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process/vm: implement access_ok()

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This commit is contained in:
Dominique Martinet
2017-09-21 17:35:13 +09:00
committed by Balazs Gerofi
parent e29a40331d
commit 42bbf5f2a4
2 changed files with 36 additions and 0 deletions
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4
kernel/include/process.h
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@ -830,4 +830,8 @@ void proc_init();
void set_timer(); void set_timer();
struct sig_pending *hassigpending(struct thread *thread); struct sig_pending *hassigpending(struct thread *thread);
#define VERIFY_READ 0
#define VERIFY_WRITE 1
int access_ok(struct process_vm *vm, int type, uintptr_t addr, size_t len);
#endif #endif

32
kernel/process.c
View File

@ -3677,3 +3677,35 @@ debug_log(unsigned long arg)
break; break;
} }
} }
int access_ok(struct process_vm *vm, int type, uintptr_t addr, size_t len) {
struct vm_range *range, *next;
range = lookup_process_memory_range(vm, addr, addr + len);
while (range) {
if ((type == VERIFY_WRITE && !(range->flag & VR_PROT_WRITE)) ||
(type == VERIFY_READ && !(range->flag & VR_PROT_READ))) {
kprintf("%s: 0x%llx - 0x%llx does not have prot %s (request was %0x%llx-0x%llx %zu)\n",
__FUNCTION__, range->start, range->end,
type == VERIFY_WRITE ? "write" : "ready",
addr, addr+len, len);
return -EACCES;
}
if (addr + len < range->end)
break;
next = next_process_memory_range(vm, range);
if (range->end != next->start) {
kprintf("%s: 0x%llx - 0x%llx and 0x%llx - 0x%llx are not adjacent (request was %0x%llx-0x%llx %zu)\n",
__FUNCTION__, range->start, range->end,
next->start, next->end,
addr, addr+len, len);
return -EFAULT;
}
range = next;
}
return 0;
}