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Commit af5c2bd1 authored by Vegard Nossum's avatar Vegard Nossum Committed by Ingo Molnar
Browse files

x86: fix virt_addr_valid() with CONFIG_DEBUG_VIRTUAL=y, v2 



virt_addr_valid() calls __pa(), which calls __phys_addr(). With
CONFIG_DEBUG_VIRTUAL=y, __phys_addr() will kill the kernel if the
address *isn't* valid. That's clearly wrong for virt_addr_valid().

We also incorporate the debugging checks into virt_addr_valid().

Signed-off-by: default avatarVegard Nossum <vegardno@ben.ifi.uio.no>
Acked-by: default avatarJiri Slaby <jirislaby@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 7f2f49a5

arch/x86/kernel/doublefault_32.c

+1 −1
Original line number Diff line number Diff line
@@ -66,6 +66,6 @@ struct tss_struct doublefault_tss __cacheline_aligned = { 
		.ds		= __USER_DS,

		.fs		= __KERNEL_PERCPU,



		.__cr3		= __phys_addr_const((unsigned long)swapper_pg_dir)

		.__cr3		= __pa_nodebug(swapper_pg_dir),

	}

};

arch/x86/mm/ioremap.c

+34 −2
Original line number Diff line number Diff line
@@ -45,6 +45,27 @@ unsigned long __phys_addr(unsigned long x) 
}

EXPORT_SYMBOL(__phys_addr);



bool __virt_addr_valid(unsigned long x)

{

	if (x >= __START_KERNEL_map) {

		x -= __START_KERNEL_map;

		if (x >= KERNEL_IMAGE_SIZE)

			return false;

		x += phys_base;

	} else {

		if (x < PAGE_OFFSET)

			return false;

		x -= PAGE_OFFSET;

		if (system_state == SYSTEM_BOOTING ?

				x > MAXMEM : !phys_addr_valid(x)) {

			return false;

		}

	}



	return pfn_valid(x >> PAGE_SHIFT);

}

EXPORT_SYMBOL(__virt_addr_valid);



#else



static inline int phys_addr_valid(unsigned long addr)
@@ -56,13 +77,24 @@ static inline int phys_addr_valid(unsigned long addr) 
unsigned long __phys_addr(unsigned long x)

{

	/* VMALLOC_* aren't constants; not available at the boot time */

	VIRTUAL_BUG_ON(x < PAGE_OFFSET || (system_state != SYSTEM_BOOTING &&

					is_vmalloc_addr((void *)x)));

	VIRTUAL_BUG_ON(x < PAGE_OFFSET);

	VIRTUAL_BUG_ON(system_state != SYSTEM_BOOTING &&

		is_vmalloc_addr((void *) x));

	return x - PAGE_OFFSET;

}

EXPORT_SYMBOL(__phys_addr);

#endif



bool __virt_addr_valid(unsigned long x)

{

	if (x < PAGE_OFFSET)

		return false;

	if (system_state != SYSTEM_BOOTING && is_vmalloc_addr((void *) x))

		return false;

	return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);

}

EXPORT_SYMBOL(__virt_addr_valid);



#endif



int page_is_ram(unsigned long pagenr)

include/asm-x86/page.h

+7 −1
Original line number Diff line number Diff line
@@ -179,6 +179,7 @@ static inline pteval_t native_pte_flags(pte_t pte) 
#endif	/* CONFIG_PARAVIRT */



#define __pa(x)		__phys_addr((unsigned long)(x))

#define __pa_nodebug(x)	__phys_addr_nodebug((unsigned long)(x))

/* __pa_symbol should be used for C visible symbols.

   This seems to be the official gcc blessed way to do such arithmetic. */

#define __pa_symbol(x)	__pa(__phys_reloc_hide((unsigned long)(x)))
@@ -188,9 +189,14 @@ static inline pteval_t native_pte_flags(pte_t pte) 
#define __boot_va(x)		__va(x)

#define __boot_pa(x)		__pa(x)



/*

 * virt_to_page(kaddr) returns a valid pointer if and only if

 * virt_addr_valid(kaddr) returns true.

 */

#define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)

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

#define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)

extern bool __virt_addr_valid(unsigned long kaddr);

#define virt_addr_valid(kaddr)	__virt_addr_valid((unsigned long) (kaddr))



#endif	/* __ASSEMBLY__ */

include/asm-x86/page_32.h

+2 −2
Original line number Diff line number Diff line
@@ -73,11 +73,11 @@ typedef struct page *pgtable_t; 
#endif



#ifndef __ASSEMBLY__

#define __phys_addr_const(x)	((x) - PAGE_OFFSET)

#define __phys_addr_nodebug(x)	((x) - PAGE_OFFSET)

#ifdef CONFIG_DEBUG_VIRTUAL

extern unsigned long __phys_addr(unsigned long);

#else

#define __phys_addr(x)		((x) - PAGE_OFFSET)

#define __phys_addr(x)		__phys_addr_nodebug(x)

#endif

#define __phys_reloc_hide(x)	RELOC_HIDE((x), 0)