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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: Vegard Nossum <vegardno@ben.ifi.uio.no>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Vegard Nossum 2008-10-03 17:54:25 +02:00 committed by Ingo Molnar
parent 7f2f49a582
commit af5c2bd16a
4 changed files with 44 additions and 6 deletions
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2
arch/x86/kernel/doublefault_32.c
View File

@ -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),
}
};

36
arch/x86/mm/ioremap.c
View File

@ -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)

8
include/asm-x86/page.h
View File

@ -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__ */

4
include/asm-x86/page_32.h
View File

@ -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)