linux-stable/arch
Jane Chu 5898b43af9 mce: fix set_mce_nospec to always unmap the whole page
The set_memory_uc() approach doesn't work well in all cases.
As Dan pointed out when "The VMM unmapped the bad page from
guest physical space and passed the machine check to the guest."
"The guest gets virtual #MC on an access to that page. When
the guest tries to do set_memory_uc() and instructs cpa_flush()
to do clean caches that results in taking another fault / exception
perhaps because the VMM unmapped the page from the guest."

Since the driver has special knowledge to handle NP or UC,
mark the poisoned page with NP and let driver handle it when
it comes down to repair.

Please refer to discussions here for more details.
https://lore.kernel.org/all/CAPcyv4hrXPb1tASBZUg-GgdVs0OOFKXMXLiHmktg_kFi7YBMyQ@mail.gmail.com/

Now since poisoned page is marked as not-present, in order to
avoid writing to a not-present page and trigger kernel Oops,
also fix pmem_do_write().

Fixes: 284ce4011b ("x86/memory_failure: Introduce {set, clear}_mce_nospec()")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/165272615484.103830.2563950688772226611.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2022-05-16 11:46:44 -07:00
..
alpha Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
arc ARC: remove redundant READ_ONCE() in cmpxchg loop 2022-04-18 14:47:05 -07:00
arm xen: branch for v5.18-rc4 2022-04-23 13:53:21 -07:00
arm64 arm64 fixes for -rc4 2022-04-22 13:49:26 -07:00
csky ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
h8300 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
hexagon ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
ia64 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
m68k Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
microblaze Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
mips - build fix for gpio 2022-04-02 12:14:38 -07:00
nios2 ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
openrisc ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
parisc Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
powerpc powerpc fixes for 5.18 #3 2022-04-24 12:11:20 -07:00
riscv RISC-V: 2022-04-22 17:58:36 -07:00
s390 RISC-V: 2022-04-22 17:58:36 -07:00
sh Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
sparc sparc: cacheflush_32.h needs struct page 2022-04-23 09:27:17 -07:00
um Kbuild fixes for v5.18 2022-04-02 12:33:31 -07:00
x86 mce: fix set_mce_nospec to always unmap the whole page 2022-05-16 11:46:44 -07:00
xtensa xtensa: fix a7 clobbering in coprocessor context load/store 2022-04-15 18:44:02 -07:00
.gitignore
Kconfig vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLOW_HUGE_VMAP 2022-04-19 12:08:57 -07:00