linux_dsm_epyc7002/arch
Tony Luck ce0fa3e56a x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages
Speculative processor accesses may reference any memory that has a
valid page table entry.  While a speculative access won't generate
a machine check, it will log the error in a machine check bank. That
could cause escalation of a subsequent error since the overflow bit
will be then set in the machine check bank status register.

Code has to be double-plus-tricky to avoid mentioning the 1:1 virtual
address of the page we want to map out otherwise we may trigger the
very problem we are trying to avoid.  We use a non-canonical address
that passes through the usual Linux table walking code to get to the
same "pte".

Thanks to Dave Hansen for reviewing several iterations of this.

Also see:

  http://marc.info/?l=linux-mm&m=149860136413338&w=2

Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Elliott, Robert (Persistent Memory) <elliott@hpe.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170816171803.28342-1-tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-17 10:30:49 +02:00
..
alpha Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
arc arc: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:21 +09:00
arm Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
arm64 Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
blackfin Blackfin: flat: Use %x to format u32 2017-07-17 11:40:33 -07:00
c6x Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
cris Kbuild updates for v4.13 (2nd) 2017-07-13 13:37:57 -07:00
frv FRV: tlbflush: move asmlinkage before return type 2017-07-12 16:26:04 -07:00
h8300 h8300: Add missing closing parenthesis in flat_get_addr_from_rp() 2017-07-16 09:24:06 -07:00
hexagon hexagon: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:26 +09:00
ia64 efi: Update efi_mem_type() to return an error rather than 0 2017-07-18 11:38:01 +02:00
m32r Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
m68k blackfin, m68k: Fix flat_set_persistent() for unsigned long to u32 changes 2017-07-16 09:24:06 -07:00
metag metag: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:30 +09:00
microblaze Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
mips Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
mn10300 kernel/watchdog: introduce arch_touch_nmi_watchdog() 2017-07-12 16:26:02 -07:00
nios2 nios2: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:43 +09:00
openrisc openrisc: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:50 +09:00
parisc Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
powerpc Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
s390 Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
score Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
sh Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc 2017-07-17 15:08:29 -07:00
tile Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
um Merge branch 'for-linus-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2017-07-15 10:49:33 -07:00
unicore32 unicore32: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:52 +09:00
x86 x86/mm, mm/hwpoison: Clear PRESENT bit for kernel 1:1 mappings of poison pages 2017-08-17 10:30:49 +02:00
xtensa Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
.gitignore
Kconfig include/linux/string.h: add the option of fortified string.h functions 2017-07-12 16:26:03 -07:00