]> www.infradead.org Git - users/jedix/linux-maple.git/commit
drivers/base/memory.c: prohibit offlining of memory blocks with missing sections
authorSeth Jennings <sjennings@variantweb.net>
Fri, 11 Dec 2015 21:40:57 +0000 (13:40 -0800)
committerBrian Maly <brian.maly@oracle.com>
Mon, 24 Dec 2018 02:32:57 +0000 (21:32 -0500)
commit82e1a54fdb2205144bbec8e64be1f4cf2d4ad85f
tree962ae04762cb83f23e67e235c72267c6dd364fb9
parentc5a60db7fb1099c444c6a81051f9a92870e6b308
drivers/base/memory.c: prohibit offlining of memory blocks with missing sections

Commit bdee237c0343 ("x86: mm: Use 2GB memory block size on large-memory
x86-64 systems") and 982792c782ef ("x86, mm: probe memory block size for
generic x86 64bit") introduced large block sizes for x86.  This made it
possible to have multiple sections per memory block where previously,
there was a only every one section per block.

Since blocks consist of contiguous ranges of section, there can be holes
in the blocks where sections are not present.  If one attempts to
offline such a block, a crash occurs since the code is not designed to
deal with this.

This patch is a quick fix to gaurd against the crash by not allowing
blocks with non-present sections to be offlined.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=107781

Orabug: 29050538

Signed-off-by: Seth Jennings <sjennings@variantweb.net>
Reported-by: Andrew Banman <abanman@sgi.com>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 26bbe7ef6d5cdc7ec08cba6d433fca4060f258f3)
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Larry Bassel <larry.bassel@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
drivers/base/memory.c