[PATCH 1/2] [CIFS] Fix signed/unsigned pointer warning

From: Kevin Cernekee
Date: Mon Nov 10 2014 - 16:09:44 EST


Commit 2ae83bf93882d1 ("[CIFS] Fix setting time before epoch (negative
time values)") changed "u64 t" to "s64 t", which makes do_div() complain
about a pointer signedness mismatch:

CC fs/cifs/netmisc.o
In file included from ./arch/mips/include/asm/div64.h:12:0,
from include/linux/kernel.h:124,
from include/linux/list.h:8,
from include/linux/wait.h:6,
from include/linux/net.h:23,
from fs/cifs/netmisc.c:25:
fs/cifs/netmisc.c: In function âcifs_NTtimeToUnixâ:
include/asm-generic/div64.h:43:28: warning: comparison of distinct pointer types lacks a cast [enabled by default]
(void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
^
fs/cifs/netmisc.c:941:22: note: in expansion of macro âdo_divâ
ts.tv_nsec = (long)do_div(t, 10000000) * 100;

Introduce a temporary "u64 abs_t" variable to fix this.

Signed-off-by: Kevin Cernekee <cernekee@xxxxxxxxx>
---
fs/cifs/netmisc.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)


Note: this is compile-tested only (on a 32-bit build).


diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c
index b333ff6..abae6dd 100644
--- a/fs/cifs/netmisc.c
+++ b/fs/cifs/netmisc.c
@@ -926,6 +926,7 @@ cifs_NTtimeToUnix(__le64 ntutc)

/* Subtract the NTFS time offset, then convert to 1s intervals. */
s64 t = le64_to_cpu(ntutc) - NTFS_TIME_OFFSET;
+ u64 abs_t;

/*
* Unfortunately can not use normal 64 bit division on 32 bit arch, but
@@ -933,13 +934,14 @@ cifs_NTtimeToUnix(__le64 ntutc)
* to special case them
*/
if (t < 0) {
- t = -t;
- ts.tv_nsec = (long)(do_div(t, 10000000) * 100);
+ abs_t = -t;
+ ts.tv_nsec = (long)(do_div(abs_t, 10000000) * 100);
ts.tv_nsec = -ts.tv_nsec;
- ts.tv_sec = -t;
+ ts.tv_sec = -abs_t;
} else {
- ts.tv_nsec = (long)do_div(t, 10000000) * 100;
- ts.tv_sec = t;
+ abs_t = t;
+ ts.tv_nsec = (long)do_div(abs_t, 10000000) * 100;
+ ts.tv_sec = abs_t;
}

return ts;
--
2.1.1

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