From: Joeseph Chang <joech...@codeaurora.org>
Since patch v1 touch ssif_info->multi_pos and ssif_info->multi_data
after ssif_i2c_send(). msg_written_handler can be called at any time
after ssif_i2c_send(). There is possible to have concurrent access to
ssif_info->multi_pos or ssif_info->multi_data at msg_written_handler.
Revert patch v1 and add new local pointer "i2c_data" which point to
i2c data and size that will be sent out to avoid concurrent access in
msg_written_handler().
Signed-off-by: Joeseph Chang <joech...@codeaurora.org>
---
drivers/char/ipmi/ipmi_ssif.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 39346ee..f36f018 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -852,6 +852,7 @@ static void msg_written_handler(struct ssif_info
*ssif_info, int result,
unsigned char *data, unsigned int len)
{
int rv;
+ unsigned char *i2c_data;
/* We are single-threaded here, so no need for a lock. */
if (result < 0) {
@@ -899,13 +900,22 @@ static void msg_written_handler(struct ssif_info
*ssif_info, int result,
left = 32;
/* Length byte. */
ssif_info->multi_data[ssif_info->multi_pos] = left;
+ i2c_data = ssif_info->multi_data + ssif_info->multi_pos;
+ ssif_info->multi_pos += left;
+ if (left < 32)
+ /*
+ * Write is finished. Note that we must end
+ * with a write of less than 32 bytes to
+ * complete the transaction, even if it is
+ * zero bytes.
+ */
+ ssif_info->multi_data = NULL;
rv = ssif_i2c_send(ssif_info, msg_written_handler,
I2C_SMBUS_WRITE,
SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
- ssif_info->multi_data + ssif_info->multi_pos,
+ i2c_data,
I2C_SMBUS_BLOCK_DATA);
-
if (rv < 0) {
/* request failed, just return the error. */
ssif_inc_stat(ssif_info, send_errors);
@@ -914,16 +924,6 @@ static void msg_written_handler(struct ssif_info
*ssif_info, int result,
pr_info("Error from i2c_non_blocking_op(3)\n");
msg_done_handler(ssif_info, -EIO, NULL, 0);
}
-
- ssif_info->multi_pos += left;
- if (left < 32)
- /*
- * Write is finished. Note that we must end
- * with a write of less than 32 bytes to
- * complete the transaction, even if it is
- * zero bytes.
- */
- ssif_info->multi_data = NULL;
} else {
/* Ready to request the result. */
unsigned long oflags, *flags;
--
1.9.1
