1 files changed, 43 insertions, 5 deletions

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 167c5edecad4..50b26f12d63c 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -19,6 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/audit.h>
 #include <linux/compat.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
@@ -26,6 +27,7 @@
 #include <linux/smp.h>
 #include <linux/ptrace.h>
 #include <linux/user.h>
+#include <linux/seccomp.h>
 #include <linux/security.h>
 #include <linux/init.h>
 #include <linux/signal.h>
@@ -39,6 +41,7 @@
 #include <asm/compat.h>
 #include <asm/debug-monitors.h>
 #include <asm/pgtable.h>
+#include <asm/syscall.h>
 #include <asm/traps.h>
 #include <asm/system_misc.h>
 
@@ -1076,7 +1079,19 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 long arch_ptrace(struct task_struct *child, long request,
 		 unsigned long addr, unsigned long data)
 {
-	return ptrace_request(child, request, addr, data);
+	int ret;
+
+	switch (request) {
+		case PTRACE_SET_SYSCALL:
+			task_pt_regs(child)->syscallno = data;
+			ret = 0;
+			break;
+		default:
+			ret = ptrace_request(child, request, addr, data);
+			break;
+	}
+
+	return ret;
 }
 
 enum ptrace_syscall_dir {
@@ -1108,19 +1123,42 @@ static void tracehook_report_syscall(struct pt_regs *regs,
 
 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 {
+	unsigned int saved_syscallno = regs->syscallno;
+
+	/* Do the secure computing check first; failures should be fast. */
+	if (secure_computing(regs->syscallno) == -1)
+		return RET_SKIP_SYSCALL_TRACE;
+
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
 
-	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
-		trace_sys_enter(regs, regs->syscallno);
+	if (IS_SKIP_SYSCALL(regs->syscallno)) {
+		/*
+		 * RESTRICTION: we can't modify a return value of user
+		 * issued syscall(-1) here. In order to ease this flavor,
+		 * we need to treat whatever value in x0 as a return value,
+		 * but this might result in a bogus value being returned.
+		 */
+		/*
+		 * NOTE: syscallno may also be set to -1 if fatal signal is
+		 * detected in tracehook_report_syscall_entry(), but since
+		 * a value set to x0 here is not used in this case, we may
+		 * neglect the case.
+		 */
+		if (!test_thread_flag(TIF_SYSCALL_TRACE) ||
+				(IS_SKIP_SYSCALL(saved_syscallno)))
+			regs->regs[0] = -ENOSYS;
+	}
+
+	audit_syscall_entry(syscall_get_arch(), regs->syscallno,
+		regs->orig_x0, regs->regs[1], regs->regs[2], regs->regs[3]);
 
 	return regs->syscallno;
 }
 
 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 {
-	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
-		trace_sys_exit(regs, regs_return_value(regs));
+	audit_syscall_exit(regs);
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);