Re: [PATCH 1/2] drm/panic: Add a drm panic handler

[kernel test robot <lkp@intel.com>]

Hi Jocelyn,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 6995e2de6891c724bfeb2db33d7b87775f913ad1]

url:    https://github.com/intel-lab-lkp/linux/commits/Jocelyn-Falempe/drm-panic-Add-a-drm-panic-handler/20230810-032733
base:   6995e2de6891c724bfeb2db33d7b87775f913ad1
patch link:    https://lore.kernel.org/r/20230809192514.158062-2-jfalempe%40redhat.com
patch subject: [PATCH 1/2] drm/panic: Add a drm panic handler
config: s390-randconfig-r044-20230809 (https://download.01.org/0day-ci/archive/20230810/202308101423.GSvLgbbe-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce: (https://download.01.org/0day-ci/archive/20230810/202308101423.GSvLgbbe-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308101423.GSvLgbbe-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/gpu/drm/drm_panic.c:9:
   In file included from include/linux/iosys-map.h:10:
   In file included from include/linux/io.h:13:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     547 |         val = __raw_readb(PCI_IOBASE + addr);
         |                           ~~~~~~~~~~ ^
   include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     560 |         val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu'
      37 | #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
         |                                                           ^
   include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
     102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
         |                                                      ^
   In file included from drivers/gpu/drm/drm_panic.c:9:
   In file included from include/linux/iosys-map.h:10:
   In file included from include/linux/io.h:13:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     573 |         val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu'
      35 | #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
         |                                                           ^
   include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
     115 | #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
         |                                                      ^
   In file included from drivers/gpu/drm/drm_panic.c:9:
   In file included from include/linux/iosys-map.h:10:
   In file included from include/linux/io.h:13:
   In file included from arch/s390/include/asm/io.h:75:
   include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     584 |         __raw_writeb(value, PCI_IOBASE + addr);
         |                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     594 |         __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     604 |         __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     692 |         readsb(PCI_IOBASE + addr, buffer, count);
         |                ~~~~~~~~~~ ^
   include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     700 |         readsw(PCI_IOBASE + addr, buffer, count);
         |                ~~~~~~~~~~ ^
   include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     708 |         readsl(PCI_IOBASE + addr, buffer, count);
         |                ~~~~~~~~~~ ^
   include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     717 |         writesb(PCI_IOBASE + addr, buffer, count);
         |                 ~~~~~~~~~~ ^
   include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     726 |         writesw(PCI_IOBASE + addr, buffer, count);
         |                 ~~~~~~~~~~ ^
   include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     735 |         writesl(PCI_IOBASE + addr, buffer, count);
         |                 ~~~~~~~~~~ ^
>> drivers/gpu/drm/drm_panic.c:246:6: warning: no previous prototype for function 'drm_panic_init_client' [-Wmissing-prototypes]
     246 | void drm_panic_init_client(struct drm_device *dev)
         |      ^
   drivers/gpu/drm/drm_panic.c:246:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     246 | void drm_panic_init_client(struct drm_device *dev)
         | ^
         | static 
>> drivers/gpu/drm/drm_panic.c:272:6: warning: no previous prototype for function 'drm_panic_init' [-Wmissing-prototypes]
     272 | void drm_panic_init(void)
         |      ^
   drivers/gpu/drm/drm_panic.c:272:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     272 | void drm_panic_init(void)
         | ^
         | static 
>> drivers/gpu/drm/drm_panic.c:282:6: warning: no previous prototype for function 'drm_panic_exit' [-Wmissing-prototypes]
     282 | void drm_panic_exit(void)
         |      ^
   drivers/gpu/drm/drm_panic.c:282:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     282 | void drm_panic_exit(void)
         | ^
         | static 
   15 warnings generated.
--
>> drivers/gpu/drm/drm_panic.c:28: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * This module displays a user friendly message on screen when a kernel panic
   drivers/gpu/drm/drm_panic.c:36: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * List of drm clients
>> drivers/gpu/drm/drm_panic.c:283: warning: expecting prototype for drm_log_exit(). Prototype was for drm_panic_exit() instead


vim +/drm_panic_init_client +246 drivers/gpu/drm/drm_panic.c

   245	
 > 246	void drm_panic_init_client(struct drm_device *dev)
   247	{
   248		struct dpanic_drm_client *new;
   249		int ret;
   250	
   251		new = kzalloc(sizeof(*new), GFP_KERNEL);
   252		if (!new)
   253			return;
   254	
   255		ret = drm_client_init(dev, &new->client, "drm_panic", NULL);
   256		if (ret < 0) {
   257			kfree(new);
   258			return;
   259		}
   260		drm_client_register(&new->client);
   261		list_add_tail(&new->head, &dpanic_clients);
   262	
   263		drm_info(dev, "Registered with drm panic\n");
   264	}
   265	EXPORT_SYMBOL(drm_panic_init_client);
   266	
   267	/**
   268	 * drm_panic_init() - Initialize drm-panic subsystem
   269	 *
   270	 * register the panic notifier
   271	 */
 > 272	void drm_panic_init(void)
   273	{
   274		/* register panic handler */
   275		atomic_notifier_chain_register(&panic_notifier_list,
   276					       &drm_panic_notifier);
   277	}
   278	
   279	/**
   280	 * drm_log_exit() - Shutdown drm-panic subsystem
   281	 */
 > 282	void drm_panic_exit(void)
 > 283	{

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki