svn commit: r319206 - stable/11/sys/arm64/arm64

[Andrew Turner]

Author: andrew
Date: Tue May 30 13:21:43 2017
New Revision: 319206
URL: https://svnweb.freebsd.org/changeset/base/319206

Log:
  MFC r317197:
  
  Restrict the arm64 supervisor all instructions to only allow a zero
  immediate value for system calls. We may wish to use other values in the
  future for other purposes.

Modified:
  stable/11/sys/arm64/arm64/trap.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/arm64/arm64/trap.c
==============================================================================
--- stable/11/sys/arm64/arm64/trap.c	Tue May 30 13:16:06 2017	(r319205)
+++ stable/11/sys/arm64/arm64/trap.c	Tue May 30 13:21:43 2017	(r319206)
@@ -135,8 +135,13 @@ svc_handler(struct thread *td, struct trapframe *frame
 	struct syscall_args sa;
 	int error;
 
-	error = syscallenter(td, &sa);
-	syscallret(td, error, &sa);
+	if ((frame->tf_esr & ESR_ELx_ISS_MASK) == 0) {
+		error = syscallenter(td, &sa);
+		syscallret(td, error, &sa);
+	} else {
+		call_trapsignal(td, SIGILL, ILL_ILLOPN, (void *)frame->tf_elr);
+		userret(td, frame);
+	}
 }
 
 static void