x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptions

The SDM says that debug exceptions clear BTF, and we need to keep
TIF_BLOCKSTEP in sync with BTF.  Clear it unconditionally and improve
the comment.

I suspect that the fact that kmemcheck could cause TIF_BLOCKSTEP not
to be cleared was just an oversight.

Signed-off-by: Andy Lutomirski <[email protected]>
Cc: Andrew Cooper <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/fa86e55d196e6dde5b38839595bde2a292c52fdc.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions