[kbuild-all] [zanussi-trace:ftrace/cleanup-hist-func-v2 2/2] kernel/trace/trace_events_trigger.c:797:26: warning: variable 'trigger_ops' is uninitialized when used here

CC: linux-kernel(a)vger.kernel.org TO: Tom Zanussi <zanussi(a)kernel.org&gt; tree: https://git.kernel.org/pub/scm/linux/kernel/git/zanussi/linux-trace.git ftrace/cleanup-hist-func-v2 head: 84eb6a8a61565e308b9908cbc63a897fde300c57 commit: 84eb6a8a61565e308b9908cbc63a897fde300c57 [2/2] tracing: Have existing event_command implementations use helpers config: riscv-buildonly-randconfig-r004-20211113 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c3dddeeafb529e769cde87bd29ef6271ac6bfa5c) 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 riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/zanussi/linux-trace.git/c... git remote add zanussi-trace https://git.kernel.org/pub/scm/linux/kernel/git/zanussi/linux-trace.git git fetch --no-tags zanussi-trace ftrace/cleanup-hist-func-v2 git checkout 84eb6a8a61565e308b9908cbc63a897fde300c57 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=riscv If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All error/warnings (new ones prefixed by >>): -- -- -- In file included from kernel/trace/trace_events_trigger.c:15: In file included from kernel/trace/trace.h:9: In file included from include/linux/clocksource.h:22: In file included from arch/riscv/include/asm/io.h:136: include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:36:51: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from kernel/trace/trace_events_trigger.c:15: In file included from kernel/trace/trace.h:9: In file included from include/linux/clocksource.h:22: In file included from arch/riscv/include/asm/io.h:136: include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:34:51: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from kernel/trace/trace_events_trigger.c:15: In file included from kernel/trace/trace.h:9: In file included from include/linux/clocksource.h:22: In file included from arch/riscv/include/asm/io.h:136: 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:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:1024:55: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port; ~~~~~~~~~~ ^ cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); ^~~~~~~~~~~ kernel/trace/trace_events_trigger.c:782:39: note: initialize the variable 'trigger_ops' to silence this warning struct event_trigger_ops *trigger_ops; ^ = NULL 8 warnings generated. vim +/trigger_ops +797 kernel/trace/trace_events_trigger.c 2b228845d7aa04 Tom Zanussi 2021-11-05 759 2a2df321158817 Tom Zanussi 2013-10-24 760 /** 2a2df321158817 Tom Zanussi 2013-10-24 761 * event_trigger_callback - Generic event_command @func implementation 2a2df321158817 Tom Zanussi 2013-10-24 762 * @cmd_ops: The command ops, used for trigger registration 7f1d2f8210195c Steven Rostedt (Red Hat 2015-05-05 763) * @file: The trace_event_file associated with the event 2a2df321158817 Tom Zanussi 2013-10-24 764 * @glob: The raw string used to register the trigger 2a2df321158817 Tom Zanussi 2013-10-24 765 * @cmd: The cmd portion of the string used to register the trigger 2a2df321158817 Tom Zanussi 2013-10-24 766 * @param: The params portion of the string used to register the trigger 2a2df321158817 Tom Zanussi 2013-10-24 767 * 2a2df321158817 Tom Zanussi 2013-10-24 768 * Common implementation for event command parsing and trigger 2a2df321158817 Tom Zanussi 2013-10-24 769 * instantiation. 2a2df321158817 Tom Zanussi 2013-10-24 770 * 2a2df321158817 Tom Zanussi 2013-10-24 771 * Usually used directly as the @func method in event command 2a2df321158817 Tom Zanussi 2013-10-24 772 * implementations. 2a2df321158817 Tom Zanussi 2013-10-24 773 * 2a2df321158817 Tom Zanussi 2013-10-24 774 * Return: 0 on success, errno otherwise 2a2df321158817 Tom Zanussi 2013-10-24 775 */ 2a2df321158817 Tom Zanussi 2013-10-24 776 static int 2a2df321158817 Tom Zanussi 2013-10-24 777 event_trigger_callback(struct event_command *cmd_ops, 7f1d2f8210195c Steven Rostedt (Red Hat 2015-05-05 778) struct trace_event_file *file, 2a2df321158817 Tom Zanussi 2013-10-24 779 char *glob, char *cmd, char *param) 2a2df321158817 Tom Zanussi 2013-10-24 780 { 2a2df321158817 Tom Zanussi 2013-10-24 781 struct event_trigger_data *trigger_data; 2a2df321158817 Tom Zanussi 2013-10-24 782 struct event_trigger_ops *trigger_ops; 2a2df321158817 Tom Zanussi 2013-10-24 783 char *trigger = NULL; 84eb6a8a61565e Tom Zanussi 2021-11-05 784 bool remove; 2a2df321158817 Tom Zanussi 2013-10-24 785 int ret; 2a2df321158817 Tom Zanussi 2013-10-24 786 84eb6a8a61565e Tom Zanussi 2021-11-05 787 ret = event_trigger_check(glob, &trigger, &param, &remove, false, true); 84eb6a8a61565e Tom Zanussi 2021-11-05 788 if (ret) 84eb6a8a61565e Tom Zanussi 2021-11-05 789 return ret; 2a2df321158817 Tom Zanussi 2013-10-24 790 2a2df321158817 Tom Zanussi 2013-10-24 791 ret = -ENOMEM; 84eb6a8a61565e Tom Zanussi 2021-11-05 792 trigger_data = event_trigger_alloc(cmd_ops, trigger, cmd, file); 2a2df321158817 Tom Zanussi 2013-10-24 793 if (!trigger_data) 2a2df321158817 Tom Zanussi 2013-10-24 794 goto out; 2a2df321158817 Tom Zanussi 2013-10-24 795 84eb6a8a61565e Tom Zanussi 2021-11-05 796 if (remove) { 2a2df321158817 Tom Zanussi 2013-10-24 @797 cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); 2a2df321158817 Tom Zanussi 2013-10-24 798 ret = 0; 2a2df321158817 Tom Zanussi 2013-10-24 799 goto out; 2a2df321158817 Tom Zanussi 2013-10-24 800 } 2a2df321158817 Tom Zanussi 2013-10-24 801 84eb6a8a61565e Tom Zanussi 2021-11-05 802 ret = event_trigger_parse_num(trigger, trigger_data); 2a2df321158817 Tom Zanussi 2013-10-24 803 if (ret) 2a2df321158817 Tom Zanussi 2013-10-24 804 goto out_free; 2a2df321158817 Tom Zanussi 2013-10-24 805 84eb6a8a61565e Tom Zanussi 2021-11-05 806 ret = event_trigger_set_filter(cmd_ops, file, param, trigger_data); 2a2df321158817 Tom Zanussi 2013-10-24 807 if (ret < 0) 2a2df321158817 Tom Zanussi 2013-10-24 808 goto out_free; 2a2df321158817 Tom Zanussi 2013-10-24 809 1863c387259b62 Steven Rostedt (VMware 2018-07-24 810) /* Up the trigger_data count to make sure reg doesn't free it on failure */ 1863c387259b62 Steven Rostedt (VMware 2018-07-24 811) event_trigger_init(trigger_ops, trigger_data); 84eb6a8a61565e Tom Zanussi 2021-11-05 812 84eb6a8a61565e Tom Zanussi 2021-11-05 813 ret = event_trigger_register(cmd_ops, file, glob, cmd, trigger, trigger_data, NULL); 84eb6a8a61565e Tom Zanussi 2021-11-05 814 if (ret) 84eb6a8a61565e Tom Zanussi 2021-11-05 815 goto out_free; 1863c387259b62 Steven Rostedt (VMware 2018-07-24 816) 1863c387259b62 Steven Rostedt (VMware 2018-07-24 817) /* Down the counter of trigger_data or free it if not used anymore */ 1863c387259b62 Steven Rostedt (VMware 2018-07-24 818) event_trigger_free(trigger_ops, trigger_data); 2a2df321158817 Tom Zanussi 2013-10-24 819 out: 2a2df321158817 Tom Zanussi 2013-10-24 820 return ret; 2a2df321158817 Tom Zanussi 2013-10-24 821 out_free: 84eb6a8a61565e Tom Zanussi 2021-11-05 822 event_trigger_reset_filter(cmd_ops, trigger_data); 2a2df321158817 Tom Zanussi 2013-10-24 823 kfree(trigger_data); 2a2df321158817 Tom Zanussi 2013-10-24 824 goto out; 2a2df321158817 Tom Zanussi 2013-10-24 825 } 2a2df321158817 Tom Zanussi 2013-10-24 826 :::::: The code at line 797 was first introduced by commit :::::: 2a2df321158817811c5dc206dce808e0aa9f6d89 tracing: Add 'traceon' and 'traceoff' event trigger commands :::::: TO: Tom Zanussi <tom.zanussi(a)linux.intel.com&gt; :::::: CC: Steven Rostedt <rostedt(a)goodmis.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org