[broonie-misc:arm64-sme 23/39] arch/arm64/kernel/fpsimd.c:1944:55: sparse: sparse: dereference of noderef expression

[broonie-misc:arm64-sme 23/39] arch/arm64/kernel/fpsimd.c:1944:55: sparse: sparse: dereference of noderef expression

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc.git arm64-sme
head:   cf8de82f465a915e8c4d1f9d484dd8a08e08bbed
commit: 4dc0043dceb973f0f61c0f0ee047655aa73c2261 [23/39] arm64/sme: Save and restore streaming mode over EFI runtime calls
config: arm64-randconfig-s031-20220418 (https://download.01.org/0day-ci/archive/20220418/202204182232.CJFTXSP9-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 11.2.0
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-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc.git/commit/?id=4dc0043dceb973f0f61c0f0ee047655aa73c2261
        git remote add broonie-misc https://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc.git
        git fetch --no-tags broonie-misc arm64-sme
        git checkout 4dc0043dceb973f0f61c0f0ee047655aa73c2261
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/kernel/

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


sparse warnings: (new ones prefixed by >>)
>> arch/arm64/kernel/fpsimd.c:1944:55: sparse: sparse: dereference of noderef expression

vim +1944 arch/arm64/kernel/fpsimd.c

  1916	
  1917	/*
  1918	 * __efi_fpsimd_end(): clean up FPSIMD after an EFI runtime services call
  1919	 */
  1920	void __efi_fpsimd_end(void)
  1921	{
  1922		if (!system_supports_fpsimd())
  1923			return;
  1924	
  1925		if (!__this_cpu_xchg(efi_fpsimd_state_used, false)) {
  1926			kernel_neon_end();
  1927		} else {
  1928			if (system_supports_sve() &&
  1929			    likely(__this_cpu_read(efi_sve_state_used))) {
  1930				char const *sve_state = this_cpu_ptr(efi_sve_state);
  1931				bool ffr = true;
  1932	
  1933				/*
  1934				 * Restore streaming mode; EFI calls are
  1935				 * normal function calls so should not return in
  1936				 * streaming mode.
  1937				 */
  1938				if (system_supports_sme()) {
  1939					if (__this_cpu_read(efi_sm_state)) {
  1940						sysreg_clear_set_s(SYS_SVCR_EL0,
  1941								   0,
  1942								   SYS_SVCR_EL0_SM_MASK);
  1943						if (!system_supports_fa64())
> 1944							ffr = efi_sm_state;
  1945					}
  1946				}
  1947	
  1948				sve_load_state(sve_state + sve_ffr_offset(sve_max_vl()),
  1949					       &this_cpu_ptr(&efi_fpsimd_state)->fpsr,
  1950					       ffr);
  1951	
  1952				__this_cpu_write(efi_sve_state_used, false);
  1953			} else {
  1954				fpsimd_load_state(this_cpu_ptr(&efi_fpsimd_state));
  1955			}
  1956		}
  1957	}
  1958	

-- 
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