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MFC r204297:

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Move the OEA64 scratchpage to the end of KVA from the beginning, and set
its PVO to map physical address 0 instead of kernelstart. This fixes a
situation in which a user process could attempt to return this address
via KVM, have it fault while being modified, and then panic the kernel
because (a) it is supposed to map a valid address and (b) it lies in the
no-fault region between VM_MIN_KERNEL_ADDRESS and virtual_avail.

While here, move msgbuf and dpcpu back into regular KVA space for
consistency with other implementations.
This commit is contained in:
Nathan Whitehorn 2010-03-20 15:27:01 +00:00
parent 1f70273a79
commit fca060b9f9
1 changed files with 14 additions and 9 deletions
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23
sys/powerpc/aim/mmu_oea64.c
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@ -970,10 +970,10 @@ moea64_bridge_bootstrap(mmu_t mmup, vm_offset_t kernelstart, vm_offset_t kernele
mtx_init(&moea64_scratchpage_mtx, "pvo zero page", NULL, MTX_DEF);
for (i = 0; i < 2; i++) {
moea64_scratchpage_va[i] = virtual_avail;
virtual_avail += PAGE_SIZE;
moea64_scratchpage_va[i] = (virtual_end+1) - PAGE_SIZE;
virtual_end -= PAGE_SIZE;
moea64_kenter(mmup,moea64_scratchpage_va[i],kernelstart);
moea64_kenter(mmup,moea64_scratchpage_va[i],0);
LOCK_TABLE();
moea64_scratchpage_pvo[i] = moea64_pvo_find_va(kernel_pmap,
@ -1004,20 +1004,25 @@ moea64_bridge_bootstrap(mmu_t mmup, vm_offset_t kernelstart, vm_offset_t kernele
* Allocate virtual address space for the message buffer.
*/
pa = msgbuf_phys = moea64_bootstrap_alloc(MSGBUF_SIZE, PAGE_SIZE);
msgbufp = (struct msgbuf *)msgbuf_phys;
while (pa - msgbuf_phys < MSGBUF_SIZE) {
moea64_kenter(mmup, pa, pa);
msgbufp = (struct msgbuf *)virtual_avail;
va = virtual_avail;
virtual_avail += round_page(MSGBUF_SIZE);
while (va < virtual_avail) {
moea64_kenter(mmup, va, pa);
pa += PAGE_SIZE;
va += PAGE_SIZE;
}
/*
* Allocate virtual address space for the dynamic percpu area.
*/
pa = moea64_bootstrap_alloc(DPCPU_SIZE, PAGE_SIZE);
dpcpu = (void *)pa;
while (pa - (vm_offset_t)dpcpu < DPCPU_SIZE) {
moea64_kenter(mmup, pa, pa);
dpcpu = (void *)virtual_avail;
virtual_avail += DPCPU_SIZE;
while (va < virtual_avail) {
moea64_kenter(mmup, va, pa);
pa += PAGE_SIZE;
va += PAGE_SIZE;
}
dpcpu_init(dpcpu, 0);
}