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Message-Id: <1457391064-6660-61-git-send-email-kamal@canonical.com>
Date: Mon, 7 Mar 2016 14:47:31 -0800
From: Kamal Mostafa <kamal@...onical.com>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org,
kernel-team@...ts.ubuntu.com
Cc: zengtao <prime.zeng@...wei.com>, fweisbec@...il.com,
Thomas Gleixner <tglx@...utronix.de>,
Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 4.2.y-ckt 060/273] cputime: Prevent 32bit overflow in time[val|spec]_to_cputime()
4.2.8-ckt5 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------
From: zengtao <prime.zeng@...wei.com>
commit 0f26922fe5dc5724b1adbbd54b21bad03590b4f3 upstream.
The datatype __kernel_time_t is u32 on 32bit platform, so its subject to
overflows in the timeval/timespec to cputime conversion.
Currently the following functions are affected:
1. setitimer()
2. timer_create/timer_settime()
3. sys_clock_nanosleep
This can happen on MIPS32 and ARM32 with "Full dynticks CPU time accounting"
enabled, which is required for CONFIG_NO_HZ_FULL.
Enforce u64 conversion to prevent the overflow.
Fixes: 31c1fc818715 ("ARM: Kconfig: allow full nohz CPU accounting")
Signed-off-by: zengtao <prime.zeng@...wei.com>
Reviewed-by: Arnd Bergmann <arnd@...db.de>
Cc: <fweisbec@...il.com>
Link: http://lkml.kernel.org/r/1454384314-154784-1-git-send-email-prime.zeng@huawei.com
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
include/asm-generic/cputime_nsecs.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/asm-generic/cputime_nsecs.h b/include/asm-generic/cputime_nsecs.h
index 0419485..0f1c6f3 100644
--- a/include/asm-generic/cputime_nsecs.h
+++ b/include/asm-generic/cputime_nsecs.h
@@ -75,7 +75,7 @@ typedef u64 __nocast cputime64_t;
*/
static inline cputime_t timespec_to_cputime(const struct timespec *val)
{
- u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_nsec;
+ u64 ret = (u64)val->tv_sec * NSEC_PER_SEC + val->tv_nsec;
return (__force cputime_t) ret;
}
static inline void cputime_to_timespec(const cputime_t ct, struct timespec *val)
@@ -91,7 +91,8 @@ static inline void cputime_to_timespec(const cputime_t ct, struct timespec *val)
*/
static inline cputime_t timeval_to_cputime(const struct timeval *val)
{
- u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_usec * NSEC_PER_USEC;
+ u64 ret = (u64)val->tv_sec * NSEC_PER_SEC +
+ val->tv_usec * NSEC_PER_USEC;
return (__force cputime_t) ret;
}
static inline void cputime_to_timeval(const cputime_t ct, struct timeval *val)
--
2.7.0
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