Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: rcu_read_lock_bh_held(): disabling irqs also disables bh
generic-ipi: Fix deadlock in __smp_call_function_single
+15
-4
+1
-1
include/linux/rcupdate.h
+1
-1
include/linux/rcupdate.h
···
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* Makes rcu_dereference_check() do the dirty work.
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*/
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#define rcu_dereference_bh(p) \
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-
rcu_dereference_check(p, rcu_read_lock_bh_held())
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+
rcu_dereference_check(p, rcu_read_lock_bh_held() || irqs_disabled())
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/**
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* rcu_dereference_sched - fetch RCU-protected pointer, checking for RCU-sched
+14
-3
kernel/smp.c
+14
-3
kernel/smp.c
···
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365
EXPORT_SYMBOL_GPL(smp_call_function_any);
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/**
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-
* __smp_call_function_single(): Run a function on another CPU
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+
* __smp_call_function_single(): Run a function on a specific CPU
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* @cpu: The CPU to run on.
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* @data: Pre-allocated and setup data structure
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+
* @wait: If true, wait until function has completed on specified CPU.
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*
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* Like smp_call_function_single(), but allow caller to pass in a
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* pre-allocated data structure. Useful for embedding @data inside
···
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void __smp_call_function_single(int cpu, struct call_single_data *data,
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int wait)
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{
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-
csd_lock(data);
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+
unsigned int this_cpu;
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+
unsigned long flags;
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+
this_cpu = get_cpu();
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/*
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* Can deadlock when called with interrupts disabled.
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* We allow cpu's that are not yet online though, as no one else can
···
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WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled()
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&& !oops_in_progress);
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389
393
-
generic_exec_single(cpu, data, wait);
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+
if (cpu == this_cpu) {
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+
local_irq_save(flags);
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+
data->func(data->info);
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+
local_irq_restore(flags);
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+
} else {
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+
csd_lock(data);
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+
generic_exec_single(cpu, data, wait);
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+
}
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+
put_cpu();
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}
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/**