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authorLaura Abbott <labbott@redhat.com>2017-01-10 13:35:50 -0800
committerWill Deacon <will.deacon@arm.com>2017-01-12 15:05:39 +0000
commitec6d06efb0bac6cd92846e42d1afe5b98b57e7c2 (patch)
treea09267b07514bc3136eec83eb7a40ff4d22b2de9
parent2077be6783b5936c3daa838d8addbb635667927f (diff)
downloadlinux-ec6d06efb0bac6cd92846e42d1afe5b98b57e7c2.tar.gz
arm64: Add support for CONFIG_DEBUG_VIRTUAL
x86 has an option CONFIG_DEBUG_VIRTUAL to do additional checks on virt_to_phys calls. The goal is to catch users who are calling virt_to_phys on non-linear addresses immediately. This inclues callers using virt_to_phys on image addresses instead of __pa_symbol. As features such as CONFIG_VMAP_STACK get enabled for arm64, this becomes increasingly important. Add checks to catch bad virt_to_phys usage. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r--arch/arm64/Kconfig1
-rw-r--r--arch/arm64/include/asm/memory.h31
-rw-r--r--arch/arm64/mm/Makefile2
-rw-r--r--arch/arm64/mm/physaddr.c30
4 files changed, 61 insertions, 3 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 111742126897..359bca239ba7 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -6,6 +6,7 @@ config ARM64
select ACPI_MCFG if ACPI
select ACPI_SPCR_TABLE if ACPI
select ARCH_CLOCKSOURCE_DATA
+ select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_ELF_RANDOMIZE
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 0ff237a75c05..7011f0857629 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -172,10 +172,33 @@ static inline unsigned long kaslr_offset(void)
* private definitions which should NOT be used outside memory.h
* files. Use virt_to_phys/phys_to_virt/__pa/__va instead.
*/
-#define __virt_to_phys(x) ({ \
+
+
+/*
+ * The linear kernel range starts in the middle of the virtual adddress
+ * space. Testing the top bit for the start of the region is a
+ * sufficient check.
+ */
+#define __is_lm_address(addr) (!!((addr) & BIT(VA_BITS - 1)))
+
+#define __lm_to_phys(addr) (((addr) & ~PAGE_OFFSET) + PHYS_OFFSET)
+#define __kimg_to_phys(addr) ((addr) - kimage_voffset)
+
+#define __virt_to_phys_nodebug(x) ({ \
phys_addr_t __x = (phys_addr_t)(x); \
- __x & BIT(VA_BITS - 1) ? (__x & ~PAGE_OFFSET) + PHYS_OFFSET : \
- (__x - kimage_voffset); })
+ __is_lm_address(__x) ? __lm_to_phys(__x) : \
+ __kimg_to_phys(__x); \
+})
+
+#define __pa_symbol_nodebug(x) __kimg_to_phys((phys_addr_t)(x))
+
+#ifdef CONFIG_DEBUG_VIRTUAL
+extern phys_addr_t __virt_to_phys(unsigned long x);
+extern phys_addr_t __phys_addr_symbol(unsigned long x);
+#else
+#define __virt_to_phys(x) __virt_to_phys_nodebug(x)
+#define __phys_addr_symbol(x) __pa_symbol_nodebug(x)
+#endif
#define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET) | PAGE_OFFSET)
#define __phys_to_kimg(x) ((unsigned long)((x) + kimage_voffset))
@@ -207,6 +230,8 @@ static inline void *phys_to_virt(phys_addr_t x)
* Drivers should NOT use these either.
*/
#define __pa(x) __virt_to_phys((unsigned long)(x))
+#define __pa_symbol(x) __phys_addr_symbol(RELOC_HIDE((unsigned long)(x), 0))
+#define __pa_nodebug(x) __virt_to_phys_nodebug((unsigned long)(x))
#define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x)))
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
#define virt_to_pfn(x) __phys_to_pfn(__virt_to_phys((unsigned long)(x)))
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
index e703fb9defad..9b0ba191e48e 100644
--- a/arch/arm64/mm/Makefile
+++ b/arch/arm64/mm/Makefile
@@ -6,6 +6,8 @@ obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_ARM64_PTDUMP_CORE) += dump.o
obj-$(CONFIG_ARM64_PTDUMP_DEBUGFS) += ptdump_debugfs.o
obj-$(CONFIG_NUMA) += numa.o
+obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
+KASAN_SANITIZE_physaddr.o += n
obj-$(CONFIG_KASAN) += kasan_init.o
KASAN_SANITIZE_kasan_init.o := n
diff --git a/arch/arm64/mm/physaddr.c b/arch/arm64/mm/physaddr.c
new file mode 100644
index 000000000000..91371daf397c
--- /dev/null
+++ b/arch/arm64/mm/physaddr.c
@@ -0,0 +1,30 @@
+#include <linux/bug.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/mmdebug.h>
+#include <linux/mm.h>
+
+#include <asm/memory.h>
+
+phys_addr_t __virt_to_phys(unsigned long x)
+{
+ WARN(!__is_lm_address(x),
+ "virt_to_phys used for non-linear address: %pK (%pS)\n",
+ (void *)x,
+ (void *)x);
+
+ return __virt_to_phys_nodebug(x);
+}
+EXPORT_SYMBOL(__virt_to_phys);
+
+phys_addr_t __phys_addr_symbol(unsigned long x)
+{
+ /*
+ * This is bounds checking against the kernel image only.
+ * __pa_symbol should only be used on kernel symbol addresses.
+ */
+ VIRTUAL_BUG_ON(x < (unsigned long) KERNEL_START ||
+ x > (unsigned long) KERNEL_END);
+ return __pa_symbol_nodebug(x);
+}
+EXPORT_SYMBOL(__phys_addr_symbol);