[kbuild-all] [peterz-queue:locking/kcsan 14/21] arch/powerpc/mm/pgtable.c:329:16: sparse: sparse: cast to non-scalar

tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git locking/kcsan head: ffed638b6a2180da8fd002a46632d746af72b299 commit: 7b364f0949ae2dd205d5e9afa4b82ee17030d928 [14/21] READ_ONCE: Drop pointer qualifiers when reading from scalar types config: powerpc-randconfig-s002-20200517 (attached as .config) reproduce: # apt-get install sparse # sparse version: v0.6.1-193-gb8fad4bc-dirty git checkout 7b364f0949ae2dd205d5e9afa4b82ee17030d928 # save the attached .config to linux build tree make C=1 ARCH=powerpc CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) arch/powerpc/mm/pgtable.c:356:16: sparse: sparse: cast to non-scalar arch/powerpc/mm/pgtable.c:356:16: sparse: sparse: cast from non-scalar arch/powerpc/mm/pgtable.c:373:16: sparse: sparse: cast to non-scalar arch/powerpc/mm/pgtable.c:373:16: sparse: sparse: cast from non-scalar arch/powerpc/include/asm/book3s/64/pgtable.h:706:20: sparse: sparse: incorrect type in initializer (different base types) @@ expected unsigned long long [usertype] mask @@ got nsigned long long [usertype] mask @@ arch/powerpc/include/asm/book3s/64/pgtable.h:706:20: sparse: expected unsigned long long [usertype] mask arch/powerpc/include/asm/book3s/64/pgtable.h:706:20: sparse: got restricted __be64 [usertype] arch/powerpc/include/asm/book3s/64/pgtable.h:708:24: sparse: sparse: restricted __be64 degrades to integer -- -- -- arch/powerpc/kvm/book3s_64_mmu_radix.c:345:6: sparse: sparse: symbol 'kvmppc_radix_set_pte_at' was not declared. Should it be static? arch/powerpc/kvm/book3s_64_mmu_radix.c:1302:23: sparse: sparse: cast to non-scalar arch/powerpc/kvm/book3s_64_mmu_radix.c:1302:23: sparse: sparse: cast from non-scalar arch/powerpc/kvm/book3s_64_mmu_radix.c:1314:23: sparse: sparse: cast to non-scalar arch/powerpc/kvm/book3s_64_mmu_radix.c:1314:23: sparse: sparse: cast from non-scalar arch/powerpc/kvm/book3s_64_mmu_radix.c:1326:31: sparse: sparse: cast to non-scalar arch/powerpc/kvm/book3s_64_mmu_radix.c:1326:31: sparse: sparse: cast from non-scalar arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __be64 arch/powerpc/include/asm/kvm_ppc.h:967:1: sparse: sparse: cast to restricted __le64 -- -- vim +329 arch/powerpc/mm/pgtable.c 0caed4de502c76 Christophe Leroy 2019-04-26 299 0caed4de502c76 Christophe Leroy 2019-04-26 300 /* 0caed4de502c76 Christophe Leroy 2019-04-26 301 * We have 4 cases for pgds and pmds: 0caed4de502c76 Christophe Leroy 2019-04-26 302 * (1) invalid (all zeroes) 0caed4de502c76 Christophe Leroy 2019-04-26 303 * (2) pointer to next table, as normal; bottom 6 bits == 0 0caed4de502c76 Christophe Leroy 2019-04-26 304 * (3) leaf pte for huge page _PAGE_PTE set 0caed4de502c76 Christophe Leroy 2019-04-26 305 * (4) hugepd pointer, _PAGE_PTE = 0 and bits [2..6] indicate size of table 0caed4de502c76 Christophe Leroy 2019-04-26 306 * 0caed4de502c76 Christophe Leroy 2019-04-26 307 * So long as we atomically load page table pointers we are safe against teardown, 0caed4de502c76 Christophe Leroy 2019-04-26 308 * we can follow the address down to the the page and take a ref on it. 0caed4de502c76 Christophe Leroy 2019-04-26 309 * This function need to be called with interrupts disabled. We use this variant 0caed4de502c76 Christophe Leroy 2019-04-26 310 * when we have MSR[EE] = 0 but the paca->irq_soft_mask = IRQS_ENABLED 0caed4de502c76 Christophe Leroy 2019-04-26 311 */ 0caed4de502c76 Christophe Leroy 2019-04-26 312 pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea, 0caed4de502c76 Christophe Leroy 2019-04-26 313 bool *is_thp, unsigned *hpage_shift) 0caed4de502c76 Christophe Leroy 2019-04-26 314 { 0caed4de502c76 Christophe Leroy 2019-04-26 315 pgd_t pgd, *pgdp; 0caed4de502c76 Christophe Leroy 2019-04-26 316 pud_t pud, *pudp; 0caed4de502c76 Christophe Leroy 2019-04-26 317 pmd_t pmd, *pmdp; 0caed4de502c76 Christophe Leroy 2019-04-26 318 pte_t *ret_pte; 0caed4de502c76 Christophe Leroy 2019-04-26 319 hugepd_t *hpdp = NULL; 0caed4de502c76 Christophe Leroy 2019-04-26 320 unsigned pdshift = PGDIR_SHIFT; 0caed4de502c76 Christophe Leroy 2019-04-26 321 0caed4de502c76 Christophe Leroy 2019-04-26 322 if (hpage_shift) 0caed4de502c76 Christophe Leroy 2019-04-26 323 *hpage_shift = 0; 0caed4de502c76 Christophe Leroy 2019-04-26 324 0caed4de502c76 Christophe Leroy 2019-04-26 325 if (is_thp) 0caed4de502c76 Christophe Leroy 2019-04-26 326 *is_thp = false; 0caed4de502c76 Christophe Leroy 2019-04-26 327 0caed4de502c76 Christophe Leroy 2019-04-26 328 pgdp = pgdir + pgd_index(ea); 0caed4de502c76 Christophe Leroy 2019-04-26 @329 pgd = READ_ONCE(*pgdp); 0caed4de502c76 Christophe Leroy 2019-04-26 330 /* 0caed4de502c76 Christophe Leroy 2019-04-26 331 * Always operate on the local stack value. This make sure the 0caed4de502c76 Christophe Leroy 2019-04-26 332 * value don't get updated by a parallel THP split/collapse, 0caed4de502c76 Christophe Leroy 2019-04-26 333 * page fault or a page unmap. The return pte_t * is still not 0caed4de502c76 Christophe Leroy 2019-04-26 334 * stable. So should be checked there for above conditions. 0caed4de502c76 Christophe Leroy 2019-04-26 335 */ 0caed4de502c76 Christophe Leroy 2019-04-26 336 if (pgd_none(pgd)) 0caed4de502c76 Christophe Leroy 2019-04-26 337 return NULL; fab9a1165bcda9 Christophe Leroy 2019-04-26 338 d6eacedd1f0ebf Aneesh Kumar K.V 2019-05-14 339 if (pgd_is_leaf(pgd)) { 0caed4de502c76 Christophe Leroy 2019-04-26 340 ret_pte = (pte_t *)pgdp; 0caed4de502c76 Christophe Leroy 2019-04-26 341 goto out; fab9a1165bcda9 Christophe Leroy 2019-04-26 342 } d6eacedd1f0ebf Aneesh Kumar K.V 2019-05-14 343 fab9a1165bcda9 Christophe Leroy 2019-04-26 344 if (is_hugepd(__hugepd(pgd_val(pgd)))) { 0caed4de502c76 Christophe Leroy 2019-04-26 345 hpdp = (hugepd_t *)&pgd; fab9a1165bcda9 Christophe Leroy 2019-04-26 346 goto out_huge; fab9a1165bcda9 Christophe Leroy 2019-04-26 347 } 26e66b08c3376b Christophe Leroy 2019-04-26 348 0caed4de502c76 Christophe Leroy 2019-04-26 349 /* 0caed4de502c76 Christophe Leroy 2019-04-26 350 * Even if we end up with an unmap, the pgtable will not 0caed4de502c76 Christophe Leroy 2019-04-26 351 * be freed, because we do an rcu free and here we are 0caed4de502c76 Christophe Leroy 2019-04-26 352 * irq disabled 0caed4de502c76 Christophe Leroy 2019-04-26 353 */ 0caed4de502c76 Christophe Leroy 2019-04-26 354 pdshift = PUD_SHIFT; 0caed4de502c76 Christophe Leroy 2019-04-26 355 pudp = pud_offset(&pgd, ea); 0caed4de502c76 Christophe Leroy 2019-04-26 356 pud = READ_ONCE(*pudp); 0caed4de502c76 Christophe Leroy 2019-04-26 357 0caed4de502c76 Christophe Leroy 2019-04-26 358 if (pud_none(pud)) 0caed4de502c76 Christophe Leroy 2019-04-26 359 return NULL; fab9a1165bcda9 Christophe Leroy 2019-04-26 360 d6eacedd1f0ebf Aneesh Kumar K.V 2019-05-14 361 if (pud_is_leaf(pud)) { 0caed4de502c76 Christophe Leroy 2019-04-26 362 ret_pte = (pte_t *)pudp; 0caed4de502c76 Christophe Leroy 2019-04-26 363 goto out; fab9a1165bcda9 Christophe Leroy 2019-04-26 364 } d6eacedd1f0ebf Aneesh Kumar K.V 2019-05-14 365 fab9a1165bcda9 Christophe Leroy 2019-04-26 366 if (is_hugepd(__hugepd(pud_val(pud)))) { 0caed4de502c76 Christophe Leroy 2019-04-26 367 hpdp = (hugepd_t *)&pud; fab9a1165bcda9 Christophe Leroy 2019-04-26 368 goto out_huge; fab9a1165bcda9 Christophe Leroy 2019-04-26 369 } d6eacedd1f0ebf Aneesh Kumar K.V 2019-05-14 370 0caed4de502c76 Christophe Leroy 2019-04-26 371 pdshift = PMD_SHIFT; 0caed4de502c76 Christophe Leroy 2019-04-26 372 pmdp = pmd_offset(&pud, ea); 0caed4de502c76 Christophe Leroy 2019-04-26 373 pmd = READ_ONCE(*pmdp); a00196a2721613 Nicholas Piggin 2019-06-07 374 0caed4de502c76 Christophe Leroy 2019-04-26 375 /* a00196a2721613 Nicholas Piggin 2019-06-07 376 * A hugepage collapse is captured by this condition, see a00196a2721613 Nicholas Piggin 2019-06-07 377 * pmdp_collapse_flush. 0caed4de502c76 Christophe Leroy 2019-04-26 378 */ 0caed4de502c76 Christophe Leroy 2019-04-26 379 if (pmd_none(pmd)) 0caed4de502c76 Christophe Leroy 2019-04-26 380 return NULL; 0caed4de502c76 Christophe Leroy 2019-04-26 381 :::::: The code at line 329 was first introduced by commit :::::: 0caed4de502c7699b7faeaea0a93b39e4f19e11a powerpc/mm: move __find_linux_pte() out of hugetlbpage.c :::::: TO: Christophe Leroy <christophe.leroy(a)c-s.fr&gt; :::::: CC: Michael Ellerman <mpe(a)ellerman.id.au&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org