net/smc/smc_llc.c:40:1: warning: alignment 1 of 'struct smc_llc_hdr' is less than 4

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

Hi Karsten,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   f41445645ab5d172e6090d00c332c335d8dba337
commit: b4ba4652b3f8b7c9bbb5786f8acf4724bdab2196 net/smc: extend LLC layer for SMC-Rv2
date:   10 months ago
config: arm-randconfig-s053-20220810 (https://download.01.org/0day-ci/archive/20220811/202208110344.tcjjNU4C-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 12.1.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-39-gce1a6720-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4ba4652b3f8b7c9bbb5786f8acf4724bdab2196
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout b4ba4652b3f8b7c9bbb5786f8acf4724bdab2196
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm SHELL=/bin/bash drivers/net/vmxnet3/ drivers/video/fbdev/aty/ net/smc/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> net/smc/smc_llc.c:40:1: warning: alignment 1 of 'struct smc_llc_hdr' is less than 4 [-Wpacked-not-aligned]
      40 | } __packed;             /* format defined in
         | ^
   In file included from <command-line>:
   net/smc/smc_llc.c: In function 'smc_llc_add_pending_send':
   include/linux/compiler_types.h:322:45: error: call to '__compiletime_assert_562' declared with attribute error: must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)
     322 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |                                             ^
   include/linux/compiler_types.h:303:25: note: in definition of macro '__compiletime_assert'
     303 |                         prefix ## suffix();                             \
         |                         ^~~~~~
   include/linux/compiler_types.h:322:9: note: in expansion of macro '_compiletime_assert'
     322 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |         ^~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
      39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
         |                                     ^~~~~~~~~~~~~~~~~~
   net/smc/smc_llc.c:409:9: note: in expansion of macro 'BUILD_BUG_ON_MSG'
     409 |         BUILD_BUG_ON_MSG(
         |         ^~~~~~~~~~~~~~~~
   include/linux/compiler_types.h:322:45: error: call to '__compiletime_assert_563' declared with attribute error: must adapt SMC_WR_TX_SIZE to sizeof(struct smc_llc_msg); if not all smc_wr upper layer protocols use the same message size any more, must start to set link->wr_tx_sges[i].length on each individual smc_wr_tx_send()
     322 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |                                             ^
   include/linux/compiler_types.h:303:25: note: in definition of macro '__compiletime_assert'
     303 |                         prefix ## suffix();                             \
         |                         ^~~~~~
   include/linux/compiler_types.h:322:9: note: in expansion of macro '_compiletime_assert'
     322 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |         ^~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
      39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
         |                                     ^~~~~~~~~~~~~~~~~~
   net/smc/smc_llc.c:412:9: note: in expansion of macro 'BUILD_BUG_ON_MSG'
     412 |         BUILD_BUG_ON_MSG(
         |         ^~~~~~~~~~~~~~~~
   In function 'smc_llc_send_message_wait',
       inlined from 'smc_llc_send_link_delete_all' at net/smc/smc_llc.c:1635:8:
   net/smc/smc_llc.c:785:9: warning: 'memcpy' reading 60 bytes from a region of size 49 [-Wstringop-overread]
     785 |         memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg));
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   net/smc/smc_llc.c: In function 'smc_llc_send_link_delete_all':
   net/smc/smc_llc.c:1622:37: note: source object 'delllc' of size 49
    1622 |         struct smc_llc_msg_del_link delllc = {};
         |                                     ^~~~~~


vim +40 net/smc/smc_llc.c

    23	
    24	struct smc_llc_hdr {
    25		struct smc_wr_rx_hdr common;
    26		union {
    27			struct {
    28				u8 length;	/* 44 */
    29		#if defined(__BIG_ENDIAN_BITFIELD)
    30				u8 reserved:4,
    31				   add_link_rej_rsn:4;
    32	#elif defined(__LITTLE_ENDIAN_BITFIELD)
    33				u8 add_link_rej_rsn:4,
    34				   reserved:4;
    35	#endif
    36			};
    37			u16 length_v2;	/* 44 - 8192*/
    38		};
    39		u8 flags;
  > 40	} __packed;		/* format defined in
    41				 * IBM Shared Memory Communications Version 2
    42				 * (https://www.ibm.com/support/pages/node/6326337)
    43				 */
    44	

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