| Message ID | 1508225421-25405-3-git-send-email-yoshihiro.shimoda.uh@renesas.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Shimoda-san, On Tue, Oct 17, 2017 at 9:30 AM, Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> wrote: > Since this driver checks if the return value of dma_map_sg() is minus > or not and keeps to enable the DMAC, it may cause kernel panic when > the dma_map_sg() returns 0. So, this patch fixes the issue. Thanks for your patch! Indeed: * dma_maps_sg_attrs returns 0 on error and > 0 on success. * It should never return a value < 0. A quick grep shows there are 4 more offenders: - drivers/crypto/qce/ablkcipher.c - drivers/crypto/qce/sha.c - drivers/hsi/controllers/omap_ssi_port.c - drivers/mailbox/bcm-flexrm-mailbox.c > Reported-by: Dirk Behme <dirk.behme@de.bosch.com> > Fixes: 2a68ea7896e3 ("mmc: renesas-sdhi: add support for R-Car Gen3 SDHI DMAC") > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c index 6c9b4b2..378fe88 100644 --- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c +++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c @@ -147,11 +147,8 @@ WARN_ON(host->sg_len > 1); /* This DMAC cannot handle if buffer is not 8-bytes alignment */ - if (!IS_ALIGNED(sg->offset, 8)) { - host->force_pio = true; - renesas_sdhi_internal_dmac_enable_dma(host, false); - return; - } + if (!IS_ALIGNED(sg->offset, 8)) + goto force_pio; if (data->flags & MMC_DATA_READ) { dtran_mode |= DTRAN_MODE_CH_NUM_CH1; @@ -164,8 +161,8 @@ } ret = dma_map_sg(&host->pdev->dev, sg, host->sg_len, dir); - if (ret < 0) - return; + if (ret == 0) + goto force_pio; renesas_sdhi_internal_dmac_enable_dma(host, true); @@ -177,6 +174,12 @@ dtran_mode); renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR, sg->dma_address); + + return; + +force_pio: + host->force_pio = true; + renesas_sdhi_internal_dmac_enable_dma(host, false); } static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)
Since this driver checks if the return value of dma_map_sg() is minus or not and keeps to enable the DMAC, it may cause kernel panic when the dma_map_sg() returns 0. So, this patch fixes the issue. Reported-by: Dirk Behme <dirk.behme@de.bosch.com> Fixes: 2a68ea7896e3 ("mmc: renesas-sdhi: add support for R-Car Gen3 SDHI DMAC") Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> --- drivers/mmc/host/renesas_sdhi_internal_dmac.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)