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authorPaul Mundt <lethal@linux-sh.org>2008-11-12 12:53:48 +0900
committerPaul Mundt <lethal@linux-sh.org>2008-11-12 12:53:48 +0900
commit185aed75570fb4f78ef283dfa26cd9da5fa06a91 (patch)
treea98cb3f46bf9426f8d4a660d63b8a3ac7d9f369d
parentade7a9b4ccd20ab8159c77a0abd20552f2d6b06c (diff)
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 <saito@densan.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
-rw-r--r--arch/sh/include/asm/io.h4
-rw-r--r--arch/sh/mm/Makefile_322
-rw-r--r--arch/sh/mm/Makefile_642
-rw-r--r--arch/sh/mm/mmap.c31
4 files changed, 37 insertions, 2 deletions
diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h
index 436c2853957..65eaae34e75 100644
--- a/arch/sh/include/asm/io.h
+++ b/arch/sh/include/asm/io.h
@@ -293,6 +293,10 @@ __ioremap_mode(unsigned long offset, unsigned long size, unsigned long flags)
*/
#define xlate_dev_kmem_ptr(p) p
+#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
+int valid_phys_addr_range(unsigned long addr, size_t size);
+int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
+
#endif /* __KERNEL__ */
#endif /* __ASM_SH_IO_H */
diff --git a/arch/sh/mm/Makefile_32 b/arch/sh/mm/Makefile_32
index 70e0906023c..f066e76da20 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-$(CONFIG_CPU_SH2) := cache-sh2.o
diff --git a/arch/sh/mm/Makefile_64 b/arch/sh/mm/Makefile_64
index 0d92a8a3ac9..9481d0f54ef 100644
--- a/arch/sh/mm/Makefile_64
+++ b/arch/sh/mm/Makefile_64
@@ -2,7 +2,7 @@
# Makefile for the Linux SuperH-specific parts of the memory manager.
#
-obj-y := init.o consistent.o
+obj-y := init.o consistent.o mmap.o
mmu-y := tlb-nommu.o pg-nommu.o extable_32.o
mmu-$(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 00000000000..1f3cc3d92d3
--- /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 <linux/io.h>
+#include <linux/mm.h>
+#include <asm/page.h>
+
+/*
+ * 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;
+}