce29f introduced the useful '-T' option to print the >> log timestamp in human-readable form. However, this option does >> not work when crash is invoked with '--minimal' mode, and if tried, >> crash will spin at 100% and continuously crash at a divide by 0 >> because machdep->hz == 0. >> >> Fix this by disallowing this option in minimal mode. In addition, >> only calculate the logic to calculate kt->boot_date.tv_sec >> when this option is enabled. >> > Hi, Dave Wysochanski > > Thank you for the patch. > >> Fixes: c86250bce29f ("Introduction of the "log -T" option...") >> Signed-off-by: Dave Wysochanski <dwysocha(a)redhat.com&gt; >> Reviewed-by: Wang Long <w(a)laoqinren.net&gt; >> Tested-by: Mathias Krause <minipli(a)grsecurity.net&gt; >> --- >> kernel.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/kernel.c b/kernel.c >> index 5ed6021..95119f3 100644 >> --- a/kernel.c >> +++ b/kernel.c >> @@ -4939,7 +4939,10 @@ cmd_log(void) >> if (argerrs) >> cmd_usage(pc->curcmd, SYNOPSIS); >> >> - if (kt->boot_date.tv_sec == 0) { >> + if (msg_flags & SHOW_LOG_CTIME && pc->flags & MINIMAL_MODE) >> + error(FATAL, "log: option 'T' not available in minimal mode\n"); >> + >> + if (msg_flags & SHOW_LOG_CTIME && kt->boot_date.tv_sec == 0) { > > The above two 'if' statements have the same checking condition, would you mind putting them together > as a statement block? E.g: > > + if (msg_flags & SHOW_LOG_CTIME) { > + if (pc->flags & MINIMAL_MODE) { > + error(WARNING, "the option '-T' not available in minimal mode\n"); > + return;

> + } > + > + if (kt->boot_date.tv_sec == 0) { > ... > + } > } > > In addition, might it be more reasonable to issue a warning instead of a fatal error? hmm, why do you think so? I think FATAL is fine because we cannot proceed anymore and there is no memory to be released.

Thanks, Kazu > > Thanks. > Lianbo > >> ulonglong uptime_jiffies; >> ulong uptime_sec; >> get_uptime(NULL, &uptime_jiffies); >> -- 2.27.0 > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility