* [peterz-queue:sched/core 13/19] kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
@ 2021-09-13 8:47 ` Dan Carpenter
0 siblings, 0 replies; 7+ messages in thread
From: kernel test robot @ 2021-09-11 2:52 UTC (permalink / raw)
To: kbuild
[-- Attachment #1: Type: text/plain, Size: 5620 bytes --]
CC: kbuild-all(a)lists.01.org
CC: linux-kernel(a)vger.kernel.org
TO: Yafang Shao <laoar.shao@gmail.com>
CC: Peter Zijlstra <peterz@infradead.org>
tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core
head: 2dfdb3d20ad50e2ae2cb84cbceb0f0fc75e79e5d
commit: 445d9e8ba05d5e9e4b26956b7fe529223e29d8d1 [13/19] sched: make struct sched_statistics independent of fair sched class
:::::: branch date: 10 hours ago
:::::: commit date: 10 hours ago
config: x86_64-randconfig-m001-20210910 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
smatch warnings:
kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
vim +/se +453 kernel/sched/debug.c
3866e845ed5222 kernel/sched/debug.c Steven Rostedt (Red Hat 2016-02-22 439)
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 440 #ifdef CONFIG_FAIR_GROUP_SCHED
5091faa449ee0b kernel/sched_debug.c Mike Galbraith 2010-11-30 441 static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 442 {
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 443 struct sched_entity *se = tg->se[cpu];
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 @444 struct sched_statistics *stats = __schedstats_from_se(se);
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 445
97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 446 #define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F)
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 447 #define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 448 #F, (long long)schedstat_val(stats->F))
97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 449 #define PN(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 450 #define PN_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", \
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 451 #F, SPLIT_NS((long long)schedstat_val(stats->F)))
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 452
cd126afe838d7e kernel/sched/debug.c Yuyang Du 2015-07-15 @453 if (!se)
18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 454 return;
18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 455
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 456 PN(se->exec_start);
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 457 PN(se->vruntime);
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 458 PN(se->sum_exec_runtime);
97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 459
cb2517653fccaf kernel/sched/debug.c Mel Gorman 2016-02-05 460 if (schedstat_enabled()) {
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 461 PN_SCHEDSTAT(wait_start);
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 462 PN_SCHEDSTAT(sleep_start);
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 463 PN_SCHEDSTAT(block_start);
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 464 PN_SCHEDSTAT(sleep_max);
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 465 PN_SCHEDSTAT(block_max);
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 466 PN_SCHEDSTAT(exec_max);
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 467 PN_SCHEDSTAT(slice_max);
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 468 PN_SCHEDSTAT(wait_max);
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 469 PN_SCHEDSTAT(wait_sum);
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 470 P_SCHEDSTAT(wait_count);
cb2517653fccaf kernel/sched/debug.c Mel Gorman 2016-02-05 471 }
97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 472
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 473 P(se->load.weight);
9d85f21c94f7f7 kernel/sched/debug.c Paul Turner 2012-10-04 474 #ifdef CONFIG_SMP
9d89c257dfb9c5 kernel/sched/debug.c Yuyang Du 2015-07-15 475 P(se->avg.load_avg);
9d89c257dfb9c5 kernel/sched/debug.c Yuyang Du 2015-07-15 476 P(se->avg.util_avg);
9f68395333ad7f kernel/sched/debug.c Vincent Guittot 2020-02-24 477 P(se->avg.runnable_avg);
9d85f21c94f7f7 kernel/sched/debug.c Paul Turner 2012-10-04 478 #endif
4fa8d299b43a91 kernel/sched/debug.c Josh Poimboeuf 2016-06-17 479
:::::: The code at line 453 was first introduced by commit
:::::: cd126afe838d7ea9b971cdea087fd498a7293c7f sched/fair: Remove rq's runnable avg
:::::: TO: Yuyang Du <yuyang.du@intel.com>
:::::: CC: Ingo Molnar <mingo@kernel.org>
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 29328 bytes --]
^ permalink raw reply [flat|nested] 7+ messages in thread
* [peterz-queue:sched/core 13/19] kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
@ 2021-09-13 8:47 ` Dan Carpenter
0 siblings, 0 replies; 7+ messages in thread
From: Dan Carpenter @ 2021-09-13 8:47 UTC (permalink / raw)
To: kbuild, Yafang Shao; +Cc: lkp, kbuild-all, linux-kernel, Peter Zijlstra
tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core
head: 2dfdb3d20ad50e2ae2cb84cbceb0f0fc75e79e5d
commit: 445d9e8ba05d5e9e4b26956b7fe529223e29d8d1 [13/19] sched: make struct sched_statistics independent of fair sched class
config: x86_64-randconfig-m001-20210910 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
smatch warnings:
kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
vim +/se +453 kernel/sched/debug.c
3866e845ed5222 kernel/sched/debug.c Steven Rostedt (Red Hat 2016-02-22 439)
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 440 #ifdef CONFIG_FAIR_GROUP_SCHED
5091faa449ee0b kernel/sched_debug.c Mike Galbraith 2010-11-30 441 static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 442 {
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 443 struct sched_entity *se = tg->se[cpu];
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 @444 struct sched_statistics *stats = __schedstats_from_se(se);
^^
New unchecked dereference.
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 445
97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 446 #define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F)
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 447 #define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 448 #F, (long long)schedstat_val(stats->F))
97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 449 #define PN(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 450 #define PN_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", \
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 451 #F, SPLIT_NS((long long)schedstat_val(stats->F)))
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 452
cd126afe838d7e kernel/sched/debug.c Yuyang Du 2015-07-15 @453 if (!se)
^^^
The old code assumed "se" can be NULL.
18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 454 return;
18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 455
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 456 PN(se->exec_start);
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 457 PN(se->vruntime);
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
^ permalink raw reply [flat|nested] 7+ messages in thread
* [peterz-queue:sched/core 13/19] kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
@ 2021-09-13 8:47 ` Dan Carpenter
0 siblings, 0 replies; 7+ messages in thread
From: Dan Carpenter @ 2021-09-13 8:47 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 3275 bytes --]
tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core
head: 2dfdb3d20ad50e2ae2cb84cbceb0f0fc75e79e5d
commit: 445d9e8ba05d5e9e4b26956b7fe529223e29d8d1 [13/19] sched: make struct sched_statistics independent of fair sched class
config: x86_64-randconfig-m001-20210910 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
smatch warnings:
kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
vim +/se +453 kernel/sched/debug.c
3866e845ed5222 kernel/sched/debug.c Steven Rostedt (Red Hat 2016-02-22 439)
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 440 #ifdef CONFIG_FAIR_GROUP_SCHED
5091faa449ee0b kernel/sched_debug.c Mike Galbraith 2010-11-30 441 static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 442 {
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 443 struct sched_entity *se = tg->se[cpu];
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 @444 struct sched_statistics *stats = __schedstats_from_se(se);
^^
New unchecked dereference.
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 445
97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 446 #define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F)
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 447 #define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 448 #F, (long long)schedstat_val(stats->F))
97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 449 #define PN(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 450 #define PN_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", \
445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 451 #F, SPLIT_NS((long long)schedstat_val(stats->F)))
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 452
cd126afe838d7e kernel/sched/debug.c Yuyang Du 2015-07-15 @453 if (!se)
^^^
The old code assumed "se" can be NULL.
18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 454 return;
18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 455
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 456 PN(se->exec_start);
ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 457 PN(se->vruntime);
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [peterz-queue:sched/core 13/19] kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
2021-09-13 8:47 ` Dan Carpenter
@ 2021-09-13 11:04 ` Yafang Shao
-1 siblings, 0 replies; 7+ messages in thread
From: Yafang Shao @ 2021-09-13 11:04 UTC (permalink / raw)
To: Dan Carpenter; +Cc: kbuild, kbuild test robot, kbuild-all, LKML, Peter Zijlstra
On Mon, Sep 13, 2021 at 4:48 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core
> head: 2dfdb3d20ad50e2ae2cb84cbceb0f0fc75e79e5d
> commit: 445d9e8ba05d5e9e4b26956b7fe529223e29d8d1 [13/19] sched: make struct sched_statistics independent of fair sched class
> config: x86_64-randconfig-m001-20210910 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> smatch warnings:
> kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
>
Sorry, my bad.
Hi Peter,
Could you pls. help amend below change to the original commit ?
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 52b4426414c0..d59f33ac06fe 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -440,11 +440,8 @@ void dirty_sched_domain_sysctl(int cpu)
#ifdef CONFIG_FAIR_GROUP_SCHED
static void print_cfs_group_stats(struct seq_file *m, int cpu, struct
task_group *tg)
{
- struct sched_statistics __maybe_unused *stats;
struct sched_entity *se = tg->se[cpu];
- stats = __schedstats_from_se(se);
-
#define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F,
(long long)F)
#define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \
#F, (long long)schedstat_val(stats->F))
@@ -460,6 +457,8 @@ static void print_cfs_group_stats(struct seq_file
*m, int cpu, struct task_group
PN(se->sum_exec_runtime);
if (schedstat_enabled()) {
+ struct sched_statistics *stats = __schedstats_from_se(se);
+
PN_SCHEDSTAT(wait_start);
PN_SCHEDSTAT(sleep_start);
PN_SCHEDSTAT(block_start);
> vim +/se +453 kernel/sched/debug.c
>
> 3866e845ed5222 kernel/sched/debug.c Steven Rostedt (Red Hat 2016-02-22 439)
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 440 #ifdef CONFIG_FAIR_GROUP_SCHED
> 5091faa449ee0b kernel/sched_debug.c Mike Galbraith 2010-11-30 441 static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 442 {
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 443 struct sched_entity *se = tg->se[cpu];
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 @444 struct sched_statistics *stats = __schedstats_from_se(se);
> ^^
> New unchecked dereference.
>
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 445
> 97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 446 #define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F)
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 447 #define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 448 #F, (long long)schedstat_val(stats->F))
> 97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 449 #define PN(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 450 #define PN_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", \
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 451 #F, SPLIT_NS((long long)schedstat_val(stats->F)))
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 452
> cd126afe838d7e kernel/sched/debug.c Yuyang Du 2015-07-15 @453 if (!se)
> ^^^
> The old code assumed "se" can be NULL.
>
> 18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 454 return;
> 18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 455
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 456 PN(se->exec_start);
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 457 PN(se->vruntime);
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
>
--
Thanks
Yafang
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [peterz-queue:sched/core 13/19] kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
@ 2021-09-13 11:04 ` Yafang Shao
0 siblings, 0 replies; 7+ messages in thread
From: Yafang Shao @ 2021-09-13 11:04 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 4723 bytes --]
On Mon, Sep 13, 2021 at 4:48 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core
> head: 2dfdb3d20ad50e2ae2cb84cbceb0f0fc75e79e5d
> commit: 445d9e8ba05d5e9e4b26956b7fe529223e29d8d1 [13/19] sched: make struct sched_statistics independent of fair sched class
> config: x86_64-randconfig-m001-20210910 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> smatch warnings:
> kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
>
Sorry, my bad.
Hi Peter,
Could you pls. help amend below change to the original commit ?
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 52b4426414c0..d59f33ac06fe 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -440,11 +440,8 @@ void dirty_sched_domain_sysctl(int cpu)
#ifdef CONFIG_FAIR_GROUP_SCHED
static void print_cfs_group_stats(struct seq_file *m, int cpu, struct
task_group *tg)
{
- struct sched_statistics __maybe_unused *stats;
struct sched_entity *se = tg->se[cpu];
- stats = __schedstats_from_se(se);
-
#define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F,
(long long)F)
#define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \
#F, (long long)schedstat_val(stats->F))
@@ -460,6 +457,8 @@ static void print_cfs_group_stats(struct seq_file
*m, int cpu, struct task_group
PN(se->sum_exec_runtime);
if (schedstat_enabled()) {
+ struct sched_statistics *stats = __schedstats_from_se(se);
+
PN_SCHEDSTAT(wait_start);
PN_SCHEDSTAT(sleep_start);
PN_SCHEDSTAT(block_start);
> vim +/se +453 kernel/sched/debug.c
>
> 3866e845ed5222 kernel/sched/debug.c Steven Rostedt (Red Hat 2016-02-22 439)
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 440 #ifdef CONFIG_FAIR_GROUP_SCHED
> 5091faa449ee0b kernel/sched_debug.c Mike Galbraith 2010-11-30 441 static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg)
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 442 {
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 443 struct sched_entity *se = tg->se[cpu];
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 @444 struct sched_statistics *stats = __schedstats_from_se(se);
> ^^
> New unchecked dereference.
>
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 445
> 97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 446 #define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F)
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 447 #define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 448 #F, (long long)schedstat_val(stats->F))
> 97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 449 #define PN(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 450 #define PN_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", \
> 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 451 #F, SPLIT_NS((long long)schedstat_val(stats->F)))
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 452
> cd126afe838d7e kernel/sched/debug.c Yuyang Du 2015-07-15 @453 if (!se)
> ^^^
> The old code assumed "se" can be NULL.
>
> 18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 454 return;
> 18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 455
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 456 PN(se->exec_start);
> ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 457 PN(se->vruntime);
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
>
--
Thanks
Yafang
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [peterz-queue:sched/core 13/19] kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
2021-09-13 11:04 ` Yafang Shao
@ 2021-09-13 12:02 ` Peter Zijlstra
-1 siblings, 0 replies; 7+ messages in thread
From: Peter Zijlstra @ 2021-09-13 12:02 UTC (permalink / raw)
To: Yafang Shao; +Cc: Dan Carpenter, kbuild, kbuild test robot, kbuild-all, LKML
On Mon, Sep 13, 2021 at 07:04:14PM +0800, Yafang Shao wrote:
> Hi Peter,
>
> Could you pls. help amend below change to the original commit ?
Yep, will do, thanks!
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [peterz-queue:sched/core 13/19] kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444)
@ 2021-09-13 12:02 ` Peter Zijlstra
0 siblings, 0 replies; 7+ messages in thread
From: Peter Zijlstra @ 2021-09-13 12:02 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 169 bytes --]
On Mon, Sep 13, 2021 at 07:04:14PM +0800, Yafang Shao wrote:
> Hi Peter,
>
> Could you pls. help amend below change to the original commit ?
Yep, will do, thanks!
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-09-13 12:03 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-11 2:52 [peterz-queue:sched/core 13/19] kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444) kernel test robot
2021-09-13 8:47 ` Dan Carpenter
2021-09-13 8:47 ` Dan Carpenter
2021-09-13 11:04 ` Yafang Shao
2021-09-13 11:04 ` Yafang Shao
2021-09-13 12:02 ` Peter Zijlstra
2021-09-13 12:02 ` Peter Zijlstra
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