[PATCH 0/8] Remove adis_initial_startup usage

[PATCH 0/8] Remove adis_initial_startup usage

[Ramona Bolboaca]

Remove adis_initial_startup usage due to the fact that it leads to a deadlock.
The same mutex is acquired twice, without releasing it, once inside
adis_initial_startup and once inside adis_enable_irq.
Instead of adis_initial_startup, use __adis_initial_startup.

Ramona Bolboaca (8):
  iio: accel: adis16201: Fix deadlock in probe
  iio: accel: adis16209: Fix deadlock in probe
  iio: gyro: adis16136: Fix deadlock in probe
  iio: gyro: adis16260: Fix deadlock in probe
  iio: imu: adis16400: Fix deadlock in probe
  staging: iio: accel: adis16203: Fix deadlock in probe
  staging: iio: accel: adis16240: Fix deadlock in probe
  iio: imu: adis: Remove adis_initial_startup function

 drivers/iio/accel/adis16201.c         |  2 +-
 drivers/iio/accel/adis16209.c         |  2 +-
 drivers/iio/gyro/adis16136.c          |  2 +-
 drivers/iio/gyro/adis16260.c          |  2 +-
 drivers/iio/imu/adis16400.c           |  2 +-
 drivers/staging/iio/accel/adis16203.c |  2 +-
 drivers/staging/iio/accel/adis16240.c |  2 +-
 include/linux/iio/imu/adis.h          | 12 ------------
 8 files changed, 7 insertions(+), 19 deletions(-)

-- 
2.25.1

[PATCH 1/8] iio: accel: adis16201: Fix deadlock in probe

[Ramona Bolboaca]

Use __adis_initial_startup instead of adis_initial_startup to
avoid deadlock.
When using adis_initial_startup mutex_lock is called twice,
without releasing it (once inside adis_initial_startup and
once inside adis_enable_irq).

Fixes: 100bfa38c8cb ("iio: imu: adis[16480]: group RW into a single lock in adis_enable_irq()")
Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
---
 drivers/iio/accel/adis16201.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/accel/adis16201.c b/drivers/iio/accel/adis16201.c
index dfb8e2e5bdf5..d054721859b3 100644
--- a/drivers/iio/accel/adis16201.c
+++ b/drivers/iio/accel/adis16201.c
@@ -281,7 +281,7 @@ static int adis16201_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	ret = adis_initial_startup(st);
+	ret = __adis_initial_startup(st);
 	if (ret)
 		return ret;
 
-- 
2.25.1

[PATCH 2/8] iio: accel: adis16209: Fix deadlock in probe

[Ramona Bolboaca]

Use __adis_initial_startup instead of adis_initial_startup to
avoid deadlock.
When using adis_initial_startup mutex_lock is called twice,
without releasing it (once inside adis_initial_startup and
once inside adis_enable_irq).

Fixes: 100bfa38c8cb ("iio: imu: adis[16480]: group RW into a single lock in adis_enable_irq()")
Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
---
 drivers/iio/accel/adis16209.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/accel/adis16209.c b/drivers/iio/accel/adis16209.c
index 5a9c6e2296f1..0035e4f4db63 100644
--- a/drivers/iio/accel/adis16209.c
+++ b/drivers/iio/accel/adis16209.c
@@ -291,7 +291,7 @@ static int adis16209_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	ret = adis_initial_startup(st);
+	ret = __adis_initial_startup(st);
 	if (ret)
 		return ret;
 
-- 
2.25.1

[PATCH 3/8] iio: gyro: adis16136: Fix deadlock in probe

[Ramona Bolboaca]

Use __adis_initial_startup instead of adis_initial_startup to
avoid deadlock.
When using adis_initial_startup mutex_lock is called twice,
without releasing it (once inside adis_initial_startup and
once inside adis_enable_irq).

Fixes: 100bfa38c8cb ("iio: imu: adis[16480]: group RW into a single lock in adis_enable_irq()")
Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
---
 drivers/iio/gyro/adis16136.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/gyro/adis16136.c b/drivers/iio/gyro/adis16136.c
index 71295709f2b9..c95cf41be34b 100644
--- a/drivers/iio/gyro/adis16136.c
+++ b/drivers/iio/gyro/adis16136.c
@@ -429,7 +429,7 @@ static int adis16136_initial_setup(struct iio_dev *indio_dev)
 	uint16_t prod_id;
 	int ret;
 
-	ret = adis_initial_startup(&adis16136->adis);
+	ret = __adis_initial_startup(&adis16136->adis);
 	if (ret)
 		return ret;
 
-- 
2.25.1

[PATCH 4/8] iio: gyro: adis16260: Fix deadlock in probe

[Ramona Bolboaca]

Use __adis_initial_startup instead of adis_initial_startup to
avoid deadlock.
When using adis_initial_startup mutex_lock is called twice,
without releasing it (once inside adis_initial_startup and
once inside adis_enable_irq).

Fixes: 100bfa38c8cb ("iio: imu: adis[16480]: group RW into a single lock in adis_enable_irq()")
Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
---
 drivers/iio/gyro/adis16260.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/gyro/adis16260.c b/drivers/iio/gyro/adis16260.c
index eaf57bd339ed..112d635b7dfd 100644
--- a/drivers/iio/gyro/adis16260.c
+++ b/drivers/iio/gyro/adis16260.c
@@ -395,7 +395,7 @@ static int adis16260_probe(struct spi_device *spi)
 		return ret;
 
 	/* Get the device into a sane initial state */
-	ret = adis_initial_startup(&adis16260->adis);
+	ret = __adis_initial_startup(&adis16260->adis);
 	if (ret)
 		return ret;
 
-- 
2.25.1

[PATCH 5/8] iio: imu: adis16400: Fix deadlock in probe

[Ramona Bolboaca]

Use __adis_initial_startup instead of adis_initial_startup to
avoid deadlock.
When using adis_initial_startup mutex_lock is called twice,
without releasing it (once inside adis_initial_startup and
once inside adis_enable_irq).

Fixes: 100bfa38c8cb ("iio: imu: adis[16480]: group RW into a single lock in adis_enable_irq()")
Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
---
 drivers/iio/imu/adis16400.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/imu/adis16400.c b/drivers/iio/imu/adis16400.c
index 17bb0c40a149..c02fc35dceb4 100644
--- a/drivers/iio/imu/adis16400.c
+++ b/drivers/iio/imu/adis16400.c
@@ -445,7 +445,7 @@ static int adis16400_initial_setup(struct iio_dev *indio_dev)
 	st->adis.spi->mode = SPI_MODE_3;
 	spi_setup(st->adis.spi);
 
-	ret = adis_initial_startup(&st->adis);
+	ret = __adis_initial_startup(&st->adis);
 	if (ret)
 		return ret;
 
-- 
2.25.1

[PATCH 6/8] staging: iio: accel: adis16203: Fix deadlock in probe

[Ramona Bolboaca]

Use __adis_initial_startup instead of adis_initial_startup to
avoid deadlock.
When using adis_initial_startup mutex_lock is called twice,
without releasing it (once inside adis_initial_startup and
once inside adis_enable_irq).

Fixes: 100bfa38c8cb ("iio: imu: adis[16480]: group RW into a single lock in adis_enable_irq()")
Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
---
 drivers/staging/iio/accel/adis16203.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/iio/accel/adis16203.c b/drivers/staging/iio/accel/adis16203.c
index 62d5397ff1f9..c0e4c9266b5f 100644
--- a/drivers/staging/iio/accel/adis16203.c
+++ b/drivers/staging/iio/accel/adis16203.c
@@ -285,7 +285,7 @@ static int adis16203_probe(struct spi_device *spi)
 		return ret;
 
 	/* Get the device into a sane initial state */
-	ret = adis_initial_startup(st);
+	ret = __adis_initial_startup(st);
 	if (ret)
 		return ret;
 
-- 
2.25.1

[PATCH 7/8] staging: iio: accel: adis16240: Fix deadlock in probe

[Ramona Bolboaca]

Use __adis_initial_startup instead of adis_initial_startup to
avoid deadlock.
When using adis_initial_startup mutex_lock is called twice,
without releasing it (once inside adis_initial_startup and
once inside adis_enable_irq).

Fixes: 100bfa38c8cb ("iio: imu: adis[16480]: group RW into a single lock in adis_enable_irq()")
Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
---
 drivers/staging/iio/accel/adis16240.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/iio/accel/adis16240.c b/drivers/staging/iio/accel/adis16240.c
index bca857eef92e..337492785f04 100644
--- a/drivers/staging/iio/accel/adis16240.c
+++ b/drivers/staging/iio/accel/adis16240.c
@@ -414,7 +414,7 @@ static int adis16240_probe(struct spi_device *spi)
 		return ret;
 
 	/* Get the device into a sane initial state */
-	ret = adis_initial_startup(st);
+	ret = __adis_initial_startup(st);
 	if (ret)
 		return ret;
 
-- 
2.25.1

[PATCH 8/8] iio: imu: adis: Remove adis_initial_startup function

[Ramona Bolboaca]

Remove adis_initial_startup function since it is not used
anymore.

Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
---
 include/linux/iio/imu/adis.h | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
index 515ca09764fe..fa12a100b6b2 100644
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -417,18 +417,6 @@ static inline int adis_check_status(struct adis *adis)
 	return ret;
 }
 
-/* locked version of __adis_initial_startup() */
-static inline int adis_initial_startup(struct adis *adis)
-{
-	int ret;
-
-	mutex_lock(&adis->state_lock);
-	ret = __adis_initial_startup(adis);
-	mutex_unlock(&adis->state_lock);
-
-	return ret;
-}
-
 static inline void adis_dev_lock(struct adis *adis)
 {
 	mutex_lock(&adis->state_lock);
-- 
2.25.1

Re: [PATCH 0/8] Remove adis_initial_startup usage

[Nuno Sá]

On Wed, 2022-11-02 at 16:18 +0200, Ramona Bolboaca wrote:
> Remove adis_initial_startup usage due to the fact that it leads to a
> deadlock.
> The same mutex is acquired twice, without releasing it, once inside
> adis_initial_startup and once inside adis_enable_irq.
> Instead of adis_initial_startup, use __adis_initial_startup.
> 

Auchhhh!!! Thanks for catching this... However, the Fixes tag is
pointing to the wrong place. I'm fairly sure I introduced this bug in 

commit b600bd7eb3335 ("iio: adis: do not disabe IRQs in 'adis_init()'")

This was where the call to adis_enable_irq() was moved to
__adis_initial_startup() and effectively creating the deadlock for some
devices (adis->data->unmasked_drdy is not set)...


I guess I did not saw this when bringing in the change because I
probably tested the full series on some device supported by adis16475.c
where this won't trigger.

From a quick look I think it's safe to drop adis_initial_startup() as
it is always called during probe() before registering the IIO device.
We could also just create an unlocked version of adis_enable_irq()
(since we don't need to grab the lock in this path) but likely not
worth the trouble.

- Nuno Sá