tree d9ac9b78413fc9867d824b109744a180bde72272
parent 8d74ea0edb83a57f793a55bb7360a17af8ade5d1
author Markos Chandras <markos.chandras@imgtec.com> 1406200202 +0100
committer Ralf Baechle <ralf@linux-mips.org> 1409012336 +0200

MIPS: scall64-o32: Fix indirect syscall detection

Commit 4c21b8fd8f14 (MIPS: seccomp: Handle indirect system calls (o32))
added indirect syscall detection for O32 processes running on MIPS64
but it did not work as expected. The reason is the the scall64-o32
implementation differs compared to scall32-o32. In the former, the v0
(syscall number) register contains the absolute syscall number
(4000 + X) whereas in the latter it contains the relative syscall
number (X). Fix the code to avoid doing an extra addition, and load
the v0 register directly to the first argument for syscall_trace_enter.
Moreover, set the .reorder assembler option in order to have better
control on this part of the assembly code.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: http://patchwork.linux-mips.org/patch/7481/
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: James Hogan <james.hogan@imgtec.com>