From: Peter Zijlstra <peterz@infradead.org>
To: "Pratik R. Sampat" <psampat@linux.ibm.com>
Cc: bristot@redhat.com, christian@brauner.io, ebiederm@xmission.com,
lizefan.x@bytedance.com, tj@kernel.org, hannes@cmpxchg.org,
mingo@kernel.org, juri.lelli@redhat.com,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
cgroups@vger.kernel.org, containers@lists.linux.dev,
containers@lists.linux-foundation.org, pratik.r.sampat@gmail.com
Subject: Re: [RFC 1/5] ns: Introduce CPU Namespace
Date: Sun, 10 Oct 2021 00:37:39 +0200 [thread overview]
Message-ID: <20211009223739.GY174703@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20211009151243.8825-2-psampat@linux.ibm.com>
On Sat, Oct 09, 2021 at 08:42:39PM +0530, Pratik R. Sampat wrote:
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 2d9ff40f4661..0413175e6d73 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -27,6 +27,8 @@
> #include "pelt.h"
> #include "smp.h"
>
> +#include <linux/cpu_namespace.h>
> +
> /*
> * Export tracepoints that act as a bare tracehook (ie: have no trace event
> * associated with them) to allow external modules to probe them.
> @@ -7559,6 +7561,7 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
> {
> cpumask_var_t cpus_allowed, new_mask;
> struct task_struct *p;
> + cpumask_t temp;
> int retval;
>
> rcu_read_lock();
You're not supposed to put a cpumask_t on stack. Those things can be
huge.
> @@ -7682,8 +7686,9 @@ SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
> long sched_getaffinity(pid_t pid, struct cpumask *mask)
> {
> struct task_struct *p;
> + cpumask_var_t temp;
> unsigned long flags;
> - int retval;
> + int retval, cpu;
>
> rcu_read_lock();
>
> @@ -7698,6 +7703,13 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
>
> raw_spin_lock_irqsave(&p->pi_lock, flags);
> cpumask_and(mask, &p->cpus_mask, cpu_active_mask);
> + cpumask_clear(temp);
There's a distinct lack of allocating temp before use. Are you sure you
actually tested this?
next prev parent reply other threads:[~2021-10-09 22:41 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-09 15:12 [RFC 0/5] kernel: Introduce CPU Namespace Pratik R. Sampat
2021-10-09 15:12 ` [RFC 1/5] ns: " Pratik R. Sampat
2021-10-09 22:37 ` Peter Zijlstra [this message]
2021-10-09 15:12 ` [RFC 2/5] ns: Add scrambling functionality to CPU namespace Pratik R. Sampat
2021-10-09 15:12 ` [RFC 3/5] cpuset/cpuns: Make cgroup CPUset CPU namespace aware Pratik R. Sampat
2021-10-09 15:12 ` [RFC 4/5] cpu/cpuns: Make sysfs " Pratik R. Sampat
2021-10-09 15:12 ` [RFC 5/5] proc/cpuns: Make procfs load stats " Pratik R. Sampat
2021-10-09 22:41 ` [RFC 0/5] kernel: Introduce CPU Namespace Peter Zijlstra
2021-10-11 10:11 ` Christian Brauner
2021-10-11 14:17 ` Michal Koutný
2021-10-11 17:42 ` Tejun Heo
2021-10-12 8:42 ` Pratik Sampat
2021-10-14 22:14 ` Tejun Heo
2021-10-18 15:29 ` Pratik Sampat
2021-10-18 16:29 ` Tejun Heo
2021-10-20 10:44 ` Pratik Sampat
2021-10-20 16:35 ` Tejun Heo
2021-10-21 7:44 ` Pratik Sampat
2021-10-21 17:06 ` Tejun Heo
2021-10-21 17:15 ` Eric W. Biederman
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