Blackfin arch: Fix bugs - Make kgdb code apparent to app debugging.

 - Skip single step if global interrupt disable bit is set.
 - Extend bernds' patch r4673 to skip single step in any interrupt entry
   that interrupts the code which is under single stepping. Bernds' patch
   only allow user space single stepping.

Singed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 3db2f4df261b..4bd971e81f1f 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -163,6 +163,8 @@ ENTRY(_ex_single_step)
         p5.l = lo(IPEND);
         p5.h = hi(IPEND);
         r6 = [p5];
+        cc = bittst(r6, 4);
+        if cc jump _bfin_return_from_exception;
         cc = bittst(r6, 5);
         if cc jump _bfin_return_from_exception;
 
@@ -186,10 +188,9 @@ ENTRY(_ex_single_step)
         if cc jump .Ldo_single_step;
         r6 += -1;
         cc = r6 < r7;
-        if cc jump _bfin_return_from_exception;
+        if cc jump 1f;
 .Ldo_single_step:
-#endif
-
+#else
         /* If we were in user mode, do the single step normally.  */
         p5.l = lo(IPEND);
         p5.h = hi(IPEND);
@@ -198,6 +199,7 @@ ENTRY(_ex_single_step)
         r7 = r7 & r6;
         cc = r7 == 0;
         if !cc jump 1f;
+#endif
 
         /* Single stepping only a single instruction, so clear the trace
          * bit here.  */