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/mmap.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 arch/sh/mm/mmap.c (limited to 'arch/sh/mm/mmap.c') diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c new file mode 100644 index 000000000000..1f3cc3d92d3d --- /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 v1.2.3 From 10840f034e2329150ce0e683e636ea13b268d333 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Thu, 13 Nov 2008 15:38:02 +0900 Subject: sh: Don't factor in PAGE_OFFSET for valid_phys_addr_range() check. Signed-off-by: Paul Mundt --- arch/sh/mm/mmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/sh/mm/mmap.c') diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c index 1f3cc3d92d3d..8837d511710a 100644 --- a/arch/sh/mm/mmap.c +++ b/arch/sh/mm/mmap.c @@ -17,7 +17,7 @@ */ int valid_phys_addr_range(unsigned long addr, size_t count) { - if (addr < (PAGE_OFFSET + (PFN_START << PAGE_SHIFT))) + if (addr < __MEMORY_START) return 0; if (addr + count > __pa(high_memory)) return 0; -- cgit v1.2.3