From: Andrei Vagin <avagin@gmail.com>
Date: Tue, 12 Nov 2019 01:27:02 +0000 (+0000)
Subject: timerfd: Make timerfd_settime() time namespace aware
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6cd889d43c40b13f81a44c41896781ce70244769;p=linux.git

timerfd: Make timerfd_settime() time namespace aware

timerfd_settime() accepts an absolute value of the expiration time if
TFD_TIMER_ABSTIME is specified. This value is in the task's time namespace
and has to be converted to the host's time namespace.

Co-developed-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-14-dima@arista.com
---

diff --git a/fs/timerfd.c b/fs/timerfd.c
index ac7f59a58f947..c5509d2448e38 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -26,6 +26,7 @@
 #include <linux/syscalls.h>
 #include <linux/compat.h>
 #include <linux/rcupdate.h>
+#include <linux/time_namespace.h>
 
 struct timerfd_ctx {
 	union {
@@ -196,6 +197,8 @@ static int timerfd_setup(struct timerfd_ctx *ctx, int flags,
 	}
 
 	if (texp != 0) {
+		if (flags & TFD_TIMER_ABSTIME)
+			texp = timens_ktime_to_host(clockid, texp);
 		if (isalarm(ctx)) {
 			if (flags & TFD_TIMER_ABSTIME)
 				alarm_start(&ctx->t.alarm, texp);