lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <20071007205958.7D8C41474B@wotan.suse.de> Date: Sun, 7 Oct 2007 22:59:58 +0200 (CEST) From: Andi Kleen <ak@...e.de> To: linux-kernel@...r.kernel.org, mingo@...e.hu Subject: [PATCH] [5/6] scheduler: Protect important kernel threads against normalize_rt Not only the migration thread, but also softlockup and stop machine need to be protected against normalize_rt(). Instead of checking for them all I added a new process flag for this. This was the last available bit in 32bit task->flags, sorry for that. This removes the is_migration_thread macro added in the last patch again because it is not needed anymore. Signed-off-by: Andi Kleen <ak@...e.de> Index: linux-2.6-sched-devel/include/linux/sched.h =================================================================== --- linux-2.6-sched-devel.orig/include/linux/sched.h +++ linux-2.6-sched-devel/include/linux/sched.h @@ -1330,6 +1330,7 @@ static inline void put_task_struct(struc #define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */ #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */ #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezeable */ +#define PF_RT_PROTECTED 0x80000000 /* RT task protected from sysrq */ /* * Only the _current_ task can read/write to tsk->flags, but other Index: linux-2.6-sched-devel/kernel/sched.c =================================================================== --- linux-2.6-sched-devel.orig/kernel/sched.c +++ linux-2.6-sched-devel/kernel/sched.c @@ -74,12 +74,6 @@ unsigned long long __attribute__((weak)) return (unsigned long long)jiffies * (1000000000 / HZ); } -#ifdef CONFIG_SMP -#define is_migration_thread(p, rq) ((p) == (rq)->migration_thread) -#else -#define is_migration_thread(p, rq) 0 -#endif - /* * Convert user-nice values [ -20 ... 0 ... 19 ] * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], @@ -5305,6 +5299,7 @@ migration_call(struct notifier_block *nf kthread_bind(p, cpu); /* Must be high prio: stop_machine expects to yield to it. */ rq = task_rq_lock(p, &flags); + p->flags |= PF_RT_PROTECTED; __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); task_rq_unlock(rq, &flags); cpu_rq(cpu)->migration_thread = p; @@ -6583,7 +6578,7 @@ void normalize_rt_tasks(void) spin_lock_irqsave(&p->pi_lock, flags); rq = __task_rq_lock(p); - if (!is_migration_thread(p, rq)) + if (!(p->flags & PF_RT_PROTECTED)) normalize_task(rq, p); __task_rq_unlock(rq); Index: linux-2.6-sched-devel/kernel/softlockup.c =================================================================== --- linux-2.6-sched-devel.orig/kernel/softlockup.c +++ linux-2.6-sched-devel/kernel/softlockup.c @@ -116,6 +116,7 @@ static int watchdog(void * __bind_cpu) { struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; + current->flags |= PF_RT_PROTECTED; sched_setscheduler(current, SCHED_FIFO, ¶m); /* initialize timestamp */ Index: linux-2.6-sched-devel/kernel/stop_machine.c =================================================================== --- linux-2.6-sched-devel.orig/kernel/stop_machine.c +++ linux-2.6-sched-devel/kernel/stop_machine.c @@ -187,6 +187,7 @@ struct task_struct *__stop_machine_run(i if (!IS_ERR(p)) { struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; + p->flags |= PF_RT_PROTECTED; /* One high-prio thread per cpu. We'll do this one. */ sched_setscheduler(p, SCHED_FIFO, ¶m); kthread_bind(p, cpu); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists