[PATCH v4 2/3] powerpc: Relax secure computing on syscall entry trace

[Bogdan Purcareata <bogdan.purcareata@freescale.com>]

The secure_computing_strict will just force the kernel to panic on
secure_computing failure. Once SECCOMP_FILTER support is enabled in the kernel,
syscalls can be denied without system failure.

v4:
- rebase on top of 3.19

v3,v2: no changes

Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com>
---
 arch/powerpc/kernel/ptrace.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 2edae06..cb9fd33 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1772,7 +1772,9 @@ long do_syscall_trace_enter(struct pt_regs *regs)
 
 	user_exit();
 
-	secure_computing_strict(regs->gpr[0]);
+	/* Do the secure computing check first; failures should be fast. */
+	if (secure_computing() == -1)
+		return -1L;
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 	    tracehook_report_syscall_entry(regs)) {
-- 
2.1.4