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Fix page table copying bug.

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This commit is contained in:
Danila Fedorin 2019-04-23 20:37:41 -07:00
parent 94b52c5730
commit 113093f919
1 changed files with 3 additions and 4 deletions
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7
kern/env.c
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@ -186,7 +186,7 @@ env_setup_vm(struct Env *e)
// - The functions in kern/pmap.h are handy. // - The functions in kern/pmap.h are handy.
p->pp_ref++; p->pp_ref++;
e->env_pgdir = page2kva(p); e->env_pgdir = page2kva(p);
memcpy(e->env_pgdir + PDX(UTOP), kern_pgdir + PDX(UTOP), NPDENTRIES - PDX(UTOP)); memcpy(e->env_pgdir + PDX(UTOP), kern_pgdir + PDX(UTOP), sizeof(pde_t) * (NPDENTRIES - PDX(UTOP)));
// UVPT maps the env's own page table read-only. // UVPT maps the env's own page table read-only.
// Permissions: kernel R, user R // Permissions: kernel R, user R
@ -276,11 +276,10 @@ region_alloc(struct Env *e, void *va, size_t len)
// You should round va down, and round (va + len) up. // You should round va down, and round (va + len) up.
// (Watch out for corner-cases!) // (Watch out for corner-cases!)
va = ROUNDDOWN(va, PGSIZE); va = ROUNDDOWN(va, PGSIZE);
len = ROUNDUP(len, PGSIZE); size_t count = ROUNDUP(len, PGSIZE) / PGSIZE;
void* last_va = va + len;
struct PageInfo* p; struct PageInfo* p;
while(va < last_va) { while(count--) {
if(!(p = page_alloc(0))) if(!(p = page_alloc(0)))
panic("Failed to allocate memory"); panic("Failed to allocate memory");
if(page_insert(e->env_pgdir, p, va, PTE_U | PTE_W)) if(page_insert(e->env_pgdir, p, va, PTE_U | PTE_W))