nfsd4: fix unlikely race in session replay case

[safe/jmp/linux-2.6] / include / asm-generic / percpu.h

diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index ca6f049..04f91c2 100644 (file)
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -41,7 +41,11 @@ extern unsigned long __per_cpu_offset[NR_CPUS];
  * Only S390 provides its own means of moving the pointer.
  */
 #ifndef SHIFT_PERCPU_PTR
-#define SHIFT_PERCPU_PTR(__p, __offset)        RELOC_HIDE((__p), (__offset))
+/* Weird cast keeps both GCC and sparse happy. */
+#define SHIFT_PERCPU_PTR(__p, __offset)        ({                              \
+       __verify_pcpu_ptr((__p));                                       \
+       RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset)); \
+})
 #endif
 
 /*