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authorTakashi Iwai <tiwai@suse.de>2018-07-04 12:03:42 +0200
committerTakashi Iwai <tiwai@suse.de>2018-07-04 12:03:42 +0200
commitcc47d169bcc76c9a4ca5b7de46bf91d1b8b4359e (patch)
treee495ce24e7b1ee52e706e46c9ecdb276487d697c
parent83fcbf77c773ee1f5b3bdb96e4e4477e60453893 (diff)
sched/sysctl: Check user input value of sysctl_sched_time_avg
(bsc#1100089).
-rw-r--r--patches.fixes/sched-sysctl-Check-user-input-value-of-sysctl_sched_.patch83
-rw-r--r--series.conf1
2 files changed, 84 insertions, 0 deletions
diff --git a/patches.fixes/sched-sysctl-Check-user-input-value-of-sysctl_sched_.patch b/patches.fixes/sched-sysctl-Check-user-input-value-of-sysctl_sched_.patch
new file mode 100644
index 0000000000..1dafee6e56
--- /dev/null
+++ b/patches.fixes/sched-sysctl-Check-user-input-value-of-sysctl_sched_.patch
@@ -0,0 +1,83 @@
+From 5ccba44ba118a5000cccc50076b0344632459779 Mon Sep 17 00:00:00 2001
+From: Ethan Zhao <ethan.zhao@oracle.com>
+Date: Mon, 4 Sep 2017 13:59:34 +0800
+Subject: [PATCH] sched/sysctl: Check user input value of sysctl_sched_time_avg
+Git-commit: 5ccba44ba118a5000cccc50076b0344632459779
+Patch-mainline: v4.14-rc3
+References: bsc#1100089
+
+System will hang if user set sysctl_sched_time_avg to 0:
+
+ [root@XXX ~]# sysctl kernel.sched_time_avg_ms=0
+
+ Stack traceback for pid 0
+ 0xffff883f6406c600 0 0 1 3 R 0xffff883f6406cf50 *swapper/3
+ ffff883f7ccc3ae8 0000000000000018 ffffffff810c4dd0 0000000000000000
+ 0000000000017800 ffff883f7ccc3d78 0000000000000003 ffff883f7ccc3bf8
+ ffffffff810c4fc9 ffff883f7ccc3c08 00000000810c5043 ffff883f7ccc3c08
+ Call Trace:
+ <IRQ> [<ffffffff810c4dd0>] ? update_group_capacity+0x110/0x200
+ [<ffffffff810c4fc9>] ? update_sd_lb_stats+0x109/0x600
+ [<ffffffff810c5507>] ? find_busiest_group+0x47/0x530
+ [<ffffffff810c5b84>] ? load_balance+0x194/0x900
+ [<ffffffff810ad5ca>] ? update_rq_clock.part.83+0x1a/0xe0
+ [<ffffffff810c6d42>] ? rebalance_domains+0x152/0x290
+ [<ffffffff810c6f5c>] ? run_rebalance_domains+0xdc/0x1d0
+ [<ffffffff8108a75b>] ? __do_softirq+0xfb/0x320
+ [<ffffffff8108ac85>] ? irq_exit+0x125/0x130
+ [<ffffffff810b3a17>] ? scheduler_ipi+0x97/0x160
+ [<ffffffff81052709>] ? smp_reschedule_interrupt+0x29/0x30
+ [<ffffffff8173a1be>] ? reschedule_interrupt+0x6e/0x80
+ <EOI> [<ffffffff815bc83c>] ? cpuidle_enter_state+0xcc/0x230
+ [<ffffffff815bc80c>] ? cpuidle_enter_state+0x9c/0x230
+ [<ffffffff815bc9d7>] ? cpuidle_enter+0x17/0x20
+ [<ffffffff810cd6dc>] ? cpu_startup_entry+0x38c/0x420
+ [<ffffffff81053373>] ? start_secondary+0x173/0x1e0
+
+Because divide-by-zero error happens in function:
+
+update_group_capacity()
+ update_cpu_capacity()
+ scale_rt_capacity()
+ {
+ ...
+ total = sched_avg_period() + delta;
+ used = div_u64(avg, total);
+ ...
+ }
+
+To fix this issue, check user input value of sysctl_sched_time_avg, keep
+it unchanged when hitting invalid input, and set the minimum limit of
+sysctl_sched_time_avg to 1 ms.
+
+Reported-by: James Puthukattukaran <james.puthukattukaran@oracle.com>
+Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
+Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Cc: Linus Torvalds <torvalds@linux-foundation.org>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Thomas Gleixner <tglx@linutronix.de>
+Cc: efault@gmx.de
+Cc: ethan.kernel@gmail.com
+Cc: keescook@chromium.org
+Cc: mcgrof@kernel.org
+Cc: <stable@vger.kernel.org>
+Link: http://lkml.kernel.org/r/1504504774-18253-1-git-send-email-ethan.zhao@oracle.com
+Signed-off-by: Ingo Molnar <mingo@kernel.org>
+Acked-by: Takashi Iwai <tiwai@suse.de>
+
+---
+ kernel/sysctl.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/kernel/sysctl.c
++++ b/kernel/sysctl.c
+@@ -364,7 +364,8 @@ static struct ctl_table kern_table[] = {
+ .data = &sysctl_sched_time_avg,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+- .proc_handler = proc_dointvec,
++ .proc_handler = proc_dointvec_minmax,
++ .extra1 = &one,
+ },
+ {
+ .procname = "sched_shares_window_ns",
diff --git a/series.conf b/series.conf
index 9250de029d..1551170876 100644
--- a/series.conf
+++ b/series.conf
@@ -3828,6 +3828,7 @@
patches.suse/asm-prototypes-Clear-any-CPP-defines-before-declarin.patch
+ patches.fixes/sched-sysctl-Check-user-input-value-of-sysctl_sched_.patch
########################################################
# interrupts/core