tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.4.y head: f299fb634f3b99d7462b2321c3ccf6773812a44e commit: c0562d5581442d5df3395674f82b80e8c243505f [671/1016] drivers/virt/fsl_hypervisor: Fix error handling path config: powerpc-randconfig-r005-20210719 (attached as .config) compiler: powerpc-linux-gcc (GCC) 10.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.gi... git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git git fetch --no-tags linux-stable-rc linux-4.4.y git checkout c0562d5581442d5df3395674f82b80e8c243505f # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross ARCH=powerpc 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 >>): In file included from drivers/virt/fsl_hypervisor.c:32: include/linux/mm.h: In function 'is_vmalloc_addr': include/linux/mm.h:386:14: warning: comparison of integer expressions of different signedness: 'long unsigned int' and 'long int' [-Wsign-compare] 386 | return addr >= VMALLOC_START && addr < VMALLOC_END; | ^~ In file included from drivers/virt/fsl_hypervisor.c:33: include/linux/pagemap.h: In function 'fault_in_multipages_readable': include/linux/pagemap.h:632:16: warning: variable 'c' set but not used [-Wunused-but-set-variable] 632 | volatile char c; | ^ In file included from arch/powerpc/include/asm/fsl_hcalls.h:46, from drivers/virt/fsl_hypervisor.c:44: arch/powerpc/include/asm/epapr_hcalls.h: In function 'epapr_hypercall': arch/powerpc/include/asm/epapr_hcalls.h:469:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 469 | unsigned long register r0 asm("r0"); | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:470:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 470 | unsigned long register r3 asm("r3") = in[0]; | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:471:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 471 | unsigned long register r4 asm("r4") = in[1]; | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:472:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 472 | unsigned long register r5 asm("r5") = in[2]; | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:473:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 473 | unsigned long register r6 asm("r6") = in[3]; | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:474:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 474 | unsigned long register r7 asm("r7") = in[4]; | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:475:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 475 | unsigned long register r8 asm("r8") = in[5]; | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:476:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 476 | unsigned long register r9 asm("r9") = in[6]; | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:477:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 477 | unsigned long register r10 asm("r10") = in[7]; | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:478:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 478 | unsigned long register r11 asm("r11") = nr; | ^~~~~~~~ arch/powerpc/include/asm/epapr_hcalls.h:479:2: warning: 'register' is not at beginning of declaration [-Wold-style-declaration] 479 | unsigned long register r12 asm("r12"); | ^~~~~~~~ drivers/virt/fsl_hypervisor.c: In function 'ioctl_memcpy': drivers/virt/fsl_hypervisor.c:173:20: warning: comparison of integer expressions of different signedness: '__u32' {aka 'unsigned int'} and 'int' [-Wsign-compare] 173 | if ((param.source == -1) == (param.target == -1)) | ^~ drivers/virt/fsl_hypervisor.c:173:44: warning: comparison of integer expressions of different signedness: '__u32' {aka 'unsigned int'} and 'int' [-Wsign-compare] 173 | if ((param.source == -1) == (param.target == -1)) | ^~ drivers/virt/fsl_hypervisor.c:252:17: warning: comparison of integer expressions of different signedness: '__u32' {aka 'unsigned int'} and 'int' [-Wsign-compare] 252 | (param.source == -1) ? 0 : FOLL_WRITE, | ^~ drivers/virt/fsl_hypervisor.c:256:17: warning: comparison of integer expressions of different signedness: 'int' and 'unsigned int' [-Wsign-compare] 256 | if (num_pinned != num_pages) { | ^~ drivers/virt/fsl_hypervisor.c:266:19: warning: comparison of integer expressions of different signedness: '__u32' {aka 'unsigned int'} and 'int' [-Wsign-compare] 266 | if (param.source == -1) { | ^~ drivers/virt/fsl_hypervisor.c:279:20: warning: comparison of integer expressions of different signedness: '__u32' {aka 'unsigned int'} and 'int' [-Wsign-compare] 279 | if (param.source == -1) { | ^~ 299 | for (i = 0; i < num_pinned; i++) | ^ vim +299 drivers/virt/fsl_hypervisor.c 137 138 /* 139 * Ioctl interface for FSL_HV_IOCTL_MEMCPY 140 * 141 * The FH_MEMCPY hypercall takes an array of address/address/size structures 142 * to represent the data being copied. As a convenience to the user, this 143 * ioctl takes a user-create buffer and a pointer to a guest physically 144 * contiguous buffer in the remote partition, and creates the 145 * address/address/size array for the hypercall. 146 */ 147 static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) 148 { 149 struct fsl_hv_ioctl_memcpy param; 150 151 struct page **pages = NULL; 152 void *sg_list_unaligned = NULL; 153 struct fh_sg_list *sg_list = NULL; 154 155 unsigned int num_pages; 156 unsigned long lb_offset; /* Offset within a page of the local buffer */ 157 158 unsigned int i; 159 long ret = 0; 160 int num_pinned = 0; /* return value from get_user_pages_fast() */ 161 phys_addr_t remote_paddr; /* The next address in the remote buffer */ 162 uint32_t count; /* The number of bytes left to copy */ 163 164 /* Get the parameters from the user */ 165 if (copy_from_user(&param, p, sizeof(struct fsl_hv_ioctl_memcpy))) 166 return -EFAULT; 167 168 /* 169 * One partition must be local, the other must be remote. In other 170 * words, if source and target are both -1, or are both not -1, then 171 * return an error. 172 */ 173 if ((param.source == -1) == (param.target == -1)) 174 return -EINVAL; 175 176 /* 177 * The array of pages returned by get_user_pages_fast() covers only 178 * page-aligned memory. Since the user buffer is probably not 179 * page-aligned, we need to handle the discrepancy. 180 * 181 * We calculate the offset within a page of the S/G list, and make 182 * adjustments accordingly. This will result in a page list that looks 183 * like this: 184 * 185 * ---- <-- first page starts before the buffer 186 * | | 187 * |////|-> ---- 188 * |////| | | 189 * ---- | | 190 * | | 191 * ---- | | 192 * |////| | | 193 * |////| | | 194 * |////| | | 195 * ---- | | 196 * | | 197 * ---- | | 198 * |////| | | 199 * |////| | | 200 * |////| | | 201 * ---- | | 202 * | | 203 * ---- | | 204 * |////| | | 205 * |////|-> ---- 206 * | | <-- last page ends after the buffer 207 * ---- 208 * 209 * The distance between the start of the first page and the start of the 210 * buffer is lb_offset. The hashed (///) areas are the parts of the 211 * page list that contain the actual buffer. 212 * 213 * The advantage of this approach is that the number of pages is 214 * equal to the number of entries in the S/G list that we give to the 215 * hypervisor. 216 */ 217 lb_offset = param.local_vaddr & (PAGE_SIZE - 1); 218 if (param.count == 0 || 219 param.count > U64_MAX - lb_offset - PAGE_SIZE + 1) 220 return -EINVAL; 221 num_pages = (param.count + lb_offset + PAGE_SIZE - 1) >> PAGE_SHIFT; 222 223 /* Allocate the buffers we need */ 224 225 /* 226 * 'pages' is an array of struct page pointers that's initialized by 227 * get_user_pages_fast(). 228 */ 229 pages = kzalloc(num_pages * sizeof(struct page *), GFP_KERNEL); 230 if (!pages) { 231 pr_debug("fsl-hv: could not allocate page list\n"); 232 return -ENOMEM; 233 } 234 235 /* 236 * sg_list is the list of fh_sg_list objects that we pass to the 237 * hypervisor. 238 */ 239 sg_list_unaligned = kmalloc(num_pages * sizeof(struct fh_sg_list) + 240 sizeof(struct fh_sg_list) - 1, GFP_KERNEL); 241 if (!sg_list_unaligned) { 242 pr_debug("fsl-hv: could not allocate S/G list\n"); 243 ret = -ENOMEM; 244 goto free_pages; 245 } 246 sg_list = PTR_ALIGN(sg_list_unaligned, sizeof(struct fh_sg_list)); 247 248 /* Get the physical addresses of the source buffer */ 249 down_read(&current->mm->mmap_sem); 250 num_pinned = get_user_pages(current, current->mm, 251 param.local_vaddr - lb_offset, num_pages, 252 (param.source == -1) ? 0 : FOLL_WRITE, 253 pages, NULL); 254 up_read(&current->mm->mmap_sem); 255 256 if (num_pinned != num_pages) { 257 pr_debug("fsl-hv: could not lock source buffer\n"); 258 ret = (num_pinned < 0) ? num_pinned : -EFAULT; 259 goto exit; 260 } 261 262 /* 263 * Build the fh_sg_list[] array. The first page is special 264 * because it's misaligned. 265 */ 266 if (param.source == -1) { 267 sg_list[0].source = page_to_phys(pages[0]) + lb_offset; 268 sg_list[0].target = param.remote_paddr; 269 } else { 270 sg_list[0].source = param.remote_paddr; 271 sg_list[0].target = page_to_phys(pages[0]) + lb_offset; 272 } 273 sg_list[0].size = min_t(uint64_t, param.count, PAGE_SIZE - lb_offset); 274 275 remote_paddr = param.remote_paddr + sg_list[0].size; 276 count = param.count - sg_list[0].size; 277 278 for (i = 1; i < num_pages; i++) { 279 if (param.source == -1) { 280 /* local to remote */ 281 sg_list[i].source = page_to_phys(pages[i]); 282 sg_list[i].target = remote_paddr; 283 } else { 284 /* remote to local */ 285 sg_list[i].source = remote_paddr; 286 sg_list[i].target = page_to_phys(pages[i]); 287 } 288 sg_list[i].size = min_t(uint64_t, count, PAGE_SIZE); 289 290 remote_paddr += sg_list[i].size; 291 count -= sg_list[i].size; 292 } 293 294 param.ret = fh_partition_memcpy(param.source, param.target, 295 virt_to_phys(sg_list), num_pages); 296 297 exit: 298 if (pages && (num_pinned > 0)) { 300 put_page(pages[i]); 301 } 302 303 kfree(sg_list_unaligned); 304 free_pages: 305 kfree(pages); 306 307 if (!ret) 308 if (copy_to_user(&p->ret, &param.ret, sizeof(__u32))) 309 return -EFAULT; 310 311 return ret; 312 } 313 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org