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Costmestic change (thanks Harry Porter)

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This commit is contained in:
Frans Kaashoek 2022-08-12 14:59:30 -04:00
parent 8f58cc7df9
commit 7a6d57235c
1 changed files with 3 additions and 4 deletions
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7
kernel/syscall.c
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@ -12,7 +12,7 @@ int
fetchaddr(uint64 addr, uint64 *ip) fetchaddr(uint64 addr, uint64 *ip)
{ {
struct proc *p = myproc(); struct proc *p = myproc();
if(addr >= p->sz || addr+sizeof(uint64) > p->sz) if(addr >= p->sz || addr+sizeof(uint64) > p->sz) // both tests needed, in case of overflow
return -1; return -1;
if(copyin(p->pagetable, (char *)ip, addr, sizeof(*ip)) != 0) if(copyin(p->pagetable, (char *)ip, addr, sizeof(*ip)) != 0)
return -1; return -1;
@ -25,9 +25,8 @@ int
fetchstr(uint64 addr, char *buf, int max) fetchstr(uint64 addr, char *buf, int max)
{ {
struct proc *p = myproc(); struct proc *p = myproc();
int err = copyinstr(p->pagetable, buf, addr, max); if(copyinstr(p->pagetable, buf, addr, max) < 0)
if(err < 0) return -1;
return err;
return strlen(buf); return strlen(buf);
} }