[android-common:android15-6.6 2/2] drivers/misc/pkvm-smc/pkvm/pkvm-smc.c:85:6: warning: no previous prototype for 'filter_smc'

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

Hi Mostafa,

FYI, the error/warning still remains.

tree:   https://android.googlesource.com/kernel/common android15-6.6
head:   69b3c870d0b8d800f7140a73551a9603ccf67c93
commit: cf50248e99752ee522843c0dd529c21f4f726e66 [2/2] ANDROID: misc: pkvm_smc: Add an allow list for SMCs
config: arm64-randconfig-r123-20241231 (https://download.01.org/0day-ci/archive/20241231/202412311725.SPemYtNa-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 14.2.0
reproduce: (https://download.01.org/0day-ci/archive/20241231/202412311725.SPemYtNa-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/202412311725.SPemYtNa-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/misc/pkvm-smc/pkvm/pkvm-smc.c:85:6: warning: no previous prototype for 'filter_smc' [-Wmissing-prototypes]
      85 | bool filter_smc(struct user_pt_regs *regs)
         |      ^~~~~~~~~~
   drivers/misc/pkvm-smc/pkvm/pkvm-smc.c:108:5: warning: no previous prototype for 'pkvm_smc_filter_hyp_init' [-Wmissing-prototypes]
     108 | int pkvm_smc_filter_hyp_init(const struct pkvm_module_ops *ops)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for USB_PHY
   Depends on [n]: USB_SUPPORT [=n]
   Selected by [y]:
   - GKI_HIDDEN_USB_CONFIGS [=y]
   WARNING: unmet direct dependencies detected for NET_DEVLINK
   Depends on [n]: NET [=n]
   Selected by [y]:
   - GKI_HIDDEN_NET_CONFIGS [=y]
   WARNING: unmet direct dependencies detected for WEXT_SPY
   Depends on [n]: NET [=n] && WIRELESS [=n]
   Selected by [y]:
   - GKI_LEGACY_WEXT_ALLCONFIG [=y]
   WARNING: unmet direct dependencies detected for WIRELESS_EXT
   Depends on [n]: NET [=n] && WIRELESS [=n]
   Selected by [y]:
   - GKI_LEGACY_WEXT_ALLCONFIG [=y]
   WARNING: unmet direct dependencies detected for WEXT_CORE
   Depends on [n]: NET [=n] && WIRELESS [=n] && (CFG80211_WEXT [=n] || WIRELESS_EXT [=y])
   Selected by [y]:
   - GKI_LEGACY_WEXT_ALLCONFIG [=y]
   WARNING: unmet direct dependencies detected for NET_PTP_CLASSIFY
   Depends on [n]: NET [=n]
   Selected by [y]:
   - GKI_HIDDEN_NET_CONFIGS [=y]
   WARNING: unmet direct dependencies detected for CAN_RX_OFFLOAD
   Depends on [n]: NETDEVICES [=n] && CAN_DEV [=n] && CAN_NETLINK [=n]
   Selected by [y]:
   - GKI_HIDDEN_MCP251XFD_CONFIGS [=y]
   WARNING: unmet direct dependencies detected for WEXT_PROC
   Depends on [n]: NET [=n] && WIRELESS [=n] && PROC_FS [=n] && WEXT_CORE [=y]
   Selected by [y]:
   - GKI_LEGACY_WEXT_ALLCONFIG [=y]
   WARNING: unmet direct dependencies detected for PAGE_POOL
   Depends on [n]: NET [=n]
   Selected by [y]:
   - GKI_HIDDEN_NET_CONFIGS [=y]
   WARNING: unmet direct dependencies detected for WEXT_PRIV
   Depends on [n]: NET [=n] && WIRELESS [=n]
   Selected by [y]:
   - GKI_LEGACY_WEXT_ALLCONFIG [=y]
   WARNING: unmet direct dependencies detected for BALLOON_COMPACTION
   Depends on [n]: COMPACTION [=n] && MEMORY_BALLOON [=y]
   Selected by [y]:
   - GKI_HIDDEN_MM_CONFIGS [=y]


vim +/filter_smc +85 drivers/misc/pkvm-smc/pkvm/pkvm-smc.c

    80	
    81	/*
    82	 * Block all by default.
    83	 * return false will allow the SMC to be forwarded.
    84	 */
  > 85	bool filter_smc(struct user_pt_regs *regs)
    86	{
    87		u64 smc_id = regs->regs[0];
    88		/*
    89		 * Ignore bits that doesn't change the functionality:
    90		 * Bit[30]: 32/64 bit convention
    91		 * Bit[16]: SVE hint
    92		 */
    93		u64 mask = ~(ARM_SMCCC_1_3_SVE_HINT | BIT(ARM_SMCCC_CALL_CONV_SHIFT));
    94		struct pkvm_smc_filter pval = {smc_id & mask, NULL};
    95		struct pkvm_smc_filter *entry;
    96	
    97		/* alternatively, we can do 2 level binary search or switch case by service. */
    98		entry = (struct pkvm_smc_filter *)__inline_bsearch((void *)&pval, allow_list,
    99								   ARRAY_SIZE(allow_list),
   100								   sizeof(allow_list[0]),
   101								   match_smc);
   102		if (!entry)
   103			return deny_smc(regs);
   104	
   105		return entry->cb ? entry->cb(regs) : false;
   106	}
   107	

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