From 0187294d227dfc42889e1da8f8ce1e44fc25f147 Mon Sep 17 00:00:00 2001 From: Dinghao Liu Date: Tue, 26 May 2020 18:47:17 +0800 Subject: iio: magnetometer: ak8974: Fix runtime PM imbalance on error When devm_regmap_init_i2c() returns an error code, a pairing runtime PM usage counter decrement is needed to keep the counter balanced. For error paths after ak8974_set_power(), ak8974_detect() and ak8974_reset(), things are the same. However, When iio_triggered_buffer_setup() returns an error code, there will be two PM usgae counter decrements. Signed-off-by: Dinghao Liu Fixes: 7c94a8b2ee8c ("iio: magn: add a driver for AK8974") Reviewed-by: Linus Walleij Cc: Signed-off-by: Jonathan Cameron --- drivers/iio/magnetometer/ak8974.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'drivers/iio/magnetometer') diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c index 810fdfd37c88..041c9007bfbe 100644 --- a/drivers/iio/magnetometer/ak8974.c +++ b/drivers/iio/magnetometer/ak8974.c @@ -862,19 +862,21 @@ static int ak8974_probe(struct i2c_client *i2c, ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); if (IS_ERR(ak8974->map)) { dev_err(&i2c->dev, "failed to allocate register map\n"); + pm_runtime_put_noidle(&i2c->dev); + pm_runtime_disable(&i2c->dev); return PTR_ERR(ak8974->map); } ret = ak8974_set_power(ak8974, AK8974_PWR_ON); if (ret) { dev_err(&i2c->dev, "could not power on\n"); - goto power_off; + goto disable_pm; } ret = ak8974_detect(ak8974); if (ret) { dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); - goto power_off; + goto disable_pm; } ret = ak8974_selftest(ak8974); @@ -884,14 +886,9 @@ static int ak8974_probe(struct i2c_client *i2c, ret = ak8974_reset(ak8974); if (ret) { dev_err(&i2c->dev, "AK8974 reset failed\n"); - goto power_off; + goto disable_pm; } - pm_runtime_set_autosuspend_delay(&i2c->dev, - AK8974_AUTOSUSPEND_DELAY); - pm_runtime_use_autosuspend(&i2c->dev); - pm_runtime_put(&i2c->dev); - indio_dev->dev.parent = &i2c->dev; switch (ak8974->variant) { case AK8974_WHOAMI_VALUE_AMI306: @@ -957,6 +954,11 @@ no_irq: goto cleanup_buffer; } + pm_runtime_set_autosuspend_delay(&i2c->dev, + AK8974_AUTOSUSPEND_DELAY); + pm_runtime_use_autosuspend(&i2c->dev); + pm_runtime_put(&i2c->dev); + return 0; cleanup_buffer: @@ -965,7 +967,6 @@ disable_pm: pm_runtime_put_noidle(&i2c->dev); pm_runtime_disable(&i2c->dev); ak8974_set_power(ak8974, AK8974_PWR_OFF); -power_off: regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); return ret; -- cgit v1.2.3 From 838e00b13bfd4cac8b24df25bfc58e2eb99bcc70 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Sun, 7 Jun 2020 16:53:49 +0100 Subject: iio:magnetometer:ak8974: Fix alignment and data leak issues One of a class of bugs pointed out by Lars in a recent review. iio_push_to_buffers_with_timestamp assumes the buffer used is aligned to the size of the timestamp (8 bytes). This is not guaranteed in this driver which uses an array of smaller elements on the stack. As Lars also noted this anti pattern can involve a leak of data to userspace and that indeed can happen here. We close both issues by moving to a suitable structure in the iio_priv() data. This data is allocated with kzalloc so no data can leak appart from previous readings. Fixes: 7c94a8b2ee8cf ("iio: magn: add a driver for AK8974") Reported-by: Lars-Peter Clausen Reviewed-by: Linus Walleij Signed-off-by: Jonathan Cameron Cc: --- drivers/iio/magnetometer/ak8974.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'drivers/iio/magnetometer') diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c index 041c9007bfbe..91c39352fba2 100644 --- a/drivers/iio/magnetometer/ak8974.c +++ b/drivers/iio/magnetometer/ak8974.c @@ -192,6 +192,11 @@ struct ak8974 { bool drdy_irq; struct completion drdy_complete; bool drdy_active_low; + /* Ensure timestamp is naturally aligned */ + struct { + __le16 channels[3]; + s64 ts __aligned(8); + } scan; }; static const char ak8974_reg_avdd[] = "avdd"; @@ -657,7 +662,6 @@ static void ak8974_fill_buffer(struct iio_dev *indio_dev) { struct ak8974 *ak8974 = iio_priv(indio_dev); int ret; - __le16 hw_values[8]; /* Three axes + 64bit padding */ pm_runtime_get_sync(&ak8974->i2c->dev); mutex_lock(&ak8974->lock); @@ -667,13 +671,13 @@ static void ak8974_fill_buffer(struct iio_dev *indio_dev) dev_err(&ak8974->i2c->dev, "error triggering measure\n"); goto out_unlock; } - ret = ak8974_getresult(ak8974, hw_values); + ret = ak8974_getresult(ak8974, ak8974->scan.channels); if (ret) { dev_err(&ak8974->i2c->dev, "error getting measures\n"); goto out_unlock; } - iio_push_to_buffers_with_timestamp(indio_dev, hw_values, + iio_push_to_buffers_with_timestamp(indio_dev, &ak8974->scan, iio_get_time_ns(indio_dev)); out_unlock: -- cgit v1.2.3