Date: Tue, 23 Aug 2016 15:48:27 +0000 (UTC) From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r304685 - head/sys/arm64/arm64 Message-ID: <201608231548.u7NFmRuP041148@repo.freebsd.org>
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Author: andrew Date: Tue Aug 23 15:48:27 2016 New Revision: 304685 URL: https://svnweb.freebsd.org/changeset/base/304685 Log: Include the offset the virtual address is within an L1 or L2 block when finding the vm_page_t in pmap_extract_and_hold. Previously it would return the vm_page_t of the first page in a block. This would cause issues when, for example, fsck reads from a device into the middle of a superpage. In this case the read call would write to the start of the block, and not to the buffer passed in. Obtained from: ABT Systems Ltd MFC after: 1 month Sponsored by: The FreeBSD Foundation Modified: head/sys/arm64/arm64/pmap.c Modified: head/sys/arm64/arm64/pmap.c ============================================================================== --- head/sys/arm64/arm64/pmap.c Tue Aug 23 15:46:20 2016 (r304684) +++ head/sys/arm64/arm64/pmap.c Tue Aug 23 15:48:27 2016 (r304685) @@ -995,6 +995,7 @@ vm_page_t pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot) { pt_entry_t *pte, tpte; + vm_offset_t off; vm_paddr_t pa; vm_page_t m; int lvl; @@ -1016,9 +1017,20 @@ retry: tpte & ATTR_DESCR_MASK)); if (((tpte & ATTR_AP_RW_BIT) == ATTR_AP(ATTR_AP_RW)) || ((prot & VM_PROT_WRITE) == 0)) { + switch(lvl) { + case 1: + off = va & L1_OFFSET; + break; + case 2: + off = va & L2_OFFSET; + break; + case 3: + default: + off = 0; + } if (vm_page_pa_tryrelock(pmap, tpte & ~ATTR_MASK, &pa)) goto retry; - m = PHYS_TO_VM_PAGE(tpte & ~ATTR_MASK); + m = PHYS_TO_VM_PAGE((tpte & ~ATTR_MASK) | off); vm_page_hold(m); } }
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