[POWERPC] spufs: Fix missing stop-and-signal

When there is pending signals, current spufs_run_spu() always returns
-ERESTARTSYS and it is called again automatically.
But, if spe already stopped by stop-and-signal or halt instruction,
returning -ERESTARTSYS makes stop-and-signal/halt lost and
spu run over the end-point.

For your convenience, I attached a sample code to restage this bug.
If there is no bug, printed NPC will be 0x4000.

Signed-off-by: Masato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 18 insertions, 10 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index 88a41d83a79b..c88fd7f9ea74 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -79,13 +79,7 @@ static inline int spu_run_fini(struct spu_context *ctx, u32 * npc,
 
         if (signal_pending(current))
                 ret = -ERESTARTSYS;
-        if (unlikely(current->ptrace & PT_PTRACED)) {
-                if ((*status & SPU_STATUS_STOPPED_BY_STOP)
-                    && (*status >> SPU_STOP_STATUS_SHIFT) == 0x3fff) {
-                        force_sig(SIGTRAP, current);
-                        ret = -ERESTARTSYS;
-                }
-        }
+
         return ret;
 }
 
@@ -232,7 +226,7 @@ long spufs_run_spu(struct file *file, struct spu_context *ctx,
                 if (unlikely(ctx->state != SPU_STATE_RUNNABLE)) {
                         ret = spu_reacquire_runnable(ctx, npc, &status);
                         if (ret)
-                                goto out;
+                                goto out2;
                         continue;
                 }
                 ret = spu_process_events(ctx);
@@ -242,10 +236,24 @@ long spufs_run_spu(struct file *file, struct spu_context *ctx,
 
         ctx->ops->runcntl_stop(ctx);
         ret = spu_run_fini(ctx, npc, &status);
-        if (!ret)
-                ret = status;
         spu_yield(ctx);
 
+out2:
+        if ((ret == 0) ||
+            ((ret == -ERESTARTSYS) &&
+             ((status & SPU_STATUS_STOPPED_BY_HALT) ||
+              ((status & SPU_STATUS_STOPPED_BY_STOP) &&
+               (status >> SPU_STOP_STATUS_SHIFT != 0x2104)))))
+                ret = status;
+
+        if (unlikely(current->ptrace & PT_PTRACED)) {
+                if ((status & SPU_STATUS_STOPPED_BY_STOP)
+                    && (status >> SPU_STOP_STATUS_SHIFT) == 0x3fff) {
+                        force_sig(SIGTRAP, current);
+                        ret = -ERESTARTSYS;
+                }
+        }
+
 out:
         *event = ctx->event_return;
         up(&ctx->run_sema);