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authorTejun Heo <tj@kernel.org>2010-03-10 18:57:54 +0900
committerTejun Heo <tj@kernel.org>2010-03-29 23:07:12 +0900
commit10fad5e46f6c7bdfb01b1a012380a38e3c6ab346 (patch)
tree9ec6e3955e7f879f64ea79812cf5ecd41baa6939 /mm/percpu.c
parent259354deaaf03d49a02dbb9975d6ec2a54675672 (diff)
downloadvexpress-lsk-10fad5e46f6c7bdfb01b1a012380a38e3c6ab346.tar.gz
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/percpu.c')
-rw-r--r--mm/percpu.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/mm/percpu.c b/mm/percpu.c
index 768419d44ad..6e09741ddc6 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
*