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Simplify freevm using deallocuvm

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This commit is contained in:
Austin Clements 2010-09-02 15:18:19 -04:00
parent c7c21467c3
commit b3cfd7fc37
1 changed files with 6 additions and 19 deletions
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25
vm.c
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@ -206,8 +206,7 @@ allocuvm(pde_t *pgdir, char *addr, uint sz)
return 1;
}
// deallocate some of the user pages, in response to sbrk()
// with a negative argument. if addr is not page-aligned,
// deallocate some of the user pages. if addr is not page-aligned,
// then only deallocates starting at the next page boundary.
int
deallocuvm(pde_t *pgdir, char *addr, uint sz)
@ -235,26 +234,14 @@ deallocuvm(pde_t *pgdir, char *addr, uint sz)
void
freevm(pde_t *pgdir)
{
uint i, j, da;
uint i;
if(!pgdir)
panic("freevm: no pgdir\n");
panic("freevm: no pgdir");
deallocuvm(pgdir, 0, USERTOP);
for(i = 0; i < NPDENTRIES; i++){
da = PTE_ADDR(pgdir[i]);
if(da != 0){
pte_t *pgtab = (pte_t*) da;
for(j = 0; j < NPTENTRIES; j++){
if(pgtab[j] != 0){
uint pa = PTE_ADDR(pgtab[j]);
uint va = PGADDR(i, j, 0);
if(va < USERTOP) // user memory
kfree((void *) pa);
pgtab[j] = 0;
}
}
kfree((void *) da);
pgdir[i] = 0;
}
if(pgdir[i] & PTE_P)
kfree((void *) PTE_ADDR(pgdir[i]));
}
kfree((void *) pgdir);
}