ARM: 7578/1: arch/move secure_computing into trace

There is very little difference in the TIF_SECCOMP and TIF_SYSCALL_WORK
path in entry-common.S, so merge TIF_SECCOMP into TIF_SYSCALL_WORK and
move seccomp into the syscall_trace_enter() handler.

Expanded some of the tracehook logic into the callers to make this code
more readable. Since tracehook needs to do register changing, this portion
is best left in its own function instead of copy/pasting into the callers.

Additionally, the return value for secure_computing() is now checked
and a -1 value will result in the system call being skipped.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Drewry <wad@chromium.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 0 insertions, 10 deletions

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 417bac1846bd..b621871dd277 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -417,16 +417,6 @@ local_restart:
         ldr     r10, [tsk, #TI_FLAGS]           @ check for syscall tracing
         stmdb   sp!, {r4, r5}                   @ push fifth and sixth args
 
-#ifdef CONFIG_SECCOMP
-        tst     r10, #_TIF_SECCOMP
-        beq     1f
-        mov     r0, scno
-        bl      __secure_computing      
-        add     r0, sp, #S_R0 + S_OFF           @ pointer to regs
-        ldmia   r0, {r0 - r3}                   @ have to reload r0 - r3
-1:
-#endif
-
         tst     r10, #_TIF_SYSCALL_WORK         @ are we tracing syscalls?
         bne     __sys_trace