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Message-Id: <1423557587-21254-6-git-send-email-tomas.winkler@intel.com>
Date: Tue, 10 Feb 2015 10:39:36 +0200
From: Tomas Winkler <tomas.winkler@...el.com>
To: gregkh@...uxfoundation.org
Cc: arnd@...db.de, linux-kernel@...r.kernel.org,
Tomas Winkler <tomas.winkler@...el.com>
Subject: [char-misc-next 07/18] mei: fix device reset on mei_cl_irq_read_msg allocation failure
On memory allocation failure mei_cl_irq_read_msg will
return with error that will cause device reset.
Instead we should propagate error to caller and
just clean the read queues.
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
---
drivers/misc/mei/bus.c | 6 +++
drivers/misc/mei/interrupt.c | 117 ++++++++++++++++++++++---------------------
drivers/misc/mei/main.c | 17 +++++--
drivers/misc/mei/mei_dev.h | 2 +
4 files changed, 80 insertions(+), 62 deletions(-)
diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index be767f4db26a..025626f4467d 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -322,10 +322,16 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
goto out;
}
+ if (cb->status) {
+ rets = cb->status;
+ goto free;
+ }
+
r_length = min_t(size_t, length, cb->buf_idx);
memcpy(buf, cb->response_buffer.data, r_length);
rets = r_length;
+free:
mei_io_cb_free(cb);
cl->reading_state = MEI_IDLE;
cl->read_cb = NULL;
diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 711cddfa9c99..587cb04a3cf5 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -69,85 +69,91 @@ static inline int mei_cl_hbm_equal(struct mei_cl *cl,
cl->me_client_id == mei_hdr->me_addr;
}
/**
- * mei_cl_is_reading - checks if the client
- * is the one to read this message
+ * mei_cl_is_reading - checks if the client is in reading state
*
* @cl: mei client
- * @mei_hdr: header of mei message
*
- * Return: true on match and false otherwise
+ * Return: true if the client is reading
*/
-static bool mei_cl_is_reading(struct mei_cl *cl, struct mei_msg_hdr *mei_hdr)
+static bool mei_cl_is_reading(struct mei_cl *cl)
{
- return mei_cl_hbm_equal(cl, mei_hdr) &&
- cl->state == MEI_FILE_CONNECTED &&
+ return cl->state == MEI_FILE_CONNECTED &&
cl->reading_state != MEI_READ_COMPLETE;
}
/**
* mei_cl_irq_read_msg - process client message
*
- * @dev: the device structure
+ * @cl: reading client
* @mei_hdr: header of mei client message
- * @complete_list: An instance of our list structure
+ * @complete_list: completion list
*
- * Return: 0 on success, <0 on failure.
+ * Return: always 0
*/
-static int mei_cl_irq_read_msg(struct mei_device *dev,
+static int mei_cl_irq_read_msg(struct mei_cl *cl,
struct mei_msg_hdr *mei_hdr,
struct mei_cl_cb *complete_list)
{
- struct mei_cl *cl;
- struct mei_cl_cb *cb, *next;
+ struct mei_device *dev = cl->dev;
+ struct mei_cl_cb *cb;
unsigned char *buffer = NULL;
- list_for_each_entry_safe(cb, next, &dev->read_list.list, list) {
- cl = cb->cl;
- if (!mei_cl_is_reading(cl, mei_hdr))
- continue;
+ list_for_each_entry(cb, &dev->read_list.list, list) {
+ if (cl == cb->cl)
+ break;
+ }
- cl->reading_state = MEI_READING;
+ if (&cb->list == &dev->read_list.list) {
+ dev_err(dev->dev, "no reader found\n");
+ goto out;
+ }
- if (cb->response_buffer.size == 0 ||
- cb->response_buffer.data == NULL) {
- cl_err(dev, cl, "response buffer is not allocated.\n");
- list_del(&cb->list);
- return -ENOMEM;
- }
+ if (!mei_cl_is_reading(cl)) {
+ cl_err(dev, cl, "cl is not reading state=%d reading state=%d\n",
+ cl->state, cl->reading_state);
+ goto out;
+ }
- if (cb->response_buffer.size < mei_hdr->length + cb->buf_idx) {
- cl_dbg(dev, cl, "message overflow. size %d len %d idx %ld\n",
- cb->response_buffer.size,
- mei_hdr->length, cb->buf_idx);
- buffer = krealloc(cb->response_buffer.data,
- mei_hdr->length + cb->buf_idx,
- GFP_KERNEL);
-
- if (!buffer) {
- list_del(&cb->list);
- return -ENOMEM;
- }
- cb->response_buffer.data = buffer;
- cb->response_buffer.size =
- mei_hdr->length + cb->buf_idx;
- }
+ cl->reading_state = MEI_READING;
- buffer = cb->response_buffer.data + cb->buf_idx;
- mei_read_slots(dev, buffer, mei_hdr->length);
+ if (cb->response_buffer.size == 0 ||
+ cb->response_buffer.data == NULL) {
+ cl_err(dev, cl, "response buffer is not allocated.\n");
+ list_move_tail(&cb->list, &complete_list->list);
+ cb->status = -ENOMEM;
+ goto out;
+ }
- cb->buf_idx += mei_hdr->length;
- if (mei_hdr->msg_complete) {
- cl->status = 0;
- list_del(&cb->list);
- cl_dbg(dev, cl, "completed read length = %lu\n",
- cb->buf_idx);
- list_add_tail(&cb->list, &complete_list->list);
+ if (cb->response_buffer.size < mei_hdr->length + cb->buf_idx) {
+ cl_dbg(dev, cl, "message overflow. size %d len %d idx %ld\n",
+ cb->response_buffer.size, mei_hdr->length, cb->buf_idx);
+ buffer = krealloc(cb->response_buffer.data,
+ mei_hdr->length + cb->buf_idx,
+ GFP_KERNEL);
+
+ if (!buffer) {
+ cb->status = -ENOMEM;
+ list_move_tail(&cb->list, &complete_list->list);
+ goto out;
}
- break;
+ cb->response_buffer.data = buffer;
+ cb->response_buffer.size = mei_hdr->length + cb->buf_idx;
}
- dev_dbg(dev->dev, "message read\n");
+ buffer = cb->response_buffer.data + cb->buf_idx;
+ mei_read_slots(dev, buffer, mei_hdr->length);
+
+ cb->buf_idx += mei_hdr->length;
+ if (mei_hdr->msg_complete) {
+ cl_dbg(dev, cl, "completed read length = %lu\n",
+ cb->buf_idx);
+ list_move_tail(&cb->list, &complete_list->list);
+ }
+
+out:
if (!buffer) {
+ /* assume that mei_hdr->length <= MEI_RD_MSG_BUF_SIZE */
+ BUG_ON(mei_hdr->length > MEI_RD_MSG_BUF_SIZE);
mei_read_slots(dev, dev->rd_msg_buf, mei_hdr->length);
dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
MEI_HDR_PRM(mei_hdr));
@@ -389,14 +395,10 @@ int mei_irq_read_handler(struct mei_device *dev,
goto end;
}
} else {
- ret = mei_cl_irq_read_msg(dev, mei_hdr, cmpl_list);
- if (ret) {
- dev_err(dev->dev, "mei_cl_irq_read_msg failed = %d\n",
- ret);
- goto end;
- }
+ ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
}
+
reset_slots:
/* reset the number of slots and header */
*slots = mei_count_full_read_slots(dev);
@@ -636,4 +638,3 @@ out:
schedule_delayed_work(&dev->timer_work, 2 * HZ);
mutex_unlock(&dev->device_lock);
}
-
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 3c019c0e60eb..cbdbf4af2bf7 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -192,8 +192,8 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
goto out;
}
- if (cl->read_cb) {
- cb = cl->read_cb;
+ cb = cl->read_cb;
+ if (cb) {
/* read what left */
if (cb->buf_idx > *offset)
goto copy_buffer;
@@ -218,7 +218,8 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
}
if (MEI_READ_COMPLETE != cl->reading_state &&
- !waitqueue_active(&cl->rx_wait)) {
+ !waitqueue_active(&cl->rx_wait)) {
+
if (file->f_flags & O_NONBLOCK) {
rets = -EAGAIN;
goto out;
@@ -248,12 +249,20 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
rets = -ENODEV;
goto out;
}
+
if (cl->reading_state != MEI_READ_COMPLETE) {
rets = 0;
goto out;
}
- /* now copy the data to user space */
+
copy_buffer:
+ /* now copy the data to user space */
+ if (cb->status) {
+ rets = cb->status;
+ dev_dbg(dev->dev, "read operation failed %d\n", rets);
+ goto free;
+ }
+
dev_dbg(dev->dev, "buf.size = %d buf.idx= %ld\n",
cb->response_buffer.size, cb->buf_idx);
if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 102cc6603eba..195e426b08f0 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -199,6 +199,7 @@ struct mei_cl;
* @buf_idx: last read index
* @read_time: last read operation time stamp (iamthif)
* @file_object: pointer to file structure
+ * @status: io status of the cb
* @internal: communication between driver and FW flag
*/
struct mei_cl_cb {
@@ -210,6 +211,7 @@ struct mei_cl_cb {
unsigned long buf_idx;
unsigned long read_time;
struct file *file_object;
+ int status;
u32 internal:1;
};
--
1.9.3
--
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