[POWERPC] spufs: Fix state_mutex leaks

Fix various state_mutex leaks.  The worst one was introduced by the
interrutible state_mutex conversion but there've been a few before
too.  Notably spufs_wait now returns without the state_mutex held
when returning an error, which actually cleans up some code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

4 files changed, 45 insertions, 30 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/fault.c b/arch/powerpc/platforms/cell/spufs/fault.c
index eff4d291ba85..e46d300e21a5 100644
--- a/arch/powerpc/platforms/cell/spufs/fault.c
+++ b/arch/powerpc/platforms/cell/spufs/fault.c
@@ -108,7 +108,7 @@ int spufs_handle_class1(struct spu_context *ctx)
         u64 ea, dsisr, access;
         unsigned long flags;
         unsigned flt = 0;
-        int ret, ret2;
+        int ret;
 
         /*
          * dar and dsisr get passed from the registers
@@ -148,13 +148,10 @@ int spufs_handle_class1(struct spu_context *ctx)
                 ret = spu_handle_mm_fault(current->mm, ea, dsisr, &flt);
 
         /*
-         * If spu_acquire fails due to a pending signal we just want to return
-         * EINTR to userspace even if that means missing the dma restart or
-         * updating the page fault statistics.
+         * This is nasty: we need the state_mutex for all the bookkeeping even
+         * if the syscall was interrupted by a signal. ewww.
          */
-        ret2 = spu_acquire(ctx);
-        if (ret2)
-                goto out;
+        mutex_lock(&ctx->state_mutex);
 
         /*
          * Clear dsisr under ctxt lock after handling the fault, so that
@@ -185,7 +182,6 @@ int spufs_handle_class1(struct spu_context *ctx)
         } else
                 spufs_handle_event(ctx, ea, SPE_EVENT_SPE_DATA_STORAGE);
 
- out:
         spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
         return ret;
 }
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index 1018acd1746b..e4ab9d5a86f0 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -358,6 +358,7 @@ static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
 {
         struct spu_context *ctx = vma->vm_file->private_data;
         unsigned long area, offset = address - vma->vm_start;
+        int ret = 0;
 
         spu_context_nospu_trace(spufs_ps_nopfn__enter, ctx);
 
@@ -379,7 +380,7 @@ static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
         if (ctx->state == SPU_STATE_SAVED) {
                 up_read(&current->mm->mmap_sem);
                 spu_context_nospu_trace(spufs_ps_nopfn__sleep, ctx);
-                spufs_wait(ctx->run_wq, ctx->state == SPU_STATE_RUNNABLE);
+                ret = spufs_wait(ctx->run_wq, ctx->state == SPU_STATE_RUNNABLE);
                 spu_context_trace(spufs_ps_nopfn__wake, ctx, ctx->spu);
                 down_read(&current->mm->mmap_sem);
         } else {
@@ -388,7 +389,8 @@ static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
                 spu_context_trace(spufs_ps_nopfn__insert, ctx, ctx->spu);
         }
 
-        spu_release(ctx);
+        if (!ret)
+                spu_release(ctx);
         return NOPFN_REFAULT;
 }
 
@@ -755,23 +757,25 @@ static ssize_t spufs_ibox_read(struct file *file, char __user *buf,
 
         count = spu_acquire(ctx);
         if (count)
-                return count;
+                goto out;
 
         /* wait only for the first element */
         count = 0;
         if (file->f_flags & O_NONBLOCK) {
-                if (!spu_ibox_read(ctx, &ibox_data))
+                if (!spu_ibox_read(ctx, &ibox_data)) {
                         count = -EAGAIN;
+                        goto out_unlock;
+                }
         } else {
                 count = spufs_wait(ctx->ibox_wq, spu_ibox_read(ctx, &ibox_data));
+                if (count)
+                        goto out;
         }
-        if (count)
-                goto out;
 
         /* if we can't write at all, return -EFAULT */
         count = __put_user(ibox_data, udata);
         if (count)
-                goto out;
+                goto out_unlock;
 
         for (count = 4, udata++; (count + 4) <= len; count += 4, udata++) {
                 int ret;
@@ -788,9 +792,9 @@ static ssize_t spufs_ibox_read(struct file *file, char __user *buf,
                         break;
         }
 
-out:
+out_unlock:
         spu_release(ctx);
-
+out:
         return count;
 }
 
@@ -905,7 +909,7 @@ static ssize_t spufs_wbox_write(struct file *file, const char __user *buf,
 
         count = spu_acquire(ctx);
         if (count)
-                return count;
+                goto out;
 
         /*
          * make sure we can at least write one element, by waiting
@@ -913,14 +917,16 @@ static ssize_t spufs_wbox_write(struct file *file, const char __user *buf,
          */
         count = 0;
         if (file->f_flags & O_NONBLOCK) {
-                if (!spu_wbox_write(ctx, wbox_data))
+                if (!spu_wbox_write(ctx, wbox_data)) {
                         count = -EAGAIN;
+                        goto out_unlock;
+                }
         } else {
                 count = spufs_wait(ctx->wbox_wq, spu_wbox_write(ctx, wbox_data));
+                if (count)
+                        goto out;
         }
 
-        if (count)
-                goto out;
 
         /* write as much as possible */
         for (count = 4, udata++; (count + 4) <= len; count += 4, udata++) {
@@ -934,8 +940,9 @@ static ssize_t spufs_wbox_write(struct file *file, const char __user *buf,
                         break;
         }
 
-out:
+out_unlock:
         spu_release(ctx);
+out:
         return count;
 }
 
@@ -1598,12 +1605,11 @@ static ssize_t spufs_mfc_read(struct file *file, char __user *buffer,
         } else {
                 ret = spufs_wait(ctx->mfc_wq,
                            spufs_read_mfc_tagstatus(ctx, &status));
+                if (ret)
+                        goto out;
         }
         spu_release(ctx);
 
-        if (ret)
-                goto out;
-
         ret = 4;
         if (copy_to_user(buffer, &status, 4))
                 ret = -EFAULT;
@@ -1732,6 +1738,8 @@ static ssize_t spufs_mfc_write(struct file *file, const char __user *buffer,
                 int status;
                 ret = spufs_wait(ctx->mfc_wq,
                                  spu_send_mfc_command(ctx, cmd, &status));
+                if (ret)
+                        goto out;
                 if (status)
                         ret = status;
         }
@@ -1785,7 +1793,7 @@ static int spufs_mfc_flush(struct file *file, fl_owner_t id)
 
         ret = spu_acquire(ctx);
         if (ret)
-                return ret;
+                goto out;
 #if 0
 /* this currently hangs */
         ret = spufs_wait(ctx->mfc_wq,
@@ -1794,12 +1802,13 @@ static int spufs_mfc_flush(struct file *file, fl_owner_t id)
                 goto out;
         ret = spufs_wait(ctx->mfc_wq,
                          ctx->ops->read_mfc_tagstatus(ctx) == ctx->tagwait);
-out:
+        if (ret)
+                goto out;
 #else
         ret = 0;
 #endif
         spu_release(ctx);
-
+out:
         return ret;
 }
 
diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index b4814c740d8a..e9c61a1a8f98 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -354,8 +354,15 @@ long spufs_run_spu(struct spu_context *ctx, u32 *npc, u32 *event)
 
         do {
                 ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, &status));
-                if (unlikely(ret))
+                if (unlikely(ret)) {
+                        /*
+                         * This is nasty: we need the state_mutex for all the
+                         * bookkeeping even if the syscall was interrupted by
+                         * a signal. ewww.
+                         */
+                        mutex_lock(&ctx->state_mutex);
                         break;
+                }
                 spu = ctx->spu;
                 if (unlikely(test_and_clear_bit(SPU_SCHED_NOTIFY_ACTIVE,
                                                 &ctx->sched_flags))) {
diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index 795a1b52538b..2c2fe3c07d72 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -268,6 +268,9 @@ extern char *isolated_loader;
  *      Same as wait_event_interruptible(), except that here
  *      we need to call spu_release(ctx) before sleeping, and
  *      then spu_acquire(ctx) when awoken.
+ *
+ *      Returns with state_mutex re-acquired when successfull or
+ *      with -ERESTARTSYS and the state_mutex dropped when interrupted.
  */
 
 #define spufs_wait(wq, condition)                                       \
@@ -278,11 +281,11 @@ extern char *isolated_loader;
                 prepare_to_wait(&(wq), &__wait, TASK_INTERRUPTIBLE);    \
                 if (condition)                                          \
                         break;                                          \
+                spu_release(ctx);                                       \
                 if (signal_pending(current)) {                          \
                         __ret = -ERESTARTSYS;                           \
                         break;                                          \
                 }                                                       \
-                spu_release(ctx);                                       \
                 schedule();                                             \
                 __ret = spu_acquire(ctx);                               \
                 if (__ret)                                              \