From: Borislav Petkov <bp@alien8.de>
To: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
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Subject: Re: [PATCH v4 11/39] x86/mm: Update pte_modify for _PAGE_COW
Date: Wed, 4 Jan 2023 14:25:57 +0100 [thread overview]
Message-ID: <Y7V+ZbTa3bWmXzKo@zn.tnic> (raw)
In-Reply-To: <060f1009199b09b7f8b9698e9f6f8375d9d1b66d.camel@intel.com>
On Tue, Dec 27, 2022 at 11:31:37PM +0000, Edgecombe, Rick P wrote:
> The comment is referring to the dirty bits possibly coming from
> newprot,
Ah right, ofc.
> but looking at it now I think the code was broken trying to
> fix the recent soft dirty test breakage. Now it might lose pre-existing
> dirty bits in the pte unessarily... I think.
Right, does this code need to be simplified?
I.e., match the shadow stack PTE (Write=0,Dirty=1) and handle that in a separate
helper?
So that the flows are separate. I'm not a mm guy but this function makes my head
hurt - dunno about other folks. :)
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2023-01-04 13:31 UTC|newest]
Thread overview: 107+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-03 0:35 [PATCH v4 00/39] Shadow stacks for userspace Rick Edgecombe
2022-12-03 0:35 ` [PATCH v4 01/39] Documentation/x86: Add CET shadow stack description Rick Edgecombe
2022-12-03 2:20 ` Kees Cook
2022-12-03 8:58 ` Bagas Sanjaya
2022-12-05 21:20 ` Edgecombe, Rick P
2022-12-03 0:35 ` [PATCH v4 02/39] x86/shstk: Add Kconfig option for Shadow Stack Rick Edgecombe
2022-12-03 2:20 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 03/39] x86/cpufeatures: Add CPU feature flags for shadow stacks Rick Edgecombe
2022-12-03 2:22 ` Kees Cook
2022-12-07 11:00 ` Borislav Petkov
2022-12-07 22:35 ` Edgecombe, Rick P
2022-12-08 11:10 ` Borislav Petkov
2022-12-03 0:35 ` [PATCH v4 04/39] x86/cpufeatures: Enable CET CR4 bit for shadow stack Rick Edgecombe
2022-12-03 2:23 ` Kees Cook
2022-12-07 12:49 ` Borislav Petkov
2022-12-07 18:35 ` Edgecombe, Rick P
2022-12-03 0:35 ` [PATCH v4 05/39] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Rick Edgecombe
2022-12-03 2:24 ` Kees Cook
2022-12-20 11:32 ` Borislav Petkov
2022-12-21 0:45 ` Edgecombe, Rick P
2022-12-03 0:35 ` [PATCH v4 06/39] x86/fpu: Add helper for modifying xstate Rick Edgecombe
2022-12-03 2:25 ` Kees Cook
2022-12-20 12:04 ` Borislav Petkov
2022-12-21 0:03 ` Edgecombe, Rick P
2022-12-21 10:31 ` Borislav Petkov
2022-12-03 0:35 ` [PATCH v4 07/39] x86: Add user control-protection fault handler Rick Edgecombe
2022-12-03 2:28 ` Kees Cook
2022-12-20 16:19 ` Borislav Petkov
2022-12-21 0:37 ` Edgecombe, Rick P
2022-12-21 10:41 ` Borislav Petkov
2022-12-21 21:42 ` Edgecombe, Rick P
2023-01-04 12:50 ` Borislav Petkov
2022-12-20 21:21 ` Borislav Petkov
2022-12-21 0:38 ` Edgecombe, Rick P
2022-12-03 0:35 ` [PATCH v4 08/39] x86/mm: Remove _PAGE_DIRTY from kernel RO pages Rick Edgecombe
2022-12-03 2:29 ` Kees Cook
2022-12-20 19:11 ` Borislav Petkov
2022-12-03 0:35 ` [PATCH v4 09/39] x86/mm: Move pmd_write(), pud_write() up in the file Rick Edgecombe
2022-12-03 0:35 ` [PATCH v4 10/39] x86/mm: Introduce _PAGE_COW Rick Edgecombe
2022-12-03 2:31 ` Kees Cook
2022-12-20 21:29 ` Borislav Petkov
2022-12-21 0:45 ` Edgecombe, Rick P
2022-12-03 0:35 ` [PATCH v4 11/39] x86/mm: Update pte_modify for _PAGE_COW Rick Edgecombe
2022-12-03 2:31 ` Kees Cook
2022-12-27 11:42 ` Borislav Petkov
2022-12-27 23:31 ` Edgecombe, Rick P
2023-01-04 13:25 ` Borislav Petkov [this message]
2023-01-05 1:06 ` Edgecombe, Rick P
2022-12-03 0:35 ` [PATCH v4 12/39] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY to _PAGE_COW Rick Edgecombe
2022-12-03 2:32 ` Kees Cook
2022-12-27 13:26 ` Borislav Petkov
2022-12-27 22:26 ` Edgecombe, Rick P
2023-01-04 13:28 ` Borislav Petkov
2022-12-03 0:35 ` [PATCH v4 13/39] x86/mm: Start actually marking _PAGE_COW Rick Edgecombe
2022-12-03 2:33 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 14/39] mm: Move VM_UFFD_MINOR_BIT from 37 to 38 Rick Edgecombe
2022-12-03 0:35 ` [PATCH v4 15/39] mm: Introduce VM_SHADOW_STACK for shadow stack memory Rick Edgecombe
2022-12-03 2:34 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 16/39] x86/mm: Check Shadow Stack page fault errors Rick Edgecombe
2023-01-04 14:32 ` Borislav Petkov
2023-01-05 1:29 ` Edgecombe, Rick P
2022-12-03 0:35 ` [PATCH v4 17/39] x86/mm: Update maybe_mkwrite() for shadow stack Rick Edgecombe
2022-12-03 2:34 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 18/39] mm: Fixup places that call pte_mkwrite() directly Rick Edgecombe
2022-12-03 2:37 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 19/39] mm: Add guard pages around a shadow stack Rick Edgecombe
2022-12-03 0:35 ` [PATCH v4 20/39] mm/mmap: Add shadow stack pages to memory accounting Rick Edgecombe
2022-12-03 2:38 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 21/39] mm/mprotect: Exclude shadow stack from preserve_write Rick Edgecombe
2022-12-03 2:38 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 22/39] mm: Re-introduce vm_flags to do_mmap() Rick Edgecombe
2022-12-03 0:35 ` [PATCH v4 23/39] mm: Don't allow write GUPs to shadow stack memory Rick Edgecombe
2022-12-03 2:39 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 24/39] mm: Warn on shadow stack memory in wrong vma Rick Edgecombe
2022-12-03 2:40 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 25/39] x86: Introduce userspace API for shadow stack Rick Edgecombe
2022-12-03 2:42 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 26/39] x86/shstk: Add user-mode shadow stack support Rick Edgecombe
2022-12-03 2:43 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 27/39] x86/shstk: Handle thread shadow stack Rick Edgecombe
2022-12-03 2:44 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 28/39] x86/shstk: Introduce routines modifying shstk Rick Edgecombe
2022-12-03 2:45 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 29/39] x86/shstk: Handle signals for shadow stack Rick Edgecombe
2022-12-03 2:46 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 30/39] x86/shstk: Introduce map_shadow_stack syscall Rick Edgecombe
2022-12-03 2:51 ` Kees Cook
2022-12-05 22:19 ` Edgecombe, Rick P
2022-12-03 0:35 ` [PATCH v4 31/39] x86/shstk: Support wrss for userspace Rick Edgecombe
2022-12-03 2:52 ` Kees Cook
2022-12-03 0:35 ` [PATCH v4 32/39] x86: Expose thread features in /proc/$PID/status Rick Edgecombe
2022-12-03 2:52 ` Kees Cook
2022-12-03 0:36 ` [PATCH v4 33/39] x86: Prevent 32 bit operations for 64 bit shstk tasks Rick Edgecombe
2022-12-03 22:49 ` Andy Lutomirski
2022-12-04 20:51 ` Edgecombe, Rick P
2022-12-15 0:25 ` Edgecombe, Rick P
2022-12-03 0:36 ` [PATCH v4 34/39] x86/shstk: Wire in shadow stack interface Rick Edgecombe
2022-12-03 0:36 ` [PATCH v4 35/39] selftests/x86: Add shadow stack test Rick Edgecombe
2022-12-03 0:36 ` [PATCH v4 36/39] x86/fpu: Add helper for initing features Rick Edgecombe
2022-12-03 0:36 ` [PATCH v4 37/39] x86: Add PTRACE interface for shadow stack Rick Edgecombe
2022-12-03 2:55 ` Kees Cook
2022-12-09 17:04 ` Mike Rapoport
2022-12-09 17:08 ` Edgecombe, Rick P
2022-12-03 0:36 ` [PATCH v4 38/39] x86/shstk: Add ARCH_SHSTK_UNLOCK Rick Edgecombe
2022-12-03 2:56 ` Kees Cook
2022-12-03 0:36 ` [PATCH v4 39/39] x86/shstk: Add ARCH_SHSTK_STATUS Rick Edgecombe
2022-12-03 2:57 ` Kees Cook
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