From 3cdbefdd31462461c6b554a361d414c7b9033405 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Thu, 27 May 2021 23:10:56 +0200 Subject: [PATCH] spi: Cleanup on failure of initial setup [ Upstream commit 2ec6f20b33eb4f62ab90bdcd620436c883ec3af6 ] Commit c7299fea6769 ("spi: Fix spi device unregister flow") changed the SPI core's behavior if the ->setup() hook returns an error upon adding an spi_device: Before, the ->cleanup() hook was invoked to free any allocations that were made by ->setup(). With the commit, that's no longer the case, so the ->setup() hook is expected to free the allocations itself. I've identified 5 drivers which depend on the old behavior and am fixing them up hereinafter: spi-bitbang.c spi-fsl-spi.c spi-omap-uwire.c spi-omap2-mcspi.c spi-pxa2xx.c Importantly, ->setup() is not only invoked on spi_device *addition*: It may subsequently be called to *change* SPI parameters. If changing these SPI parameters fails, freeing memory allocations would be wrong. That should only be done if the spi_device is finally destroyed. I am therefore using a bool "initial_setup" in 4 of the affected drivers to differentiate between the invocation on *adding* the spi_device and any subsequent invocations: spi-bitbang.c spi-fsl-spi.c spi-omap-uwire.c spi-omap2-mcspi.c In spi-pxa2xx.c, it seems the ->setup() hook can only fail on spi_device addition, not any subsequent calls. It therefore doesn't need the bool. It's worth noting that 5 other drivers already perform a cleanup if the ->setup() hook fails. Before c7299fea6769, they caused a double-free if ->setup() failed on spi_device addition. Since the commit, they're fine. These drivers are: spi-mpc512x-psc.c spi-pl022.c spi-s3c64xx.c spi-st-ssc4.c spi-tegra114.c (spi-pxa2xx.c also already performs a cleanup, but only in one of several error paths.) Fixes: c7299fea6769 ("spi: Fix spi device unregister flow") Signed-off-by: Lukas Wunner Cc: Saravana Kannan Acked-by: Andy Shevchenko # pxa2xx Link: https://lore.kernel.org/r/f76a0599469f265b69c371538794101fa37b5536.1622149321.git.lukas@wunner.de Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-bitbang.c | 18 ++++++++++++---- drivers/spi/spi-fsl-spi.c | 4 ++++ drivers/spi/spi-omap-uwire.c | 9 +++++++- drivers/spi/spi-omap2-mcspi.c | 39 +++++++++++++++++++++-------------- drivers/spi/spi-pxa2xx.c | 9 +++++++- 5 files changed, 57 insertions(+), 22 deletions(-) diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c index d84e22dd6f9f..7d61a3b71ee5 100644 --- a/drivers/spi/spi-bitbang.c +++ b/drivers/spi/spi-bitbang.c @@ -181,6 +181,8 @@ int spi_bitbang_setup(struct spi_device *spi) { struct spi_bitbang_cs *cs = spi->controller_state; struct spi_bitbang *bitbang; + bool initial_setup = false; + int retval; bitbang = spi_master_get_devdata(spi->master); @@ -189,22 +191,30 @@ int spi_bitbang_setup(struct spi_device *spi) if (!cs) return -ENOMEM; spi->controller_state = cs; + initial_setup = true; } /* per-word shift register access, in hardware or bitbanging */ cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)]; - if (!cs->txrx_word) - return -EINVAL; + if (!cs->txrx_word) { + retval = -EINVAL; + goto err_free; + } if (bitbang->setup_transfer) { - int retval = bitbang->setup_transfer(spi, NULL); + retval = bitbang->setup_transfer(spi, NULL); if (retval < 0) - return retval; + goto err_free; } dev_dbg(&spi->dev, "%s, %u nsec/bit\n", __func__, 2 * cs->nsecs); return 0; + +err_free: + if (initial_setup) + kfree(cs); + return retval; } EXPORT_SYMBOL_GPL(spi_bitbang_setup); diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index 18a93a2854d8..02b999d48ca1 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -442,6 +442,7 @@ static int fsl_spi_setup(struct spi_device *spi) { struct mpc8xxx_spi *mpc8xxx_spi; struct fsl_spi_reg *reg_base; + bool initial_setup = false; int retval; u32 hw_mode; struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi); @@ -454,6 +455,7 @@ static int fsl_spi_setup(struct spi_device *spi) if (!cs) return -ENOMEM; spi_set_ctldata(spi, cs); + initial_setup = true; } mpc8xxx_spi = spi_master_get_devdata(spi->master); @@ -477,6 +479,8 @@ static int fsl_spi_setup(struct spi_device *spi) retval = fsl_spi_setup_transfer(spi, NULL); if (retval < 0) { cs->hw_mode = hw_mode; /* Restore settings */ + if (initial_setup) + kfree(cs); return retval; } diff --git a/drivers/spi/spi-omap-uwire.c b/drivers/spi/spi-omap-uwire.c index ce8dbdbce312..85ee907e28f9 100644 --- a/drivers/spi/spi-omap-uwire.c +++ b/drivers/spi/spi-omap-uwire.c @@ -424,15 +424,22 @@ done: static int uwire_setup(struct spi_device *spi) { struct uwire_state *ust = spi->controller_state; + bool initial_setup = false; + int status; if (ust == NULL) { ust = kzalloc(sizeof(*ust), GFP_KERNEL); if (ust == NULL) return -ENOMEM; spi->controller_state = ust; + initial_setup = true; } - return uwire_setup_transfer(spi, NULL); + status = uwire_setup_transfer(spi, NULL); + if (status && initial_setup) + kfree(ust); + + return status; } static void uwire_cleanup(struct spi_device *spi) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 7646b4b56bed..38f4be209234 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -1043,8 +1043,25 @@ static void omap2_mcspi_release_dma(struct spi_master *master) } } +static void omap2_mcspi_cleanup(struct spi_device *spi) +{ + struct omap2_mcspi_cs *cs; + + if (spi->controller_state) { + /* Unlink controller state from context save list */ + cs = spi->controller_state; + list_del(&cs->node); + + kfree(cs); + } + + if (gpio_is_valid(spi->cs_gpio)) + gpio_free(spi->cs_gpio); +} + static int omap2_mcspi_setup(struct spi_device *spi) { + bool initial_setup = false; int ret; struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); struct omap2_mcspi_regs *ctx = &mcspi->ctx; @@ -1062,6 +1079,7 @@ static int omap2_mcspi_setup(struct spi_device *spi) spi->controller_state = cs; /* Link this to context save list */ list_add_tail(&cs->node, &ctx->cs); + initial_setup = true; if (gpio_is_valid(spi->cs_gpio)) { ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev)); @@ -1077,33 +1095,22 @@ static int omap2_mcspi_setup(struct spi_device *spi) ret = pm_runtime_get_sync(mcspi->dev); if (ret < 0) { pm_runtime_put_noidle(mcspi->dev); + if (initial_setup) + omap2_mcspi_cleanup(spi); return ret; } ret = omap2_mcspi_setup_transfer(spi, NULL); + if (ret && initial_setup) + omap2_mcspi_cleanup(spi); + pm_runtime_mark_last_busy(mcspi->dev); pm_runtime_put_autosuspend(mcspi->dev); return ret; } -static void omap2_mcspi_cleanup(struct spi_device *spi) -{ - struct omap2_mcspi_cs *cs; - - if (spi->controller_state) { - /* Unlink controller state from context save list */ - cs = spi->controller_state; - list_del(&cs->node); - - kfree(cs); - } - - if (gpio_is_valid(spi->cs_gpio)) - gpio_free(spi->cs_gpio); -} - static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data) { struct omap2_mcspi *mcspi = data; diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index f5a10a94f156..e32d51f27944 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -1241,6 +1241,8 @@ static int setup_cs(struct spi_device *spi, struct chip_data *chip, chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH; err = gpiod_direction_output(gpiod, !chip->gpio_cs_inverted); + if (err) + gpiod_put(chip->gpiod_cs); } return err; @@ -1254,6 +1256,7 @@ static int setup(struct spi_device *spi) struct driver_data *drv_data = spi_controller_get_devdata(spi->controller); uint tx_thres, tx_hi_thres, rx_thres; + int err; switch (drv_data->ssp_type) { case QUARK_X1000_SSP: @@ -1400,7 +1403,11 @@ static int setup(struct spi_device *spi) if (drv_data->ssp_type == CE4100_SSP) return 0; - return setup_cs(spi, chip, chip_info); + err = setup_cs(spi, chip, chip_info); + if (err) + kfree(chip); + + return err; } static void cleanup(struct spi_device *spi)