This is incorrect. These values *must* be set before ssif_i2c_send() is
done.
Once ssif_i2c_send() is called, msg_written_handler can be called at any
time after that, including before where you moved the new code.
If I understand this correctly, I think you need to add a variable,
maybe named "bytes_to_write" and do
bytes_to_write = ssif_info->multi_data + ssif_info->multi_pos;
before the comparison and pass bytes_to_write into
ssif_i2c_send().
Thanks,
-corey
On 03/23/2017 02:07 AM, Joeseph Chang wrote:
From: Joeseph Chang <joech...@codeaurora.org>
msg_written_handler() may set ssif_info->multi_data to NULL
when using ipmitool to write fru.
Change the ssif i2c send data sequence in msg_written_handler()
to fix NULL pointer kernel panic and incorrect ssif_info->multi_pos.
Signed-off-by: Joeseph Chang <joech...@codeaurora.org>
---
drivers/char/ipmi/ipmi_ssif.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index cca6e5b..39346ee 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -899,21 +899,13 @@ 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;
- 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_SMBUS_BLOCK_DATA);
+
if (rv < 0) {
/* request failed, just return the error. */
ssif_inc_stat(ssif_info, send_errors);
@@ -922,6 +914,16 @@ 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;
