From: Boris Lukashev <blukashev@sempervictus.com>
To: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: dave.hansen@intel.com, luto@kernel.org, peterz@infradead.org,
x86@kernel.org, akpm@linux-foundation.org,
keescook@chromium.org, shakeelb@google.com, vbabka@suse.cz,
rppt@kernel.org, linux-mm@kvack.org,
linux-hardening@vger.kernel.org,
kernel-hardening@lists.openwall.com, ira.weiny@intel.com,
dan.j.williams@intel.com, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH v2 00/19] PKS write protected page tables
Date: Fri, 15 Mar 2024 23:14:09 -0400 [thread overview]
Message-ID: <CAFUG7Cfy6nmWk9xmTD4rp80i4_RA12V7SA6851BvD=JaWRZeyA@mail.gmail.com> (raw)
In-Reply-To: <20210830235927.6443-1-rick.p.edgecombe@intel.com>
IIRC shoot-downs are one of the reasons for using per-cpu PGDs, which
can in-turn enable/underpin other hardening functions... presuming the
churn of recent years has softened attitudes toward such core MM
changes.
https://forum.osdev.org/viewtopic.php?f=15&t=29661
-Boris
On Mon, Aug 30, 2021 at 8:02 PM Rick Edgecombe
<rick.p.edgecombe@intel.com> wrote:
>
> Hi,
>
> This is a second RFC for the PKS write protected tables concept. I'm sharing to
> show the progress to interested people. I'd also appreciate any comments,
> especially on the direct map page table protection solution (patch 17).
>
> Since v1[1], the improvements are:
> - Fully handle direct map page tables, and handle hotplug/unplug path.
> - Create a debug time checker that scans page tables and verifies
> their protection.
> - Fix odds-and-ends kernel page tables that showed up with debug
> checker. At this point all of the typical normal page tables should be
> protected.
> - Fix toggling of writablility for odds-and-ends page table modifications found
> that don't use the normal helpers.
> - Create atomic context grouped page allocator, after finding some page table
> allocations that are passing GFP_ATOMIC.
> - Create "soft" mode that warns and disables protection on violation instead
> of oopsing.
> - Boot parameters for disabling pks tables
> - Change PageTable set clear to ctor/dtor (peterz)
> - Remove VM_BUG_ON_PAGE in alloc_table() (Shakeel Butt)
> - PeterZ/Vlastimil had suggested to also build a non-PKS mode for use in
> debugging. I skipped it for now because the series was too big.
> - Rebased to latest PKS core v7 [2]
>
> Also, Mike Rapoport has been experimenting[3] with this usage to work on how to
> share caches of permissioned/broken pages between use cases. This RFCv2 still
> uses the "grouped pages" concept, where each usage would maintain its own
> cache, but should be able to integrate with a central solution if something is
> developed.
>
> Next I was planning to look into characterizing/tuning the performance, although
> what page allocation scheme is ultimately used will probably impact that.
>
> This applies on top of the PKS core v7 series[2] and this patch[4]. Testing is
> still pretty light.
>
> This RFC has been acked by Dave Hansen.
>
> [1] https://lore.kernel.org/lkml/20210505003032.489164-1-rick.p.edgecombe@intel.com/
> [2] https://lore.kernel.org/lkml/20210804043231.2655537-1-ira.weiny@intel.com/
> [3] https://lore.kernel.org/lkml/20210823132513.15836-1-rppt@kernel.org/
> [4] https://lore.kernel.org/lkml/20210818221026.10794-1-rick.p.edgecombe@intel.com/
>
> Rick Edgecombe (19):
> list: Support getting most recent element in list_lru
> list: Support list head not in object for list_lru
> x86/mm/cpa: Add grouped page allocations
> mm: Explicitly zero page table lock ptr
> x86, mm: Use cache of page tables
> x86/mm/cpa: Add perm callbacks to grouped pages
> x86/cpufeatures: Add feature for pks tables
> x86/mm/cpa: Add get_grouped_page_atomic()
> x86/mm: Support GFP_ATOMIC in alloc_table_node()
> x86/mm: Use alloc_table() for fill_pte(), etc
> mm/sparsemem: Use alloc_table() for table allocations
> x86/mm: Use free_table in unmap path
> mm/debug_vm_page_table: Use setters instead of WRITE_ONCE
> x86/efi: Toggle table protections when copying
> x86/mm/cpa: Add set_memory_pks()
> x86/mm: Protect page tables with PKS
> x86/mm/cpa: PKS protect direct map page tables
> x86/mm: Add PKS table soft mode
> x86/mm: Add PKS table debug checking
>
> .../admin-guide/kernel-parameters.txt | 4 +
> arch/x86/boot/compressed/ident_map_64.c | 5 +
> arch/x86/include/asm/cpufeatures.h | 2 +-
> arch/x86/include/asm/pgalloc.h | 6 +-
> arch/x86/include/asm/pgtable.h | 31 +-
> arch/x86/include/asm/pgtable_64.h | 33 +-
> arch/x86/include/asm/pkeys_common.h | 1 -
> arch/x86/include/asm/set_memory.h | 24 +
> arch/x86/mm/init.c | 90 +++
> arch/x86/mm/init_64.c | 29 +-
> arch/x86/mm/pat/set_memory.c | 527 +++++++++++++++++-
> arch/x86/mm/pgtable.c | 183 +++++-
> arch/x86/mm/pkeys.c | 4 +
> arch/x86/platform/efi/efi_64.c | 8 +
> include/asm-generic/pgalloc.h | 46 +-
> include/linux/list_lru.h | 26 +
> include/linux/mm.h | 16 +-
> include/linux/pkeys.h | 1 +
> mm/Kconfig | 23 +
> mm/debug_vm_pgtable.c | 36 +-
> mm/list_lru.c | 38 +-
> mm/memory.c | 1 +
> mm/sparse-vmemmap.c | 22 +-
> mm/swap.c | 6 +
> mm/swap_state.c | 5 +
> .../arch/x86/include/asm/disabled-features.h | 8 +-
> 26 files changed, 1123 insertions(+), 52 deletions(-)
>
> --
> 2.17.1
>
--
Boris Lukashev
Systems Architect
Semper Victus
prev parent reply other threads:[~2024-03-16 3:14 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-30 23:59 [RFC PATCH v2 00/19] PKS write protected page tables Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 01/19] list: Support getting most recent element in list_lru Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 02/19] list: Support list head not in object for list_lru Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 03/19] x86/mm/cpa: Add grouped page allocations Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 04/19] mm: Explicitly zero page table lock ptr Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 05/19] x86, mm: Use cache of page tables Rick Edgecombe
2021-08-31 8:40 ` Mike Rapoport
2021-08-31 19:09 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 06/19] x86/mm/cpa: Add perm callbacks to grouped pages Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 07/19] x86/cpufeatures: Add feature for pks tables Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 08/19] x86/mm/cpa: Add get_grouped_page_atomic() Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 09/19] x86/mm: Support GFP_ATOMIC in alloc_table_node() Rick Edgecombe
2021-08-31 8:32 ` Mike Rapoport
2021-08-30 23:59 ` [RFC PATCH v2 10/19] x86/mm: Use alloc_table() for fill_pte(), etc Rick Edgecombe
2021-08-31 8:47 ` Mike Rapoport
2021-08-31 18:48 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 11/19] mm/sparsemem: Use alloc_table() for table allocations Rick Edgecombe
2021-08-31 8:55 ` Mike Rapoport
2021-08-31 18:25 ` Edgecombe, Rick P
2021-09-01 7:22 ` Mike Rapoport
2021-09-02 13:56 ` Vlastimil Babka
2021-08-30 23:59 ` [RFC PATCH v2 12/19] x86/mm: Use free_table in unmap path Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 13/19] mm/debug_vm_page_table: Use setters instead of WRITE_ONCE Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 14/19] x86/efi: Toggle table protections when copying Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 15/19] x86/mm/cpa: Add set_memory_pks() Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 16/19] x86/mm: Protect page tables with PKS Rick Edgecombe
2021-08-31 8:56 ` Mike Rapoport
2021-08-31 17:55 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 17/19] x86/mm/cpa: PKS protect direct map page tables Rick Edgecombe
2021-08-31 10:14 ` Mike Rapoport
2021-08-31 17:58 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 18/19] x86/mm: Add PKS table soft mode Rick Edgecombe
2021-08-31 3:49 ` Randy Dunlap
2021-08-31 17:55 ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 19/19] x86/mm: Add PKS table debug checking Rick Edgecombe
2024-03-14 16:27 ` [RFC PATCH v2 00/19] PKS write protected page tables Kees Cook
2024-03-14 17:10 ` Edgecombe, Rick P
2024-03-14 18:25 ` Ira Weiny
2024-03-14 21:02 ` Boris Lukashev
2024-03-16 3:14 ` Boris Lukashev [this message]
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