From e3100c82abd9aa643dc15828202aceeae3504e03 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 27 Feb 2008 20:57:40 +0100 Subject: [PATCH] x86: check physical address range in ioremap 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: [] 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 Signed-off-by: Ingo Molnar --- arch/x86/mm/ioremap.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 868bbde74698..17f518839028 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -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.. */ -- 2.11.0