diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index b91411371ae19b1ae75c2184b4b26ec6c9b06193..ebfac782593f048c9cf81a5619f0b3d24900ca8c 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -523,7 +523,21 @@ int __init arm_add_memory(phys_addr_t start, unsigned long size) */ size -= start & ~PAGE_MASK; bank->start = PAGE_ALIGN(start); - bank->size = size & PAGE_MASK; + +#ifndef CONFIG_LPAE + if (bank->start + size < bank->start) { + printk(KERN_CRIT "Truncating memory at 0x%08llx to fit in " + "32-bit physical address space\n", (long long)start); + /* + * To ensure bank->start + bank->size is representable in + * 32 bits, we use ULONG_MAX as the upper limit rather than 4GB. + * This means we lose a page after masking. + */ + size = ULONG_MAX - bank->start; + } +#endif + + bank->size = size & PAGE_MASK; /* * Check whether this memory region has non-zero size or