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author | Tejun Heo <tj@kernel.org> | 2010-03-10 18:57:54 +0900 |
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committer | Tejun Heo <tj@kernel.org> | 2010-03-29 23:07:12 +0900 |
commit | 10fad5e46f6c7bdfb01b1a012380a38e3c6ab346 (patch) | |
tree | 9ec6e3955e7f879f64ea79812cf5ecd41baa6939 /mm | |
parent | 259354deaaf03d49a02dbb9975d6ec2a54675672 (diff) | |
download | lwn-10fad5e46f6c7bdfb01b1a012380a38e3c6ab346.tar.gz lwn-10fad5e46f6c7bdfb01b1a012380a38e3c6ab346.zip |
percpu, module: implement and use is_kernel/module_percpu_address()
lockdep has custom code to check whether a pointer belongs to static
percpu area which is somewhat broken. Implement proper
is_kernel/module_percpu_address() and replace the custom code.
On UP, percpu variables are regular static variables and can't be
distinguished from them. Always return %false on UP.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/percpu.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/mm/percpu.c b/mm/percpu.c index 768419d44ad7..6e09741ddc62 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1304,6 +1304,32 @@ void free_percpu(void __percpu *ptr) EXPORT_SYMBOL_GPL(free_percpu); /** + * is_kernel_percpu_address - test whether address is from static percpu area + * @addr: address to test + * + * Test whether @addr belongs to in-kernel static percpu area. Module + * static percpu areas are not considered. For those, use + * is_module_percpu_address(). + * + * RETURNS: + * %true if @addr is from in-kernel static percpu area, %false otherwise. + */ +bool is_kernel_percpu_address(unsigned long addr) +{ + const size_t static_size = __per_cpu_end - __per_cpu_start; + void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); + unsigned int cpu; + + for_each_possible_cpu(cpu) { + void *start = per_cpu_ptr(base, cpu); + + if ((void *)addr >= start && (void *)addr < start + static_size) + return true; + } + return false; +} + +/** * per_cpu_ptr_to_phys - convert translated percpu address to physical address * @addr: the address to be converted to physical address * |