x86: check physical address range in ioremap (e3100c82) · Commits · 戴 / test

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>

arch/x86/mm/ioremap.c

+19 −0

Original line number	Original line	Diff line number	Diff line
	@@ -35,6 +35,18 @@ unsigned long __phys_addr(unsigned long x)
	}		}
	EXPORT_SYMBOL(__phys_addr);		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		#endif

	int page_is_ram(unsigned long pagenr)		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)		if (!size \|\| last_addr < phys_addr)
	return NULL;		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..		* Don't remap the low PCI/ISA area, it's always mapped..
	*/		*/

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