Commit e377cd82 authored by Florian Fainelli's avatar Florian Fainelli Committed by Russell King
Browse files

ARM: 8640/1: 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 includes caller
using __virt_to_phys() on image addresses instead of __pa_symbol(). This
is a generally useful debug feature to spot bad code (particulary in
drivers).

Acked-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Acked-by: default avatarLaura Abbott <labbott@redhat.com>
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 399f157a

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ config ARM 
	bool

	default y

	select ARCH_CLOCKSOURCE_DATA

	select ARCH_HAS_DEBUG_VIRTUAL

	select ARCH_HAS_DEVMEM_IS_ALLOWED

	select ARCH_HAS_ELF_RANDOMIZE

	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST

arch/arm/include/asm/memory.h

+13 −2
Original line number Diff line number Diff line
@@ -213,7 +213,7 @@ extern const void *__pv_table_begin, *__pv_table_end; 
	: "r" (x), "I" (__PV_BITS_31_24)		\

	: "cc")



static inline phys_addr_t __virt_to_phys(unsigned long x)

static inline phys_addr_t __virt_to_phys_nodebug(unsigned long x)

{

	phys_addr_t t;
@@ -245,7 +245,7 @@ static inline unsigned long __phys_to_virt(phys_addr_t x) 
#define PHYS_OFFSET	PLAT_PHYS_OFFSET

#define PHYS_PFN_OFFSET	((unsigned long)(PHYS_OFFSET >> PAGE_SHIFT))



static inline phys_addr_t __virt_to_phys(unsigned long x)

static inline phys_addr_t __virt_to_phys_nodebug(unsigned long x)

{

	return (phys_addr_t)x - PAGE_OFFSET + PHYS_OFFSET;

}
@@ -261,6 +261,16 @@ static inline unsigned long __phys_to_virt(phys_addr_t x) 
	((((unsigned long)(kaddr) - PAGE_OFFSET) >> PAGE_SHIFT) + \

	 PHYS_PFN_OFFSET)



#define __pa_symbol_nodebug(x)	__virt_to_phys_nodebug((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



/*

 * These are *only* valid on the kernel direct mapped RAM memory.

 * Note: Drivers should NOT use these.  They are the wrong
@@ -283,6 +293,7 @@ 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 __va(x)			((void *)__phys_to_virt((phys_addr_t)(x)))

#define pfn_to_kaddr(pfn)	__va((phys_addr_t)(pfn) << PAGE_SHIFT)

arch/arm/mm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ endif 


obj-$(CONFIG_ARM_PTDUMP)	+= dump.o

obj-$(CONFIG_MODULES)		+= proc-syms.o

obj-$(CONFIG_DEBUG_VIRTUAL)	+= physaddr.o



obj-$(CONFIG_ALIGNMENT_TRAP)	+= alignment.o

obj-$(CONFIG_HIGHMEM)		+= highmem.o

arch/arm/mm/physaddr.c

0 → 100644
+57 −0
Original line number Diff line number Diff line 
#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/memory.h>

#include <asm/fixmap.h>

#include <asm/dma.h>



#include "mm.h"



static inline bool __virt_addr_valid(unsigned long x)

{

	/*

	 * high_memory does not get immediately defined, and there

	 * are early callers of __pa() against PAGE_OFFSET

	 */

	if (!high_memory && x >= PAGE_OFFSET)

		return true;



	if (high_memory && x >= PAGE_OFFSET && x < (unsigned long)high_memory)

		return true;



	/*

	 * MAX_DMA_ADDRESS is a virtual address that may not correspond to an

	 * actual physical address. Enough code relies on __pa(MAX_DMA_ADDRESS)

	 * that we just need to work around it and always return true.

	 */

	if (x == MAX_DMA_ADDRESS)

		return true;



	return false;

}



phys_addr_t __virt_to_phys(unsigned long x)

{

	WARN(!__virt_addr_valid(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);

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