diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trampoline.S | 2 | ||||
| -rw-r--r-- | kernel/vm.c | 9 |
2 files changed, 8 insertions, 3 deletions
diff --git a/kernel/trampoline.S b/kernel/trampoline.S index d7308cc..693f8a1 100644 --- a/kernel/trampoline.S +++ b/kernel/trampoline.S @@ -15,6 +15,7 @@ .section trampsec .globl trampoline +.globl usertrap trampoline: .align 4 .globl uservec @@ -80,7 +81,6 @@ uservec: # load the address of usertrap(), from p->trapframe->kernel_trap ld t0, 16(a0) - # fetch the kernel page table address, from p->trapframe->kernel_satp. ld t1, 0(a0) diff --git a/kernel/vm.c b/kernel/vm.c index 9f69783..486945e 100644 --- a/kernel/vm.c +++ b/kernel/vm.c @@ -352,12 +352,17 @@ int copyout(pagetable_t pagetable, uint64 dstva, char *src, uint64 len) { uint64 n, va0, pa0; + pte_t *pte; while(len > 0){ va0 = PGROUNDDOWN(dstva); - pa0 = walkaddr(pagetable, va0); - if(pa0 == 0) + if(va0 >= MAXVA) + return -1; + pte = walk(pagetable, va0, 0); + if(pte == 0 || (*pte & PTE_V) == 0 || (*pte & PTE_U) == 0 || + (*pte & PTE_W) == 0) return -1; + pa0 = PTE2PA(*pte); n = PGSIZE - (dstva - va0); if(n > len) n = len; |