[Crash-utility] [PATCH] Fix "log" command when crash is started with "--minimal" option

[Dave Wysochanski]

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.

Fixes: c86250bce29f ("Introduction of the "log -T" option...")
Signed-off-by: Dave Wysochanski <dwysocha at redhat.com>
---
 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) {
 		ulonglong uptime_jiffies;
 		ulong  uptime_sec;
 		get_uptime(NULL, &uptime_jiffies);
-- 
2.27.0