Subject: Re: linux-next: build warning after merge of the akpm-current tree

From: Minchan Kim <[email-masked]>
Date: Mon, 7 May 2018 23:10:39 +0900

On Fri, May 04, 2018 at 08:39:43AM -0700, Randy Dunlap wrote:
> On 05/03/2018 09:17 PM, Stephen Rothwell wrote:
> > Hi Andrew,
> > 
> > After merging the akpm-current tree, today's linux-next build
> > (x86_64_allmodconfig) produced this warning:
> > 
> > drivers/block/zram/zram_drv.c: In function 'read_block_state':
> > drivers/block/zram/zram_drv.c:674:16: warning: format '%llu' expects argument of type 'long long unsigned int', but argument 5 has type '__kernel_time_t {aka long int}' [-Wformat=]
> >     "%12lu %12llu.%06lu %c%c%c\n",
> >            ~~~~~^
> >            %12lu
> >     (unsigned long)index, ts.tv_sec,
> >                           ~~~~~~~~~
> > 
> > Introduced by commit
> > 
> >   827c7dbda8eb ("zram-introduce-zram-memory-tracking-update-fix-fix")
> > 
> 
> typedef __s64 time64_t;
> 
> struct timespec64 {
> 	time64_t	tv_sec;			/* seconds */
> 	long		tv_nsec;		/* nanoseconds */
> };
> 
> time64_t is signed. Also, %lu on i386 et al is for 32-bit longs.
> I guess that "we" will need to cast ts.tv_sec to (s64) and use %lld to print it
> in order to satisfy other $arch.
> 
> Andrew, want to add a fix-fix-fix patch?

Thanks for the fix during I am absent, Andrew and Randy.
Here goes fix.
Andrew please fold this patchset.

>>From 16569c7abb641930b4e4ec66b4dc2005e6c87be8 Mon Sep 17 00:00:00 2001
From: Minchan Kim <[email-masked]>
Date: Mon, 7 May 2018 23:00:16 +0900
Subject: [PATCH] zram-introduce-zram-memory-tracking-update-fix-fix-fix

fix compile warning

drivers/block/zram/zram_drv.c: In function 'read_block_state':
drivers/block/zram/zram_drv.c:674:16: warning: format '%llu' expects argument of type 'long long unsigned int', but argument 5 has type '__kernel_time_t {aka long int}' [-Wformat=]
    "%12lu %12llu.%06lu %c%c%c\n",
           ~~~~~^
           %12lu
    (unsigned long)index, ts.tv_sec,
                          ~~~~~~~~~
Cc: Greg Kroah-Hartman <[email-masked]>
Cc: Randy Dunlap <[email-masked]>
Cc: Sergey Senozhatsky <[email-masked]>
Cc: Andrew Morton <[email-masked]>
Cc: Stephen Rothwell <[email-masked]>
Signed-off-by: Minchan Kim <[email-masked]>
---
 drivers/block/zram/zram_drv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index f2f3104b2b48..635307e3238b 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -671,8 +671,8 @@ static ssize_t read_block_state(struct file *file, char __user *buf,
 
 		ts = ktime_to_timespec64(zram->table[index].ac_time);
 		copied = snprintf(kbuf + written, count,
-			"%12lu %12llu.%06lu %c%c%c\n",
-			(unsigned long)index, ts.tv_sec,
+			"%12lu %12lld.%06ld %c%c%c\n",
+			(unsigned long)index, (s64)ts.tv_sec,
 			ts.tv_nsec / NSEC_PER_USEC,
 			zram_test_flag(zram, index, ZRAM_SAME) ? 's' : '.',
 			zram_test_flag(zram, index, ZRAM_WB) ? 'w' : '.',
-- 
2.17.0.441.gb46fe60e1d-goog