Author: cem Date: Wed Feb 14 23:35:47 2018 New Revision: 329281 URL: https://svnweb.freebsd.org/changeset/base/329281
Log: x86 pmap: Make memory mapped via pmap_qenter() non-executable The idea is, the pmap_qenter() API is now defined to not produce executable mappings. If you need executable mappings, use another API. Add pg_nx flag in pmap_qenter on x86 to make kernel pages non-executable. Other architectures that support execute-specific permissons on page table entries should subsequently be updated to match. Submitted by: Darrick Lew <darrick.freebsd AT gmail.com> Reviewed by: markj Discussed with: alc, jhb, kib Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D14062 Modified: head/sys/amd64/amd64/pmap.c head/sys/i386/i386/pmap.c Modified: head/sys/amd64/amd64/pmap.c ============================================================================== --- head/sys/amd64/amd64/pmap.c Wed Feb 14 21:39:10 2018 (r329280) +++ head/sys/amd64/amd64/pmap.c Wed Feb 14 23:35:47 2018 (r329281) @@ -2338,7 +2338,7 @@ pmap_qenter(vm_offset_t sva, vm_page_t *ma, int count) pa = VM_PAGE_TO_PHYS(m) | cache_bits; if ((*pte & (PG_FRAME | X86_PG_PTE_CACHE)) != pa) { oldpte |= *pte; - pte_store(pte, pa | pg_g | X86_PG_RW | X86_PG_V); + pte_store(pte, pa | pg_g | pg_nx | X86_PG_RW | X86_PG_V); } pte++; } Modified: head/sys/i386/i386/pmap.c ============================================================================== --- head/sys/i386/i386/pmap.c Wed Feb 14 21:39:10 2018 (r329280) +++ head/sys/i386/i386/pmap.c Wed Feb 14 23:35:47 2018 (r329281) @@ -1677,7 +1677,11 @@ pmap_qenter(vm_offset_t sva, vm_page_t *ma, int count) pa = VM_PAGE_TO_PHYS(m) | pmap_cache_bits(m->md.pat_mode, 0); if ((*pte & (PG_FRAME | PG_PTE_CACHE)) != pa) { oldpte |= *pte; +#if defined(PAE) || defined(PAE_TABLES) + pte_store(pte, pa | pgeflag | pg_nx | PG_RW | PG_V); +#else pte_store(pte, pa | pgeflag | PG_RW | PG_V); +#endif } pte++; } _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
