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Subject[PATCH v2] kdb: use ktime_get_mono_fast_ns() instead of ktime_get_ts()
Date
The kdb code will print the monotonic time by ktime_get_ts(), but
the ktime_get_ts() will be protected by a sequence lock, that will
introduce one deadlock risk if the lock was already held in the
context from which we entered the debugger.

Thus we can use the ktime_get_mono_fast_ns() to get the monotonic
time, which is NMI safe access to clock monotonic. Moreover we can
remove the 'struct timespec', which is not y2038 safe.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
Changes since v1:
- Use ktime_get_mono_fast_ns() instead of ktime_get_seconds().
---
kernel/debug/kdb/kdb_main.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 69e70f4..bf1d0e0 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2486,10 +2486,10 @@ static int kdb_kill(int argc, const char **argv)
*/
static void kdb_sysinfo(struct sysinfo *val)
{
- struct timespec uptime;
- ktime_get_ts(&uptime);
+ u64 uptime = ktime_get_mono_fast_ns();
+
memset(val, 0, sizeof(*val));
- val->uptime = uptime.tv_sec;
+ val->uptime = div_u64(uptime, NSEC_PER_SEC);
val->loads[0] = avenrun[0];
val->loads[1] = avenrun[1];
val->loads[2] = avenrun[2];
--
1.7.9.5
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