]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
mm/gup: check page posion status for coredump.
authorAili Yao <yaoaili@kingsoft.com>
Fri, 9 Apr 2021 20:27:19 +0000 (13:27 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 9 Apr 2021 21:54:23 +0000 (14:54 -0700)
commitd3378e86d1822b6d0bebfbc18a8348691c05dfa0
tree2227be458aa753929524f8ecc88ea34050897f36
parenta5c5e441518f1f39da7ed3ef8e61361a9ea90c8b
mm/gup: check page posion status for coredump.

When we do coredump for user process signal, this may be an SIGBUS signal
with BUS_MCEERR_AR or BUS_MCEERR_AO code, which means this signal is
resulted from ECC memory fail like SRAR or SRAO, we expect the memory
recovery work is finished correctly, then the get_dump_page() will not
return the error page as its process pte is set invalid by
memory_failure().

But memory_failure() may fail, and the process's related pte may not be
correctly set invalid, for current code, we will return the poison page,
get it dumped, and then lead to system panic as its in kernel code.

So check the poison status in get_dump_page(), and if TRUE, return NULL.

There maybe other scenario that is also better to check the posion status
and not to panic, so make a wrapper for this check, Thanks to David's
suggestion(<david@redhat.com>).

[akpm@linux-foundation.org: s/0/false/]
[yaoaili@kingsoft.com: is_page_poisoned() arg cannot be null, per Matthew]

Link: https://lkml.kernel.org/r/20210322115233.05e4e82a@alex-virtual-machine
Link: https://lkml.kernel.org/r/20210319104437.6f30e80d@alex-virtual-machine
Signed-off-by: Aili Yao <yaoaili@kingsoft.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Aili Yao <yaoaili@kingsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/gup.c
mm/internal.h