The patch titled sched_setscheduler: fix? policy checks has been removed from the -mm tree. Its filename is sched_setscheduler-fix-policy-checks.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ Subject: sched_setscheduler: fix? policy checks From: Oleg Nesterov <oleg@xxxxxxxxxx> I am not sure this patch is correct: I can't understand what the current code does, and I don't know what it was supposed to do. The comment says: * can't change policy, except between SCHED_NORMAL * and SCHED_BATCH: The code: if (((policy != SCHED_NORMAL && p->policy != SCHED_BATCH) && (policy != SCHED_BATCH && p->policy != SCHED_NORMAL)) && But this is equivalent to: if ( (is_rt_policy(policy) && has_rt_policy(p)) && which means something different. We can't _decrease_ the current ->rt_priority with such a check (if rlim[RLIMIT_RTPRIO] == 0). Probably, it was supposed to be: if ( !(policy == SCHED_NORMAL && p->policy == SCHED_BATCH) && !(policy == SCHED_BATCH && p->policy == SCHED_NORMAL) this matches the comment, but strange: it doesn't allow to _drop_ the realtime priority when rlim[RLIMIT_RTPRIO] == 0. I think the right check would be: /* can't set/change rt policy */ if (is_rt_policy(policy) && policy != p->policy && !rlim_rtprio) return -EPERM; Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxx> --- kernel/sched.c | 38 ++++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 20 deletions(-) diff -puN kernel/sched.c~sched_setscheduler-fix-policy-checks kernel/sched.c --- a/kernel/sched.c~sched_setscheduler-fix-policy-checks +++ a/kernel/sched.c @@ -4116,27 +4116,25 @@ recheck: * Allow unprivileged RT tasks to decrease priority: */ if (!capable(CAP_SYS_NICE)) { - unsigned long rlim_rtprio; - unsigned long flags; - - if (!lock_task_sighand(p, &flags)) - return -ESRCH; - rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; - unlock_task_sighand(p, &flags); + if (is_rt_policy(policy)) { + unsigned long rlim_rtprio; + unsigned long flags; + + if (!lock_task_sighand(p, &flags)) + return -ESRCH; + rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; + unlock_task_sighand(p, &flags); + + /* can't set/change the rt policy */ + if (policy != p->policy && !rlim_rtprio) + return -EPERM; + + /* can't increase priority */ + if (param->sched_priority > p->rt_priority && + param->sched_priority > rlim_rtprio) + return -EPERM; + } - /* - * can't change policy, except between SCHED_NORMAL - * and SCHED_BATCH: - */ - if (((policy != SCHED_NORMAL && p->policy != SCHED_BATCH) && - (policy != SCHED_BATCH && p->policy != SCHED_NORMAL)) && - !rlim_rtprio) - return -EPERM; - /* can't increase priority */ - if (is_rt_policy(policy) && - param->sched_priority > p->rt_priority && - param->sched_priority > rlim_rtprio) - return -EPERM; /* can't change other user's priorities */ if ((current->euid != p->euid) && (current->euid != p->uid)) _ Patches currently in -mm which might be from oleg@xxxxxxxxxx are origin.patch git-block.patch proc-readdir-race-fix-take-3-race-fix.patch vt-rework-the-console-spawning-variables.patch vt-make-vt_pid-a-struct-pid-making-it-pid-wrap-around-safe.patch simplify-pid-iterators.patch file-add-locking-to-f_getown.patch proc-convert-task_sig-to-use-lock_task_sighand.patch proc-convert-do_task_stat-to-use-lock_task_sighand.patch proc-drop-tasklist-lock-in-task_state.patch proc-properly-compute-tgid_offset.patch proc-remove-trailing-blank-entry-from-pid_entry-arrays.patch proc-remove-the-useless-smp-safe-comments-from-proc.patch proc-comment-what-proc_fill_cache-does.patch introduce-get_task_pid-to-fix-unsafe-get_pid.patch rcu-simplify-improve-batch-tuning.patch pidhash-temporary-debug-checks.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html