From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Quentin Perret <qperret@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.19 04/23] sched/deadline: Fix reset_on_fork reporting of DL tasks
Date: Sun, 5 Sep 2021 21:23:03 -0400 [thread overview]
Message-ID: <20210906012322.930668-4-sashal@kernel.org> (raw)
In-Reply-To: <20210906012322.930668-1-sashal@kernel.org>
From: Quentin Perret <qperret@google.com>
[ Upstream commit f95091536f78971b269ec321b057b8d630b0ad8a ]
It is possible for sched_getattr() to incorrectly report the state of
the reset_on_fork flag when called on a deadline task.
Indeed, if the flag was set on a deadline task using sched_setattr()
with flags (SCHED_FLAG_RESET_ON_FORK | SCHED_FLAG_KEEP_PARAMS), then
p->sched_reset_on_fork will be set, but __setscheduler() will bail out
early, which means that the dl_se->flags will not get updated by
__setscheduler_params()->__setparam_dl(). Consequently, if
sched_getattr() is then called on the task, __getparam_dl() will
override kattr.sched_flags with the now out-of-date copy in dl_se->flags
and report the stale value to userspace.
To fix this, make sure to only copy the flags that are relevant to
sched_deadline to and from the dl_se->flags field.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210727101103.2729607-2-qperret@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/sched/deadline.c | 7 ++++---
kernel/sched/sched.h | 2 ++
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index aa592dc3cb40..9b2bb5f3ce09 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -2615,7 +2615,7 @@ void __setparam_dl(struct task_struct *p, const struct sched_attr *attr)
dl_se->dl_runtime = attr->sched_runtime;
dl_se->dl_deadline = attr->sched_deadline;
dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline;
- dl_se->flags = attr->sched_flags;
+ dl_se->flags = attr->sched_flags & SCHED_DL_FLAGS;
dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime);
dl_se->dl_density = to_ratio(dl_se->dl_deadline, dl_se->dl_runtime);
}
@@ -2628,7 +2628,8 @@ void __getparam_dl(struct task_struct *p, struct sched_attr *attr)
attr->sched_runtime = dl_se->dl_runtime;
attr->sched_deadline = dl_se->dl_deadline;
attr->sched_period = dl_se->dl_period;
- attr->sched_flags = dl_se->flags;
+ attr->sched_flags &= ~SCHED_DL_FLAGS;
+ attr->sched_flags |= dl_se->flags;
}
/*
@@ -2703,7 +2704,7 @@ bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)
if (dl_se->dl_runtime != attr->sched_runtime ||
dl_se->dl_deadline != attr->sched_deadline ||
dl_se->dl_period != attr->sched_period ||
- dl_se->flags != attr->sched_flags)
+ dl_se->flags != (attr->sched_flags & SCHED_DL_FLAGS))
return true;
return false;
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 7b7ba91e319b..55e695080fc6 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -209,6 +209,8 @@ static inline int task_has_dl_policy(struct task_struct *p)
*/
#define SCHED_FLAG_SUGOV 0x10000000
+#define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV)
+
static inline bool dl_entity_is_special(struct sched_dl_entity *dl_se)
{
#ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
--
2.30.2
next prev parent reply other threads:[~2021-09-06 1:32 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-06 1:23 [PATCH AUTOSEL 4.19 01/23] locking/mutex: Fix HANDOFF condition Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 02/23] regmap: fix the offset of register error log Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 03/23] crypto: mxs-dcp - Check for DMA mapping errors Sasha Levin
2021-09-06 1:23 ` Sasha Levin [this message]
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 05/23] power: supply: axp288_fuel_gauge: Report register-address on readb / writeb errors Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 06/23] crypto: omap-sham - clear dma flags only after omap_sham_update_dma_stop() Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 07/23] sched/deadline: Fix missing clock update in migrate_task_rq_dl() Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 08/23] posix-cpu-timers: Force next expiration recalc after itimer reset Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 09/23] hrtimer: Avoid double reprogramming in __hrtimer_start_range_ns() Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 10/23] udf: Check LVID earlier Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 11/23] isofs: joliet: Fix iocharset=utf8 mount option Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 12/23] bcache: add proper error unwinding in bcache_device_init Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 13/23] nvme-rdma: don't update queue count when failing to set io queues Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 14/23] power: supply: max17042_battery: fix typo in MAx17042_TOFF Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 15/23] s390/cio: add dev_busid sysfs entry for each subchannel Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 16/23] libata: fix ata_host_start() Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 17/23] crypto: qat - do not ignore errors from enable_vf2pf_comms() Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 18/23] crypto: qat - handle both source of interrupt in VF ISR Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 19/23] crypto: qat - fix reuse of completion variable Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 20/23] crypto: qat - fix naming for init/shutdown VF to PF notifications Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 21/23] crypto: qat - do not export adf_iov_putmsg() Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 22/23] fcntl: fix potential deadlock for &fasync_struct.fa_lock Sasha Levin
2021-09-06 1:23 ` [PATCH AUTOSEL 4.19 23/23] udf_get_extendedattr() had no boundary checks Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210906012322.930668-4-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=qperret@google.com \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).