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fix possible memory leak in deallocuvm

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when a zero PDE is encountered while searching for present PTEs to free,
resume searching at first entry of the next page table instead of the
current entry of the next page table.
This commit is contained in:
Cody Cutler 2016-09-26 12:21:01 -04:00
parent 91fd3470b0
commit ffe444926e
1 changed files with 1 additions and 1 deletions
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2
vm.c
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@ -266,7 +266,7 @@ deallocuvm(pde_t *pgdir, uint oldsz, uint newsz)
for(; a < oldsz; a += PGSIZE){ for(; a < oldsz; a += PGSIZE){
pte = walkpgdir(pgdir, (char*)a, 0); pte = walkpgdir(pgdir, (char*)a, 0);
if(!pte) if(!pte)
a += (NPTENTRIES - 1) * PGSIZE; a = PGADDR(PDX(a) + 1, 0, 0) - PGSIZE;
else if((*pte & PTE_P) != 0){ else if((*pte & PTE_P) != 0){
pa = PTE_ADDR(*pte); pa = PTE_ADDR(*pte);
if(pa == 0) if(pa == 0)