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    • /[pkg-src]/trunk/kernel26-alx/patches-2.6.17-r6/0010-2.6.17-sched-limit_policy_changes.patch

    Contents of /trunk/kernel26-alx/patches-2.6.17-r6/0010-2.6.17-sched-limit_policy_changes.patch

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    Revision 199 - (show annotations) (download)
    Fri May 18 11:04:36 2007 UTC (16 years, 11 months ago) by niro
    File size: 2425 byte(s) 
    -import
    1 Many applications explicitly set SCHED_NORMAL on threads thus undoing the
    2 usefulness of the SCHED_ISO, SCHED_BATCH and SCHED_IDLEPRIO policies.
    3
    4 For unprivileged users:
    5
    6 Only allow non realtime policies to be downgraded from ISO->BATCH->IDLEPRIO
    7 but not back to NORMAL.
    8
    9 Signed-off-by: Con Kolivas <kernel@kolivas.org>
    10
    11 ---
    12 kernel/sched.c | 52 +++++++++++++++++++++++++++++++++++++++-------------
    13 1 files changed, 39 insertions(+), 13 deletions(-)
    14
    15 Index: linux-ck-dev/kernel/sched.c
    16 ===================================================================
    17 --- linux-ck-dev.orig/kernel/sched.c 2006-06-18 15:23:46.000000000 +1000
    18 +++ linux-ck-dev/kernel/sched.c 2006-06-18 15:23:49.000000000 +1000
    19 @@ -3700,19 +3700,44 @@ recheck:
    20 * Allow unprivileged RT tasks to decrease priority:
    21 */
    22 if (!capable(CAP_SYS_NICE)) {
    23 - /*
    24 - * can't change policy, except between SCHED_NORMAL
    25 - * and SCHED_BATCH:
    26 - */
    27 - if (SCHED_RT(policy) && policy != p->policy &&
    28 - !p->signal->rlim[RLIMIT_RTPRIO].rlim_cur)
    29 - return -EPERM;
    30 - /* can't increase priority */
    31 - if (SCHED_RT(policy) &&
    32 - param->sched_priority > p->rt_priority &&
    33 - param->sched_priority >
    34 - p->signal->rlim[RLIMIT_RTPRIO].rlim_cur)
    35 - return -EPERM;
    36 + if (SCHED_RT(policy)) {
    37 + /*
    38 + * can't change policy to a realtime policy
    39 + */
    40 + if (policy != p->policy &&
    41 + !p->signal->rlim[RLIMIT_RTPRIO].rlim_cur)
    42 + return -EPERM;
    43 + /* can't increase priority */
    44 + if (param->sched_priority > p->rt_priority &&
    45 + param->sched_priority >
    46 + p->signal->rlim[RLIMIT_RTPRIO].rlim_cur)
    47 + return -EPERM;
    48 + } else {
    49 + switch (p->policy) {
    50 + /*
    51 + * Can only downgrade policies but not back to
    52 + * SCHED_NORMAL
    53 + */
    54 + case SCHED_ISO:
    55 + if (policy == SCHED_ISO)
    56 + goto out;
    57 + if (policy == SCHED_NORMAL)
    58 + return -EPERM;
    59 + break;
    60 + case SCHED_BATCH:
    61 + if (policy == SCHED_BATCH)
    62 + goto out;
    63 + if (policy != SCHED_IDLEPRIO)
    64 + return -EPERM;
    65 + break;
    66 + case SCHED_IDLEPRIO:
    67 + if (policy == SCHED_IDLEPRIO)
    68 + goto out;
    69 + return -EPERM;
    70 + default:
    71 + break;
    72 + }
    73 + }
    74 /* can't change other user's priorities */
    75 if ((current->euid != p->euid) &&
    76 (current->euid != p->uid))
    77 @@ -3756,6 +3781,7 @@ recheck:
    78 preempt(p, rq);
    79 }
    80 task_rq_unlock(rq, &flags);
    81 +out:
    82 return 0;
    83 }
    84 EXPORT_SYMBOL_GPL(sched_setscheduler);