diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2018-02-23 11:42:01 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-25 11:03:53 +0100 |
| commit | f136b56017ad7848449ac8b8aaebc340346acbbd (patch) | |
| tree | 6165de4aac4da3dec6e72079514bce617d8f23fd /arch/x86/entry/common.c | |
| parent | 37b33b59ec6096c207d12df2c4b3ab6711fb952c (diff) | |
x86: Implement array_index_mask_nospec
(cherry picked from commit babdde2698d482b6c0de1eab4f697cf5856c5859)
array_index_nospec() uses a mask to sanitize user controllable array
indexes, i.e. generate a 0 mask if 'index' >= 'size', and a ~0 mask
otherwise. While the default array_index_mask_nospec() handles the
carry-bit from the (index - size) result in software.
The x86 array_index_mask_nospec() does the same, but the carry-bit is
handled in the processor CF flag without conditional instructions in the
control flow.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727414808.33451.1873237130672785331.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
[jwang:chery pick to 4.4]
Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/entry/common.c')
0 files changed, 0 insertions, 0 deletions