From 185aed75570fb4f78ef283dfa26cd9da5fa06a91 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Wed, 12 Nov 2008 12:53:48 +0900 Subject: sh: Provide a sane valid_phys_addr_range() to prevent TLB reset with PMB. With the PMB enabled, only P1SEG and up are covered by the PMB mappings, meaning that situations where out-of-bounds physical addresses are read from will lead to TLB reset after the PMB miss, allowing for use cases like dd if=/dev/mem to reset the TLB. Fix this up to make sure the reference is between __MEMORY_START (phys) and __pa(high_memory). This is coherent across all variants of sh/sh64 with and without MMU, though the PMB bug itself is only applicable to SH-4A parts. Reported-by: Hideo Saito Signed-off-by: Paul Mundt --- arch/sh/mm/Makefile_32 | 2 +- arch/sh/mm/Makefile_64 | 2 +- arch/sh/mm/mmap.c | 31 +++++++++++++++++++++++++++++++ 3 files changed, 33 insertions(+), 2 deletions(-) create mode 100644 arch/sh/mm/mmap.c (limited to 'arch/sh/mm') diff --git a/arch/sh/mm/Makefile_32 b/arch/sh/mm/Makefile_32 index 70e0906..f066e76 100644 --- a/arch/sh/mm/Makefile_32 +++ b/arch/sh/mm/Makefile_32 @@ -2,7 +2,7 @@ # Makefile for the Linux SuperH-specific parts of the memory manager. # -obj-y := init.o extable_32.o consistent.o +obj-y := init.o extable_32.o consistent.o mmap.o ifndef CONFIG_CACHE_OFF cache-$(CONFIG_CPU_SH2) := cache-sh2.o diff --git a/arch/sh/mm/Makefile_64 b/arch/sh/mm/Makefile_64 index 0d92a8a..9481d0f 100644 --- a/arch/sh/mm/Makefile_64 +++ b/arch/sh/mm/Makefile_64 @@ -2,7 +2,7 @@ # Makefile for the Linux SuperH-specific parts of the memory manager. # -obj-y := init.o consistent.o +obj-y := init.o consistent.o mmap.o mmu-y := tlb-nommu.o pg-nommu.o extable_32.o mmu-$(CONFIG_MMU) := fault_64.o ioremap_64.o tlbflush_64.o tlb-sh5.o \ diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c new file mode 100644 index 0000000..1f3cc3d --- /dev/null +++ b/arch/sh/mm/mmap.c @@ -0,0 +1,31 @@ +/* + * arch/sh/mm/mmap.c + * + * Copyright (C) 2008 Paul Mundt + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include +#include +#include + +/* + * You really shouldn't be using read() or write() on /dev/mem. This + * might go away in the future. + */ +int valid_phys_addr_range(unsigned long addr, size_t count) +{ + if (addr < (PAGE_OFFSET + (PFN_START << PAGE_SHIFT))) + return 0; + if (addr + count > __pa(high_memory)) + return 0; + + return 1; +} + +int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) +{ + return 1; +} -- cgit v1.1