]> git.karo-electronics.de Git - karo-tx-linux.git/commit
x86/mm, x86/mce: Add memcpy_mcsafe()
authorTony Luck <tony.luck@intel.com>
Thu, 18 Feb 2016 19:47:26 +0000 (11:47 -0800)
committerIngo Molnar <mingo@kernel.org>
Tue, 8 Mar 2016 16:54:38 +0000 (17:54 +0100)
commit92b0729c34cab1f46d89aace3e66015f0bb4a682
treec1509bb8d1dc7044bb2d68a280799e4ccdca2da9
parentea2ca36b658cfc6081ee454e97593c81f646806e
x86/mm, x86/mce: Add memcpy_mcsafe()

Make use of the EXTABLE_FAULT exception table entries to write
a kernel copy routine that doesn't crash the system if it
encounters a machine check. Prime use case for this is to copy
from large arrays of non-volatile memory used as storage.

We have to use an unrolled copy loop for now because current
hardware implementations treat a machine check in "rep mov"
as fatal. When that is fixed we can simplify.

Return type is a "bool". True means that we copied OK, false means
that it didn't.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@gmail.com>
Link: http://lkml.kernel.org/r/a44e1055efc2d2a9473307b22c91caa437aa3f8b.1456439214.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/include/asm/string_64.h
arch/x86/kernel/x8664_ksyms_64.c
arch/x86/lib/memcpy_64.S