diff options
Diffstat (limited to 'arch/i386/mm/ioremap.c')
| -rw-r--r-- | arch/i386/mm/ioremap.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/arch/i386/mm/ioremap.c b/arch/i386/mm/ioremap.c index b3fd2bdc5..740f4551f 100644 --- a/arch/i386/mm/ioremap.c +++ b/arch/i386/mm/ioremap.c @@ -90,13 +90,34 @@ void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flag void * addr; struct vm_struct * area; - if (phys_addr < virt_to_phys(high_memory)) + /* + * Don't remap the low PCI/ISA area, it's always mapped.. + */ + if (phys_addr >= 0xA0000 && (phys_addr+size) <= 0x100000) return phys_to_virt(phys_addr); + + /* + * Don't allow anybody to remap normal RAM that we're using.. + */ + if (phys_addr < virt_to_phys(high_memory)) + return NULL; + + /* + * Mappings have to be page-aligned + */ if (phys_addr & ~PAGE_MASK) return NULL; size = PAGE_ALIGN(size); + + /* + * Don't allow mappings that wrap.. + */ if (!size || size > phys_addr + size) return NULL; + + /* + * Ok, go for it.. + */ area = get_vm_area(size); if (!area) return NULL; |