Date: Wed, 9 May 2018 12:03:41 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r333404 - head/sys/amd64/amd64 Message-ID: <201805091203.w49C3fMX011500@repo.freebsd.org>
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Author: kib Date: Wed May 9 12:03:40 2018 New Revision: 333404 URL: https://svnweb.freebsd.org/changeset/base/333404 Log: Remove PG_U from the recursive pte for kernel pmap' PML4 page. This PML4 page is never used for the userspace process, so there is no security implications. But the configuration trips SMAP check, which should be corrected. Reviewed by: alc, markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Modified: head/sys/amd64/amd64/pmap.c Modified: head/sys/amd64/amd64/pmap.c ============================================================================== --- head/sys/amd64/amd64/pmap.c Wed May 9 11:59:24 2018 (r333403) +++ head/sys/amd64/amd64/pmap.c Wed May 9 12:03:40 2018 (r333404) @@ -1060,7 +1060,7 @@ 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 | pg_nx; + p4_p[PML4PML4I] |= X86_PG_RW | X86_PG_V | pg_nx; /* Connect the Direct Map slot(s) up to the PML4. */ for (i = 0; i < ndmpdpphys; i++) {
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