Date: Thu, 25 Feb 2010 03:53:21 +0000 (UTC) From: Nathan Whitehorn <nwhitehorn@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r204297 - head/sys/powerpc/aim Message-ID: <201002250353.o1P3rLxX095091@svn.freebsd.org>
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Author: nwhitehorn Date: Thu Feb 25 03:53:21 2010 New Revision: 204297 URL: http://svn.freebsd.org/changeset/base/204297 Log: 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 make into regular KVA space for consistency with other implementations. Modified: head/sys/powerpc/aim/mmu_oea64.c Modified: head/sys/powerpc/aim/mmu_oea64.c ============================================================================== --- head/sys/powerpc/aim/mmu_oea64.c Thu Feb 25 03:49:17 2010 (r204296) +++ head/sys/powerpc/aim/mmu_oea64.c Thu Feb 25 03:53:21 2010 (r204297) @@ -970,10 +970,10 @@ moea64_bridge_bootstrap(mmu_t mmup, vm_o 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_o * 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); }
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