static void check_kern_pgdir(void) { uint32_t i, n; pde_t *pgdir; pgdir = kern_pgdir; // check pages array n = ROUNDUP(npages*sizeof(struct Page), PGSIZE); for (i = 0; i < n; i += PGSIZE) assert(check_va2pa(pgdir, UPAGES + i) == PADDR(pages) + i); // check envs array (new test for lab 3) n = ROUNDUP(NENV*sizeof(struct Env), PGSIZE); for (i = 0; i < n; i += PGSIZE) assert(check_va2pa(pgdir, UENVS + i) == PADDR(envs) + i); // check phys mem for (i = 0; i < npages * PGSIZE; i += PGSIZE) assert(check_va2pa(pgdir, KERNBASE + i) == i); // check IO mem (new in lab 4) // for (i = IOMEMBASE; i < -PGSIZE; i += PGSIZE) // assert(check_va2pa(pgdir, i) == i); // check kernel stack // (updated in lab 4 to check per-CPU kernel stacks) for (n = 0; n < NCPU; n++) { uint32_t base = KSTACKTOP - (KSTKSIZE + KSTKGAP) * (n + 1); for (i = 0; i < KSTKSIZE; i += PGSIZE) assert(check_va2pa(pgdir, base + KSTKGAP + i) == PADDR(percpu_kstacks[n]) + i); for (i = 0; i < KSTKGAP; i += PGSIZE) assert(check_va2pa(pgdir, base + i) == ~0); } // check PDE permissions for (i = 0; i < NPDENTRIES; i++) { switch (i) { case PDX(UVPT): case PDX(KSTACKTOP-1): case PDX(UPAGES): case PDX(UENVS): assert(pgdir[i] & PTE_P); break; default: if (i >= PDX(KERNBASE)) { assert(pgdir[i] & PTE_P); assert(pgdir[i] & PTE_W); } else assert(pgdir[i] == 0); break; } } cprintf("check_kern_pgdir() succeeded!\n"); }
static void check_boot_pml4e(pml4e_t *pml4e) { uint32_t i, n; pml4e = boot_pml4e; // check pages array n = ROUNDUP(npages*sizeof(struct Page), PGSIZE); for (i = 0; i < n; i += PGSIZE) assert(check_va2pa(pml4e, UPAGES + i) == PADDR(pages) + i); // check envs array (new test for lab 3) n = ROUNDUP(NENV*sizeof(struct Env), PGSIZE); for (i = 0; i < n; i += PGSIZE) assert(check_va2pa(pml4e, UENVS + i) == PADDR(envs) + i); // check phys mem for (i = 0; i < npages * PGSIZE; i += PGSIZE) assert(check_va2pa(pml4e, KERNBASE + i) == i); // check kernel stack // (updated in lab 4 to check per-CPU kernel stacks) for (n = 0; n < NCPU; n++) { uint32_t base = KSTACKTOP - (KSTKSIZE + KSTKGAP) * (n + 1); for (i = 0; i < KSTKSIZE; i += PGSIZE) assert(check_va2pa(pml4e, base + KSTKGAP + i) == PADDR(percpu_kstacks[n]) + i); for (i = 0; i < KSTKGAP; i += PGSIZE) assert(check_va2pa(pml4e, base + i) == ~0); } pdpe_t *pdpe = KADDR(PTE_ADDR(boot_pml4e[0])); pde_t *pgdir = KADDR(PTE_ADDR(pdpe[3])); // check PDE permissions for (i = 0; i < NPDENTRIES; i++) { switch (i) { //case PDX(UVPT): case PDX(KSTACKTOP-1): case PDX(UPAGES): case PDX(UENVS): case PDX(MMIOBASE): assert(pgdir[i] & PTE_P); break; default: if (i >= PDX(KERNBASE)) { assert(pgdir[i] & PTE_P); assert(pgdir[i] & PTE_W); } else assert(pgdir[i] == 0); break; } } cprintf("check_boot_pml4e() succeeded!\n"); }
static void check_kern_pgdir(void) { uint32_t i, n; pde_t *pgdir; pgdir = kern_pgdir; // check phys mem for (i = 0; i < npages * PGSIZE; i += PGSIZE) assert(check_va2pa(pgdir, KERNBASE + i) == i); // check kernel stack for (i = 0; i < KSTKSIZE; i += PGSIZE) assert(check_va2pa(pgdir, KSTACKTOP - KSTKSIZE + i) == PADDR(entry_stack) + i); assert(check_va2pa(pgdir, KSTACKTOP - PTSIZE) == (physaddr_t) ~0); // check for zero/non-zero in PDEs for (i = 0; i < NPDENTRIES; i++) { switch (i) { case PDX(UVPT): case PDX(KSTACKTOP-1): case PDX(UPAGES): case PDX(UENVS): assert(pgdir[i]); break; default: if (i >= PDX(KERNBASE + npages * PGSIZE)) /* either way is OK */; else if (i >= PDX(KERNBASE)) assert(pgdir[i]); else assert(pgdir[i] == 0); break; } } // check pages array n = ROUNDUP(npages*sizeof(struct Page), PGSIZE); for (i = 0; i < n; i += PGSIZE) assert(check_va2pa(pgdir, UPAGES + i) == PADDR(pages) + i); // check envs array (new test for lab 3) n = ROUNDUP(NENV*sizeof(struct Env), PGSIZE); for (i = 0; i < n; i += PGSIZE) assert(check_va2pa(pgdir, UENVS + i) == PADDR(envs) + i); cprintf("check_kern_pgdir() succeeded!\n"); }
static void check_kern_pgdir(void) { uint32_t i, n; pde_t *pgdir; pgdir = kern_pgdir; // check pages array n = ROUNDUP(npages*sizeof(struct PageInfo), PGSIZE); for (i = 0; i < n; i += PGSIZE) assert(check_va2pa(pgdir, UPAGES + i) == PADDR(pages) + i); // check envs array (new test for lab 3) n = ROUNDUP(NENV*sizeof(struct Env), PGSIZE); for (i = 0; i < n; i += PGSIZE) assert(check_va2pa(pgdir, UENVS + i) == PADDR(envs) + i); // check phys mem for (i = 0; i < npages * PGSIZE; i += PGSIZE) assert(check_va2pa(pgdir, KERNBASE + i) == i); // check kernel stack for (i = 0; i < KSTKSIZE; i += PGSIZE) assert(check_va2pa(pgdir, KSTACKTOP - KSTKSIZE + i) == PADDR(bootstack) + i); assert(check_va2pa(pgdir, KSTACKTOP - PTSIZE) == ~0); // check PDE permissions for (i = 0; i < NPDENTRIES; i++) { switch (i) { case PDX(UVPT): case PDX(KSTACKTOP-1): case PDX(UPAGES): case PDX(UENVS): assert(pgdir[i] & PTE_P); break; default: if (i >= PDX(KERNBASE)) { assert(pgdir[i] & PTE_P); assert(pgdir[i] & PTE_W); } else { assert(pgdir[i] == 0); } break; } } cprintf("check_kern_pgdir() succeeded!\n"); }
// check page_insert, page_remove, &c static void check_page(void) { struct Page *pp, *pp0, *pp1, *pp2; struct Page *fl; pte_t *ptep, *ptep1; void *va; uintptr_t mm1, mm2; int i; extern pde_t entry_pgdir[]; // should be able to allocate three pages pp0 = pp1 = pp2 = 0; assert((pp0 = page_alloc(0))); assert((pp1 = page_alloc(0))); assert((pp2 = page_alloc(0))); assert(pp0); assert(pp1 && pp1 != pp0); assert(pp2 && pp2 != pp1 && pp2 != pp0); // temporarily steal the rest of the free pages fl = page_free_list; page_free_list = 0; // should be no free memory assert(!page_alloc(0)); // there is no page allocated at address 0 assert(page_lookup(kern_pgdir, (void *) 0x0, &ptep) == NULL); // there is no free memory, so we can't allocate a page table assert(page_insert(kern_pgdir, pp1, 0x0, PTE_W) < 0); // free pp0 and try again: pp0 should be used for page table page_free(pp0); assert(page_insert(kern_pgdir, pp1, 0x0, PTE_W) == 0); assert(PTE_ADDR(kern_pgdir[0]) == page2pa(pp0)); assert(check_va2pa(kern_pgdir, 0x0) == page2pa(pp1)); assert(pp1->pp_ref == 1); assert(pp0->pp_ref == 1); // should be able to map pp2 at PGSIZE because pp0 is already allocated for page table assert(page_insert(kern_pgdir, pp2, (void*) PGSIZE, PTE_W) == 0); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp2)); assert(pp2->pp_ref == 1); // should be no free memory assert(!page_alloc(0)); // should be able to map pp2 at PGSIZE because it's already there assert(page_insert(kern_pgdir, pp2, (void*) PGSIZE, PTE_W) == 0); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp2)); assert(pp2->pp_ref == 1); // pp2 should NOT be on the free list // could happen in ref counts are handled sloppily in page_insert assert(!page_alloc(0)); // check that pgdir_walk returns a pointer to the pte ptep = (pte_t *) KADDR(PTE_ADDR(kern_pgdir[PDX(PGSIZE)])); assert(pgdir_walk(kern_pgdir, (void*)PGSIZE, 0) == ptep+PTX(PGSIZE)); // should be able to change permissions too. assert(page_insert(kern_pgdir, pp2, (void*) PGSIZE, PTE_W|PTE_U) == 0); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp2)); assert(pp2->pp_ref == 1); assert(*pgdir_walk(kern_pgdir, (void*) PGSIZE, 0) & PTE_U); assert(kern_pgdir[0] & PTE_U); // should be able to remap with fewer permissions assert(page_insert(kern_pgdir, pp2, (void*) PGSIZE, PTE_W) == 0); assert(*pgdir_walk(kern_pgdir, (void*) PGSIZE, 0) & PTE_W); assert(!(*pgdir_walk(kern_pgdir, (void*) PGSIZE, 0) & PTE_U)); // should not be able to map at PTSIZE because need free page for page table assert(page_insert(kern_pgdir, pp0, (void*) PTSIZE, PTE_W) < 0); // insert pp1 at PGSIZE (replacing pp2) assert(page_insert(kern_pgdir, pp1, (void*) PGSIZE, PTE_W) == 0); assert(!(*pgdir_walk(kern_pgdir, (void*) PGSIZE, 0) & PTE_U)); // should have pp1 at both 0 and PGSIZE, pp2 nowhere, ... assert(check_va2pa(kern_pgdir, 0) == page2pa(pp1)); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp1)); // ... and ref counts should reflect this assert(pp1->pp_ref == 2); assert(pp2->pp_ref == 0); // pp2 should be returned by page_alloc assert((pp = page_alloc(0)) && pp == pp2); // unmapping pp1 at 0 should keep pp1 at PGSIZE page_remove(kern_pgdir, 0x0); assert(check_va2pa(kern_pgdir, 0x0) == ~0); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp1)); assert(pp1->pp_ref == 1); assert(pp2->pp_ref == 0); // unmapping pp1 at PGSIZE should free it page_remove(kern_pgdir, (void*) PGSIZE); assert(check_va2pa(kern_pgdir, 0x0) == ~0); assert(check_va2pa(kern_pgdir, PGSIZE) == ~0); assert(pp1->pp_ref == 0); assert(pp2->pp_ref == 0); // so it should be returned by page_alloc assert((pp = page_alloc(0)) && pp == pp1); // should be no free memory assert(!page_alloc(0)); // forcibly take pp0 back assert(PTE_ADDR(kern_pgdir[0]) == page2pa(pp0)); kern_pgdir[0] = 0; assert(pp0->pp_ref == 1); pp0->pp_ref = 0; // check pointer arithmetic in pgdir_walk page_free(pp0); va = (void*)(PGSIZE * NPDENTRIES + PGSIZE); ptep = pgdir_walk(kern_pgdir, va, 1); ptep1 = (pte_t *) KADDR(PTE_ADDR(kern_pgdir[PDX(va)])); assert(ptep == ptep1 + PTX(va)); kern_pgdir[PDX(va)] = 0; pp0->pp_ref = 0; // check that new page tables get cleared memset(page2kva(pp0), 0xFF, PGSIZE); page_free(pp0); pgdir_walk(kern_pgdir, 0x0, 1); ptep = (pte_t *) page2kva(pp0); for(i=0; i<NPTENTRIES; i++) assert((ptep[i] & PTE_P) == 0); kern_pgdir[0] = 0; pp0->pp_ref = 0; // give free list back page_free_list = fl; // free the pages we took page_free(pp0); page_free(pp1); page_free(pp2); // test mmio_map_region mm1 = (uintptr_t) mmio_map_region(0, 4097); mm2 = (uintptr_t) mmio_map_region(0, 4096); // check that they're in the right region assert(mm1 >= MMIOBASE && mm1 + 8096 < MMIOLIM); assert(mm2 >= MMIOBASE && mm2 + 8096 < MMIOLIM); // check that they're page-aligned assert(mm1 % PGSIZE == 0 && mm2 % PGSIZE == 0); // check that they don't overlap assert(mm1 + 8096 <= mm2); // check page mappings assert(check_va2pa(kern_pgdir, mm1) == 0); assert(check_va2pa(kern_pgdir, mm1+PGSIZE) == PGSIZE); assert(check_va2pa(kern_pgdir, mm2) == 0); assert(check_va2pa(kern_pgdir, mm2+PGSIZE) == ~0); // check permissions assert(*pgdir_walk(kern_pgdir, (void*) mm1, 0) & (PTE_W|PTE_PWT|PTE_PCD)); assert(!(*pgdir_walk(kern_pgdir, (void*) mm1, 0) & PTE_U)); // clear the mappings *pgdir_walk(kern_pgdir, (void*) mm1, 0) = 0; *pgdir_walk(kern_pgdir, (void*) mm1 + PGSIZE, 0) = 0; *pgdir_walk(kern_pgdir, (void*) mm2, 0) = 0; cprintf("check_page() succeeded!\n"); }
// check page_insert, page_remove, &c static void page_check(void) { struct Page *pp0, *pp1, *pp2,*pp3,*pp4,*pp5; struct Page * fl; pte_t *ptep, *ptep1; pdpe_t *pdpe; pde_t *pde; void *va; int i; uintptr_t mm1, mm2; pp0 = pp1 = pp2 = pp3 = pp4 = pp5 =0; assert(pp0 = page_alloc(0)); assert(pp1 = page_alloc(0)); assert(pp2 = page_alloc(0)); assert(pp3 = page_alloc(0)); assert(pp4 = page_alloc(0)); assert(pp5 = page_alloc(0)); assert(pp0); assert(pp1 && pp1 != pp0); assert(pp2 && pp2 != pp1 && pp2 != pp0); assert(pp3 && pp3 != pp2 && pp3 != pp1 && pp3 != pp0); assert(pp4 && pp4 != pp3 && pp4 != pp2 && pp4 != pp1 && pp4 != pp0); assert(pp5 && pp5 != pp4 && pp5 != pp3 && pp5 != pp2 && pp5 != pp1 && pp5 != pp0); // temporarily steal the rest of the free pages fl = page_free_list; page_free_list = NULL; // should be no free memory assert(!page_alloc(0)); // there is no page allocated at address 0 assert(page_lookup(boot_pml4e, (void *) 0x0, &ptep) == NULL); // there is no free memory, so we can't allocate a page table assert(page_insert(boot_pml4e, pp1, 0x0, 0) < 0); // free pp0 and try again: pp0 should be used for page table page_free(pp0); assert(page_insert(boot_pml4e, pp1, 0x0, 0) < 0); page_free(pp2); page_free(pp3); //cprintf("pp1 ref count = %d\n",pp1->pp_ref); //cprintf("pp0 ref count = %d\n",pp0->pp_ref); //cprintf("pp2 ref count = %d\n",pp2->pp_ref); assert(page_insert(boot_pml4e, pp1, 0x0, 0) == 0); assert((PTE_ADDR(boot_pml4e[0]) == page2pa(pp0) || PTE_ADDR(boot_pml4e[0]) == page2pa(pp2) || PTE_ADDR(boot_pml4e[0]) == page2pa(pp3) )); assert(check_va2pa(boot_pml4e, 0x0) == page2pa(pp1)); assert(pp1->pp_ref == 1); assert(pp0->pp_ref == 1); assert(pp2->pp_ref == 1); //should be able to map pp3 at PGSIZE because pp0 is already allocated for page table assert(page_insert(boot_pml4e, pp3, (void*) PGSIZE, 0) == 0); assert(check_va2pa(boot_pml4e, PGSIZE) == page2pa(pp3)); assert(pp3->pp_ref == 2); // should be no free memory assert(!page_alloc(0)); // should be able to map pp3 at PGSIZE because it's already there assert(page_insert(boot_pml4e, pp3, (void*) PGSIZE, 0) == 0); assert(check_va2pa(boot_pml4e, PGSIZE) == page2pa(pp3)); assert(pp3->pp_ref == 2); // pp3 should NOT be on the free list // could happen in ref counts are handled sloppily in page_insert assert(!page_alloc(0)); // check that pgdir_walk returns a pointer to the pte pdpe = KADDR(PTE_ADDR(boot_pml4e[PML4(PGSIZE)])); pde = KADDR(PTE_ADDR(pdpe[PDPE(PGSIZE)])); ptep = KADDR(PTE_ADDR(pde[PDX(PGSIZE)])); assert(pml4e_walk(boot_pml4e, (void*)PGSIZE, 0) == ptep+PTX(PGSIZE)); // should be able to change permissions too. assert(page_insert(boot_pml4e, pp3, (void*) PGSIZE, PTE_U) == 0); assert(check_va2pa(boot_pml4e, PGSIZE) == page2pa(pp3)); assert(pp3->pp_ref == 2); assert(*pml4e_walk(boot_pml4e, (void*) PGSIZE, 0) & PTE_U); assert(boot_pml4e[0] & PTE_U); // should not be able to map at PTSIZE because need free page for page table assert(page_insert(boot_pml4e, pp0, (void*) PTSIZE, 0) < 0); // insert pp1 at PGSIZE (replacing pp3) assert(page_insert(boot_pml4e, pp1, (void*) PGSIZE, 0) == 0); assert(!(*pml4e_walk(boot_pml4e, (void*) PGSIZE, 0) & PTE_U)); // should have pp1 at both 0 and PGSIZE assert(check_va2pa(boot_pml4e, 0) == page2pa(pp1)); assert(check_va2pa(boot_pml4e, PGSIZE) == page2pa(pp1)); // ... and ref counts should reflect this assert(pp1->pp_ref == 2); assert(pp3->pp_ref == 1); // unmapping pp1 at 0 should keep pp1 at PGSIZE page_remove(boot_pml4e, 0x0); assert(check_va2pa(boot_pml4e, 0x0) == ~0); assert(check_va2pa(boot_pml4e, PGSIZE) == page2pa(pp1)); assert(pp1->pp_ref == 1); assert(pp3->pp_ref == 1); // Test re-inserting pp1 at PGSIZE. // Thanks to Varun Agrawal for suggesting this test case. assert(page_insert(boot_pml4e, pp1, (void*) PGSIZE, 0) == 0); assert(pp1->pp_ref); assert(pp1->pp_link == NULL); // unmapping pp1 at PGSIZE should free it page_remove(boot_pml4e, (void*) PGSIZE); assert(check_va2pa(boot_pml4e, 0x0) == ~0); assert(check_va2pa(boot_pml4e, PGSIZE) == ~0); assert(pp1->pp_ref == 0); assert(pp3->pp_ref == 1); #if 0 // should be able to page_insert to change a page // and see the new data immediately. memset(page2kva(pp1), 1, PGSIZE); memset(page2kva(pp2), 2, PGSIZE); page_insert(boot_pgdir, pp1, 0x0, 0); assert(pp1->pp_ref == 1); assert(*(int*)0 == 0x01010101); page_insert(boot_pgdir, pp2, 0x0, 0); assert(*(int*)0 == 0x02020202); assert(pp2->pp_ref == 1); assert(pp1->pp_ref == 0); page_remove(boot_pgdir, 0x0); assert(pp2->pp_ref == 0); #endif // forcibly take pp3 back assert(PTE_ADDR(boot_pml4e[0]) == page2pa(pp3)); boot_pml4e[0] = 0; assert(pp3->pp_ref == 1); page_decref(pp3); // check pointer arithmetic in pml4e_walk page_decref(pp0); page_decref(pp2); va = (void*)(PGSIZE * 100); ptep = pml4e_walk(boot_pml4e, va, 1); pdpe = KADDR(PTE_ADDR(boot_pml4e[PML4(va)])); pde = KADDR(PTE_ADDR(pdpe[PDPE(va)])); ptep1 = KADDR(PTE_ADDR(pde[PDX(va)])); assert(ptep == ptep1 + PTX(va)); // check that new page tables get cleared page_decref(pp4); memset(page2kva(pp4), 0xFF, PGSIZE); pml4e_walk(boot_pml4e, 0x0, 1); pdpe = KADDR(PTE_ADDR(boot_pml4e[0])); pde = KADDR(PTE_ADDR(pdpe[0])); ptep = KADDR(PTE_ADDR(pde[0])); for(i=0; i<NPTENTRIES; i++) assert((ptep[i] & PTE_P) == 0); boot_pml4e[0] = 0; // give free list back page_free_list = fl; // free the pages we took page_decref(pp0); page_decref(pp1); page_decref(pp2); // test mmio_map_region mm1 = (uintptr_t) mmio_map_region(0, 4097); mm2 = (uintptr_t) mmio_map_region(0, 4096); // check that they're in the right region assert(mm1 >= MMIOBASE && mm1 + 8096 < MMIOLIM); assert(mm2 >= MMIOBASE && mm2 + 8096 < MMIOLIM); // check that they're page-aligned assert(mm1 % PGSIZE == 0 && mm2 % PGSIZE == 0); // check that they don't overlap assert(mm1 + 8096 <= mm2); // check page mappingsasdfasd assert(check_va2pa(boot_pml4e, mm1) == 0); assert(check_va2pa(boot_pml4e, mm1+PGSIZE) == PGSIZE); assert(check_va2pa(boot_pml4e, mm2) == 0); assert(check_va2pa(boot_pml4e, mm2+PGSIZE) == ~0); // check permissions assert(*pml4e_walk(boot_pml4e, (void*) mm1, 0) & (PTE_W|PTE_PWT|PTE_PCD)); assert(!(*pml4e_walk(boot_pml4e, (void*) mm1, 0) & PTE_U)); // clear the mappings *pml4e_walk(boot_pml4e, (void*) mm1, 0) = 0; *pml4e_walk(boot_pml4e, (void*) mm1 + PGSIZE, 0) = 0; *pml4e_walk(boot_pml4e, (void*) mm2, 0) = 0; cprintf("check_page() succeeded!\n"); }
// check page_insert, page_remove, &c static void check_page(void) { struct Page *pp, *pp0, *pp1, *pp2; struct Page *fl; pte_t *ptep, *ptep1; uintptr_t va; int i; // should be able to allocate three pages pp0 = pp1 = pp2 = 0; assert((pp0 = page_alloc())); assert((pp1 = page_alloc())); assert((pp2 = page_alloc())); assert(pp0); assert(pp1 && pp1 != pp0); assert(pp2 && pp2 != pp1 && pp2 != pp0); // temporarily steal the rest of the free pages fl = page_free_list; page_free_list = 0; // should be no free memory assert(!page_alloc()); // there is no page allocated at address 0 assert(page_lookup(kern_pgdir, 0x0, &ptep) == NULL); // there is no free memory, so we can't allocate a page table assert(page_insert(kern_pgdir, pp1, 0x0, PTE_W) < 0); // free pp0 and try again: pp0 should be used for page table page_free(pp0); assert(page_insert(kern_pgdir, pp1, 0x0, PTE_W) == 0); assert(PTE_ADDR(kern_pgdir[0]) == page2pa(pp0)); assert(check_va2pa(kern_pgdir, 0x0) == page2pa(pp1)); assert(pp1->pp_ref == 1); assert(pp0->pp_ref == 1); // should be able to map pp2 at PGSIZE because pp0 is already allocated for page table assert(page_insert(kern_pgdir, pp2, PGSIZE, PTE_W) == 0); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp2)); assert(pp2->pp_ref == 1); // should be no free memory assert(!page_alloc()); // should be able to map pp2 at PGSIZE because it's already there assert(page_insert(kern_pgdir, pp2, PGSIZE, PTE_W) == 0); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp2)); assert(pp2->pp_ref == 1); // pp2 should NOT be on the free list // could happen in ref counts are handled sloppily in page_insert assert(!page_alloc()); // check that pgdir_walk returns a pointer to the pte ptep = (pte_t *) KADDR(PTE_ADDR(kern_pgdir[PDX(PGSIZE)])); assert(pgdir_walk(kern_pgdir, PGSIZE, false) == ptep+PTX(PGSIZE)); // should be able to change permissions too. assert(page_insert(kern_pgdir, pp2, PGSIZE, PTE_W|PTE_U) == 0); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp2)); assert(pp2->pp_ref == 1); assert(*pgdir_walk(kern_pgdir, PGSIZE, false) & PTE_U); assert(kern_pgdir[0] & PTE_U); // should not be able to map at PTSIZE because need free page for page table assert(page_insert(kern_pgdir, pp0, PTSIZE, PTE_W) < 0); // insert pp1 at PGSIZE (replacing pp2) assert(page_insert(kern_pgdir, pp1, PGSIZE, PTE_W) == 0); assert(!(*pgdir_walk(kern_pgdir, PGSIZE, false) & PTE_U)); // should have pp1 at both 0 and PGSIZE, pp2 nowhere, ... assert(check_va2pa(kern_pgdir, 0) == page2pa(pp1)); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp1)); // ... and ref counts should reflect this assert(pp1->pp_ref == 2); assert(pp2->pp_ref == 0); // pp2 should be returned by page_alloc assert((pp = page_alloc()) && pp == pp2); // unmapping pp1 at 0 should keep pp1 at PGSIZE page_remove(kern_pgdir, 0x0); assert(check_va2pa(kern_pgdir, 0x0) == (physaddr_t) ~0); assert(check_va2pa(kern_pgdir, PGSIZE) == page2pa(pp1)); assert(pp1->pp_ref == 1); assert(pp2->pp_ref == 0); // unmapping pp1 at PGSIZE should free it page_remove(kern_pgdir, PGSIZE); assert(check_va2pa(kern_pgdir, 0x0) == (physaddr_t) ~0); assert(check_va2pa(kern_pgdir, PGSIZE) == (physaddr_t) ~0); assert(pp1->pp_ref == 0); assert(pp2->pp_ref == 0); // so it should be returned by page_alloc assert((pp = page_alloc()) && pp == pp1); // should be no free memory assert(!page_alloc()); // forcibly take pp0 back assert(PTE_ADDR(kern_pgdir[0]) == page2pa(pp0)); kern_pgdir[0] = 0; assert(pp0->pp_ref == 1); pp0->pp_ref = 0; // check pointer arithmetic in pgdir_walk page_free(pp0); va = PGSIZE * NPDENTRIES + PGSIZE; ptep = pgdir_walk(kern_pgdir, va, true); ptep1 = (pte_t *) KADDR(PTE_ADDR(kern_pgdir[PDX(va)])); assert(ptep == ptep1 + PTX(va)); kern_pgdir[PDX(va)] = 0; pp0->pp_ref = 0; // check that new page tables get cleared memset(page2kva(pp0), 0xFF, PGSIZE); page_free(pp0); pgdir_walk(kern_pgdir, 0x0, true); ptep = (pte_t *) page2kva(pp0); for(i=0; i<NPTENTRIES; i++) assert((ptep[i] & PTE_P) == 0); kern_pgdir[0] = 0; pp0->pp_ref = 0; // give free list back page_free_list = fl; // free the pages we took page_free(pp0); page_free(pp1); page_free(pp2); cprintf("check_page() succeeded!\n"); }