Re: [PATCH] sched/fair: sanitize vruntime of entity being placed
From: kernel test robot
Date: Sat Jan 28 2023 - 02:46:41 EST
Hi Roman,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/sched/core]
[also build test WARNING on linus/master v6.2-rc5]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Roman-Kagan/sched-fair-sanitize-vruntime-of-entity-being-placed/20230128-130846
patch link: https://lore.kernel.org/r/20230127163230.3339408-1-rkagan%40amazon.de
patch subject: [PATCH] sched/fair: sanitize vruntime of entity being placed
config: hexagon-randconfig-r041-20230123 (https://download.01.org/0day-ci/archive/20230128/202301281536.CiaoBlBO-lkp@xxxxxxxxx/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 4196ca3278f78c6e19246e54ab0ecb364e37d66a)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/2db31a18bcb88c280481672d7721f7e003d8df5a
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Roman-Kagan/sched-fair-sanitize-vruntime-of-entity-being-placed/20230128-130846
git checkout 2db31a18bcb88c280481672d7721f7e003d8df5a
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/sched/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
All warnings (new ones prefixed by >>):
In file included from kernel/sched/fair.c:28:
In file included from include/linux/highmem.h:12:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __raw_readb(PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu'
#define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
^
In file included from kernel/sched/fair.c:28:
In file included from include/linux/highmem.h:12:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
^
In file included from kernel/sched/fair.c:28:
In file included from include/linux/highmem.h:12:
In file included from include/linux/hardirq.h:11:
In file included from ./arch/hexagon/include/generated/asm/hardirq.h:1:
In file included from include/asm-generic/hardirq.h:17:
In file included from include/linux/irq.h:20:
In file included from include/linux/io.h:13:
In file included from arch/hexagon/include/asm/io.h:334:
include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
>> kernel/sched/fair.c:4697:27: warning: overflow in expression; result is -129542144 with type 'long' [-Winteger-overflow]
if ((s64)sleep_time > 60 * NSEC_PER_SEC)
^
kernel/sched/fair.c:6078:6: warning: no previous prototype for function 'init_cfs_bandwidth' [-Wmissing-prototypes]
void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
^
kernel/sched/fair.c:6078:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
^
static
kernel/sched/fair.c:12498:6: warning: no previous prototype for function 'free_fair_sched_group' [-Wmissing-prototypes]
void free_fair_sched_group(struct task_group *tg) { }
^
kernel/sched/fair.c:12498:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void free_fair_sched_group(struct task_group *tg) { }
^
static
kernel/sched/fair.c:12500:5: warning: no previous prototype for function 'alloc_fair_sched_group' [-Wmissing-prototypes]
int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
^
kernel/sched/fair.c:12500:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
^
static
kernel/sched/fair.c:12505:6: warning: no previous prototype for function 'online_fair_sched_group' [-Wmissing-prototypes]
void online_fair_sched_group(struct task_group *tg) { }
^
kernel/sched/fair.c:12505:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void online_fair_sched_group(struct task_group *tg) { }
^
static
kernel/sched/fair.c:12507:6: warning: no previous prototype for function 'unregister_fair_sched_group' [-Wmissing-prototypes]
void unregister_fair_sched_group(struct task_group *tg) { }
^
kernel/sched/fair.c:12507:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void unregister_fair_sched_group(struct task_group *tg) { }
^
static
kernel/sched/fair.c:535:20: warning: unused function 'list_del_leaf_cfs_rq' [-Wunused-function]
static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
^
kernel/sched/fair.c:556:19: warning: unused function 'tg_is_idle' [-Wunused-function]
static inline int tg_is_idle(struct task_group *tg)
^
kernel/sched/fair.c:6051:20: warning: unused function 'cfs_bandwidth_used' [-Wunused-function]
static inline bool cfs_bandwidth_used(void)
^
kernel/sched/fair.c:6059:20: warning: unused function 'sync_throttle' [-Wunused-function]
static inline void sync_throttle(struct task_group *tg, int cpu) {}
^
kernel/sched/fair.c:6084:37: warning: unused function 'tg_cfs_bandwidth' [-Wunused-function]
static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
^
kernel/sched/fair.c:6088:20: warning: unused function 'destroy_cfs_bandwidth' [-Wunused-function]
static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
^
18 warnings generated.
vim +/long +4697 kernel/sched/fair.c
4654
4655 static void
4656 place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
4657 {
4658 u64 vruntime = cfs_rq->min_vruntime;
4659 u64 sleep_time;
4660
4661 /*
4662 * The 'current' period is already promised to the current tasks,
4663 * however the extra weight of the new task will slow them down a
4664 * little, place the new task so that it fits in the slot that
4665 * stays open at the end.
4666 */
4667 if (initial && sched_feat(START_DEBIT))
4668 vruntime += sched_vslice(cfs_rq, se);
4669
4670 /* sleeps up to a single latency don't count. */
4671 if (!initial) {
4672 unsigned long thresh;
4673
4674 if (se_is_idle(se))
4675 thresh = sysctl_sched_min_granularity;
4676 else
4677 thresh = sysctl_sched_latency;
4678
4679 /*
4680 * Halve their sleep time's effect, to allow
4681 * for a gentler effect of sleepers:
4682 */
4683 if (sched_feat(GENTLE_FAIR_SLEEPERS))
4684 thresh >>= 1;
4685
4686 vruntime -= thresh;
4687 }
4688
4689 /*
4690 * Pull vruntime of the entity being placed to the base level of
4691 * cfs_rq, to prevent boosting it if placed backwards. If the entity
4692 * slept for a long time, don't even try to compare its vruntime with
4693 * the base as it may be too far off and the comparison may get
4694 * inversed due to s64 overflow.
4695 */
4696 sleep_time = rq_clock_task(rq_of(cfs_rq)) - se->exec_start;
> 4697 if ((s64)sleep_time > 60 * NSEC_PER_SEC)
4698 se->vruntime = vruntime;
4699 else
4700 se->vruntime = max_vruntime(se->vruntime, vruntime);
4701 }
4702
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https://github.com/intel/lkp-tests