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x86: check physical address range in ioremap

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Roland Dreier reported in http://lkml.org/lkml/2008/2/27/194

[ 8425.915139] BUG: unable to handle kernel paging request at ffffc20001a0a000
[ 8425.919087] IP: [<ffffffff8021dacc>] clflush_cache_range+0xc/0x25
[ 8425.919087] PGD 1bf80e067 PUD 1bf80f067 PMD 1bb497067 PTE 80000047000ee17b

This is on a Intel machine with 36bit physical address space. The PTE
entry references 47000ee000, which is outside of it.

Add a check for the physical address space and warn/printk about the
stupid caller.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner 2008-02-27 20:57:40 +01:00 committed by Ingo Molnar
parent b8c2d3dfbc
commit e3100c82ab
1 changed files with 19 additions and 0 deletions
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19
arch/x86/mm/ioremap.c
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@ -35,6 +35,18 @@ unsigned long __phys_addr(unsigned long x)
}
EXPORT_SYMBOL(__phys_addr);
static inline int phys_addr_valid(unsigned long addr)
{
return addr < (1UL << boot_cpu_data.x86_phys_bits);
}
#else
static inline int phys_addr_valid(unsigned long addr)
{
return 1;
}
#endif
int page_is_ram(unsigned long pagenr)
@ -118,6 +130,13 @@ static void __iomem *__ioremap(resource_size_t phys_addr, unsigned long size,
if (!size || last_addr < phys_addr)
return NULL;
if (!phys_addr_valid(phys_addr)) {
printk(KERN_WARNING "ioremap: invalid physical address %lx\n",
phys_addr);
WARN_ON_ONCE(1);
return NULL;
}
/*
* Don't remap the low PCI/ISA area, it's always mapped..
*/