linux-stable/arch/x86/include
Dan Williams 12c89130a5 x86/asm/memcpy_mcsafe: Add write-protection-fault handling
In preparation for using memcpy_mcsafe() to handle user copies it needs
to be to handle write-protection faults while writing user pages. Add
MMU-fault handlers alongside the machine-check exception handlers.

Note that the machine check fault exception handling makes assumptions
about source buffer alignment and poison alignment. In the write fault
case, given the destination buffer is arbitrarily aligned, it needs a
separate / additional fault handling approach. The mcsafe_handle_tail()
helper is reused. The @limit argument is set to @len since there is no
safety concern about retriggering an MMU fault, and this simplifies the
assembly.

Co-developed-by: Tony Luck <tony.luck@intel.com>
Reported-by: Mika Penttilä <mika.penttila@nextfour.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
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 <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: hch@lst.de
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/152539238635.31796.14056325365122961778.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-15 08:32:42 +02:00
..
asm x86/asm/memcpy_mcsafe: Add write-protection-fault handling 2018-05-15 08:32:42 +02:00
uapi/asm x86/ipc: Fix x32 version of shmid64_ds and msqid64_ds 2018-04-27 17:06:29 +02:00