tree 7a10c36fb5078d0bd74308b2298ce12d8be5ad66
parent e4d5474a5b587eebf9596b83d36bf8e282754d2b
author Andy Lutomirski <luto@amacapital.net> 1405993754 -0700
committer Kees Cook <keescook@google.com> 1460143939 -0700

BACKPORT: seccomp,x86,arm,mips,s390: Remove nr parameter from secure_computing

The secure_computing function took a syscall number parameter, but
it only paid any attention to that parameter if seccomp mode 1 was
enabled.  Rather than coming up with a kludge to get the parameter
to work in mode 2, just remove the parameter.

To avoid churn in arches that don't have seccomp filters (and may
not even support syscall_get_nr right now), this leaves the
parameter in secure_computing_strict, which is now a real function.

For ARM, this is a bit ugly due to the fact that ARM conditionally
supports seccomp filters.  Fixing that would probably only be a
couple of lines of code, but it should be coordinated with the audit
maintainers.

This will be a slight slowdown on some arches.  The right fix is to
pass in all of seccomp_data instead of trying to make just the
syscall nr part be fast.

This is a prerequisite for making two-phase seccomp work cleanly.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: x86@kernel.org
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Kees Cook <keescook@chromium.org>

Bug: 28020023
Patchset: seccomp

(cherry picked from kernel/msm commit 7ae89c27e2fa2ef24e374400d9e19aa4f1192f81)
Signed-off-by: Kees Cook <keescook@google.com>
Change-Id: I9ada75ad967c3814fd0657077eee5a709d1549e9