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pc64: fix segattach

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the comment about Physseg.size being in pages is wrong,
change type to uintptr and correct the comment.

change the length parameter of segattach() and isoverlap()
to uintptr as well. segments can grow over 4GB in pc64 now
and globalsegattach() in devsegment calculates len argument
of isoverlap() by s->top - s->bot. note that the syscall
still takes 32bit ulong argument for the length!

check for integer overflow in segattach(), make sure segment
goes not beyond USTKTOP.

change PTEMAPMEM constant to uvlong as it is used to calculate
SEGMAXSIZE.
This commit is contained in:
cinap_lenrek 2014-03-04 22:37:15 +01:00
parent 06c8a5b391
commit 316d8ad76b
5 changed files with 11 additions and 12 deletions
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13
sys/src/9/port/segment.c
View file

@ -558,7 +558,7 @@ out:
}
Segment*
isoverlap(Proc *p, uintptr va, int len)
isoverlap(Proc *p, uintptr va, uintptr len)
{
int i;
Segment *ns;
@ -621,7 +621,7 @@ isphysseg(char *name)
}
uintptr
segattach(Proc *p, ulong attr, char *name, uintptr va, ulong len)
segattach(Proc *p, ulong attr, char *name, uintptr va, uintptr len)
{
int sno;
Segment *s, *os;
@ -671,13 +671,12 @@ segattach(Proc *p, ulong attr, char *name, uintptr va, ulong len)
error(Enovmem);
va -= len;
}
va &= ~(BY2PG-1);
} else {
va &= ~(BY2PG-1);
if(va == 0 || va >= USTKTOP)
error(Ebadarg);
}
va &= ~(BY2PG-1);
if(va == 0 || (va+len) > USTKTOP || (va+len) < va)
error(Ebadarg);
if(isoverlap(p, va, len) != nil)
error(Esoverlap);