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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-20 10:43:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-20 10:43:03 -0700 |
| commit | 4b01f5a4c9c4f0c502875c1fb31dcd5d0df86475 (patch) | |
| tree | a2433b3625612de7458b28dfc8da96a069e10bf8 | |
| parent | 70e6e1b971e46f5c1c2d72217ba62401a2edc22b (diff) | |
| parent | 19dbdcb8039cff16669a05136a29180778d16d0a (diff) | |
Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp fix from Thomas Gleixner:
"Add warnings to the smp function calls so callers from wrong contexts
get detected"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
smp: Warn on function calls from softirq context
| -rw-r--r-- | kernel/smp.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/kernel/smp.c b/kernel/smp.c index 616d4d114847..7dbcb402c2fc 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -291,6 +291,14 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info, WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled() && !oops_in_progress); + /* + * When @wait we can deadlock when we interrupt between llist_add() and + * arch_send_call_function_ipi*(); when !@wait we can deadlock due to + * csd_lock() on because the interrupt context uses the same csd + * storage. + */ + WARN_ON_ONCE(!in_task()); + csd = &csd_stack; if (!wait) { csd = this_cpu_ptr(&csd_data); @@ -416,6 +424,14 @@ void smp_call_function_many(const struct cpumask *mask, WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled() && !oops_in_progress && !early_boot_irqs_disabled); + /* + * When @wait we can deadlock when we interrupt between llist_add() and + * arch_send_call_function_ipi*(); when !@wait we can deadlock due to + * csd_lock() on because the interrupt context uses the same csd + * storage. + */ + WARN_ON_ONCE(!in_task()); + /* Try to fastpath. So, what's a CPU they want? Ignoring this one. */ cpu = cpumask_first_and(mask, cpu_online_mask); if (cpu == this_cpu) |