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Ingo Molnar authored
The following commit: a0acda91 ("acpi, numa, mem_hotplug: mark all nodes the kernel resides un-hotpluggable") Introduced numa_clear_kernel_node_hotplug(), which function is executed during early bootup, and which marks all currently reserved memblock regions as hot-memory-unswappable as well. y14sg1 <y14sg1@comcast.net> reported that when running 32-bit NUMA kernels, the grsecurity/PAX kernel patch flagged a size overflow in this function: PAX: size overflow detected in function x86_numa_init arch/x86/mm/numa.c:691 [...] ... the reason for the overflow is that memblock_clear_hotplug() takes physical addresses as arguments, while the start/end variables used by numa_clear_kernel_node_hotplug() are 'unsigned long', which is 32-bit on PAE kernels, but which has 64-bit physical addresses. So on 32-bit PAE kernels that have physical memory above the 4GB boundary, we truncate a 64-bit physical address range to 32 bits and pass it to memblock_clear_hotplug(), which at minimum prevents the original memory-hotplug bugfix from working, but might have other side effects as well. The fix is to use the proper type to handle physical addresses, phys_addr_t. Reported-by:
y14sg1 <y14sg1@comcast.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Brad Spengler <spender@grsecurity.net> Cc: Chen Tang <imtangchen@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: PaX Team <pageexec@freemail.hu> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: linux-kernel@vger.kernel.org Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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