From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754526AbaHLSZ7 (ORCPT ); Tue, 12 Aug 2014 14:25:59 -0400 Received: from smtp.outflux.net ([198.145.64.163]:54530 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754383AbaHLSZ4 (ORCPT ); Tue, 12 Aug 2014 14:25:56 -0400 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Rabin Vincent , Laura Abbott , Rob Herring , Leif Lindholm , Mark Salter , Liu hua , Nikolay Borisov , Nicolas Pitre , Tomasz Figa , Doug Anderson , Jason Wessel , Will Deacon , Catalin Marinas , Russell King - ARM Linux , linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 2/7] arm: fixmap: implement __set_fixmap() Date: Tue, 12 Aug 2014 11:24:24 -0700 Message-Id: <1407867869-5194-3-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1407867869-5194-1-git-send-email-keescook@chromium.org> References: <1407867869-5194-1-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 --- arch/arm/include/asm/fixmap.h | 2 ++ arch/arm/mm/mmu.c | 19 +++++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index a7add6f9315d..48935cc5004f 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..48ba2b1d7d8e 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -392,6 +393,24 @@ SET_MEMORY_FN(rw, pte_set_rw) SET_MEMORY_FN(x, pte_set_x) SET_MEMORY_FN(nx, pte_set_nx) +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(FIXADDR_START), 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); + flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE); +} + /* * Adjust the PMD section entries according to the CPU in use. */ -- 1.9.1