[patch] Staging: iio/dds: double locking bugs
Hennerich, Michael
Michael.Hennerich at analog.com
Sun Nov 14 20:46:13 UTC 2010
Dan Carpenter wrote on 2010-11-13:
> This is a static checker patch and I don't have this hardware.
>
> This code is unusual because while I've often seen a double lock, this
> is the first time I've seen code that takes a lock 11 times in a row.
> I feel like I must have missed something. But I've looked very
> carefully I don't see any way the original code is correct. Does
> spi_sync() somehow release the lock in a way that I can't see? Even
> if it does, the locking would still be wrong.
This is simply bad code, and likely committed untested.
> Signed-off-by: Dan Carpenter <error27 at gmail.com>
Acked-by: Michael Hennerich <michael.hennerich at analog.com>
> ---
> This should be easy to test for someone with the hardware. The ad9910
> driver should lock up on init.
>
> diff --git a/drivers/staging/iio/dds/ad9951.c
> b/drivers/staging/iio/dds/ad9951.c index bc3beff..57eddf6 100644 ---
> a/drivers/staging/iio/dds/ad9951.c +++
> b/drivers/staging/iio/dds/ad9951.c @@ -79,7 +79,6 @@ static ssize_t
> ad9951_set_parameter(struct device *dev,
>
> xfer.len = 2;
> xfer.tx_buf = &config->arr[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -89,7 +88,6 @@ static ssize_t ad9951_set_parameter(struct device *dev,
>
> xfer.len = 5;
> xfer.tx_buf = &config->ftw0[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -99,7 +97,6 @@ static ssize_t ad9951_set_parameter(struct device *dev,
>
> xfer.len = 3;
> xfer.tx_buf = &config->ftw1[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); @@ -143,8
> +140,6 @@ static void ad9951_init(struct ad9951_state *st) cfr[2] =
> HSPD_SYNC; cfr[3] = 0;
> - mutex_lock(&st->lock);
> -
> xfer.len = 4;
> xfer.tx_buf = 𝔠
> diff --git a/drivers/staging/iio/dds/ad9910.c
> b/drivers/staging/iio/dds/ad9910.c index c59b4079..e8fb75c 100644 ---
> a/drivers/staging/iio/dds/ad9910.c +++
> b/drivers/staging/iio/dds/ad9910.c @@ -138,7 +138,6 @@ static ssize_t
> ad9910_set_parameter(struct device *dev,
>
> xfer.len = 5;
> xfer.tx_buf = &config->ioupd[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -148,7 +147,6 @@ static ssize_t ad9910_set_parameter(struct device
> *dev,
>
> xfer.len = 5;
> xfer.tx_buf = &config->ftw[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -158,7 +156,6 @@ static ssize_t ad9910_set_parameter(struct device
> *dev,
>
> xfer.len = 3;
> xfer.tx_buf = &config->pow[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -168,7 +165,6 @@ static ssize_t ad9910_set_parameter(struct device
> *dev,
>
> xfer.len = 5;
> xfer.tx_buf = &config->asf[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -178,7 +174,6 @@ static ssize_t ad9910_set_parameter(struct device
> *dev,
>
> xfer.len = 5;
> xfer.tx_buf = &config->multc[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -188,7 +183,6 @@ static ssize_t ad9910_set_parameter(struct device
> *dev,
>
> xfer.len = 9;
> xfer.tx_buf = &config->dig_rampl[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -198,7 +192,6 @@ static ssize_t ad9910_set_parameter(struct device
> *dev,
>
> xfer.len = 9;
> xfer.tx_buf = &config->dig_ramps[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -208,7 +201,6 @@ static ssize_t ad9910_set_parameter(struct device
> *dev,
>
> xfer.len = 5;
> xfer.tx_buf = &config->dig_rampr[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -218,25 +210,24 @@ static ssize_t ad9910_set_parameter(struct
> device *dev,
>
> xfer.len = 9;
> xfer.tx_buf = &config->sin_tonep0[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); ret =
> spi_sync(st->sdev, &msg); if (ret) goto error_ret; + xfer.len = 9;
> xfer.tx_buf = &config->sin_tonep1[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); ret =
> spi_sync(st->sdev, &msg); if (ret) goto error_ret; + xfer.len = 9;
> xfer.tx_buf = &config->sin_tonep2[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -245,43 +236,42 @@ static ssize_t ad9910_set_parameter(struct
> device *dev,
> goto error_ret;
> xfer.len = 9;
> xfer.tx_buf = &config->sin_tonep3[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); ret =
> spi_sync(st->sdev, &msg); if (ret) goto error_ret; + xfer.len = 9;
> xfer.tx_buf = &config->sin_tonep4[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); ret =
> spi_sync(st->sdev, &msg); if (ret) goto error_ret; + xfer.len = 9;
> xfer.tx_buf = &config->sin_tonep5[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); ret =
> spi_sync(st->sdev, &msg); if (ret) goto error_ret; + xfer.len = 9;
> xfer.tx_buf = &config->sin_tonep6[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); ret =
> spi_sync(st->sdev, &msg); if (ret) goto error_ret; + xfer.len = 9;
> xfer.tx_buf = &config->sin_tonep7[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); @@ -326,8
> +316,6 @@ static void ad9910_init(struct ad9910_state *st) cfr[3] =
> TX_ENA | PDCLK_INV | PDCLK_ENB; cfr[4] = PARA_ENA;
> - mutex_lock(&st->lock);
> -
> xfer.len = 5;
> xfer.tx_buf = 𝔠
> @@ -343,8 +331,6 @@ static void ad9910_init(struct ad9910_state *st)
> cfr[3] = REFCLK_RST | REFCLK_BYP;
> cfr[4] = 0;
> - mutex_lock(&st->lock);
> -
> xfer.len = 5;
> xfer.tx_buf = 𝔠
> diff --git a/drivers/staging/iio/dds/ad9852.c
> b/drivers/staging/iio/dds/ad9852.c index 0a41d25..594fb6a 100644 ---
> a/drivers/staging/iio/dds/ad9852.c +++
> b/drivers/staging/iio/dds/ad9852.c @@ -86,7 +86,6 @@ static ssize_t
> ad9852_set_parameter(struct device *dev,
>
> xfer.len = 3;
> xfer.tx_buf = &config->phajst1[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -96,7 +95,6 @@ static ssize_t ad9852_set_parameter(struct device *dev,
>
> xfer.len = 6;
> xfer.tx_buf = &config->fretun1[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -106,7 +104,6 @@ static ssize_t ad9852_set_parameter(struct device
> *dev,
>
> xfer.len = 6;
> xfer.tx_buf = &config->fretun2[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -116,7 +113,6 @@ static ssize_t ad9852_set_parameter(struct device
> *dev,
>
> xfer.len = 6;
> xfer.tx_buf = &config->dltafre[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -126,7 +122,6 @@ static ssize_t ad9852_set_parameter(struct device
> *dev,
>
> xfer.len = 5;
> xfer.tx_buf = &config->updtclk[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -136,7 +131,6 @@ static ssize_t ad9852_set_parameter(struct device
> *dev,
>
> xfer.len = 4;
> xfer.tx_buf = &config->ramprat[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -146,7 +140,6 @@ static ssize_t ad9852_set_parameter(struct device
> *dev,
>
> xfer.len = 5;
> xfer.tx_buf = &config->control[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -156,7 +149,6 @@ static ssize_t ad9852_set_parameter(struct device
> *dev,
>
> xfer.len = 3;
> xfer.tx_buf = &config->outpskm[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> @@ -166,16 +158,15 @@ static ssize_t ad9852_set_parameter(struct
> device *dev,
>
> xfer.len = 2;
> xfer.tx_buf = &config->outpskr[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); ret =
> spi_sync(st->sdev, &msg); if (ret) goto error_ret; + xfer.len = 3;
> xfer.tx_buf = &config->daccntl[0];
> - mutex_lock(&st->lock);
>
> spi_message_init(&msg);
> spi_message_add_tail(&xfer, &msg);
> diff --git a/drivers/staging/iio/dds/ad9832.c
> b/drivers/staging/iio/dds/ad9832.c index a4bb048..e911893 100644 ---
> a/drivers/staging/iio/dds/ad9832.c +++
> b/drivers/staging/iio/dds/ad9832.c @@ -166,8 +166,6 @@ static void
> ad9832_init(struct ad9832_state *st)
>
> config = 0x3 << 14;
> - mutex_lock(&st->lock);
> -
> xfer.len = 2;
> xfer.tx_buf = &config;
Greetings,
Michael
--
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