diff mbox

[RFC,01/12] time: Rename mktime() to mktime_unsafe()

Message ID 1414388748-3333-1-git-send-email-pang.xunlei@linaro.org
State New
Headers show

Commit Message

pang.xunlei Oct. 27, 2014, 5:45 a.m. UTC 
The kernel uses 32-bit signed value(time_t) for seconds since 1970-01-01:00:00:00, thus it
will overflow at 2038-01-19 03:14:08 on 32-bit systems. We call this "2038 safety" issue.

Currently, mktime() deals with "unsigned long" which is 2038 unsafe on 32-bit systems.

As part of addressing 2038 saftey for in-kernel uses, this patch renames mktime() to
mktime_unsafe(), and changes all its calling users correspondingly. The safe version
of mktime() will be added in the following patch.

Signed-off-by: pang.xunlei <pang.xunlei@linaro.org>
---
 arch/avr32/kernel/time.c                     |    2 +-
 arch/frv/kernel/time.c                       |    2 +-
 arch/ia64/kernel/efi.c                       |    2 +-
 arch/m32r/kernel/time.c                      |    2 +-
 arch/m68k/kernel/time.c                      |    2 +-
 arch/m68k/mac/misc.c                         |    2 +-
 arch/mips/dec/time.c                         |    2 +-
 arch/mips/include/asm/mc146818-time.h        |    2 +-
 arch/mips/sibyte/swarm/rtc_m41t81.c          |    2 +-
 arch/mips/sibyte/swarm/rtc_xicor1241.c       |    2 +-
 arch/mips/sibyte/swarm/setup.c               |    2 +-
 arch/mn10300/kernel/rtc.c                    |    4 ++--
 arch/parisc/include/asm/rtc.h                |    2 +-
 arch/powerpc/kernel/rtas-proc.c              |    2 +-
 arch/powerpc/kernel/rtas-rtc.c               |    2 +-
 arch/powerpc/kernel/time.c                   |    2 +-
 arch/powerpc/platforms/8xx/m8xx_setup.c      |    2 +-
 arch/powerpc/platforms/cell/beat.c           |    2 +-
 arch/powerpc/platforms/maple/time.c          |    2 +-
 arch/powerpc/platforms/pasemi/time.c         |    2 +-
 arch/powerpc/platforms/powermac/time.c       |    2 +-
 arch/powerpc/platforms/powernv/opal-rtc.c    |    2 +-
 arch/sh/boards/mach-sh03/rtc.c               |    2 +-
 arch/sh/kernel/time.c                        |    2 +-
 arch/x86/kernel/rtc.c                        |    2 +-
 arch/x86/platform/efi/efi.c                  |    2 +-
 arch/x86/platform/intel-mid/intel_mid_vrtc.c |    2 +-
 drivers/rtc/rtc-lib.c                        |    2 +-
 drivers/rtc/rtc-ls1x.c                       |    2 +-
 drivers/rtc/rtc-tps6586x.c                   |    2 +-
 drivers/rtc/rtc-vr41xx.c                     |    8 ++++----
 include/linux/time.h                         |    6 +++---
 kernel/time/time.c                           |    4 ++--
 33 files changed, 40 insertions(+), 40 deletions(-)

Comments

Thomas Gleixner Oct. 27, 2014, 9:38 p.m. UTC | #1 
On Mon, 27 Oct 2014, pang.xunlei wrote:

> The kernel uses 32-bit signed value(time_t) for seconds since 1970-01-01:00:00:00, thus it
> will overflow at 2038-01-19 03:14:08 on 32-bit systems. We call this "2038 safety" issue.
> 
> Currently, mktime() deals with "unsigned long" which is 2038 unsafe on 32-bit systems.
> 
> As part of addressing 2038 saftey for in-kernel uses, this patch renames mktime() to
> mktime_unsafe(), and changes all its calling users correspondingly. The safe version
> of mktime() will be added in the following patch.

This is a flag day change. We really want to avoid that. Can we please
add a new interface first, then convert all the existing users and
kill the old interface.

If we really care we can rename it back to the old name once all that
has been done, but I personally do not care whether its mktime or
mktime64 as long as it is fixed proper.

Thanks,

	tglx


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John Stultz Oct. 27, 2014, 9:54 p.m. UTC | #2 
On Mon, Oct 27, 2014 at 2:38 PM, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Mon, 27 Oct 2014, pang.xunlei wrote:
>
>> The kernel uses 32-bit signed value(time_t) for seconds since 1970-01-01:00:00:00, thus it
>> will overflow at 2038-01-19 03:14:08 on 32-bit systems. We call this "2038 safety" issue.
>>
>> Currently, mktime() deals with "unsigned long" which is 2038 unsafe on 32-bit systems.
>>
>> As part of addressing 2038 saftey for in-kernel uses, this patch renames mktime() to
>> mktime_unsafe(), and changes all its calling users correspondingly. The safe version
>> of mktime() will be added in the following patch.
>
> This is a flag day change. We really want to avoid that. Can we please
> add a new interface first, then convert all the existing users and
> kill the old interface.
>
> If we really care we can rename it back to the old name once all that
> has been done, but I personally do not care whether its mktime or
> mktime64 as long as it is fixed proper.

This was my bad, as I gave him guidance here. I was hoping to avoid
doing the one-by-one function renaming dance twice, just to fix the
function.

But you're probably right, and someone will probably add a new usage
right before this gets merged and we'll have some pain there.

-john
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Thomas Gleixner Oct. 27, 2014, 10:11 p.m. UTC | #3 
On Mon, 27 Oct 2014, John Stultz wrote:
> On Mon, Oct 27, 2014 at 2:38 PM, Thomas Gleixner <tglx@linutronix.de> wrote:
> > On Mon, 27 Oct 2014, pang.xunlei wrote:
> >
> >> The kernel uses 32-bit signed value(time_t) for seconds since 1970-01-01:00:00:00, thus it
> >> will overflow at 2038-01-19 03:14:08 on 32-bit systems. We call this "2038 safety" issue.
> >>
> >> Currently, mktime() deals with "unsigned long" which is 2038 unsafe on 32-bit systems.
> >>
> >> As part of addressing 2038 saftey for in-kernel uses, this patch renames mktime() to
> >> mktime_unsafe(), and changes all its calling users correspondingly. The safe version
> >> of mktime() will be added in the following patch.
> >
> > This is a flag day change. We really want to avoid that. Can we please
> > add a new interface first, then convert all the existing users and
> > kill the old interface.
> >
> > If we really care we can rename it back to the old name once all that
> > has been done, but I personally do not care whether its mktime or
> > mktime64 as long as it is fixed proper.
> 
> This was my bad, as I gave him guidance here. I was hoping to avoid
> doing the one-by-one function renaming dance twice, just to fix the
> function.
> 
> But you're probably right, and someone will probably add a new usage
> right before this gets merged and we'll have some pain there.

It's not only that. The whole series is a purely mechanical approach
to the problem.

Rename A
Fixup some stuff
Rename B
Fixup some more stuff
Rename C
Fixup some more stuff

I completely understand why you tried to take that approach, but TBH
at the point where the "Fixup some more" started to touch the same
file again, you should have noticed that adding intermediate (old
style) timespecs is a non starter as it just introduces another level
of conversion complexity which you wanted to avoid with the
"mechanical" fixup approach in the first place.

Thanks,

	tglx
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diff mbox

Patch

diff --git a/arch/avr32/kernel/time.c b/arch/avr32/kernel/time.c
index d0f771b..37ba222 100644
--- a/arch/avr32/kernel/time.c
+++ b/arch/avr32/kernel/time.c
@@ -123,7 +123,7 @@  static struct clock_event_device comparator = {
 
 void read_persistent_clock(struct timespec *ts)
 {
-	ts->tv_sec = mktime(2007, 1, 1, 0, 0, 0);
+	ts->tv_sec = mktime_unsafe(2007, 1, 1, 0, 0, 0);
 	ts->tv_nsec = 0;
 }
 
diff --git a/arch/frv/kernel/time.c b/arch/frv/kernel/time.c
index 332e00b..b695e0e 100644
--- a/arch/frv/kernel/time.c
+++ b/arch/frv/kernel/time.c
@@ -101,7 +101,7 @@  void read_persistent_clock(struct timespec *ts)
 
 	if ((year += 1900) < 1970)
 		year += 100;
-	ts->tv_sec = mktime(year, mon, day, hour, min, sec);
+	ts->tv_sec = mktime_unsafe(year, mon, day, hour, min, sec);
 	ts->tv_nsec = 0;
 }
 
diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index 741b99c..c2ae0fd 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -245,7 +245,7 @@  efi_gettimeofday (struct timespec *ts)
 		return;
 	}
 
-	ts->tv_sec = mktime(tm.year, tm.month, tm.day,
+	ts->tv_sec = mktime_unsafe(tm.year, tm.month, tm.day,
 			    tm.hour, tm.minute, tm.second);
 	ts->tv_nsec = tm.nanosecond;
 }
diff --git a/arch/m32r/kernel/time.c b/arch/m32r/kernel/time.c
index 093f276..56956ea 100644
--- a/arch/m32r/kernel/time.c
+++ b/arch/m32r/kernel/time.c
@@ -157,7 +157,7 @@  void read_persistent_clock(struct timespec *ts)
 		epoch = 1952;
 	year += epoch;
 
-	ts->tv_sec = mktime(year, mon, day, hour, min, sec);
+	ts->tv_sec = mktime_unsafe(year, mon, day, hour, min, sec);
 	ts->tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
 }
 
diff --git a/arch/m68k/kernel/time.c b/arch/m68k/kernel/time.c
index 3857737..4ed21ea 100644
--- a/arch/m68k/kernel/time.c
+++ b/arch/m68k/kernel/time.c
@@ -81,7 +81,7 @@  void read_persistent_clock(struct timespec *ts)
 
 		if ((time.tm_year += 1900) < 1970)
 			time.tm_year += 100;
-		ts->tv_sec = mktime(time.tm_year, time.tm_mon, time.tm_mday,
+		ts->tv_sec = mktime_unsafe(time.tm_year, time.tm_mon, time.tm_mday,
 				      time.tm_hour, time.tm_min, time.tm_sec);
 	}
 }
diff --git a/arch/m68k/mac/misc.c b/arch/m68k/mac/misc.c
index 707b61a..85be5f3 100644
--- a/arch/m68k/mac/misc.c
+++ b/arch/m68k/mac/misc.c
@@ -730,7 +730,7 @@  int mac_hwclk(int op, struct rtc_time *t)
 			t->tm_hour, t->tm_min, t->tm_sec);
 #endif
 
-		now = mktime(t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
+		now = mktime_unsafe(t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
 			     t->tm_hour, t->tm_min, t->tm_sec);
 
 		switch (macintosh_config->adb_type) {
diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c
index 1914e56..d9905cb 100644
--- a/arch/mips/dec/time.c
+++ b/arch/mips/dec/time.c
@@ -53,7 +53,7 @@  void read_persistent_clock(struct timespec *ts)
 
 	year += real_year - 72 + 2000;
 
-	ts->tv_sec = mktime(year, mon, day, hour, min, sec);
+	ts->tv_sec = mktime_unsafe(year, mon, day, hour, min, sec);
 	ts->tv_nsec = 0;
 }
 
diff --git a/arch/mips/include/asm/mc146818-time.h b/arch/mips/include/asm/mc146818-time.h
index 9e1ad26..a5df6b0 100644
--- a/arch/mips/include/asm/mc146818-time.h
+++ b/arch/mips/include/asm/mc146818-time.h
@@ -113,7 +113,7 @@  static inline unsigned long mc146818_get_cmos_time(void)
 	spin_unlock_irqrestore(&rtc_lock, flags);
 	year = mc146818_decode_year(year);
 
-	return mktime(year, mon, day, hour, min, sec);
+	return mktime_unsafe(year, mon, day, hour, min, sec);
 }
 
 #endif /* __ASM_MC146818_TIME_H */
diff --git a/arch/mips/sibyte/swarm/rtc_m41t81.c b/arch/mips/sibyte/swarm/rtc_m41t81.c
index b732600..c117804 100644
--- a/arch/mips/sibyte/swarm/rtc_m41t81.c
+++ b/arch/mips/sibyte/swarm/rtc_m41t81.c
@@ -218,7 +218,7 @@  unsigned long m41t81_get_time(void)
 
 	year += 2000;
 
-	return mktime(year, mon, day, hour, min, sec);
+	return mktime_unsafe(year, mon, day, hour, min, sec);
 }
 
 int m41t81_probe(void)
diff --git a/arch/mips/sibyte/swarm/rtc_xicor1241.c b/arch/mips/sibyte/swarm/rtc_xicor1241.c
index 178a824..ba9e4b40 100644
--- a/arch/mips/sibyte/swarm/rtc_xicor1241.c
+++ b/arch/mips/sibyte/swarm/rtc_xicor1241.c
@@ -201,7 +201,7 @@  unsigned long xicor_get_time(void)
 
 	year += (y2k * 100);
 
-	return mktime(year, mon, day, hour, min, sec);
+	return mktime_unsafe(year, mon, day, hour, min, sec);
 }
 
 int xicor_probe(void)
diff --git a/arch/mips/sibyte/swarm/setup.c b/arch/mips/sibyte/swarm/setup.c
index 3462c83..8c5aca1 100644
--- a/arch/mips/sibyte/swarm/setup.c
+++ b/arch/mips/sibyte/swarm/setup.c
@@ -102,7 +102,7 @@  void read_persistent_clock(struct timespec *ts)
 
 	case RTC_NONE:
 	default:
-		sec = mktime(2000, 1, 1, 0, 0, 0);
+		sec = mktime_unsafe(2000, 1, 1, 0, 0, 0);
 		break;
 	}
 	ts->tv_sec = sec;
diff --git a/arch/mn10300/kernel/rtc.c b/arch/mn10300/kernel/rtc.c
index 48d7058..35915d5 100644
--- a/arch/mn10300/kernel/rtc.c
+++ b/arch/mn10300/kernel/rtc.c
@@ -30,12 +30,12 @@  void read_persistent_clock(struct timespec *ts)
 	get_rtc_time(&tm);
 
 	ts->tv_nsec = 0;
-	ts->tv_sec = mktime(tm.tm_year, tm.tm_mon, tm.tm_mday,
+	ts->tv_sec = mktime_unsafe(tm.tm_year, tm.tm_mon, tm.tm_mday,
 			    tm.tm_hour, tm.tm_min, tm.tm_sec);
 
 	/* if rtc is way off in the past, set something reasonable */
 	if (ts->tv_sec < 0)
-		ts->tv_sec = mktime(2009, 1, 1, 12, 0, 0);
+		ts->tv_sec = mktime_unsafe(2009, 1, 1, 12, 0, 0);
 }
 
 /*
diff --git a/arch/parisc/include/asm/rtc.h b/arch/parisc/include/asm/rtc.h
index 099d641..c360087 100644
--- a/arch/parisc/include/asm/rtc.h
+++ b/arch/parisc/include/asm/rtc.h
@@ -100,7 +100,7 @@  static int set_rtc_time(struct rtc_time *wtime)
 {
 	u_int32_t secs;
 
-	secs = mktime(wtime->tm_year + 1900, wtime->tm_mon + 1, wtime->tm_mday, 
+	secs = mktime_unsafe(wtime->tm_year + 1900, wtime->tm_mon + 1, wtime->tm_mday,
 		      wtime->tm_hour, wtime->tm_min, wtime->tm_sec);
 
 	if(pdc_tod_set(secs, 0) < 0)
diff --git a/arch/powerpc/kernel/rtas-proc.c b/arch/powerpc/kernel/rtas-proc.c
index 8777fb0..1183005 100644
--- a/arch/powerpc/kernel/rtas-proc.c
+++ b/arch/powerpc/kernel/rtas-proc.c
@@ -403,7 +403,7 @@  static int ppc_rtas_clock_show(struct seq_file *m, void *v)
 		year = ret[0]; mon  = ret[1]; day  = ret[2];
 		hour = ret[3]; min  = ret[4]; sec  = ret[5];
 		seq_printf(m, "%lu\n",
-				mktime(year, mon, day, hour, min, sec));
+				mktime_unsafe(year, mon, day, hour, min, sec));
 	}
 	return 0;
 }
diff --git a/arch/powerpc/kernel/rtas-rtc.c b/arch/powerpc/kernel/rtas-rtc.c
index c57c193..ba1655a 100644
--- a/arch/powerpc/kernel/rtas-rtc.c
+++ b/arch/powerpc/kernel/rtas-rtc.c
@@ -37,7 +37,7 @@  unsigned long __init rtas_get_boot_time(void)
 		return 0;
 	}
 
-	return mktime(ret[0], ret[1], ret[2], ret[3], ret[4], ret[5]);
+	return mktime_unsafe(ret[0], ret[1], ret[2], ret[3], ret[4], ret[5]);
 }
 
 /* NOTE: get_rtc_time will get an error if executed in interrupt context
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 7505599..e78f82f 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -713,7 +713,7 @@  static void __read_persistent_clock(struct timespec *ts)
 	}
 	ppc_md.get_rtc_time(&tm);
 
-	ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
+	ts->tv_sec = mktime_unsafe(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
 			    tm.tm_hour, tm.tm_min, tm.tm_sec);
 }
 
diff --git a/arch/powerpc/platforms/8xx/m8xx_setup.c b/arch/powerpc/platforms/8xx/m8xx_setup.c
index d303774..5e3e471 100644
--- a/arch/powerpc/platforms/8xx/m8xx_setup.c
+++ b/arch/powerpc/platforms/8xx/m8xx_setup.c
@@ -172,7 +172,7 @@  int mpc8xx_set_rtc_time(struct rtc_time *tm)
 
 	sys_tmr1 = immr_map(im_sitk);
 	sys_tmr2 = immr_map(im_sit);
-	time = mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
+	time = mktime_unsafe(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
 	              tm->tm_hour, tm->tm_min, tm->tm_sec);
 
 	out_be32(&sys_tmr1->sitk_rtck, KAPWR_KEY);
diff --git a/arch/powerpc/platforms/cell/beat.c b/arch/powerpc/platforms/cell/beat.c
index affcf56..48b1b79 100644
--- a/arch/powerpc/platforms/cell/beat.c
+++ b/arch/powerpc/platforms/cell/beat.c
@@ -58,7 +58,7 @@  void beat_halt(void)
 int beat_set_rtc_time(struct rtc_time *rtc_time)
 {
 	u64 tim;
-	tim = mktime(rtc_time->tm_year+1900,
+	tim = mktime_unsafe(rtc_time->tm_year+1900,
 		     rtc_time->tm_mon+1, rtc_time->tm_mday,
 		     rtc_time->tm_hour, rtc_time->tm_min, rtc_time->tm_sec);
 	if (beat_rtc_write(tim))
diff --git a/arch/powerpc/platforms/maple/time.c b/arch/powerpc/platforms/maple/time.c
index b4a369d..2f6d1cb 100644
--- a/arch/powerpc/platforms/maple/time.c
+++ b/arch/powerpc/platforms/maple/time.c
@@ -170,7 +170,7 @@  unsigned long __init maple_get_boot_time(void)
 	request_resource(&ioport_resource, &rtc_iores);
 
 	maple_get_rtc_time(&tm);
-	return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
+	return mktime_unsafe(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
 		      tm.tm_hour, tm.tm_min, tm.tm_sec);
 }
 
diff --git a/arch/powerpc/platforms/pasemi/time.c b/arch/powerpc/platforms/pasemi/time.c
index fa54351..656c2c5 100644
--- a/arch/powerpc/platforms/pasemi/time.c
+++ b/arch/powerpc/platforms/pasemi/time.c
@@ -24,5 +24,5 @@ 
 unsigned long __init pas_get_boot_time(void)
 {
 	/* Let's just return a fake date right now */
-	return mktime(2006, 1, 1, 12, 0, 0);
+	return mktime_unsafe(2006, 1, 1, 12, 0, 0);
 }
diff --git a/arch/powerpc/platforms/powermac/time.c b/arch/powerpc/platforms/powermac/time.c
index 8680bb6..1b591c0 100644
--- a/arch/powerpc/platforms/powermac/time.c
+++ b/arch/powerpc/platforms/powermac/time.c
@@ -96,7 +96,7 @@  static void to_rtc_time(unsigned long now, struct rtc_time *tm)
     defined(CONFIG_PMAC_SMU)
 static unsigned long from_rtc_time(struct rtc_time *tm)
 {
-	return mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
+	return mktime_unsafe(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
 		      tm->tm_hour, tm->tm_min, tm->tm_sec);
 }
 #endif
diff --git a/arch/powerpc/platforms/powernv/opal-rtc.c b/arch/powerpc/platforms/powernv/opal-rtc.c
index 499707d..5e9c80a 100644
--- a/arch/powerpc/platforms/powernv/opal-rtc.c
+++ b/arch/powerpc/platforms/powernv/opal-rtc.c
@@ -58,7 +58,7 @@  unsigned long __init opal_get_boot_time(void)
 	y_m_d = be32_to_cpu(__y_m_d);
 	h_m_s_ms = be64_to_cpu(__h_m_s_ms);
 	opal_to_tm(y_m_d, h_m_s_ms, &tm);
-	return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+	return mktime_unsafe(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 		      tm.tm_hour, tm.tm_min, tm.tm_sec);
 out:
 	ppc_md.get_rtc_time = NULL;
diff --git a/arch/sh/boards/mach-sh03/rtc.c b/arch/sh/boards/mach-sh03/rtc.c
index f83ac79..67ce035 100644
--- a/arch/sh/boards/mach-sh03/rtc.c
+++ b/arch/sh/boards/mach-sh03/rtc.c
@@ -74,7 +74,7 @@  unsigned long get_cmos_time(void)
 	}
 
 	spin_unlock(&sh03_rtc_lock);
-	return mktime(year, mon, day, hour, min, sec);
+	return mktime_unsafe(year, mon, day, hour, min, sec);
 }
 
 void sh03_rtc_gettimeofday(struct timespec *tv)
diff --git a/arch/sh/kernel/time.c b/arch/sh/kernel/time.c
index d6d0a98..ec1d24b 100644
--- a/arch/sh/kernel/time.c
+++ b/arch/sh/kernel/time.c
@@ -26,7 +26,7 @@ 
 /* Dummy RTC ops */
 static void null_rtc_get_time(struct timespec *tv)
 {
-	tv->tv_sec = mktime(2000, 1, 1, 0, 0, 0);
+	tv->tv_sec = mktime_unsafe(2000, 1, 1, 0, 0, 0);
 	tv->tv_nsec = 0;
 }
 
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index ca9622a..820958d 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -108,7 +108,7 @@  void mach_get_cmos_time(struct timespec *now)
 	} else
 		year += CMOS_YEARS_OFFS;
 
-	now->tv_sec = mktime(year, mon, day, hour, min, sec);
+	now->tv_sec = mktime_unsafe(year, mon, day, hour, min, sec);
 	now->tv_nsec = 0;
 }
 
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 850da94..cb4116a 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -114,7 +114,7 @@  void efi_get_time(struct timespec *now)
 	if (status != EFI_SUCCESS)
 		pr_err("Oops: efitime: can't read time!\n");
 
-	now->tv_sec = mktime(eft.year, eft.month, eft.day, eft.hour,
+	now->tv_sec = mktime_unsafe(eft.year, eft.month, eft.day, eft.hour,
 			     eft.minute, eft.second);
 	now->tv_nsec = 0;
 }
diff --git a/arch/x86/platform/intel-mid/intel_mid_vrtc.c b/arch/x86/platform/intel-mid/intel_mid_vrtc.c
index 4762cff..5685ca2 100644
--- a/arch/x86/platform/intel-mid/intel_mid_vrtc.c
+++ b/arch/x86/platform/intel-mid/intel_mid_vrtc.c
@@ -82,7 +82,7 @@  void vrtc_get_time(struct timespec *now)
 	pr_info("vRTC: sec: %d min: %d hour: %d day: %d "
 		"mon: %d year: %d\n", sec, min, hour, mday, mon, year);
 
-	now->tv_sec = mktime(year, mon, mday, hour, min, sec);
+	now->tv_sec = mktime_unsafe(year, mon, mday, hour, min, sec);
 	now->tv_nsec = 0;
 }
 
diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c
index c4cf057..a0b473a 100644
--- a/drivers/rtc/rtc-lib.c
+++ b/drivers/rtc/rtc-lib.c
@@ -113,7 +113,7 @@  EXPORT_SYMBOL(rtc_valid_tm);
  */
 int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
 {
-	*time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
+	*time = mktime_unsafe(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
 			tm->tm_hour, tm->tm_min, tm->tm_sec);
 	return 0;
 }
diff --git a/drivers/rtc/rtc-ls1x.c b/drivers/rtc/rtc-ls1x.c
index 682ecb0..04687c9 100644
--- a/drivers/rtc/rtc-ls1x.c
+++ b/drivers/rtc/rtc-ls1x.c
@@ -93,7 +93,7 @@  static int ls1x_rtc_read_time(struct device *dev, struct rtc_time *rtm)
 	t = readl(SYS_TOYREAD1);
 
 	memset(rtm, 0, sizeof(struct rtc_time));
-	t  = mktime((t & LS1X_YEAR_MASK), ls1x_get_month(v),
+	t  = mktime_unsafe((t & LS1X_YEAR_MASK), ls1x_get_month(v),
 			ls1x_get_day(v), ls1x_get_hour(v),
 			ls1x_get_min(v), ls1x_get_sec(v));
 	rtc_time_to_tm(t, rtm);
diff --git a/drivers/rtc/rtc-tps6586x.c b/drivers/rtc/rtc-tps6586x.c
index 426901c..5f8d726 100644
--- a/drivers/rtc/rtc-tps6586x.c
+++ b/drivers/rtc/rtc-tps6586x.c
@@ -261,7 +261,7 @@  static int tps6586x_rtc_probe(struct platform_device *pdev)
 	rtc->irq = platform_get_irq(pdev, 0);
 
 	/* Set epoch start as 00:00:00:01:01:2009 */
-	rtc->epoch_start = mktime(2009, 1, 1, 0, 0, 0);
+	rtc->epoch_start = mktime_unsafe(2009, 1, 1, 0, 0, 0);
 
 	/* 1 kHz tick mode, enable tick counting */
 	ret = tps6586x_update(tps_dev, RTC_CTRL,
diff --git a/drivers/rtc/rtc-vr41xx.c b/drivers/rtc/rtc-vr41xx.c
index 88c9c92..a3d5772 100644
--- a/drivers/rtc/rtc-vr41xx.c
+++ b/drivers/rtc/rtc-vr41xx.c
@@ -140,7 +140,7 @@  static int vr41xx_rtc_read_time(struct device *dev, struct rtc_time *time)
 {
 	unsigned long epoch_sec, elapsed_sec;
 
-	epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
+	epoch_sec = mktime_unsafe(epoch, 1, 1, 0, 0, 0);
 	elapsed_sec = read_elapsed_second();
 
 	rtc_time_to_tm(epoch_sec + elapsed_sec, time);
@@ -152,8 +152,8 @@  static int vr41xx_rtc_set_time(struct device *dev, struct rtc_time *time)
 {
 	unsigned long epoch_sec, current_sec;
 
-	epoch_sec = mktime(epoch, 1, 1, 0, 0, 0);
-	current_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
+	epoch_sec = mktime_unsafe(epoch, 1, 1, 0, 0, 0);
+	current_sec = mktime_unsafe(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
 			     time->tm_hour, time->tm_min, time->tm_sec);
 
 	write_elapsed_second(current_sec - epoch_sec);
@@ -185,7 +185,7 @@  static int vr41xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 	unsigned long alarm_sec;
 	struct rtc_time *time = &wkalrm->time;
 
-	alarm_sec = mktime(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
+	alarm_sec = mktime_unsafe(time->tm_year + 1900, time->tm_mon + 1, time->tm_mday,
 			   time->tm_hour, time->tm_min, time->tm_sec);
 
 	spin_lock_irq(&rtc_lock);
diff --git a/include/linux/time.h b/include/linux/time.h
index 8c42cf8..e49d421 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -39,9 +39,9 @@  static inline int timeval_compare(const struct timeval *lhs, const struct timeva
 	return lhs->tv_usec - rhs->tv_usec;
 }
 
-extern unsigned long mktime(const unsigned int year, const unsigned int mon,
-			    const unsigned int day, const unsigned int hour,
-			    const unsigned int min, const unsigned int sec);
+extern unsigned long mktime_unsafe(const unsigned int year, const unsigned int mon,
+                            const unsigned int day, const unsigned int hour,
+                            const unsigned int min, const unsigned int sec);
 
 extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
 
diff --git a/kernel/time/time.c b/kernel/time/time.c
index a9ae20f..d6a4464 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -320,7 +320,7 @@  EXPORT_SYMBOL(timespec_trunc);
  * will already get problems at other places on 2038-01-19 03:14:08)
  */
 unsigned long
-mktime(const unsigned int year0, const unsigned int mon0,
+mktime_unsafe(const unsigned int year0, const unsigned int mon0,
        const unsigned int day, const unsigned int hour,
        const unsigned int min, const unsigned int sec)
 {
@@ -340,7 +340,7 @@  mktime(const unsigned int year0, const unsigned int mon0,
 	)*60 + sec; /* finally seconds */
 }
 
-EXPORT_SYMBOL(mktime);
+EXPORT_SYMBOL(mktime_unsafe);
 
 /**
  * set_normalized_timespec - set timespec sec and nsec parts and normalize