Re: [PATCH] scsi: cxlflash: Mark expected switch fall-throughs

Kees Cook
2019-07-29T16:47:50Z

On Sun, Jul 28, 2019 at 07:21:19PM -0500, Gustavo A. R. Silva wrote:
> Mark switch cases where we are expecting to fall through.
>
> This patch fixes the following warnings:
>
> drivers/scsi/cxlflash/main.c: In function 'send_afu_cmd':
> drivers/scsi/cxlflash/main.c:2347:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
> if (rc) {
> ^
> drivers/scsi/cxlflash/main.c:2357:2: note: here
> case -EAGAIN:
> ^~~~
> drivers/scsi/cxlflash/main.c: In function 'term_intr':
> drivers/scsi/cxlflash/main.c:754:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
> if (index == PRIMARY_HWQ)
> ^
> drivers/scsi/cxlflash/main.c:756:2: note: here
> case UNMAP_TWO:
> ^~~~
> drivers/scsi/cxlflash/main.c:757:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
> cfg->ops->unmap_afu_irq(hwq->ctx_cookie, 2, hwq);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/scsi/cxlflash/main.c:758:2: note: here
> case UNMAP_ONE:
> ^~~~
> drivers/scsi/cxlflash/main.c:759:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
> cfg->ops->unmap_afu_irq(hwq->ctx_cookie, 1, hwq);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/scsi/cxlflash/main.c:760:2: note: here
> case FREE_IRQ:
> ^~~~
> drivers/scsi/cxlflash/main.c: In function 'cxlflash_remove':
> drivers/scsi/cxlflash/main.c:975:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
> cxlflash_release_chrdev(cfg);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/scsi/cxlflash/main.c:976:2: note: here
> case INIT_STATE_SCSI:
> ^~~~
> drivers/scsi/cxlflash/main.c:978:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
> scsi_remove_host(cfg->host);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/scsi/cxlflash/main.c:979:2: note: here
> case INIT_STATE_AFU:
> ^~~~
> drivers/scsi/cxlflash/main.c:980:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
> term_afu(cfg);
> ^~~~~~~~~~~~~
> drivers/scsi/cxlflash/main.c:981:2: note: here
> case INIT_STATE_PCI:
> ^~~~
> drivers/scsi/cxlflash/main.c:983:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
> pci_disable_device(pdev);
> ^~~~~~~~~~~~~~~~~~~~~~~~
> drivers/scsi/cxlflash/main.c:984:2: note: here
> case INIT_STATE_NONE:
> ^~~~
> drivers/scsi/cxlflash/main.c: In function 'num_hwqs_store':
> drivers/scsi/cxlflash/main.c:3018:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
> if (cfg->state == STATE_NORMAL)
> ^
> drivers/scsi/cxlflash/main.c:3020:2: note: here
> default:
> ^~~~~~~
>
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
> drivers/scsi/cxlflash/main.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
> index b1f4724efde2..93ef97af22df 100644
> --- a/drivers/scsi/cxlflash/main.c
> +++ b/drivers/scsi/cxlflash/main.c
> @@ -753,10 +753,13 @@ static void term_intr(struct cxlflash_cfg *cfg, enum undo_level level,
> /* SISL_MSI_ASYNC_ERROR is setup only for the primary HWQ */
> if (index == PRIMARY_HWQ)
> cfg->ops->unmap_afu_irq(hwq->ctx_cookie, 3, hwq);
> + /* fall through */
> case UNMAP_TWO:
> cfg->ops->unmap_afu_irq(hwq->ctx_cookie, 2, hwq);
> + /* fall through */
> case UNMAP_ONE:
> cfg->ops->unmap_afu_irq(hwq->ctx_cookie, 1, hwq);
> + /* fall through */
> case FREE_IRQ:
> cfg->ops->free_afu_irqs(hwq->ctx_cookie);
> /* fall through */
> @@ -973,14 +976,18 @@ static void cxlflash_remove(struct pci_dev *pdev)
> switch (cfg->init_state) {
> case INIT_STATE_CDEV:
> cxlflash_release_chrdev(cfg);
> + /* fall through */
> case INIT_STATE_SCSI:
> cxlflash_term_local_luns(cfg);
> scsi_remove_host(cfg->host);
> + /* fall through */
> case INIT_STATE_AFU:
> term_afu(cfg);
> + /* fall through */
> case INIT_STATE_PCI:
> cfg->ops->destroy_afu(cfg->afu_cookie);
> pci_disable_device(pdev);
> + /* fall through */
> case INIT_STATE_NONE:
> free_mem(cfg);
> scsi_host_put(cfg->host);
> @@ -2353,11 +2360,11 @@ static int send_afu_cmd(struct afu *afu, struct sisl_ioarcb *rcb)
> cxlflash_schedule_async_reset(cfg);
> break;
> }
> - /* fall through to retry */
> + /* fall through - to retry */
> case -EAGAIN:
> if (++nretry < 2)
> goto retry;
> - /* fall through to exit */
> + /* fall through - to exit */
> default:
> break;
> }
> @@ -3017,6 +3024,7 @@ static ssize_t num_hwqs_store(struct device *dev,
> wait_event(cfg->reset_waitq, cfg->state != STATE_RESET);
> if (cfg->state == STATE_NORMAL)
> goto retry;
> + /* else, fall through */
> default:
> /* Ideally should not happen */
> dev_err(dev, "%s: Device is not ready, state=%d\n",
> --
> 2.22.0
>

--
Kees Cook