From: Catalin Marinas <catalin.marinas@arm.com>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 05/20] ARM: LPAE: Introduce L_PTE_NOEXEC and L_PTE_NOWRITE
Date: Tue, 16 Nov 2010 15:18:03 +0000 [thread overview]
Message-ID: <AANLkTikCVCuR2mxyoE7e=V_FauTxztLHUJp97+rroUe-@mail.gmail.com> (raw)
In-Reply-To: <20101115183014.GD31421@n2100.arm.linux.org.uk>
On 15 November 2010 18:30, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Fri, Nov 12, 2010 at 06:00:25PM +0000, Catalin Marinas wrote:
>> The LPAE page table format needs to explicitly disable execution or
>> write permissions on a page by setting the corresponding bits (similar
>> to the classic page table format with Access Flag enabled). This patch
>> introduces null definitions for the 2-level format and the actual noexec
>> and nowrite bits for the LPAE format. It also changes several PTE
>> maintenance macros and masks.
>>
>> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
>> ---
>> arch/arm/include/asm/pgtable-2level.h | 2 +
>> arch/arm/include/asm/pgtable.h | 44 +++++++++++++++++++++------------
>> arch/arm/mm/mmu.c | 6 ++--
>> 3 files changed, 33 insertions(+), 19 deletions(-)
>>
>> diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h
>> index 36bdef7..4e21166 100644
>> --- a/arch/arm/include/asm/pgtable-2level.h
>> +++ b/arch/arm/include/asm/pgtable-2level.h
>> @@ -128,6 +128,8 @@
>> #define L_PTE_USER (1 << 8)
>> #define L_PTE_EXEC (1 << 9)
>> #define L_PTE_SHARED (1 << 10) /* shared(v6), coherent(xsc3) */
>> +#define L_PTE_NOEXEC (0)
>> +#define L_PTE_NOWRITE (0)
>
> Let's not make this more complicated than it has to be. If we need the
> inverse of WRITE and EXEC, then that's what we should change everyone to,
> not invent a new system to work along side the old system.
This adds an additional instruction in set_pte_ext, unless you can
write the bit checking in a better way:
tst r1, #L_PTE_NOWRITE
orrne r3, r3, #PTE_EXT_APX
tsteq r1, #L_PTE_DIRTY
orreq r3, r3, #PTE_EXT_APX
--
Catalin
next prev parent reply other threads:[~2010-11-16 15:18 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-12 18:00 [PATCH v2 00/20] ARM: Add support for the Large Physical Address Extensions Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 01/20] ARM: LPAE: Use PMD_(SHIFT|SIZE|MASK) instead of PGDIR_* Catalin Marinas
2010-11-22 12:43 ` Russell King - ARM Linux
2010-11-22 13:00 ` Catalin Marinas
2010-11-22 13:28 ` Russell King - ARM Linux
2010-11-12 18:00 ` [PATCH v2 02/20] ARM: LPAE: Factor out 2-level page table definitions into separate files Catalin Marinas
2010-11-15 23:31 ` Russell King - ARM Linux
2010-11-16 9:14 ` Catalin Marinas
2010-11-16 9:59 ` Russell King - ARM Linux
2010-11-16 10:02 ` Catalin Marinas
2010-11-16 10:04 ` Russell King - ARM Linux
2010-11-16 10:11 ` Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 03/20] ARM: LPAE: use u32 instead of unsigned long for 32-bit ptes Catalin Marinas
2010-11-14 13:19 ` Russell King - ARM Linux
2010-11-14 14:09 ` Catalin Marinas
2010-11-14 14:13 ` Catalin Marinas
2010-11-14 15:14 ` Russell King - ARM Linux
2010-11-15 9:39 ` Catalin Marinas
2010-11-15 9:47 ` Arnd Bergmann
2010-11-15 9:51 ` Catalin Marinas
2010-11-15 22:11 ` Nicolas Pitre
2010-11-15 23:35 ` Russell King - ARM Linux
2010-11-16 9:19 ` Catalin Marinas
2010-11-15 22:07 ` Nicolas Pitre
2010-11-15 17:36 ` Russell King - ARM Linux
2010-11-15 17:39 ` Catalin Marinas
2010-11-16 19:34 ` Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 04/20] ARM: LPAE: Do not assume Linux PTEs are always at PTRS_PER_PTE offset Catalin Marinas
2010-11-15 17:42 ` Russell King - ARM Linux
2010-11-15 21:46 ` Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 05/20] ARM: LPAE: Introduce L_PTE_NOEXEC and L_PTE_NOWRITE Catalin Marinas
2010-11-15 18:30 ` Russell King - ARM Linux
2010-11-16 10:07 ` Catalin Marinas
2010-11-16 15:18 ` Catalin Marinas [this message]
2010-11-16 15:32 ` Catalin Marinas
2010-11-16 18:19 ` Russell King - ARM Linux
2010-11-17 17:02 ` Catalin Marinas
2010-11-17 17:16 ` Russell King - ARM Linux
2010-11-17 17:22 ` Catalin Marinas
2010-11-17 17:24 ` Russell King - ARM Linux
2010-11-17 17:30 ` Catalin Marinas
2010-11-17 17:32 ` Russell King - ARM Linux
2010-11-17 17:34 ` Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 06/20] ARM: LPAE: Introduce the 3-level page table format definitions Catalin Marinas
2010-11-15 18:34 ` Russell King - ARM Linux
2010-11-16 9:57 ` Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 07/20] ARM: LPAE: Page table maintenance for the 3-level format Catalin Marinas
2010-11-22 12:58 ` Russell King - ARM Linux
2010-11-12 18:00 ` [PATCH v2 08/20] ARM: LPAE: MMU setup for the 3-level page table format Catalin Marinas
2010-11-14 10:13 ` Catalin Marinas
2010-11-22 13:10 ` Russell King - ARM Linux
2010-11-23 11:38 ` Catalin Marinas
2010-11-23 17:33 ` Russell King - ARM Linux
2010-11-23 17:35 ` Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 09/20] ARM: LPAE: Change setup_mm_for_reboot() to work with LPAE Catalin Marinas
2010-11-22 13:11 ` Russell King - ARM Linux
2010-11-12 18:00 ` [PATCH v2 10/20] ARM: LPAE: Remove the FIRST_USER_PGD_NR and USER_PTRS_PER_PGD definitions Catalin Marinas
2010-11-22 13:11 ` Russell King - ARM Linux
2010-11-12 18:00 ` [PATCH v2 11/20] ARM: LPAE: Add fault handling support Catalin Marinas
2010-11-22 13:15 ` Russell King - ARM Linux
2010-11-22 13:19 ` Catalin Marinas
2010-11-22 13:32 ` Russell King - ARM Linux
2010-11-22 13:38 ` Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 12/20] ARM: LPAE: Add context switching support Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 13/20] ARM: LPAE: Add SMP support for the 3-level page table format Catalin Marinas
2010-11-22 13:37 ` Russell King - ARM Linux
2010-11-12 18:00 ` [PATCH v2 14/20] ARM: LPAE: use phys_addr_t instead of unsigned long for physical addresses Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 15/20] ARM: LPAE: Use generic dma_addr_t type definition Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 16/20] ARM: LPAE: mark memory banks with start > ULONG_MAX as highmem Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 17/20] ARM: LPAE: use phys_addr_t for physical start address in early_mem Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 18/20] ARM: LPAE: add support for ATAG_MEM64 Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 19/20] ARM: LPAE: define printk format for physical addresses and page table entries Catalin Marinas
2010-11-22 13:43 ` Russell King - ARM Linux
2010-11-22 13:49 ` Catalin Marinas
2010-11-12 18:00 ` [PATCH v2 20/20] ARM: LPAE: Add the Kconfig entries Catalin Marinas
2010-11-13 12:38 ` Sergei Shtylyov
2010-11-14 10:11 ` Catalin Marinas
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