Moving the qrwlock struct definition into a header file introduced a subtle bug on all little-endian machines, where some files in some configurations would see the fields in an incorrect order. This was found by building with an LTO enabled compiler that warns every time we try to link together files with incompatible data structures.
A second patch changes linux/kconfig.h to always define the symbols, but this seems to be the root cause of most of the issues, so I'd suggest we do both.
On a current linux-next kernel, I verified that this header is responsible for all type mismatches as a result from the endianess confusion.
Cc: stable@vger.kernel.org Cc: Will Deacon will.deacon@arm.com Cc: Peter Zijlstra peterz@infradead.org Fixes: e0d02285f16e ("locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock'") Signed-off-by: Arnd Bergmann arnd@arndb.de --- include/asm-generic/qrwlock_types.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/asm-generic/qrwlock_types.h b/include/asm-generic/qrwlock_types.h index 137ecdd16daa..c36f1d5a2572 100644 --- a/include/asm-generic/qrwlock_types.h +++ b/include/asm-generic/qrwlock_types.h @@ -3,6 +3,7 @@ #define __ASM_GENERIC_QRWLOCK_TYPES_H
#include <linux/types.h> +#include <asm/byteorder.h> #include <asm/spinlock_types.h>
/*