per_cpu: fix DEFINE_PER_CPU_SHARED_ALIGNED for modules

Current module loader lookups ".data.percpu" ELF section to perform
per_cpu relocation.  But DEFINE_PER_CPU_SHARED_ALIGNED() uses another
section (".data.percpu.shared_aligned"), currently only handled in
vmlinux.lds, not by module loader.

To correct this problem, instead of adding logic into module loader, or
using at build time a module.lds file for all arches to group
".data.percpu.shared_aligned" into ".data.percpu", just use ".data.percpu"
for modules.

Alignment requirements are correctly handled by ld and module loader.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index d746a2a..4cdd393 100644 (file)
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -13,8 +13,14 @@
        __attribute__((__section__(".data.percpu")))                    \
        PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name
 
+#ifdef MODULE
+#define SHARED_ALIGNED_SECTION ".data.percpu"
+#else
+#define SHARED_ALIGNED_SECTION ".data.percpu.shared_aligned"
+#endif
+
 #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name)                      \
-       __attribute__((__section__(".data.percpu.shared_aligned")))     \
+       __attribute__((__section__(SHARED_ALIGNED_SECTION)))            \
        PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name             \
        ____cacheline_aligned_in_smp
 #else