From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============3276356765844491013==" MIME-Version: 1.0 From: kernel test robot Subject: [ardb:for-kernelci 13/17] arch/arm64/kernel/pi/early_map_kernel.c:134:31: warning: Comparing pointers that point to different objects [comparePointers] Date: Thu, 07 Jul 2022 16:06:37 +0800 Message-ID: <202207071540.joMsMwGI-lkp@intel.com> List-Id: To: kbuild@lists.01.org --===============3276356765844491013== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable :::::: = :::::: Manual check reason: "low confidence static check warning: arch/arm6= 4/kernel/pi/early_map_kernel.c:134:31: warning: Comparing pointers that poi= nt to different objects [comparePointers]" :::::: = CC: kbuild-all(a)lists.01.org BCC: lkp(a)intel.com CC: linux-kernel(a)vger.kernel.org TO: Ard Biesheuvel tree: git://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git for-ke= rnelci head: 3ed2d2fa189b2f472547045b3af344e7806f7779 commit: 32a20e7c99cc0d6b5948880ea9cfc14068b22f7b [13/17] arm64: head: move = early kernel mapping and relocation code to C code :::::: branch date: 7 days ago :::::: commit date: 7 days ago compiler: aarch64-linux-gcc (GCC) 11.3.0 reproduce (cppcheck warning): # apt-get install cppcheck git checkout 32a20e7c99cc0d6b5948880ea9cfc14068b22f7b cppcheck --quiet --enable=3Dstyle,performance,portability --templat= e=3Dgcc FILE If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot cppcheck possible warnings: (new ones prefixed by >>, may not real problems) >> arch/arm64/kernel/pi/early_map_kernel.c:134:31: warning: Comparing point= ers that point to different objects [comparePointers] for (rela =3D rela_start; rela < rela_end; rela++) { ^ arch/arm64/kernel/pi/early_map_kernel.c:125:25: note: Variable declared = here. extern const Elf64_Rela rela_start[], rela_end[]; ^ arch/arm64/kernel/pi/early_map_kernel.c:134:14: note: Array decayed to p= ointer here. for (rela =3D rela_start; rela < rela_end; rela++) { ^ arch/arm64/kernel/pi/early_map_kernel.c:125:39: note: Variable declared = here. extern const Elf64_Rela rela_start[], rela_end[]; ^ arch/arm64/kernel/pi/early_map_kernel.c:134:33: note: Array decayed to p= ointer here. for (rela =3D rela_start; rela < rela_end; rela++) { ^ arch/arm64/kernel/pi/early_map_kernel.c:134:31: note: Comparing pointers= that point to different objects for (rela =3D rela_start; rela < rela_end; rela++) { ^ arch/arm64/kernel/pi/early_map_kernel.c:169:31: warning: Comparing point= ers that point to different objects [comparePointers] for (relr =3D relr_start; relr < relr_end; relr++) { ^ arch/arm64/kernel/pi/early_map_kernel.c:126:18: note: Variable declared = here. extern const u64 relr_start[], relr_end[]; ^ arch/arm64/kernel/pi/early_map_kernel.c:169:14: note: Array decayed to p= ointer here. for (relr =3D relr_start; relr < relr_end; relr++) { ^ arch/arm64/kernel/pi/early_map_kernel.c:126:32: note: Variable declared = here. extern const u64 relr_start[], relr_end[]; ^ arch/arm64/kernel/pi/early_map_kernel.c:169:33: note: Array decayed to p= ointer here. for (relr =3D relr_start; relr < relr_end; relr++) { ^ arch/arm64/kernel/pi/early_map_kernel.c:169:31: note: Comparing pointers= that point to different objects for (relr =3D relr_start; relr < relr_end; relr++) { ^ vim +134 arch/arm64/kernel/pi/early_map_kernel.c 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 127 = 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 128 static void relocate_kernel= (u64 offset) 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 129 { 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 130 const Elf64_Rela *rela; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 131 const u64 *relr; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 132 u64 *place; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 133 = 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 @134 for (rela =3D rela_start; = rela < rela_end; rela++) { 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 135 if (ELF64_R_TYPE(rela->r_= info) !=3D R_AARCH64_RELATIVE) 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 136 continue; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 137 place =3D (u64 *)(rela->r= _offset + offset); 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 138 *place =3D rela->r_addend= + offset; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 139 } 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 140 = 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 141 if (!IS_ENABLED(CONFIG_REL= R) || !offset) 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 142 return; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 143 = 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 144 /* 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 145 * Apply RELR relocations. 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 146 * 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 147 * RELR is a compressed fo= rmat for storing relative relocations. The 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 148 * encoded sequence of ent= ries looks like: 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 149 * [ AAAAAAAA BBBBBBB1 BBB= BBBB1 ... AAAAAAAA BBBBBB1 ... ] 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 150 * 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 151 * i.e. start with an addr= ess, followed by any number of bitmaps. The 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 152 * address entry encodes 1= relocation. The subsequent bitmap entries 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 153 * encode up to 63 relocat= ions each, at subsequent offsets following 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 154 * the last address entry. 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 155 * 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 156 * The bitmap entries must= have 1 in the least significant bit. The 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 157 * assumption here is that= an address cannot have 1 in lsb. Odd 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 158 * addresses are not suppo= rted. Any odd addresses are stored in the 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 159 * RELA section, which is = handled above. 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 160 * 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 161 * Excluding the least sig= nificant bit in the bitmap, each non-zero bit 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 162 * in the bitmap represent= s a relocation to be applied to a 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 163 * corresponding machine w= ord that follows the base address word. The 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 164 * second least significan= t bit represents the machine word immediately 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 165 * following the initial a= ddress, and each bit that follows represents 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 166 * the next word, in linea= r order. As such, a single bitmap can encode 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 167 * up to 63 relocations in= a 64-bit object. 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 168 */ 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 169 for (relr =3D relr_start; = relr < relr_end; relr++) { 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 170 u64 *p, r =3D *relr; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 171 = 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 172 if ((r & 1) =3D=3D 0) { 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 173 place =3D (u64 *)(r + of= fset); 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 174 *place++ +=3D offset; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 175 } else { 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 176 for (p =3D place; r; p++= ) { 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 177 r >>=3D 1; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 178 if (r & 1) 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 179 *p +=3D offset; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 180 } 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 181 place +=3D 63; 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 182 } 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 183 } 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 184 } 32a20e7c99cc0d6 Ard Biesheuvel 2022-06-29 185 = -- = 0-DAY CI Kernel Test Service https://01.org/lkp --===============3276356765844491013==--