Provide hooks to intercept bad usages of virt_to_phys() and
__pa_symbol() throughout the kernel. To make this possible, we need to
rename the current implement of virt_to_phys() into
__virt_to_phys_nodebug() and wrap it around depending on
CONFIG_DEBUG_VIRTUAL.
A similar thing is needed for __pa_symbol() which is now aliased to
__phys_addr_symbol() whose implementation is either the direct return of
RELOC_HIDE or goes through the debug version.
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
arch/mips/Kconfig | 1 +
arch/mips/include/asm/io.h | 14 +++++++++++++-
arch/mips/include/asm/page.h | 9 ++++++++-
arch/mips/mm/Makefile | 2 ++
arch/mips/mm/physaddr.c | 40 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 64 insertions(+), 2 deletions(-)
create mode 100644 arch/mips/mm/physaddr.c
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 2afb41c52ba0..724457b5a7eb 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -70,6 +70,7 @@ config MIPS
select HAVE_EXIT_THREAD
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_ARCH_HARDENED_USERCOPY
+ select ARCH_HAS_DEBUG_VIRTUAL
menu "Machine selection"
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index ecabc00c1e66..016e12161c9d 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -116,11 +116,23 @@ static inline void set_io_port_base(unsigned long base)
* almost all conceivable cases a device driver should not be using
* this function
*/
-static inline unsigned long virt_to_phys(volatile const void *address)
+static inline unsigned long __virt_to_phys_nodebug(volatile const void *address)
{
return __pa(address);
}
+#ifdef CONFIG_DEBUG_VIRTUAL
+extern phys_addr_t __virt_to_phys(volatile const void *x);
+#else
+#define __virt_to_phys(x) __virt_to_phys_nodebug(x)
+#endif
+
+#define virt_to_phys virt_to_phys
+static inline phys_addr_t virt_to_phys(const volatile void *x)
+{
+ return __virt_to_phys(x);
+}
+
/*
* phys_to_virt - map physical address to virtual
* @address: address to remap
diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h
index 5f987598054f..bf8bd7d77fce 100644
--- a/arch/mips/include/asm/page.h
+++ b/arch/mips/include/asm/page.h
@@ -205,9 +205,16 @@ static inline unsigned long ___pa(unsigned long x)
* until GCC 3.x has been retired before we can apply
* https://patchwork.linux-mips.org/patch/1541/
*/
+#define __pa_symbol_nodebug(x) __pa(RELOC_HIDE((unsigned long)(x), 0))
+
+#ifdef CONFIG_DEBUG_VIRTUAL
+extern phys_addr_t __phys_addr_symbol(unsigned long x);
+#else
+#define __phys_addr_symbol(x) __pa_symbol_nodebug(x)
+#endif
#ifndef __pa_symbol
-#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0))
+#define __pa_symbol(x) __phys_addr_symbol((unsigned long)(x))
#endif
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
diff --git a/arch/mips/mm/Makefile b/arch/mips/mm/Makefile
index b4cc8811a664..0a1d241c50fb 100644
--- a/arch/mips/mm/Makefile
+++ b/arch/mips/mm/Makefile
@@ -29,3 +29,5 @@ obj-$(CONFIG_R5000_CPU_SCACHE) += sc-r5k.o
obj-$(CONFIG_RM7000_CPU_SCACHE) += sc-rm7k.o
obj-$(CONFIG_MIPS_CPU_SCACHE) += sc-mips.o
obj-$(CONFIG_SCACHE_DEBUGFS) += sc-debugfs.o
+
+obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
diff --git a/arch/mips/mm/physaddr.c b/arch/mips/mm/physaddr.c
new file mode 100644
index 000000000000..6123a9b3b3c0
--- /dev/null
+++ b/arch/mips/mm/physaddr.c
@@ -0,0 +1,40 @@
+#include <linux/bug.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/mmdebug.h>
+#include <linux/mm.h>
+
+#include <asm/sections.h>
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/dma.h>
+
+static inline bool __debug_virt_addr_valid(unsigned long x)
+{
+ if (x >= PAGE_OFFSET && x < (unsigned long)high_memory)
+ return true;
+
+ return false;
+}
+
+phys_addr_t __virt_to_phys(volatile const void *x)
+{
+ WARN(!__debug_virt_addr_valid((unsigned long)x),
+ "virt_to_phys used for non-linear address: %pK (%pS)\n",
+ x, 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)_text ||
+ x > (unsigned long)_end);
+
+ return __pa_symbol_nodebug(x);
+}
+EXPORT_SYMBOL(__phys_addr_symbol);
--
2.9.3
