Author: jtl Date: Mon Mar 5 15:12:35 2018 New Revision: 330511 URL: https://svnweb.freebsd.org/changeset/base/330511
Log: We shouldn't need to execute code in the recursive page table mappings; therefore, it should be safe to set the NX bit on the PML4E for the recursive page table mappings. According to the Intel docs, the effect of the NX bit should propogate to any page reached through a PML4E which has the NX bit set. Reviewed by: kib, markj MFC after: 2 weeks Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D14333 Modified: head/sys/amd64/amd64/pmap.c Modified: head/sys/amd64/amd64/pmap.c ============================================================================== --- head/sys/amd64/amd64/pmap.c Mon Mar 5 15:10:17 2018 (r330510) +++ head/sys/amd64/amd64/pmap.c Mon Mar 5 15:12:35 2018 (r330511) @@ -983,7 +983,7 @@ create_pagetables(vm_paddr_t *firstaddr) /* And recursively map PML4 to itself in order to get PTmap */ p4_p = (pml4_entry_t *)KPML4phys; p4_p[PML4PML4I] = KPML4phys; - p4_p[PML4PML4I] |= X86_PG_RW | X86_PG_V | PG_U; + p4_p[PML4PML4I] |= X86_PG_RW | X86_PG_V | PG_U | pg_nx; /* Connect the Direct Map slot(s) up to the PML4. */ for (i = 0; i < ndmpdpphys; i++) { _______________________________________________ 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"
