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When aligned to > PAGE_SIZE boundary, don't map any pages before where the

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psection starts.  Allocate unused VA space between psections as unreadable.
This commit is contained in:
matt 2003-02-28 19:09:08 +00:00
parent a4314c450c
commit 261ba66908
1 changed files with 30 additions and 23 deletions
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53
sys/kern/exec_elf32.c
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@ -1,4 +1,4 @@
/* $NetBSD: exec_elf32.c,v 1.86 2003/02/28 00:11:14 matt Exp $ */
/* $NetBSD: exec_elf32.c,v 1.87 2003/02/28 19:09:08 matt Exp $ */
/*-
* Copyright (c) 1994, 2000 The NetBSD Foundation, Inc.
@ -64,7 +64,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(1, "$NetBSD: exec_elf32.c,v 1.86 2003/02/28 00:11:14 matt Exp $");
__KERNEL_RCSID(1, "$NetBSD: exec_elf32.c,v 1.87 2003/02/28 19:09:08 matt Exp $");
/* If not included by exec_elf64.c, ELFSIZE won't be defined. */
#ifndef ELFSIZE
@ -237,30 +237,37 @@ void
ELFNAME(load_psection)(struct exec_vmcmd_set *vcset, struct vnode *vp,
const Elf_Phdr *ph, Elf_Addr *addr, u_long *size, int *prot, int flags)
{
u_long uaddr, msize, psize, rm, rf;
u_long msize, psize, rm, rf;
long diff, offset;
/*
* If the user specified an address, then we load there.
*/
if (*addr != ELFDEFNNAME(NO_ADDR)) {
if (ph->p_align > 1) {
*addr = ELF_TRUNC(*addr, ph->p_align);
uaddr = ELF_TRUNC(ph->p_vaddr, ph->p_align);
} else
uaddr = ph->p_vaddr;
diff = ph->p_vaddr - uaddr;
} else {
*addr = uaddr = ph->p_vaddr;
if (ph->p_align > 1)
*addr = ELF_TRUNC(uaddr, ph->p_align);
diff = uaddr - *addr;
}
if (*addr == ELFDEFNNAME(NO_ADDR))
*addr = ph->p_vaddr;
if (ph->p_align > 1) {
/*
* Make sure we are virtually aligned as we are supposed to be.
*/
diff = ph->p_vaddr - ELF_TRUNC(ph->p_vaddr, ph->p_align);
KASSERT(*addr - diff == ELF_TRUNC(*addr, ph->p_align));
/*
* But make sure to not map any pages before the start of the
* psection by limiting the difference to within a page.
*/
diff &= PAGE_MASK;
} else
diff = 0;
*prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0;
*prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0;
*prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0;
/*
* Adjust everything so it all starts on a page boundary.
*/
*addr -= diff;
offset = ph->p_offset - diff;
*size = ph->p_filesz + diff;
msize = ph->p_memsz + diff;
@ -284,15 +291,16 @@ ELFNAME(load_psection)(struct exec_vmcmd_set *vcset, struct vnode *vp,
NEW_VMCMD2(vcset, ph->p_align < PAGE_SIZE ?
vmcmd_map_readvn : vmcmd_map_pagedvn, psize, *addr, vp,
offset, *prot, flags);
flags &= VMCMD_RELATIVE;
}
if (psize < *size) {
NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize,
*addr + psize, vp, offset + psize, *prot,
psize > 0 ? flags & VMCMD_RELATIVE : flags);
*addr + psize, vp, offset + psize, *prot, flags);
}
/*
* Check if we need to extend the size of the segment
* Check if we need to extend the size of the segment (does
* bss extend page the next page boundary)?
*/
rm = round_page(*addr + msize);
rf = round_page(*addr + *size);
@ -441,8 +449,7 @@ ELFNAME(load_file)(struct proc *p, struct exec_package *epp, char *path,
} else {
u_long limit = round_page(last_ph->p_vaddr
+ last_ph->p_memsz);
u_long base = trunc_page(
ELF_TRUNC(ph0->p_vaddr, ph0->p_align));
u_long base = trunc_page(ph0->p_vaddr);
/*
* If there is a gap in between the psections,
@ -452,8 +459,8 @@ ELFNAME(load_file)(struct proc *p, struct exec_package *epp, char *path,
if (limit != base) {
NEW_VMCMD2(vcset, vmcmd_map_zero,
base - limit,
limit - base_ph->p_vaddr,
NULLVP, 0, 0, VMCMD_RELATIVE);
limit - base_ph->p_vaddr, NULLVP,
0, VM_PROT_NONE, VMCMD_RELATIVE);
}
addr = ph0->p_vaddr - base_ph->p_vaddr;