https://github.com/torvalds/linux
Revision 641fe2e9387a36f9ee01d7c69382d1fe147a5e98 authored by David Hildenbrand on 19 October 2019, 03:19:16 UTC, committed by Linus Torvalds on 19 October 2019, 10:32:31 UTC
Uninitialized memmaps contain garbage and in the worst case trigger kernel
BUGs, especially with CONFIG_PAGE_POISONING. They should not get touched.
Right now, when trying to soft-offline a PFN that resides on a memory
block that was never onlined, one gets a misleading error with
CONFIG_PAGE_POISONING:
:/# echo 5637144576 > /sys/devices/system/memory/soft_offline_page
[ 23.097167] soft offline: 0x150000 page already poisoned
But the actual result depends on the garbage in the memmap.
soft_offline_page() can only work with online pages, it returns -EIO in
case of ZONE_DEVICE. Make sure to only forward pages that are online
(iow, managed by the buddy) and, therefore, have an initialized memmap.
Add a check against pfn_to_online_page() and similarly return -EIO.
Link: http://lkml.kernel.org/r/20191010141200.8985-1-david@redhat.com
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319]
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: <stable@vger.kernel.org> [4.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent b9959c7
Tip revision: 641fe2e9387a36f9ee01d7c69382d1fe147a5e98 authored by David Hildenbrand on 19 October 2019, 03:19:16 UTC
drivers/base/memory.c: don't access uninitialized memmaps in soft_offline_page_store()
drivers/base/memory.c: don't access uninitialized memmaps in soft_offline_page_store()
Tip revision: 641fe2e
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| .clang-format | -rw-r--r-- | 15.0 KB |
| .cocciconfig | -rw-r--r-- | 59 bytes |
| .get_maintainer.ignore | -rw-r--r-- | 71 bytes |
| .gitattributes | -rw-r--r-- | 30 bytes |
| .gitignore | -rw-r--r-- | 1.7 KB |
| .mailmap | -rw-r--r-- | 13.1 KB |
| COPYING | -rw-r--r-- | 423 bytes |
| CREDITS | -rw-r--r-- | 97.2 KB |
| Kbuild | -rw-r--r-- | 1.3 KB |
| Kconfig | -rw-r--r-- | 595 bytes |
| MAINTAINERS | -rw-r--r-- | 516.7 KB |
| Makefile | -rw-r--r-- | 59.4 KB |
| README | -rw-r--r-- | 727 bytes |
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