sh: Add SECCOMP_FILTER

Port sh to use the new SECCOMP_FILTER code.
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Rich Felker <dalias@libc.org>

arch/sh/Kconfig

@@ -28,6 +28,7 @@ config SUPERH
 	select GUP_GET_PTE_LOW_HIGH if X2TLB
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_KGDB
+	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_COPY_THREAD_TLS
 	select HAVE_DEBUG_BUGVERBOSE

arch/sh/kernel/entry-common.S

@@ -368,6 +368,8 @@ syscall_trace_entry:
 	mov.l	7f, r11		! Call do_syscall_trace_enter which notifies
 	jsr	@r11	    	! superior (will chomp R[0-7])
 	 nop
+	cmp/eq	#-1, r0
+	bt	syscall_exit
 	mov.l	r0, @(OFF_R0,r15)	! Save return value
 	!			Reload R0-R4 from kernel stack, where the
 	!   	    	    	parent may have modified them using

arch/sh/kernel/ptrace_32.c

@@ -485,8 +485,6 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 {
 	long ret = 0;
 
-	secure_computing_strict(regs->regs[0]);
-
 	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 	    tracehook_report_syscall_entry(regs))
 		/*
@@ -496,6 +494,9 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 		 */
 		ret = -1L;
 
+	if (secure_computing() == -1)
+		return -1;
+
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->regs[0]);
 

tools/testing/selftests/seccomp/seccomp_bpf.c

@@ -122,6 +122,8 @@ struct seccomp_data {
 #  define __NR_seccomp 358
 # elif defined(__s390__)
 #  define __NR_seccomp 348
+# elif defined(__sh__)
+#  define __NR_seccomp 372
 # else
 #  warning "seccomp syscall number unknown for this architecture"
 #  define __NR_seccomp 0xffff
@@ -1622,6 +1624,10 @@ TEST_F(TRACE_poke, getpid_runs_normally)
 # define SYSCALL_SYSCALL_NUM regs[4]
 # define SYSCALL_RET	regs[2]
 # define SYSCALL_NUM_RET_SHARE_REG
+#elif defined(__sh__)
+# define ARCH_REGS	struct pt_regs
+# define SYSCALL_NUM	gpr[3]
+# define SYSCALL_RET	gpr[0]
 #else
 # error "Do not know how to find your architecture's registers and syscalls"
 #endif
@@ -1693,7 +1699,7 @@ void change_syscall(struct __test_metadata *_metadata,
 	EXPECT_EQ(0, ret) {}
 
 #if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
-	defined(__s390__) || defined(__hppa__) || defined(__riscv)
+	defined(__s390__) || defined(__hppa__) || defined(__riscv) || defined(__sh__)
 	{
 		regs.SYSCALL_NUM = syscall;
 	}