[linux-stable-rc:linux-4.4.y 671/1016] drivers/virt/fsl_hypervisor.c:299:17: warning: comparison of integer expressions of different signedness: 'unsigned int' and 'int'

From: kernel test robot
Date: Mon Jul 19 2021 - 15:02:47 EST

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.git/commit/?id=c0562d5581442d5df3395674f82b80e8c243505f
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@xxxxxxxxx>

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) {
| ^~
>> drivers/virt/fsl_hypervisor.c:299:17: warning: comparison of integer expressions of different signedness: 'unsigned int' and 'int' [-Wsign-compare]
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)) {
> 299 for (i = 0; i < num_pinned; i++)
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
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Attachment: .config.gz
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