tree: https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git queue-5.3 head: 5daab9bb2bd2bf447eec337bab8cc1106fa410b7 commit: b62612cacd5c4efe4a74d437654dba8d622f21c4 [71/83] io_uring: only flush workqueues on fileset removal config: x86_64-randconfig-a001-201941 (attached as .config) compiler: gcc-5 (Ubuntu 5.5.0-12ubuntu1) 5.5.0 20171010 reproduce: git checkout b62612cacd5c4efe4a74d437654dba8d622f21c4 # save the attached .config to linux build tree make ARCH=x86_64 If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): fs/io_uring.c: In function 'io_destruct_skb': fs/io_uring.c:2570:2: error: invalid use of undefined type 'struct workqueue_struct' for (i = 0; i < ARRAY_SIZE(ctx->sqo_wq); i++) ^ In file included from fs/io_uring.c:42:0: include/linux/kernel.h:47:52: error: dereferencing pointer to incomplete type 'struct workqueue_struct' #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) ^ fs/io_uring.c:2570:18: note: in expansion of macro 'ARRAY_SIZE' for (i = 0; i < ARRAY_SIZE(ctx->sqo_wq); i++) ^ In file included from include/linux/kernel.h:16:0, from fs/io_uring.c:42: #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); })) ^ include/linux/compiler.h:357:28: note: in expansion of macro 'BUILD_BUG_ON_ZERO' #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) ^ include/linux/kernel.h:47:59: note: in expansion of macro '__must_be_array' #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) ^ fs/io_uring.c:2570:18: note: in expansion of macro 'ARRAY_SIZE' for (i = 0; i < ARRAY_SIZE(ctx->sqo_wq); i++) ^ include/linux/build_bug.h:16:45: error: bit-field '<anonymous>' width not an integer constant #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); })) ^ include/linux/compiler.h:357:28: note: in expansion of macro 'BUILD_BUG_ON_ZERO' #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) ^ include/linux/kernel.h:47:59: note: in expansion of macro '__must_be_array' #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) ^ fs/io_uring.c:2570:18: note: in expansion of macro 'ARRAY_SIZE' for (i = 0; i < ARRAY_SIZE(ctx->sqo_wq); i++) ^ fs/io_uring.c:2571:3: error: invalid use of undefined type 'struct workqueue_struct' if (ctx->sqo_wq[i]) ^ fs/io_uring.c:2572:4: error: invalid use of undefined type 'struct workqueue_struct' flush_workqueue(ctx->sqo_wq[i]); ^ vim +16 include/linux/build_bug.h bc6245e5efd70c Ian Abbott 2017-07-10 6 bc6245e5efd70c Ian Abbott 2017-07-10 7 #ifdef __CHECKER__ bc6245e5efd70c Ian Abbott 2017-07-10 8 #define BUILD_BUG_ON_ZERO(e) (0) bc6245e5efd70c Ian Abbott 2017-07-10 9 #else /* __CHECKER__ */ bc6245e5efd70c Ian Abbott 2017-07-10 10 /* bc6245e5efd70c Ian Abbott 2017-07-10 11 * Force a compilation error if condition is true, but also produce a bc6245e5efd70c Ian Abbott 2017-07-10 12 * result (of value 0 and type size_t), so the expression can be used bc6245e5efd70c Ian Abbott 2017-07-10 13 * e.g. in a structure initializer (or where-ever else comma expressions bc6245e5efd70c Ian Abbott 2017-07-10 14 * aren't permitted). bc6245e5efd70c Ian Abbott 2017-07-10 15 */ bc6245e5efd70c Ian Abbott 2017-07-10 @16 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); })) 527edbc18a70e7 Masahiro Yamada 2019-01-03 17 #endif /* __CHECKER__ */ 527edbc18a70e7 Masahiro Yamada 2019-01-03 18 :::::: The code at line 16 was first introduced by commit :::::: bc6245e5efd70c41eaf9334b1b5e646745cb0fb3 bug: split BUILD_BUG stuff out into <linux/build_bug.h> :::::: TO: Ian Abbott <abbotti(a)mev.co.uk&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation