From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756860AbaIRTWE (ORCPT ); Thu, 18 Sep 2014 15:22:04 -0400 Received: from smtp.outflux.net ([198.145.64.163]:40491 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755856AbaIRTWA (ORCPT ); Thu, 18 Sep 2014 15:22:00 -0400 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Rabin Vincent , Will Deacon , Laura Abbott , Rob Herring , Leif Lindholm , Mark Salter , Liu hua , Nikolay Borisov , Nicolas Pitre , Doug Anderson , Jason Wessel , Catalin Marinas , Russell King - ARM Linux , linux-arm-kernel@lists.infradead.org Subject: [PATCH v6 3/8] arm: fixmap: implement __set_fixmap() Date: Thu, 18 Sep 2014 12:19:04 -0700 Message-Id: <1411067949-10913-4-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1411067949-10913-1-git-send-email-keescook@chromium.org> References: <1411067949-10913-1-git-send-email-keescook@chromium.org> X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is used from set_fixmap() and clear_fixmap() via asm-generic/fixmap.h. Also makes sure that the fixmap allocation fits into the expected range. Based on patch by Rabin Vincent. Signed-off-by: Kees Cook Cc: Rabin Vincent Acked-by: Nicolas Pitre --- arch/arm/include/asm/fixmap.h | 2 ++ arch/arm/mm/mmu.c | 24 ++++++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index d984ca69ce19..714606f70425 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -14,6 +14,8 @@ enum fixed_addresses { __end_of_fixed_addresses }; +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); + #include #endif diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 7fa0966cd15f..bdf5c94f7c36 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -393,6 +394,29 @@ SET_MEMORY_FN(x, pte_set_x) SET_MEMORY_FN(nx, pte_set_nx) /* + * To avoid TLB flush broadcasts, this uses local_flush_tlb_kernel_range(). + * As a result, this can only be called with preemption disabled, as under + * stop_machine(). + */ +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) +{ + unsigned long vaddr = __fix_to_virt(idx); + pte_t *pte = pte_offset_kernel(pmd_off_k(vaddr), vaddr); + + /* Make sure fixmap region does not exceed available allocation. */ + BUILD_BUG_ON(FIXADDR_START + (__end_of_fixed_addresses * PAGE_SIZE) > + FIXADDR_END); + BUG_ON(idx >= __end_of_fixed_addresses); + + if (pgprot_val(prot)) + set_pte_at(NULL, vaddr, pte, + pfn_pte(phys >> PAGE_SHIFT, prot)); + else + pte_clear(NULL, vaddr, pte); + local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE); +} + +/* * Adjust the PMD section entries according to the CPU in use. */ static void __init build_mem_type_table(void) -- 1.9.1