Hi Axel, [FYI, it's a private test report for your RFC patch.] [auto build test ERROR on tip/locking/core] [also build test ERROR on tip/perf/core linux/master linus/master v5.8-rc1 next-20200618] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Axel-Rasmussen/Add-rwsem-contend... base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git c935cd62d3fe985d7f0ebea185d2759e8992e96f config: s390-randconfig-r005-20200619 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 487ca07fcc75d52755c9fe2ee05bcb3b6eeeec44) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install s390 cross compiling tool for clang build # apt-get install binutils-s390-linux-gnu # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:490:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : \ ^ include/uapi/linux/swab.h:20:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \ ^ In file included from kernel/trace/trace_events_hist.c:22: In file included from kernel/trace/trace_synth.h:5: In file included from kernel/trace/trace_dynevent.h:14: In file included from kernel/trace/trace.h:9: In file included from include/linux/clocksource.h:21: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:490:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : \ ^ include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \ ^ In file included from kernel/trace/trace_events_hist.c:22: In file included from kernel/trace/trace_synth.h:5: In file included from kernel/trace/trace_dynevent.h:14: In file included from kernel/trace/trace.h:9: In file included from include/linux/clocksource.h:21: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:490:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32' ___constant_swab32(x) : \ ^ include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32' (((__u32)(x) & (__u32)0xff000000UL) >> 24))) ^ In file included from kernel/trace/trace_events_hist.c:22: In file included from kernel/trace/trace_synth.h:5: In file included from kernel/trace/trace_dynevent.h:14: In file included from kernel/trace/trace.h:9: In file included from include/linux/clocksource.h:21: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:490:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32' __fswab32(x)) ^ In file included from kernel/trace/trace_events_hist.c:22: In file included from kernel/trace/trace_synth.h:5: In file included from kernel/trace/trace_dynevent.h:14: In file included from kernel/trace/trace.h:9: In file included from include/linux/clocksource.h:21: In file included from arch/s390/include/asm/io.h:72: include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:511:46: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew(cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:46: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel(cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ In file included from kernel/trace/trace_events_hist.c:22: In file included from kernel/trace/trace_synth.h:5: In file included from kernel/trace/trace_dynevent.h:14: unsigned int val = current->trace_recursion; ~~~~~~~ ^ kernel/trace/trace.h:694:11: error: no member named 'trace_recursion' in 'struct task_struct' current->trace_recursion = val; ~~~~~~~ ^ kernel/trace/trace.h:702:30: error: no member named 'trace_recursion' in 'struct task_struct' unsigned int val = current->trace_recursion; ~~~~~~~ ^ kernel/trace/trace.h:711:11: error: no member named 'trace_recursion' in 'struct task_struct' current->trace_recursion = val; ~~~~~~~ ^ trace_array_put(tr); ^ kernel/trace/trace_events_hist.c:834:3: note: did you mean 'trace_array_get'? kernel/trace/trace.h:384:12: note: 'trace_array_get' declared here extern int trace_array_get(struct trace_array *tr); ^ kernel/trace/trace_events_hist.c:860:2: error: implicit declaration of function 'trace_array_put' [-Werror,-Wimplicit-function-declaration] trace_array_put(tr); ^ 20 warnings and 6 errors generated. vim +682 kernel/trace/trace.h edc15cafcbfa3d7 Steven Rostedt 2012-11-02 679 edc15cafcbfa3d7 Steven Rostedt 2012-11-02 680 static __always_inline int trace_test_and_set_recursion(int start, int max) edc15cafcbfa3d7 Steven Rostedt 2012-11-02 681 { edc15cafcbfa3d7 Steven Rostedt 2012-11-02 @682 unsigned int val = current->trace_recursion; edc15cafcbfa3d7 Steven Rostedt 2012-11-02 683 int bit; edc15cafcbfa3d7 Steven Rostedt 2012-11-02 684 edc15cafcbfa3d7 Steven Rostedt 2012-11-02 685 /* A previous recursion check was made */ edc15cafcbfa3d7 Steven Rostedt 2012-11-02 686 if ((val & TRACE_CONTEXT_MASK) > max) edc15cafcbfa3d7 Steven Rostedt 2012-11-02 687 return 0; edc15cafcbfa3d7 Steven Rostedt 2012-11-02 688 edc15cafcbfa3d7 Steven Rostedt 2012-11-02 689 bit = trace_get_context_bit() + start; edc15cafcbfa3d7 Steven Rostedt 2012-11-02 690 if (unlikely(val & (1 << bit))) edc15cafcbfa3d7 Steven Rostedt 2012-11-02 691 return -1; edc15cafcbfa3d7 Steven Rostedt 2012-11-02 692 edc15cafcbfa3d7 Steven Rostedt 2012-11-02 693 val |= 1 << bit; edc15cafcbfa3d7 Steven Rostedt 2012-11-02 694 current->trace_recursion = val; edc15cafcbfa3d7 Steven Rostedt 2012-11-02 695 barrier(); edc15cafcbfa3d7 Steven Rostedt 2012-11-02 696 edc15cafcbfa3d7 Steven Rostedt 2012-11-02 697 return bit; edc15cafcbfa3d7 Steven Rostedt 2012-11-02 698 } edc15cafcbfa3d7 Steven Rostedt 2012-11-02 699 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org