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Subject[PATCH 10/22] spufs: fix missing stop-and-signal
From: Masato Noguchi <Masato.Noguchi@jp.sony.com>

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>

---
run.c | 28 ++++++++++++++++++----------
1 files changed, 18 insertions(+), 10 deletions(-)

Index: linux-2.6/arch/powerpc/platforms/cell/spufs/run.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/run.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/run.c
@@ -79,13 +79,7 @@ static inline int spu_run_fini(struct sp

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, st
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, st

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);
--

-
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