[joro:x86-testing 39/45] arch/x86/kernel/sev.c:2027:26: warning: no previous prototype for 'snp_find_cc_blob' - kbuild-all

Friday, 19 November 2021

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git x86-testing
head:   139c88cae82e33dfd6e49ecc4b015a5c7d39c80a
commit: d35494e7aba4b3a2e7b1c9be9add9968be6d8ffd [39/45] x86/sev: add SEV-SNP feature
detection/setup
config: x86_64-buildonly-randconfig-r005-20211115 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        #
https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git/commit/?id...
        git remote add joro
https://git.kernel.org/pub/scm/linux/kernel/git/joro/linux.git
        git fetch --no-tags joro x86-testing
        git checkout d35494e7aba4b3a2e7b1c9be9add9968be6d8ffd
        # save the attached .config to linux build tree
        make W=1 ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp(a)intel.com&gt;

All warnings (new ones prefixed by >>):

...
> arch/x86/kernel/sev.c:2027:26: warning: no previous prototype for
'snp_find_cc_blob' [-Wmissing-prototypes]     2027 | struct cc_blob_sev_info
*snp_find_cc_blob(struct boot_params *bp)
         |                          ^~~~~~~~~~~~~~~~

vim +/snp_find_cc_blob +2027 arch/x86/kernel/sev.c

  2013	
  2014	/*
  2015	 * Initial set up of SEV-SNP relies on information provided by the
  2016	 * Confidential Computing blob, which can be passed to the kernel
  2017	 * in the following ways, depending on how it is booted:
  2018	 *
  2019	 * - when booted via the boot/decompress kernel:
  2020	 *   - via boot_params
  2021	 *
  2022	 * - when booted directly by firmware/bootloader (e.g. CONFIG_PVH):
  2023	 *   - via a setup_data entry, as defined by the Linux Boot Protocol
  2024	 *
  2025	 * Scan for the blob in that order.
  2026	 */
...
 2027	struct cc_blob_sev_info *snp_find_cc_blob(struct boot_params
*bp)   2028	{
  2029		struct cc_blob_sev_info *cc_info;
  2030	
  2031		/* Boot kernel would have passed the CC blob via boot_params. */
  2032		if (bp->cc_blob_address) {
  2033			cc_info = (struct cc_blob_sev_info *)
  2034				  (unsigned long)bp->cc_blob_address;
  2035			goto found_cc_info;
  2036		}
  2037	
  2038		/*
  2039		 * If kernel was booted directly, without the use of the
  2040		 * boot/decompression kernel, the CC blob may have been passed via
  2041		 * setup_data instead.
  2042		 */
  2043		cc_info = snp_find_cc_blob_setup_data(bp);
  2044		if (!cc_info)
  2045			return NULL;
  2046	
  2047	found_cc_info:
  2048		if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC)
  2049			sev_es_terminate(1, GHCB_SNP_UNSUPPORTED);
  2050	
  2051		return cc_info;
  2052	}
  2053	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org