x86/signals: Add build-time checks to the siginfo compat code

There were at least 3 features added to the __SI_FAULT area of the
siginfo struct that did not make it to the compat siginfo:

	1. The si_addr_lsb used in SIGBUS's sent for machine checks
	2. The upper/lower bounds for MPX SIGSEGV faults
	3. The protection key for pkey faults

There was also some turmoil when I was attempting to add the pkey
field because it needs to be a fixed size on 32 and 64-bit and
not have any alignment constraints.

This patch adds some compile-time checks to the compat code to
make it harder to screw this up.  Basically, the checks are
supposed to trip any time someone changes the siginfo structure.
That sounds bad, but it's what we want.  If someone changes
siginfo, we want them to also be _forced_ to go look at the
compat code.

The details are in the comments.

Signed-off-by: Dave Hansen <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[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]>
Cc: Tony Luck <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions