[PATCH 1/4] spufs: fix state_mutex leaks
Jeremy Kerr
jk at ozlabs.org
Fri Feb 8 15:50:41 EST 2008
From: Christoph Hellwig <hch at lst.de>
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 at lst.de>
Signed-off-by: Luke Browning <lukebrowning at us.ibm.com>
Signed-off-by: Jeremy Kerr <jk at ozlabs.org>
---
arch/powerpc/platforms/cell/spufs/fault.c | 12 ++-----
arch/powerpc/platforms/cell/spufs/file.c | 49 +++++++++++++++++-------------
arch/powerpc/platforms/cell/spufs/run.c | 9 ++++-
arch/powerpc/platforms/cell/spufs/spufs.h | 5 ++-
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 eff4d29..e46d300 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 1018acd..e4ab9d5 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(¤t->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(¤t->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 b4814c7..e9c61a1 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 795a1b5..2c2fe3c 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) \
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