[tip:x86/shstk 31/42] arch/x86/kernel/shstk.c:244:29: sparse: sparse: incorrect type in argument 1 (different address spaces)

From: kernel test robot
Date: Thu Jul 13 2023 - 04:49:25 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/shstk
head: 727f2a6ea02467c331f86ec5fde8e70dab418baa
commit: 6bf19cec9a198b8f6af939b5f7bd5d3e721c9e7e [31/42] x86/shstk: Handle signals for shadow stack
config: x86_64-randconfig-x061-20230713 (https://download.01.org/0day-ci/archive/20230713/202307131601.a3YybdUr-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230713/202307131601.a3YybdUr-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202307131601.a3YybdUr-lkp@xxxxxxxxx/

sparse warnings: (new ones prefixed by >>)
>> arch/x86/kernel/shstk.c:244:29: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected unsigned long long [noderef] [usertype] __user *addr @@ got void *[noderef] __user @@
arch/x86/kernel/shstk.c:244:29: sparse: expected unsigned long long [noderef] [usertype] __user *addr
arch/x86/kernel/shstk.c:244:29: sparse: got void *[noderef] __user
>> arch/x86/kernel/shstk.c:295:55: sparse: sparse: cast removes address space '__user' of expression

vim +244 arch/x86/kernel/shstk.c

234
235 static int shstk_push_sigframe(unsigned long *ssp)
236 {
237 unsigned long target_ssp = *ssp;
238
239 /* Token must be aligned */
240 if (!IS_ALIGNED(target_ssp, 8))
241 return -EINVAL;
242
243 *ssp -= SS_FRAME_SIZE;
> 244 if (put_shstk_data((void *__user)*ssp, target_ssp))
245 return -EFAULT;
246
247 return 0;
248 }
249
250 static int shstk_pop_sigframe(unsigned long *ssp)
251 {
252 unsigned long token_addr;
253 int err;
254
255 err = get_shstk_data(&token_addr, (unsigned long __user *)*ssp);
256 if (unlikely(err))
257 return err;
258
259 /* Restore SSP aligned? */
260 if (unlikely(!IS_ALIGNED(token_addr, 8)))
261 return -EINVAL;
262
263 /* SSP in userspace? */
264 if (unlikely(token_addr >= TASK_SIZE_MAX))
265 return -EINVAL;
266
267 *ssp = token_addr;
268
269 return 0;
270 }
271
272 int setup_signal_shadow_stack(struct ksignal *ksig)
273 {
274 void __user *restorer = ksig->ka.sa.sa_restorer;
275 unsigned long ssp;
276 int err;
277
278 if (!cpu_feature_enabled(X86_FEATURE_USER_SHSTK) ||
279 !features_enabled(ARCH_SHSTK_SHSTK))
280 return 0;
281
282 if (!restorer)
283 return -EINVAL;
284
285 ssp = get_user_shstk_addr();
286 if (unlikely(!ssp))
287 return -EINVAL;
288
289 err = shstk_push_sigframe(&ssp);
290 if (unlikely(err))
291 return err;
292
293 /* Push restorer address */
294 ssp -= SS_FRAME_SIZE;
> 295 err = write_user_shstk_64((u64 __user *)ssp, (u64)restorer);
296 if (unlikely(err))
297 return -EFAULT;
298
299 fpregs_lock_and_load();
300 wrmsrl(MSR_IA32_PL3_SSP, ssp);
301 fpregs_unlock();
302
303 return 0;
304 }
305

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