x86/mm/numa: Check for failures in numa_clear_kernel_node_hotplug()

numa_clear_kernel_node_hotplug() uses memblock_set_node() without
checking for failures.

memblock_set_node() is a complex function that might extend the
memblock array - which extension might fail - so check for this
possibility.

It's not supposed to happen (because realistically if we have so
little memory that this fails then we likely won't be able to
boot anyway), but do the check nevertheless.

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: y14sg1 <y14sg1@comcast.net>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index ede4506abb18890d50ef942c751193ae78556f0f..f70c1ff4612515b310ee59fdb843ae15eb2b2a33 100644 (file)
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -491,8 +491,10 @@ static void __init numa_clear_kernel_node_hotplug(void)
         */
        for (i = 0; i < numa_meminfo.nr_blks; i++) {
                struct numa_memblk *mb = numa_meminfo.blk + i;
+               int ret;
 
-               memblock_set_node(mb->start, mb->end - mb->start, &memblock.reserved, mb->nid);
+               ret = memblock_set_node(mb->start, mb->end - mb->start, &memblock.reserved, mb->nid);
+               WARN_ON_ONCE(ret);
        }
 
        /*