[PATCH v2] sh: dma: Add missing IS_ERR_OR_NULL test

From: Rolf Evers-Fischer
Date: Wed Jun 12 2019 - 04:39:37 EST


get_dma_channel may return ERR_PTR or NULL, so a check is added.

Changes since v1:
- Removed unnecessary parentheses
- Replaced IS_ERR with IS_ERR_OR_NULL

Signed-off-by: Rolf Evers-Fischer <embedded24@xxxxxxxxxxxxxxxx>
---
arch/sh/drivers/dma/dma-api.c | 20 +++++++++++++++++++-
arch/sh/drivers/dma/dma-sysfs.c | 2 +-
2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/arch/sh/drivers/dma/dma-api.c b/arch/sh/drivers/dma/dma-api.c
index ab9170494dcc..aedce0b9ecc5 100644
--- a/arch/sh/drivers/dma/dma-api.c
+++ b/arch/sh/drivers/dma/dma-api.c
@@ -94,7 +94,7 @@ int get_dma_residue(unsigned int chan)
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = get_dma_channel(chan);

- if (info->ops->get_residue)
+ if (!IS_ERR_OR_NULL(channel) && info->ops->get_residue)
return info->ops->get_residue(channel);

return 0;
@@ -195,6 +195,9 @@ int request_dma(unsigned int chan, const char *dev_id)
int result;

channel = get_dma_channel(chan);
+ if (IS_ERR_OR_NULL(channel))
+ return PTR_ERR(channel);
+
if (atomic_xchg(&channel->busy, 1))
return -EBUSY;

@@ -217,6 +220,9 @@ void free_dma(unsigned int chan)
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = get_dma_channel(chan);

+ if (IS_ERR_OR_NULL(channel))
+ return;
+
if (info->ops->free)
info->ops->free(channel);

@@ -229,6 +235,9 @@ void dma_wait_for_completion(unsigned int chan)
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = get_dma_channel(chan);

+ if (IS_ERR_OR_NULL(channel))
+ return;
+
if (channel->flags & DMA_TEI_CAPABLE) {
wait_event(channel->wait_queue,
(info->ops->get_residue(channel) == 0));
@@ -274,6 +283,9 @@ void dma_configure_channel(unsigned int chan, unsigned long flags)
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = get_dma_channel(chan);

+ if (IS_ERR_OR_NULL(channel))
+ return;
+
if (info->ops->configure)
info->ops->configure(channel, flags);
}
@@ -285,6 +297,9 @@ int dma_xfer(unsigned int chan, unsigned long from,
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = get_dma_channel(chan);

+ if (IS_ERR_OR_NULL(channel))
+ return PTR_ERR(channel);
+
channel->sar = from;
channel->dar = to;
channel->count = size;
@@ -299,6 +314,9 @@ int dma_extend(unsigned int chan, unsigned long op, void *param)
struct dma_info *info = get_dma_info(chan);
struct dma_channel *channel = get_dma_channel(chan);

+ if (IS_ERR_OR_NULL(channel))
+ return PTR_ERR(channel);
+
if (info->ops->extend)
return info->ops->extend(channel, op, param);

diff --git a/arch/sh/drivers/dma/dma-sysfs.c b/arch/sh/drivers/dma/dma-sysfs.c
index 8ef318150f84..6ba5b569d446 100644
--- a/arch/sh/drivers/dma/dma-sysfs.c
+++ b/arch/sh/drivers/dma/dma-sysfs.c
@@ -30,7 +30,7 @@ static ssize_t dma_show_devices(struct device *dev,
struct dma_info *info = get_dma_info(i);
struct dma_channel *channel = get_dma_channel(i);

- if (unlikely(!info) || !channel)
+ if (unlikely(!info) || IS_ERR_OR_NULL(channel))
continue;

len += sprintf(buf + len, "%2d: %14s %s\n",
--
2.21.0