The clang build with named address spaces enabled currently fails with:
error: multiple identical address spaces specified for type [-Werror,-Wduplicate-decl-specifier]
The warning is emitted when accessing const_pcpu_hot structure,
which is already declared in __seg_gs named address space.
Use specialized accessor for __raw_cpu_read_const() instead, avoiding
redeclaring __seg_gs named address space via __raw_cpu_read().
Signed-off-by: Uros Bizjak <[email protected]>
Acked-by: Nathan Chancellor <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Bill Wendling <[email protected]>
Cc: Justin Stitt <[email protected]>
---
arch/x86/include/asm/percpu.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index c55a79d5feae..aeea5c8a17de 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -160,7 +160,10 @@ do { \
*(qual __my_cpu_type(pcp) *)__my_cpu_ptr(&(pcp)) = (val); \
} while (0)
-#define __raw_cpu_read_const(pcp) __raw_cpu_read(, , pcp)
+#define __raw_cpu_read_const(pcp) \
+({ \
+ *(typeof(pcp) *)(__force uintptr_t)(&(pcp)); \
+})
#else /* !CONFIG_USE_X86_SEG_SUPPORT: */
--
2.45.2