From: Catalin Marinas <catalin.marinas@arm.com> To: Andrew Morton <akpm@linux-foundation.org>, Hugh Dickins <hughd@google.com>, Russell King - ARM Linux <linux@arm.linux.org.uk> Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org Subject: [PATCH 2/2] arm: Set the page table freeing ceiling to TASK_SIZE Date: Mon, 18 Feb 2013 16:18:31 +0000 [thread overview] Message-ID: <1361204311-14127-3-git-send-email-catalin.marinas@arm.com> (raw) In-Reply-To: <1361204311-14127-1-git-send-email-catalin.marinas@arm.com> ARM processors with LPAE enabled use 3 levels of page tables, with an entry in the top level (pgd) covering 1GB of virtual space. Because of the branch relocation limitations on ARM, the loadable modules are mapped 16MB below PAGE_OFFSET, making the corresponding 1GB pgd shared between kernel modules and user space. If free_pgtables() is called with the default ceiling 0, free_pgd_range() (and subsequently called functions) also frees the page table shared between user space and kernel modules (which is normally handled by the ARM-specific pgd_free() function). This patch changes defines the ARM USER_PGTABLES_CEILING to TASK_SIZE. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> --- arch/arm/include/asm/pgtable.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index c094749..8f06ee5 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -61,6 +61,13 @@ extern void __pgd_error(const char *file, int line, pgd_t); #define FIRST_USER_ADDRESS PAGE_SIZE /* + * Use TASK_SIZE as the ceiling argument for free_pgtables() and + * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd + * page shared between user and kernel). + */ +#define USER_PGTABLES_CEILING TASK_SIZE + +/* * The pgprot_* and protection_map entries will be fixed up in runtime * to include the cachable and bufferable bits based on memory policy, * as well as any architecture dependent bits like global/ASID and SMP
WARNING: multiple messages have this Message-ID (diff)
From: Catalin Marinas <catalin.marinas@arm.com> To: Andrew Morton <akpm@linux-foundation.org>, Hugh Dickins <hughd@google.com>, Russell King - ARM Linux <linux@arm.linux.org.uk> Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org Subject: [PATCH 2/2] arm: Set the page table freeing ceiling to TASK_SIZE Date: Mon, 18 Feb 2013 16:18:31 +0000 [thread overview] Message-ID: <1361204311-14127-3-git-send-email-catalin.marinas@arm.com> (raw) In-Reply-To: <1361204311-14127-1-git-send-email-catalin.marinas@arm.com> ARM processors with LPAE enabled use 3 levels of page tables, with an entry in the top level (pgd) covering 1GB of virtual space. Because of the branch relocation limitations on ARM, the loadable modules are mapped 16MB below PAGE_OFFSET, making the corresponding 1GB pgd shared between kernel modules and user space. If free_pgtables() is called with the default ceiling 0, free_pgd_range() (and subsequently called functions) also frees the page table shared between user space and kernel modules (which is normally handled by the ARM-specific pgd_free() function). This patch changes defines the ARM USER_PGTABLES_CEILING to TASK_SIZE. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> --- arch/arm/include/asm/pgtable.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index c094749..8f06ee5 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -61,6 +61,13 @@ extern void __pgd_error(const char *file, int line, pgd_t); #define FIRST_USER_ADDRESS PAGE_SIZE /* + * Use TASK_SIZE as the ceiling argument for free_pgtables() and + * free_pgd_range() to avoid freeing the modules pmd when LPAE is enabled (pmd + * page shared between user and kernel). + */ +#define USER_PGTABLES_CEILING TASK_SIZE + +/* * The pgprot_* and protection_map entries will be fixed up in runtime * to include the cachable and bufferable bits based on memory policy, * as well as any architecture dependent bits like global/ASID and SMP -- 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:[~2013-02-18 16:18 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-02-18 16:18 [PATCH 0/2] Arch-specific user pgtables ceiling Catalin Marinas 2013-02-18 16:18 ` Catalin Marinas 2013-02-18 16:18 ` [PATCH 1/2] mm: Allow arch code to control the user page table ceiling Catalin Marinas 2013-02-18 16:18 ` Catalin Marinas 2013-02-19 18:08 ` Hugh Dickins 2013-02-19 18:08 ` Hugh Dickins 2013-02-19 22:33 ` Catalin Marinas 2013-02-19 22:33 ` Catalin Marinas 2013-02-18 16:18 ` Catalin Marinas [this message] 2013-02-18 16:18 ` [PATCH 2/2] arm: Set the page table freeing ceiling to TASK_SIZE Catalin Marinas 2013-02-19 18:20 ` Hugh Dickins 2013-02-19 18:20 ` Hugh Dickins 2013-02-19 22:55 ` Catalin Marinas 2013-02-19 22:55 ` Catalin Marinas
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=1361204311-14127-3-git-send-email-catalin.marinas@arm.com \ --to=catalin.marinas@arm.com \ --cc=akpm@linux-foundation.org \ --cc=hughd@google.com \ --cc=linux-arch@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=linux@arm.linux.org.uk \ /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.