From: Tycho Andersen <tycho@docker.com> To: Laura Abbott <labbott@redhat.com> Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com, Marco Benatto <marco.antonio.780@gmail.com>, Juerg Haefliger <juerg.haefliger@canonical.com> Subject: Re: [kernel-hardening] [PATCH v5 06/10] arm64/mm: Disable section mappings if XPFO is enabled Date: Fri, 11 Aug 2017 15:13:02 -0600 [thread overview] Message-ID: <20170811211302.limmjv4rmq23b25b@smitten> (raw) In-Reply-To: <f6a42032-d4e5-f488-3d55-1da4c8a4dbaf@redhat.com> Hi Laura, On Fri, Aug 11, 2017 at 10:25:14AM -0700, Laura Abbott wrote: > On 08/09/2017 01:07 PM, Tycho Andersen wrote: > > From: Juerg Haefliger <juerg.haefliger@hpe.com> > > > > XPFO (eXclusive Page Frame Ownership) doesn't support section mappings > > yet, so disable it if XPFO is turned on. > > > > Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com> > > Tested-by: Tycho Andersen <tycho@docker.com> > > --- > > arch/arm64/mm/mmu.c | 14 +++++++++++++- > > 1 file changed, 13 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > > index f1eb15e0e864..38026b3ccb46 100644 > > --- a/arch/arm64/mm/mmu.c > > +++ b/arch/arm64/mm/mmu.c > > @@ -176,6 +176,18 @@ static void alloc_init_cont_pte(pmd_t *pmd, unsigned long addr, > > } while (addr = next, addr != end); > > } > > > > +static inline bool use_section_mapping(unsigned long addr, unsigned long next, > > + unsigned long phys) > > +{ > > + if (IS_ENABLED(CONFIG_XPFO)) > > + return false; > > + > > + if (((addr | next | phys) & ~SECTION_MASK) != 0) > > + return false; > > + > > + return true; > > +} > > + > > static void init_pmd(pud_t *pud, unsigned long addr, unsigned long end, > > phys_addr_t phys, pgprot_t prot, > > phys_addr_t (*pgtable_alloc)(void), int flags) > > @@ -190,7 +202,7 @@ static void init_pmd(pud_t *pud, unsigned long addr, unsigned long end, > > next = pmd_addr_end(addr, end); > > > > /* try section mapping first */ > > - if (((addr | next | phys) & ~SECTION_MASK) == 0 && > > + if (use_section_mapping(addr, next, phys) && > > (flags & NO_BLOCK_MAPPINGS) == 0) { > > pmd_set_huge(pmd, phys, prot); > > > > > > There is already similar logic to disable section mappings for > debug_pagealloc at the start of map_mem, can you take advantage > of that? You're suggesting something like this instead? Seems to work fine. diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 38026b3ccb46..3b2c17bbbf12 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -434,6 +434,8 @@ static void __init map_mem(pgd_t *pgd) if (debug_pagealloc_enabled()) flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; + if (IS_ENABLED(CONFIG_XPFO)) + flags |= NO_BLOCK_MAPPINGS; /* * Take care not to create a writable alias for the Cheers, Tycho
WARNING: multiple messages have this Message-ID (diff)
From: Tycho Andersen <tycho@docker.com> To: Laura Abbott <labbott@redhat.com> Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com, Marco Benatto <marco.antonio.780@gmail.com>, Juerg Haefliger <juerg.haefliger@canonical.com> Subject: Re: [kernel-hardening] [PATCH v5 06/10] arm64/mm: Disable section mappings if XPFO is enabled Date: Fri, 11 Aug 2017 15:13:02 -0600 [thread overview] Message-ID: <20170811211302.limmjv4rmq23b25b@smitten> (raw) In-Reply-To: <f6a42032-d4e5-f488-3d55-1da4c8a4dbaf@redhat.com> Hi Laura, On Fri, Aug 11, 2017 at 10:25:14AM -0700, Laura Abbott wrote: > On 08/09/2017 01:07 PM, Tycho Andersen wrote: > > From: Juerg Haefliger <juerg.haefliger@hpe.com> > > > > XPFO (eXclusive Page Frame Ownership) doesn't support section mappings > > yet, so disable it if XPFO is turned on. > > > > Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com> > > Tested-by: Tycho Andersen <tycho@docker.com> > > --- > > arch/arm64/mm/mmu.c | 14 +++++++++++++- > > 1 file changed, 13 insertions(+), 1 deletion(-) > > > > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > > index f1eb15e0e864..38026b3ccb46 100644 > > --- a/arch/arm64/mm/mmu.c > > +++ b/arch/arm64/mm/mmu.c > > @@ -176,6 +176,18 @@ static void alloc_init_cont_pte(pmd_t *pmd, unsigned long addr, > > } while (addr = next, addr != end); > > } > > > > +static inline bool use_section_mapping(unsigned long addr, unsigned long next, > > + unsigned long phys) > > +{ > > + if (IS_ENABLED(CONFIG_XPFO)) > > + return false; > > + > > + if (((addr | next | phys) & ~SECTION_MASK) != 0) > > + return false; > > + > > + return true; > > +} > > + > > static void init_pmd(pud_t *pud, unsigned long addr, unsigned long end, > > phys_addr_t phys, pgprot_t prot, > > phys_addr_t (*pgtable_alloc)(void), int flags) > > @@ -190,7 +202,7 @@ static void init_pmd(pud_t *pud, unsigned long addr, unsigned long end, > > next = pmd_addr_end(addr, end); > > > > /* try section mapping first */ > > - if (((addr | next | phys) & ~SECTION_MASK) == 0 && > > + if (use_section_mapping(addr, next, phys) && > > (flags & NO_BLOCK_MAPPINGS) == 0) { > > pmd_set_huge(pmd, phys, prot); > > > > > > There is already similar logic to disable section mappings for > debug_pagealloc at the start of map_mem, can you take advantage > of that? You're suggesting something like this instead? Seems to work fine. diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 38026b3ccb46..3b2c17bbbf12 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -434,6 +434,8 @@ static void __init map_mem(pgd_t *pgd) if (debug_pagealloc_enabled()) flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; + if (IS_ENABLED(CONFIG_XPFO)) + flags |= NO_BLOCK_MAPPINGS; /* * Take care not to create a writable alias for the Cheers, Tycho -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-08-11 21:13 UTC|newest] Thread overview: 135+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-08-09 20:07 [PATCH v5 00/10] Add support for eXclusive Page Frame Ownership Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-09 20:07 ` [PATCH v5 01/10] mm: add MAP_HUGETLB support to vm_mmap Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-09 20:07 ` [PATCH v5 02/10] mm, x86: Add support for eXclusive Page Frame Ownership (XPFO) Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-14 18:51 ` Laura Abbott 2017-08-14 18:51 ` [kernel-hardening] " Laura Abbott 2017-08-14 18:51 ` Laura Abbott 2017-08-14 22:30 ` Laura Abbott 2017-08-14 22:30 ` [kernel-hardening] " Laura Abbott 2017-08-14 22:30 ` Laura Abbott 2017-08-15 3:47 ` Tycho Andersen 2017-08-15 3:47 ` [kernel-hardening] " Tycho Andersen 2017-08-15 3:47 ` Tycho Andersen 2017-08-15 3:51 ` Tycho Andersen 2017-08-15 3:51 ` [kernel-hardening] " Tycho Andersen 2017-08-15 3:51 ` Tycho Andersen 2017-08-09 20:07 ` [PATCH v5 03/10] swiotlb: Map the buffer if it was unmapped by XPFO Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-10 13:01 ` Konrad Rzeszutek Wilk 2017-08-10 13:01 ` [kernel-hardening] " Konrad Rzeszutek Wilk 2017-08-10 13:01 ` Konrad Rzeszutek Wilk 2017-08-10 16:22 ` Tycho Andersen 2017-08-10 16:22 ` [kernel-hardening] " Tycho Andersen 2017-08-10 16:22 ` Tycho Andersen 2017-09-20 16:19 ` Dave Hansen 2017-09-20 16:19 ` [kernel-hardening] " Dave Hansen 2017-09-20 16:19 ` Dave Hansen 2017-09-20 22:47 ` Tycho Andersen 2017-09-20 22:47 ` [kernel-hardening] " Tycho Andersen 2017-09-20 22:47 ` Tycho Andersen 2017-09-20 23:25 ` Dave Hansen 2017-09-20 23:25 ` [kernel-hardening] " Dave Hansen 2017-09-20 23:25 ` Dave Hansen 2017-08-09 20:07 ` [PATCH v5 04/10] arm64: Add __flush_tlb_one() Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-12 11:26 ` [kernel-hardening] " Mark Rutland 2017-08-12 11:26 ` Mark Rutland 2017-08-14 16:35 ` Tycho Andersen 2017-08-14 16:35 ` Tycho Andersen 2017-08-14 16:50 ` Mark Rutland 2017-08-14 16:50 ` Mark Rutland 2017-08-14 17:01 ` Tycho Andersen 2017-08-14 17:01 ` Tycho Andersen 2017-08-23 16:58 ` Tycho Andersen 2017-08-23 16:58 ` Tycho Andersen 2017-08-23 17:04 ` Mark Rutland 2017-08-23 17:04 ` Mark Rutland 2017-08-23 17:13 ` Tycho Andersen 2017-08-23 17:13 ` Tycho Andersen 2017-08-24 15:45 ` Mark Rutland 2017-08-24 15:45 ` Mark Rutland 2017-08-29 17:24 ` Tycho Andersen 2017-08-29 17:24 ` Tycho Andersen 2017-08-30 5:31 ` Juerg Haefliger 2017-08-30 16:47 ` Tycho Andersen 2017-08-30 16:47 ` Tycho Andersen 2017-08-31 9:43 ` Juerg Haefliger 2017-08-31 9:47 ` Mark Rutland 2017-08-31 9:47 ` Mark Rutland 2017-08-31 21:21 ` Tycho Andersen 2017-08-31 21:21 ` Tycho Andersen 2017-08-09 20:07 ` [PATCH v5 05/10] arm64/mm: Add support for XPFO Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-11 18:01 ` [kernel-hardening] " Laura Abbott 2017-08-11 18:01 ` Laura Abbott 2017-08-11 20:19 ` Tycho Andersen 2017-08-11 20:19 ` Tycho Andersen 2017-08-09 20:07 ` [PATCH v5 06/10] arm64/mm: Disable section mappings if XPFO is enabled Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-11 17:25 ` [kernel-hardening] " Laura Abbott 2017-08-11 17:25 ` Laura Abbott 2017-08-11 21:13 ` Tycho Andersen [this message] 2017-08-11 21:13 ` Tycho Andersen 2017-08-11 21:52 ` Tycho Andersen 2017-08-11 21:52 ` Tycho Andersen 2017-08-12 11:17 ` Mark Rutland 2017-08-12 11:17 ` Mark Rutland 2017-08-14 16:22 ` Tycho Andersen 2017-08-14 16:22 ` Tycho Andersen 2017-08-14 18:42 ` Laura Abbott 2017-08-14 18:42 ` Laura Abbott 2017-08-14 20:28 ` Tycho Andersen 2017-08-14 20:28 ` Tycho Andersen 2017-08-09 20:07 ` [PATCH v5 07/10] arm64/mm: Don't flush the data cache if the page is unmapped by XPFO Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-12 11:57 ` [kernel-hardening] " Mark Rutland 2017-08-12 11:57 ` Mark Rutland 2017-08-14 16:54 ` Mark Rutland 2017-08-14 16:54 ` Mark Rutland 2017-08-14 20:27 ` Tycho Andersen 2017-08-14 20:27 ` Tycho Andersen 2017-08-15 9:39 ` Mark Rutland 2017-08-15 9:39 ` Mark Rutland 2017-08-09 20:07 ` [PATCH v5 08/10] arm64/mm: Add support for XPFO to swiotlb Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-10 13:11 ` Konrad Rzeszutek Wilk 2017-08-10 13:11 ` [kernel-hardening] " Konrad Rzeszutek Wilk 2017-08-10 13:11 ` Konrad Rzeszutek Wilk 2017-08-10 16:35 ` Tycho Andersen 2017-08-10 16:35 ` [kernel-hardening] " Tycho Andersen 2017-08-10 16:35 ` Tycho Andersen 2017-08-09 20:07 ` [PATCH v5 09/10] mm: add a user_virt_to_phys symbol Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-09 20:07 ` [PATCH v5 10/10] lkdtm: Add test for XPFO Tycho Andersen 2017-08-09 20:07 ` [kernel-hardening] " Tycho Andersen 2017-08-09 20:07 ` Tycho Andersen 2017-08-12 20:24 ` kbuild test robot 2017-08-12 20:24 ` [kernel-hardening] " kbuild test robot 2017-08-12 20:24 ` kbuild test robot 2017-08-14 16:21 ` Tycho Andersen 2017-08-14 16:21 ` [kernel-hardening] " Tycho Andersen 2017-08-14 16:21 ` Tycho Andersen 2017-08-12 21:05 ` kbuild test robot 2017-08-12 21:05 ` [kernel-hardening] " kbuild test robot 2017-08-12 21:05 ` kbuild test robot 2017-08-14 19:10 ` Kees Cook 2017-08-14 19:10 ` [kernel-hardening] " Kees Cook 2017-08-14 19:10 ` Kees Cook 2017-08-14 20:29 ` Tycho Andersen 2017-08-14 20:29 ` [kernel-hardening] " Tycho Andersen 2017-08-14 20:29 ` Tycho Andersen 2017-08-11 23:35 ` [kernel-hardening] [PATCH v5 00/10] Add support for eXclusive Page Frame Ownership Laura Abbott 2017-08-11 23:35 ` Laura Abbott
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20170811211302.limmjv4rmq23b25b@smitten \ --to=tycho@docker.com \ --cc=juerg.haefliger@canonical.com \ --cc=kernel-hardening@lists.openwall.com \ --cc=labbott@redhat.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=marco.antonio.780@gmail.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.