Hi Tianyi, kernel test robot noticed the following build warnings: [auto build test WARNING on 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa] url: https://github.com/intel-lab-lkp/linux/commits/Tianyi-Liu/KVM-Add-arch-specific-interfaces-for-sampling-guest-callchains/20231008-230042 base: 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa patch link: https://lore.kernel.org/r/SY4P282MB108433024762F1F292D47C2A9DCFA%40SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM patch subject: [PATCH v2 4/5] perf kvm: Support sampling guest callchains config: i386-tinyconfig (https://download.01.org/0day-ci/archive/20231009/202310090338.4PmYjmBS-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231009/202310090338.4PmYjmBS-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202310090338.4PmYjmBS-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): arch/x86/events/core.c: In function 'perf_callchain_guest32': >> arch/x86/events/core.c:2784:43: warning: passing argument 1 of 'perf_guest_read_virt' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] 2784 | if (!perf_guest_read_virt(&fp->next_frame, &frame.next_frame, | ^~~~~~~~~~~~~~~ In file included from arch/x86/events/core.c:15: include/linux/perf_event.h:1531:41: note: expected 'void *' but argument is of type 'const u32 *' {aka 'const unsigned int *'} 1531 | static inline bool perf_guest_read_virt(void*, void*, unsigned int) { return 0; } | ^~~~~ arch/x86/events/core.c:2787:43: warning: passing argument 1 of 'perf_guest_read_virt' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] 2787 | if (!perf_guest_read_virt(&fp->return_address, &frame.return_address, | ^~~~~~~~~~~~~~~~~~~ include/linux/perf_event.h:1531:41: note: expected 'void *' but argument is of type 'const u32 *' {aka 'const unsigned int *'} 1531 | static inline bool perf_guest_read_virt(void*, void*, unsigned int) { return 0; } | ^~~~~ arch/x86/events/core.c: In function 'perf_callchain_guest': arch/x86/events/core.c:2808:51: warning: passing argument 1 of 'perf_guest_read_virt' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] 2808 | if (!perf_guest_read_virt(&fp->next_frame, &frame.next_frame, | ^~~~~~~~~~~~~~~ include/linux/perf_event.h:1531:41: note: expected 'void *' but argument is of type 'struct stack_frame * const*' 1531 | static inline bool perf_guest_read_virt(void*, void*, unsigned int) { return 0; } | ^~~~~ arch/x86/events/core.c:2811:51: warning: passing argument 1 of 'perf_guest_read_virt' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] 2811 | if (!perf_guest_read_virt(&fp->return_address, &frame.return_address, | ^~~~~~~~~~~~~~~~~~~ include/linux/perf_event.h:1531:41: note: expected 'void *' but argument is of type 'const long unsigned int *' 1531 | static inline bool perf_guest_read_virt(void*, void*, unsigned int) { return 0; } | ^~~~~ vim +2784 arch/x86/events/core.c 2775 2776 static inline void 2777 perf_callchain_guest32(struct perf_callchain_entry_ctx *entry) 2778 { 2779 struct stack_frame_ia32 frame; 2780 const struct stack_frame_ia32 *fp; 2781 2782 fp = (void *)perf_guest_get_frame_pointer(); 2783 while (fp && entry->nr < entry->max_stack) { > 2784 if (!perf_guest_read_virt(&fp->next_frame, &frame.next_frame, 2785 sizeof(frame.next_frame))) 2786 break; 2787 if (!perf_guest_read_virt(&fp->return_address, &frame.return_address, 2788 sizeof(frame.return_address))) 2789 break; 2790 perf_callchain_store(entry, frame.return_address); 2791 fp = (void *)frame.next_frame; 2792 } 2793 } 2794 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
