diff options
| author | Tony Luck <tony.luck@intel.com> | 2016-02-18 11:47:26 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-03-08 17:54:38 +0100 |
| commit | 92b0729c34cab1f46d89aace3e66015f0bb4a682 (patch) | |
| tree | c1509bb8d1dc7044bb2d68a280799e4ccdca2da9 /arch/x86/kernel/x8664_ksyms_64.c | |
| parent | ea2ca36b658cfc6081ee454e97593c81f646806e (diff) | |
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>
Diffstat (limited to 'arch/x86/kernel/x8664_ksyms_64.c')
| -rw-r--r-- | arch/x86/kernel/x8664_ksyms_64.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index a0695be19864..cd05942bc918 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -37,6 +37,8 @@ EXPORT_SYMBOL(__copy_user_nocache); EXPORT_SYMBOL(_copy_from_user); EXPORT_SYMBOL(_copy_to_user); +EXPORT_SYMBOL_GPL(memcpy_mcsafe); + EXPORT_SYMBOL(copy_page); EXPORT_SYMBOL(clear_page); |