On Tue, Feb 16, 2021 at 11:17 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> Smatch complains that sometimes when we return success we are holding
> the mutex and sometimes we have released the mutex. It turns out that
> the bug is a missing error code if the mbox is not ready. It should
> return -EBUSY instead of success.
>
> Fixes: cc1967ac93ab ("cxl/mem: Find device capabilities")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> drivers/cxl/mem.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
> index 3bca8451348a..2ebc84e4d202 100644
> --- a/drivers/cxl/mem.c
> +++ b/drivers/cxl/mem.c
> @@ -383,8 +383,8 @@ static int __cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm,
> static int cxl_mem_mbox_get(struct cxl_mem *cxlm)
> {
> struct device *dev = &cxlm->pdev->dev;
> - int rc = -EBUSY;
> u64 md_status;
> + int rc;
>
> mutex_lock_io(&cxlm->mbox_mutex);
>
> @@ -414,6 +414,7 @@ static int cxl_mem_mbox_get(struct cxl_mem *cxlm)
> md_status = readq(cxlm->memdev_regs + CXLMDEV_STATUS_OFFSET);
> if (!(md_status & CXLMDEV_MBOX_IF_READY && CXLMDEV_READY(md_status))) {
> dev_err(dev, "mbox: reported doorbell ready, but not mbox ready\n");
> + rc = -EBUSY;
> goto out;
Hey, Smatch gave a more thorough report than Coverity:
http://lore.kernel.org/r/20210215195313.90231-1-colin.king@xxxxxxxxxxxxx
