Commits
Pi-Hsun Shih committed 40c6d718d78
include/linux/swap.h: use offsetof() instead of custom __swapoffset macro [ Upstream commit a4046c06be50a4f01d435aa7fe57514818e6cc82 ] Use offsetof() to calculate offset of a field to take advantage of compiler built-in version when possible, and avoid UBSAN warning when compiling with Clang: UBSAN: Undefined behaviour in mm/swapfile.c:3010:38 member access within null pointer of type 'union swap_header' CPU: 6 PID: 1833 Comm: swapon Tainted: G S 4.19.23 #43 Call trace: dump_backtrace+0x0/0x194 show_stack+0x20/0x2c __dump_stack+0x20/0x28 dump_stack+0x70/0x94 ubsan_epilogue+0x14/0x44 ubsan_type_mismatch_common+0xf4/0xfc __ubsan_handle_type_mismatch_v1+0x34/0x54 __se_sys_swapon+0x654/0x1084 __arm64_sys_swapon+0x1c/0x24 el0_svc_common+0xa8/0x150 el0_svc_compat_handler+0x2c/0x38 el0_svc_compat+0x8/0x18 Link: http://lkml.kernel.org/r/20190312081902.223764-1-pihsun@chromium.org Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>