Subject: Re: [PATCH net-next v1 2/7] net: hsr: replace fallthrough comments with fallthrough macro

From: kernel test robot <[email-masked]>
Date: Fri, 27 Mar 2026 05:31:19 +0800

Hi,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/luka-gejak-linux-dev/net-hsr-constify-hsr_ops-and-prp_ops-protocol-operation-structures/20260326-143638
base:   net-next/main
patch link:    https://lore.kernel.org/r/20260324144630.189094-3-luka.gejak%40linux.dev
patch subject: [PATCH net-next v1 2/7] net: hsr: replace fallthrough comments with fallthrough macro
config: parisc-randconfig-002-20260327 (https://download.01.org/0day-ci/archive/20260327/[email-masked]/config)
compiler: hppa-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260327/[email-masked]/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 <[email-masked]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email-masked]/

All errors (new ones prefixed by >>):

   In file included from include/linux/compiler_types.h:88,
                    from <command-line>:
   net/hsr/hsr_netlink.c: In function 'hsr_get_node_list':
>> include/linux/compiler_attributes.h:214:41: error: invalid use of attribute 'fallthrough'
    # define fallthrough                    __attribute__((__fallthrough__))
                                            ^~~~~~~~~~~~~
   net/hsr/hsr_netlink.c:527:2: note: in expansion of macro 'fallthrough'
     fallthrough;
     ^~~~~~~~~~~
   net/hsr/hsr_netlink.c: In function 'hsr_get_node_status':
>> include/linux/compiler_attributes.h:214:41: error: invalid use of attribute 'fallthrough'
    # define fallthrough                    __attribute__((__fallthrough__))
                                            ^~~~~~~~~~~~~
   net/hsr/hsr_netlink.c:436:2: note: in expansion of macro 'fallthrough'
     fallthrough;
     ^~~~~~~~~~~

vim +/fallthrough +214 include/linux/compiler_attributes.h

294f69e662d157 Joe Perches   2019-10-05  201  
294f69e662d157 Joe Perches   2019-10-05  202  /*
294f69e662d157 Joe Perches   2019-10-05  203   * Add the pseudo keyword 'fallthrough' so case statement blocks
294f69e662d157 Joe Perches   2019-10-05  204   * must end with any of these keywords:
294f69e662d157 Joe Perches   2019-10-05  205   *   break;
294f69e662d157 Joe Perches   2019-10-05  206   *   fallthrough;
ca0760e7d79e2b Wei Ming Chen 2021-05-06  207   *   continue;
294f69e662d157 Joe Perches   2019-10-05  208   *   goto <label>;
294f69e662d157 Joe Perches   2019-10-05  209   *   return [expression];
294f69e662d157 Joe Perches   2019-10-05  210   *
294f69e662d157 Joe Perches   2019-10-05  211   *  gcc: https://gcc.gnu.org/onlinedocs/gcc/Statement-Attributes.html#Statement-Attributes
294f69e662d157 Joe Perches   2019-10-05  212   */
294f69e662d157 Joe Perches   2019-10-05  213  #if __has_attribute(__fallthrough__)
294f69e662d157 Joe Perches   2019-10-05 @214  # define fallthrough                    __attribute__((__fallthrough__))
294f69e662d157 Joe Perches   2019-10-05  215  #else
294f69e662d157 Joe Perches   2019-10-05  216  # define fallthrough                    do {} while (0)  /* fallthrough */
a3f8a30f3f0079 Miguel Ojeda  2018-08-30  217  #endif
a3f8a30f3f0079 Miguel Ojeda  2018-08-30  218  

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