Commit 9383d9679056e6cc4e7ff70f31da945a268238f4
Committed by
Thomas Gleixner
Thomas Gleixner
1 parent
9c44bc03ff
Exists in
master
and in
4 other branches
softlockup: fix softlockup_thresh unaligned access and disable detection at runtime
Fix unaligned access errors when setting softlockup_thresh on 64 bit platforms. Allow softlockup detection to be disabled by setting softlockup_thresh <= 0. Detect that boot time softlockup detection has been disabled earlier in softlockup_tick. Signed-off-by: Dimitri Sivanich <sivanich@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Showing 3 changed files with 16 additions and 7 deletions Side-by-side Diff
include/linux/sched.h
| ... | ... | @@ -295,10 +295,10 @@ |
| 295 | 295 | extern void touch_softlockup_watchdog(void); |
| 296 | 296 | extern void touch_all_softlockup_watchdogs(void); |
| 297 | 297 | extern unsigned int softlockup_panic; |
| 298 | -extern unsigned long softlockup_thresh; | |
| 299 | 298 | extern unsigned long sysctl_hung_task_check_count; |
| 300 | 299 | extern unsigned long sysctl_hung_task_timeout_secs; |
| 301 | 300 | extern unsigned long sysctl_hung_task_warnings; |
| 301 | +extern int softlockup_thresh; | |
| 302 | 302 | #else |
| 303 | 303 | static inline void softlockup_tick(void) |
| 304 | 304 | { |
kernel/softlockup.c
| ... | ... | @@ -25,7 +25,7 @@ |
| 25 | 25 | static DEFINE_PER_CPU(struct task_struct *, watchdog_task); |
| 26 | 26 | |
| 27 | 27 | static int __read_mostly did_panic; |
| 28 | -unsigned long __read_mostly softlockup_thresh = 60; | |
| 28 | +int __read_mostly softlockup_thresh = 60; | |
| 29 | 29 | |
| 30 | 30 | /* |
| 31 | 31 | * Should we panic (and reboot, if panic_timeout= is set) when a |
| ... | ... | @@ -94,6 +94,14 @@ |
| 94 | 94 | struct pt_regs *regs = get_irq_regs(); |
| 95 | 95 | unsigned long now; |
| 96 | 96 | |
| 97 | + /* Is detection switched off? */ | |
| 98 | + if (!per_cpu(watchdog_task, this_cpu) || softlockup_thresh <= 0) { | |
| 99 | + /* Be sure we don't false trigger if switched back on */ | |
| 100 | + if (touch_timestamp) | |
| 101 | + per_cpu(touch_timestamp, this_cpu) = 0; | |
| 102 | + return; | |
| 103 | + } | |
| 104 | + | |
| 97 | 105 | if (touch_timestamp == 0) { |
| 98 | 106 | touch_softlockup_watchdog(); |
| 99 | 107 | return; |
| ... | ... | @@ -104,7 +112,7 @@ |
| 104 | 112 | /* report at most once a second */ |
| 105 | 113 | if ((print_timestamp >= touch_timestamp && |
| 106 | 114 | print_timestamp < (touch_timestamp + 1)) || |
| 107 | - did_panic || !per_cpu(watchdog_task, this_cpu)) { | |
| 115 | + did_panic) { | |
| 108 | 116 | return; |
| 109 | 117 | } |
| 110 | 118 |
kernel/sysctl.c
| ... | ... | @@ -84,12 +84,13 @@ |
| 84 | 84 | extern int sysctl_nr_open_min, sysctl_nr_open_max; |
| 85 | 85 | |
| 86 | 86 | /* Constants used for minimum and maximum */ |
| 87 | -#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM) | |
| 87 | +#ifdef CONFIG_HIGHMEM | |
| 88 | 88 | static int one = 1; |
| 89 | 89 | #endif |
| 90 | 90 | |
| 91 | 91 | #ifdef CONFIG_DETECT_SOFTLOCKUP |
| 92 | 92 | static int sixty = 60; |
| 93 | +static int neg_one = -1; | |
| 93 | 94 | #endif |
| 94 | 95 | |
| 95 | 96 | #ifdef CONFIG_MMU |
| 96 | 97 | |
| 97 | 98 | |
| ... | ... | @@ -742,11 +743,11 @@ |
| 742 | 743 | .ctl_name = CTL_UNNUMBERED, |
| 743 | 744 | .procname = "softlockup_thresh", |
| 744 | 745 | .data = &softlockup_thresh, |
| 745 | - .maxlen = sizeof(unsigned long), | |
| 746 | + .maxlen = sizeof(int), | |
| 746 | 747 | .mode = 0644, |
| 747 | - .proc_handler = &proc_doulongvec_minmax, | |
| 748 | + .proc_handler = &proc_dointvec_minmax, | |
| 748 | 749 | .strategy = &sysctl_intvec, |
| 749 | - .extra1 = &one, | |
| 750 | + .extra1 = &neg_one, | |
| 750 | 751 | .extra2 = &sixty, |
| 751 | 752 | }, |
| 752 | 753 | { |