| Message ID | 20210814134106.14275-1-biju.das.jz@bp.renesas.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ASoC: sh: rz-ssi: Improve error handling in rz_ssi_dma_request function | expand |
Hi All, I have send v2. So please drop this patch. Cheers, Biju > -----Original Message----- > From: Biju Das <biju.das.jz@bp.renesas.com> > Sent: 14 August 2021 14:41 > To: Jaroslav Kysela <perex@perex.cz>; Takashi Iwai <tiwai@suse.com> > Cc: Biju Das <biju.das.jz@bp.renesas.com>; Liam Girdwood > <lgirdwood@gmail.com>; Mark Brown <broonie@kernel.org>; Prabhakar Mahadev > Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>; alsa-devel@alsa- > project.org; Geert Uytterhoeven <geert+renesas@glider.be>; Chris Paterson > <Chris.Paterson2@renesas.com>; Biju Das <biju.das@bp.renesas.com>; linux- > renesas-soc@vger.kernel.org > Subject: [PATCH] ASoC: sh: rz-ssi: Improve error handling in > rz_ssi_dma_request function > > The rz_ssi_dma_request function only checks the NULL condition for the > value returned by the dma_request_chan function, but this function can > also return an error. If it happens, the subsequent function call to > rz_ssi_dma_slave_config can lead to a kernel crash. > > This patch fixes the issue by checking both error and NULL condition > returned by dma_request_chan. > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> > --- > sound/soc/sh/rz-ssi.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/sound/soc/sh/rz-ssi.c b/sound/soc/sh/rz-ssi.c index > ea8d33ede5d2..3867e2efd3e0 100644 > --- a/sound/soc/sh/rz-ssi.c > +++ b/sound/soc/sh/rz-ssi.c > @@ -676,11 +676,19 @@ static void rz_ssi_release_dma_channels(struct > rz_ssi_priv *ssi) static int rz_ssi_dma_request(struct rz_ssi_priv *ssi, > struct device *dev) { > ssi->playback.dma_ch = dma_request_chan(dev, "tx"); > + if (IS_ERR_OR_NULL(ssi->playback.dma_ch)) > + ssi->playback.dma_ch = NULL; > + > ssi->capture.dma_ch = dma_request_chan(dev, "rx"); > + if (IS_ERR_OR_NULL(ssi->capture.dma_ch)) > + ssi->capture.dma_ch = NULL; > + > if (!ssi->playback.dma_ch && !ssi->capture.dma_ch) { > ssi->playback.dma_ch = dma_request_chan(dev, "rt"); > - if (!ssi->playback.dma_ch) > + if (IS_ERR_OR_NULL(ssi->playback.dma_ch)) { > + ssi->playback.dma_ch = NULL; > goto no_dma; > + } > > ssi->dma_rt = true; > } > -- > 2.17.1
diff --git a/sound/soc/sh/rz-ssi.c b/sound/soc/sh/rz-ssi.c index ea8d33ede5d2..3867e2efd3e0 100644 --- a/sound/soc/sh/rz-ssi.c +++ b/sound/soc/sh/rz-ssi.c @@ -676,11 +676,19 @@ static void rz_ssi_release_dma_channels(struct rz_ssi_priv *ssi) static int rz_ssi_dma_request(struct rz_ssi_priv *ssi, struct device *dev) { ssi->playback.dma_ch = dma_request_chan(dev, "tx"); + if (IS_ERR_OR_NULL(ssi->playback.dma_ch)) + ssi->playback.dma_ch = NULL; + ssi->capture.dma_ch = dma_request_chan(dev, "rx"); + if (IS_ERR_OR_NULL(ssi->capture.dma_ch)) + ssi->capture.dma_ch = NULL; + if (!ssi->playback.dma_ch && !ssi->capture.dma_ch) { ssi->playback.dma_ch = dma_request_chan(dev, "rt"); - if (!ssi->playback.dma_ch) + if (IS_ERR_OR_NULL(ssi->playback.dma_ch)) { + ssi->playback.dma_ch = NULL; goto no_dma; + } ssi->dma_rt = true; }
The rz_ssi_dma_request function only checks the NULL condition for the value returned by the dma_request_chan function, but this function can also return an error. If it happens, the subsequent function call to rz_ssi_dma_slave_config can lead to a kernel crash. This patch fixes the issue by checking both error and NULL condition returned by dma_request_chan. Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> --- sound/soc/sh/rz-ssi.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)