From: Peter Zijlstra <peterz@infradead.org> mainline inclusion from mainline-v6.7-rc1 commit 92c2ec5bc1081e6bbbe172bcfb1a566ad7b4f809 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IDC9YK Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... -------------------------------- Use guards to reduce gotos and simplify control flow. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Zicheng Qu <quzicheng@huawei.com> --- kernel/sched/core.c | 53 ++++++++++++--------------------------------- 1 file changed, 14 insertions(+), 39 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e341a0a5ec54..32f4181fd342 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8460,39 +8460,24 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) { struct affinity_context ac; struct cpumask *user_mask; - struct task_struct *p; int retval; - rcu_read_lock(); - - p = find_process_by_pid(pid); - if (!p) { - rcu_read_unlock(); + CLASS(find_get_task, p)(pid); + if (!p) return -ESRCH; - } - - /* Prevent p going away */ - get_task_struct(p); - rcu_read_unlock(); - if (p->flags & PF_NO_SETAFFINITY) { - retval = -EINVAL; - goto out_put_task; - } + if (p->flags & PF_NO_SETAFFINITY) + return -EINVAL; if (!check_same_owner(p)) { - rcu_read_lock(); - if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { - rcu_read_unlock(); - retval = -EPERM; - goto out_put_task; - } - rcu_read_unlock(); + guard(rcu)(); + if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) + return -EPERM; } retval = security_task_setscheduler(p); if (retval) - goto out_put_task; + return retval; /* * With non-SMP configs, user_cpus_ptr/user_mask isn't used and @@ -8502,8 +8487,7 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) if (user_mask) { cpumask_copy(user_mask, in_mask); } else if (IS_ENABLED(CONFIG_SMP)) { - retval = -ENOMEM; - goto out_put_task; + return -ENOMEM; } ac = (struct affinity_context){ @@ -8515,8 +8499,6 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) retval = __sched_setaffinity(p, &ac); kfree(ac.user_mask); -out_put_task: - put_task_struct(p); return retval; } @@ -8558,28 +8540,21 @@ SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, long sched_getaffinity(pid_t pid, struct cpumask *mask) { struct task_struct *p; - unsigned long flags; int retval; - rcu_read_lock(); - - retval = -ESRCH; + guard(rcu)(); p = find_process_by_pid(pid); if (!p) - goto out_unlock; + return -ESRCH; retval = security_task_getscheduler(p); if (retval) - goto out_unlock; + return retval; - raw_spin_lock_irqsave(&p->pi_lock, flags); + guard(raw_spinlock_irqsave)(&p->pi_lock); cpumask_and(mask, &p->cpus_mask, cpu_active_mask); - raw_spin_unlock_irqrestore(&p->pi_lock, flags); -out_unlock: - rcu_read_unlock(); - - return retval; + return 0; } /** -- 2.34.1