From: Andy Lutomirski <luto@kernel.org>
To: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>,
X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@intel.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Juergen Gross <jgross@suse.com>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Brian Gerst <brgerst@gmail.com>,
David Laight <David.Laight@aculab.com>,
Denys Vlasenko <dvlasenk@redhat.com>,
Eduardo Valentin <eduval@amazon.com>,
Greg KH <gregkh@linuxfoundation.org>,
Will Deacon <will.deacon@arm.com>,
"Liguori, Anthony" <aliguori@amazon.com>,
Daniel Gruss <daniel.gruss@iaik.tugraz.at>,
Hugh Dickins <hughd@google.com>, Kees Cook <keescook@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Waiman Long <llong@redhat.com>, Pavel Machek <pavel@ucw.cz>,
"David H . Gutteridge" <dhgutteridge@sympatico.ca>,
Joerg Roedel <jroedel@suse.de>
Subject: Re: [PATCH 28/39] x86/mm/pti: Keep permissions when cloning kernel text in pti_clone_kernel_text()
Date: Fri, 13 Jul 2018 16:25:25 -0700 [thread overview]
Message-ID: <CALCETrXj7TT5tm8m+9ycuRDDWDiqQy4u5gLLVrz8DhNWWw1fXA@mail.gmail.com> (raw)
In-Reply-To: <1531308586-29340-29-git-send-email-joro@8bytes.org>
On Wed, Jul 11, 2018 at 4:29 AM, Joerg Roedel <joro@8bytes.org> wrote:
> From: Joerg Roedel <jroedel@suse.de>
>
> Mapping the kernel text area to user-space makes only sense
> if it has the same permissions as in the kernel page-table.
> If permissions are different this will cause a TLB reload
> when using the kernel page-table, which is as good as not
> mapping it at all.
>
> On 64-bit kernels this patch makes no difference, as the
> whole range cloned by pti_clone_kernel_text() is mapped RO
> anyway. On 32 bit there are writeable mappings in the range,
> so just keep the permissions as they are.
Reviewed-by: Andy Lutomirski <luto@kernel.org>
next prev parent reply other threads:[~2018-07-13 23:25 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-11 11:29 [PATCH 00/39 v7] PTI support for x86-32 Joerg Roedel
2018-07-11 11:29 ` [PATCH 01/39] x86/asm-offsets: Move TSS_sp0 and TSS_sp1 to asm-offsets.c Joerg Roedel
2018-07-12 20:44 ` Andy Lutomirski
2018-07-11 11:29 ` [PATCH 02/39] x86/entry/32: Rename TSS_sysenter_sp0 to TSS_entry_stack Joerg Roedel
2018-07-12 20:44 ` Andy Lutomirski
2018-07-11 11:29 ` [PATCH 03/39] x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler Joerg Roedel
2018-07-12 20:49 ` Andy Lutomirski
2018-07-13 9:48 ` Joerg Roedel
2018-07-13 17:19 ` Andy Lutomirski
2018-07-13 23:17 ` Andy Lutomirski
2018-07-17 7:05 ` Joerg Roedel
2018-07-17 20:04 ` Andy Lutomirski
2018-07-11 11:29 ` [PATCH 04/39] x86/entry/32: Put ESPFIX code into a macro Joerg Roedel
2018-07-11 11:29 ` [PATCH 05/39] x86/entry/32: Unshare NMI return path Joerg Roedel
2018-07-12 20:53 ` Andy Lutomirski
2018-07-13 10:05 ` Joerg Roedel
2018-07-13 17:26 ` Andy Lutomirski
2018-07-11 11:29 ` [PATCH 06/39] x86/entry/32: Split off return-to-kernel path Joerg Roedel
2018-07-11 11:29 ` [PATCH 07/39] x86/entry/32: Enter the kernel via trampoline stack Joerg Roedel
2018-07-12 21:09 ` Andy Lutomirski
2018-07-13 10:56 ` Joerg Roedel
2018-07-13 17:21 ` Andy Lutomirski
2018-07-17 7:07 ` Joerg Roedel
2018-07-11 11:29 ` [PATCH 08/39] x86/entry/32: Leave " Joerg Roedel
2018-07-11 11:29 ` [PATCH 09/39] x86/entry/32: Introduce SAVE_ALL_NMI and RESTORE_ALL_NMI Joerg Roedel
2018-07-11 11:29 ` [PATCH 10/39] x86/entry/32: Handle Entry from Kernel-Mode on Entry-Stack Joerg Roedel
2018-07-13 23:31 ` Andy Lutomirski
2018-07-14 5:21 ` Joerg Roedel
2018-07-14 6:26 ` Andy Lutomirski
2018-07-14 8:01 ` Joerg Roedel
2018-07-14 14:36 ` Andy Lutomirski
2018-07-17 7:15 ` Joerg Roedel
2018-07-17 20:06 ` Andy Lutomirski
2018-07-18 11:59 ` Joerg Roedel
2018-07-11 11:29 ` [PATCH 11/39] x86/entry/32: Simplify debug entry point Joerg Roedel
2018-07-11 11:29 ` [PATCH 12/39] x86/32: Use tss.sp1 as cpu_current_top_of_stack Joerg Roedel
2018-07-11 11:29 ` [PATCH 13/39] x86/entry/32: Add PTI cr3 switch to non-NMI entry/exit points Joerg Roedel
2018-07-11 11:29 ` [PATCH 14/39] x86/entry/32: Add PTI cr3 switches to NMI handler code Joerg Roedel
2018-07-11 11:29 ` [PATCH 15/39] x86/pgtable: Rename pti_set_user_pgd to pti_set_user_pgtbl Joerg Roedel
2018-07-11 11:29 ` [PATCH 16/39] x86/pgtable/pae: Unshare kernel PMDs when PTI is enabled Joerg Roedel
2018-07-11 11:29 ` [PATCH 17/39] x86/pgtable/32: Allocate 8k page-tables " Joerg Roedel
2018-07-11 11:29 ` [PATCH 18/39] x86/pgtable: Move pgdp kernel/user conversion functions to pgtable.h Joerg Roedel
2018-07-11 11:29 ` [PATCH 19/39] x86/pgtable: Move pti_set_user_pgtbl() " Joerg Roedel
2018-07-11 11:29 ` [PATCH 20/39] x86/pgtable: Move two more functions from pgtable_64.h " Joerg Roedel
2018-07-11 11:29 ` [PATCH 21/39] x86/mm/pae: Populate valid user PGD entries Joerg Roedel
2018-07-11 11:29 ` [PATCH 22/39] x86/mm/pae: Populate the user page-table with user pgd's Joerg Roedel
2018-07-11 11:29 ` [PATCH 23/39] x86/mm/legacy: " Joerg Roedel
2018-07-11 11:29 ` [PATCH 24/39] x86/mm/pti: Add an overflow check to pti_clone_pmds() Joerg Roedel
2018-07-11 11:29 ` [PATCH 25/39] x86/mm/pti: Define X86_CR3_PTI_PCID_USER_BIT on x86_32 Joerg Roedel
2018-07-11 11:29 ` [PATCH 26/39] x86/mm/pti: Clone CPU_ENTRY_AREA on PMD level " Joerg Roedel
2018-07-11 11:29 ` [PATCH 27/39] x86/mm/pti: Make pti_clone_kernel_text() compile on 32 bit Joerg Roedel
2018-07-11 11:29 ` [PATCH 28/39] x86/mm/pti: Keep permissions when cloning kernel text in pti_clone_kernel_text() Joerg Roedel
2018-07-13 23:25 ` Andy Lutomirski [this message]
2018-07-11 11:29 ` [PATCH 29/39] x86/mm/pti: Introduce pti_finalize() Joerg Roedel
2018-07-11 11:29 ` [PATCH 30/39] x86/mm/pti: Clone entry-text again in pti_finalize() Joerg Roedel
2018-07-13 23:21 ` Andy Lutomirski
2018-07-14 5:04 ` Joerg Roedel
2018-07-11 11:29 ` [PATCH 31/39] x86/mm/dump_pagetables: Define INIT_PGD Joerg Roedel
2018-07-11 11:29 ` [PATCH 32/39] x86/pgtable/pae: Use separate kernel PMDs for user page-table Joerg Roedel
2018-07-11 11:29 ` [PATCH 33/39] x86/ldt: Reserve address-space range on 32 bit for the LDT Joerg Roedel
2018-07-11 11:29 ` [PATCH 34/39] x86/ldt: Define LDT_END_ADDR Joerg Roedel
2018-07-13 17:29 ` Andy Lutomirski
2018-07-11 11:29 ` [PATCH 35/39] x86/ldt: Split out sanity check in map_ldt_struct() Joerg Roedel
2018-07-13 23:18 ` Andy Lutomirski
2018-07-11 11:29 ` [PATCH 36/39] x86/ldt: Enable LDT user-mapping for PAE Joerg Roedel
2018-07-11 11:29 ` [PATCH 37/39] x86/pti: Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32 Joerg Roedel
2018-07-11 11:29 ` [PATCH 38/39] x86/mm/pti: Add Warning when booting on a PCID capable CPU Joerg Roedel
2018-07-13 18:59 ` Andy Lutomirski
2018-07-14 5:08 ` Joerg Roedel
2018-07-11 11:29 ` [PATCH 39/39] x86/entry/32: Add debug code to check entry/exit cr3 Joerg Roedel
2018-07-13 17:28 ` Andy Lutomirski
2018-07-14 5:09 ` Joerg Roedel
2018-07-11 16:28 ` [PATCH 00/39 v7] PTI support for x86-32 Linus Torvalds
2018-07-11 17:28 ` Jiri Kosina
2018-07-11 19:57 ` Thomas Backlund
2018-07-12 13:59 ` Boris Ostrovsky
2018-07-11 21:07 ` Pavel Machek
2018-07-16 7:51 ` Pavel Machek
2018-07-17 2:07 ` David H. Gutteridge
2018-07-17 6:16 ` Joerg Roedel
2018-07-18 9:40 [PATCH 00/39 v8] " Joerg Roedel
2018-07-18 9:41 ` [PATCH 28/39] x86/mm/pti: Keep permissions when cloning kernel text in pti_clone_kernel_text() Joerg Roedel
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