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It's legal to mmap pages in the lower part of the stack (< limit), and

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use them, so allow this by relaxing the check for it.
This commit is contained in:
fvdl 1999-10-04 17:36:37 +00:00
parent e09818f9fd
commit 5c04333d5d
1 changed files with 12 additions and 5 deletions
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17
sys/arch/i386/i386/trap.c
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@ -1,4 +1,4 @@
/* $NetBSD: trap.c,v 1.132 1999/06/17 00:12:12 thorpej Exp $ */
/* $NetBSD: trap.c,v 1.133 1999/10/04 17:36:37 fvdl Exp $ */
/*-
* Copyright (c) 1998 The NetBSD Foundation, Inc.
@ -472,8 +472,16 @@ trap(frame)
&& map != kernel_map) {
nss = clrnd(btoc(USRSTACK-(unsigned)va));
if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
rv = KERN_FAILURE;
goto nogo;
/*
* We used to fail here. However, it may
* just have been an mmap()ed page low
* in the stack, which is legal. If it
* wasn't, uvm_fault() will fail below.
*
* Set nss to 0, since this case is not
* a "stack extension".
*/
nss = 0;
}
}
@ -488,7 +496,6 @@ trap(frame)
goto out;
}
nogo:
if (type == T_PAGEFLT) {
if (pcb->pcb_onfault != 0)
goto copyfault;
@ -576,7 +583,7 @@ trapwrite(addr)
if ((caddr_t)va >= vm->vm_maxsaddr) {
nss = clrnd(btoc(USRSTACK-(unsigned)va));
if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
return 1;
nss = 0;
}
if (uvm_fault(&vm->vm_map, va, 0, VM_PROT_READ | VM_PROT_WRITE)