Blackfin: check for bad syscalls after tracing it

We want to report all system calls (even invalid ones) to the tracing
layers, so check the NR only after we've notified.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 14 insertions, 9 deletions

diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 0a9e458d0f7e..6c20044c7f4c 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -626,13 +626,6 @@ ENTRY(_system_call)
         p0 = [sp + PT_ORIG_P0];
 #endif /* CONFIG_IPIPE */
 
-        /* Check the System Call */
-        r7 = __NR_syscall;
-        /* System call number is passed in P0 */
-        r6 = p0;
-        cc = r6 < r7;
-        if ! cc jump .Lbadsys;
-
         /* are we tracing syscalls?*/
         r7 = sp;
         r6.l = lo(ALIGN_PAGE_MASK);
@@ -645,6 +638,12 @@ ENTRY(_system_call)
         CC = BITTST(r7,TIF_SINGLESTEP);
         if CC JUMP _sys_trace;
 
+        /* Make sure the system call # is valid */
+        p4 = __NR_syscall;
+        /* System call number is passed in P0 */
+        cc = p4 <= p0;
+        if cc jump .Lbadsys;
+
         /* Execute the appropriate system call */
 
         p4 = p0;
@@ -741,9 +740,14 @@ _sys_trace:
         r0 = sp;
         pseudo_long_call _syscall_trace_enter, p5;
 
-        /* Execute the appropriate system call */
-
+        /* Make sure the system call # is valid */
         p4 = [SP + PT_P0];
+        p3 = __NR_syscall;
+        cc = p3 <= p4;
+        r0 = -ENOSYS;
+        if cc jump .Lsys_trace_badsys;
+
+        /* Execute the appropriate system call */
         p5.l = _sys_call_table;
         p5.h = _sys_call_table;
         p5 = p5 + (p4 << 2);
@@ -761,6 +765,7 @@ _sys_trace:
         SP += -12;
         call (p5);
         SP += 24;
+.Lsys_trace_badsys:
         [sp + PT_R0] = r0;
 
         r0 = sp;