On Thu, 3 Dec 2015, Dave Hansen wrote: > vma->vm_flags is an 'unsigned long', so has space for 32 flags > on 32-bit architectures. The high 32 bits are unused on 64-bit > platforms. We've steered away from using the unused high VMA > bits for things because we would have difficulty supporting it > on 32-bit. > > Protection Keys are not available in 32-bit mode, so there is > no concern about supporting this feature in 32-bit mode or on > 32-bit CPUs. > > This patch carves out 4 bits from the high half of > vma->vm_flags and allows architectures to set config option > to make them available. > > Sparse complains about these constants unless we explicitly > call them "UL". > > Signed-off-by: Dave Hansen <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
