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Message-ID: <CAJuYYwTB-Y8LwnxN-wX=XSSk9tuXHhUCOvwNDmHgRH+uZcyVNQ@mail.gmail.com>
Date: Tue, 16 Oct 2012 16:19:23 +0530
From: Thomas Abraham <thomas.abraham@...aro.org>
To: James Hogan <james.hogan@...tec.com>
Cc: Chris Ball <cjb@...top.org>, Will Newton <will.newton@...tec.com>,
Jaehoon Chung <jh80.chung@...sung.com>,
Seungwon Jeon <tgih.jun@...sung.com>,
linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] dw_mmc: fix multiple drv_data NULL dereferences
On 16 October 2012 14:13, James Hogan <james.hogan@...tec.com> wrote:
> Commit 800d78bfccb3d38116abfda2a5b9c8afdbd5ea21 ("mmc: dw_mmc: add
> support for implementation specific callbacks") merged in v3.7-rc1.
>
> The above commit introduced multiple NULL pointer dereferences when
> the default dw_mci_pltfm_probe() is used, as it sets host->drv_data to
> NULL, and that's only checked against NULL in 1 out of the 7 cases where
> it is dereferenced.
>
> Signed-off-by: James Hogan <james.hogan@...tec.com>
> ---
> drivers/mmc/host/dw_mmc-pltfm.c | 4 ++--
> drivers/mmc/host/dw_mmc.c | 29 +++++++++++++++++------------
> 2 files changed, 19 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c
> index c960ca7..e595721 100644
> --- a/drivers/mmc/host/dw_mmc-pltfm.c
> +++ b/drivers/mmc/host/dw_mmc-pltfm.c
> @@ -50,8 +50,8 @@ int dw_mci_pltfm_register(struct platform_device *pdev,
> if (!host->regs)
> return -ENOMEM;
>
> - if (host->drv_data->init) {
> - ret = host->drv_data->init(host);
> + if (drv_data && drv_data->init) {
> + ret = drv_data->init(host);
> if (ret)
> return ret;
> }
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index c2828f3..0dc6e33 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -232,6 +232,7 @@ static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd)
> {
> struct mmc_data *data;
> struct dw_mci_slot *slot = mmc_priv(mmc);
> + struct dw_mci_drv_data *drv_data = slot->host->drv_data;
> u32 cmdr;
> cmd->error = -EINPROGRESS;
>
> @@ -261,8 +262,8 @@ static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd)
> cmdr |= SDMMC_CMD_DAT_WR;
> }
>
> - if (slot->host->drv_data->prepare_command)
> - slot->host->drv_data->prepare_command(slot->host, &cmdr);
> + if (drv_data && drv_data->prepare_command)
> + drv_data->prepare_command(slot->host, &cmdr);
>
> return cmdr;
> }
> @@ -772,6 +773,7 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
> static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> {
> struct dw_mci_slot *slot = mmc_priv(mmc);
> + struct dw_mci_drv_data *drv_data = slot->host->drv_data;
> u32 regs;
>
> /* set default 1 bit mode */
> @@ -807,8 +809,8 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> slot->clock = ios->clock;
> }
>
> - if (slot->host->drv_data->set_ios)
> - slot->host->drv_data->set_ios(slot->host, ios);
> + if (drv_data && drv_data->set_ios)
> + drv_data->set_ios(slot->host, ios);
>
> switch (ios->power_mode) {
> case MMC_POWER_UP:
> @@ -1815,6 +1817,7 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
> {
> struct mmc_host *mmc;
> struct dw_mci_slot *slot;
> + struct dw_mci_drv_data *drv_data = host->drv_data;
> int ctrl_id, ret;
> u8 bus_width;
>
> @@ -1854,8 +1857,8 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
> } else {
> ctrl_id = to_platform_device(host->dev)->id;
> }
> - if (host->drv_data && host->drv_data->caps)
> - mmc->caps |= host->drv_data->caps[ctrl_id];
> + if (drv_data && drv_data->caps)
> + mmc->caps |= drv_data->caps[ctrl_id];
>
> if (host->pdata->caps2)
> mmc->caps2 = host->pdata->caps2;
> @@ -1867,10 +1870,10 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
> else
> bus_width = 1;
>
> - if (host->drv_data->setup_bus) {
> + if (drv_data && drv_data->setup_bus) {
> struct device_node *slot_np;
> slot_np = dw_mci_of_find_slot_node(host->dev, slot->id);
> - ret = host->drv_data->setup_bus(host, slot_np, bus_width);
> + ret = drv_data->setup_bus(host, slot_np, bus_width);
> if (ret)
> goto err_setup_bus;
> }
> @@ -2035,6 +2038,7 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
> struct dw_mci_board *pdata;
> struct device *dev = host->dev;
> struct device_node *np = dev->of_node;
> + struct dw_mci_drv_data *drv_data = host->drv_data;
> int idx, ret;
>
> pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> @@ -2062,8 +2066,8 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
>
> of_property_read_u32(np, "card-detect-delay", &pdata->detect_delay_ms);
>
> - if (host->drv_data->parse_dt) {
> - ret = host->drv_data->parse_dt(host);
> + if (drv_data && drv_data->parse_dt) {
> + ret = drv_data->parse_dt(host);
> if (ret)
> return ERR_PTR(ret);
> }
> @@ -2080,6 +2084,7 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
>
> int dw_mci_probe(struct dw_mci *host)
> {
> + struct dw_mci_drv_data *drv_data = host->drv_data;
> int width, i, ret = 0;
> u32 fifo_size;
> int init_slots = 0;
> @@ -2127,8 +2132,8 @@ int dw_mci_probe(struct dw_mci *host)
> else
> host->bus_hz = clk_get_rate(host->ciu_clk);
>
> - if (host->drv_data->setup_clock) {
> - ret = host->drv_data->setup_clock(host);
> + if (drv_data && drv_data->setup_clock) {
> + ret = drv_data->setup_clock(host);
> if (ret) {
> dev_err(host->dev,
> "implementation specific clock setup failed\n");
> --
> 1.7.7.6
>
>
Acked-by: Thomas Abraham <thomas.abraham@...aro.org>
--
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