microblaze: fix handling of multiple pending signals

We need to keep building sigframes until no pending signals remain.
Wrap do_notify_resume() calls into loops; do _not_ allow syscall
restart logics to trigger after the first iteration.

Incidentally, comments about pending signals that should (somehow)
be in r18 are pure BS.  Doesn't work that way and cannot work that
way, sorry...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 11 insertions, 2 deletions

diff --git a/arch/microblaze/kernel/entry-nommu.S b/arch/microblaze/kernel/entry-nommu.S
index 96f97f845495..7e394fc2c439 100644
--- a/arch/microblaze/kernel/entry-nommu.S
+++ b/arch/microblaze/kernel/entry-nommu.S
@@ -124,6 +124,7 @@ ret_from_intr:
         lwi     r11, r1, PT_MODE
         bneid   r11, no_intr_resched
 
+3:
         lwi     r6, r31, TS_THREAD_INFO /* get thread info */
         lwi     r19, r6, TI_FLAGS       /* get flags in thread info */
                                 /* do an extra work if any bits are set */
@@ -132,11 +133,13 @@ ret_from_intr:
         beqi    r11, 1f
         bralid  r15, schedule
         nop
+        bri     3b
 1:      andi    r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
         beqid   r11, no_intr_resched
         addk    r5, r1, r0
         bralid  r15, do_notify_resume
         addk    r6, r0, r0
+        bri     3b
 
 no_intr_resched:
         /* Disable interrupts, we are now committed to the state restore */
@@ -486,18 +489,24 @@ ENTRY(ret_from_kernel_thread)
 work_pending:
         lwi     r11, r1, PT_MODE
         bneid   r11, 2f
+3:
         enable_irq
-
         andi    r11, r19, _TIF_NEED_RESCHED
         beqi    r11, 1f
         bralid  r15, schedule
         nop
+        bri     4f
 1:      andi    r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME
         beqi    r11, no_work_pending
         addk    r5, r30, r0
         bralid  r15, do_notify_resume
         addik   r6, r0, 1
-        bri     no_work_pending
+        addk    r30, r0, r0     /* no restarts from now on */
+4:
+        disable_irq
+        lwi     r6, r31, TS_THREAD_INFO /* get thread info */
+        lwi     r19, r6, TI_FLAGS /* get flags in thread info */
+        bri     3b
 
 ENTRY(ret_to_user)
         disable_irq