[PATCH] iio: adc: meson_saradc: Fix memory allocation order

[PATCH] iio: adc: meson_saradc: Fix memory allocation order

[Remi Pommarel]

meson_saradc's irq handler uses priv->regmap so make sure that it is
allocated before the irq get enabled.

This also fixes crash when CONFIG_DEBUG_SHIRQ is enabled, as device
managed resources are freed in the inverted order they had been
allocated, priv->regmap was freed before the spurious fake irq that
CONFIG_DEBUG_SHIRQ adds called the handler.

Reported-by: Elie Roudninski <xademax@gmail.com>
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
---
 drivers/iio/adc/meson_saradc.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index 7b28d045d271..7b27306330a3 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -1219,6 +1219,11 @@ static int meson_sar_adc_probe(struct platform_device *pdev)
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 
+	priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+					     priv->param->regmap_config);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
 	irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
 	if (!irq)
 		return -EINVAL;
@@ -1228,11 +1233,6 @@ static int meson_sar_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
-					     priv->param->regmap_config);
-	if (IS_ERR(priv->regmap))
-		return PTR_ERR(priv->regmap);
-
 	priv->clkin = devm_clk_get(&pdev->dev, "clkin");
 	if (IS_ERR(priv->clkin)) {
 		dev_err(&pdev->dev, "failed to get clkin\n");
-- 
2.20.1

Re: [PATCH] iio: adc: meson_saradc: Fix memory allocation order

[Martin Blumenstingl]

On Sun, Sep 1, 2019 at 12:45 PM Remi Pommarel <repk@triplefau.lt> wrote:
>
> meson_saradc's irq handler uses priv->regmap so make sure that it is
> allocated before the irq get enabled.
>
> This also fixes crash when CONFIG_DEBUG_SHIRQ is enabled, as device
> managed resources are freed in the inverted order they had been
> allocated, priv->regmap was freed before the spurious fake irq that
> CONFIG_DEBUG_SHIRQ adds called the handler.
>

Fixes: 3af109131b7eb8 ("iio: adc: meson-saradc: switch from polling to
interrupt mode")
> Reported-by: Elie Roudninski <xademax@gmail.com>
> Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

thank you for fixing this!


Martin

Re: [PATCH] iio: adc: meson_saradc: Fix memory allocation order

[Elie Roudninski]

On Sun, Sep 1, 2019 at 12:29 PM Martin Blumenstingl
<martin.blumenstingl@googlemail.com> wrote:
>
> On Sun, Sep 1, 2019 at 12:45 PM Remi Pommarel <repk@triplefau.lt> wrote:
> >
> > meson_saradc's irq handler uses priv->regmap so make sure that it is
> > allocated before the irq get enabled.
> >
> > This also fixes crash when CONFIG_DEBUG_SHIRQ is enabled, as device
> > managed resources are freed in the inverted order they had been
> > allocated, priv->regmap was freed before the spurious fake irq that
> > CONFIG_DEBUG_SHIRQ adds called the handler.
> >
>
> Fixes: 3af109131b7eb8 ("iio: adc: meson-saradc: switch from polling to
> interrupt mode")
> > Reported-by: Elie Roudninski <xademax@gmail.com>
> > Signed-off-by: Remi Pommarel <repk@triplefau.lt>
> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
>
> thank you for fixing this!
The patch fixed the kernel panic I had, i can now successfully boot my
meson-gxl-s905x-libretech-cc boad using patched linux 5.2.11

Tested-by: Elie ROUDNINSKI <xademax@gmail.com>

Elie
>
>
> Martin

Re: [PATCH] iio: adc: meson_saradc: Fix memory allocation order

[Kevin Hilman]

Remi Pommarel <repk@triplefau.lt> writes:

> meson_saradc's irq handler uses priv->regmap so make sure that it is
> allocated before the irq get enabled.
>
> This also fixes crash when CONFIG_DEBUG_SHIRQ is enabled, as device
> managed resources are freed in the inverted order they had been
> allocated, priv->regmap was freed before the spurious fake irq that
> CONFIG_DEBUG_SHIRQ adds called the handler.
>
> Reported-by: Elie Roudninski <xademax@gmail.com>
> Signed-off-by: Remi Pommarel <repk@triplefau.lt>

Reviewed-by: Kevin Hilman <khilman@baylibre.com>

Re: [PATCH] iio: adc: meson_saradc: Fix memory allocation order

[Jonathan Cameron]

On Mon, 2 Sep 2019 21:40:49 +0100
Elie Roudninski <xademax@gmail.com> wrote:

> On Sun, Sep 1, 2019 at 12:29 PM Martin Blumenstingl
> <martin.blumenstingl@googlemail.com> wrote:
> >
> > On Sun, Sep 1, 2019 at 12:45 PM Remi Pommarel <repk@triplefau.lt> wrote:  
> > >
> > > meson_saradc's irq handler uses priv->regmap so make sure that it is
> > > allocated before the irq get enabled.
> > >
> > > This also fixes crash when CONFIG_DEBUG_SHIRQ is enabled, as device
> > > managed resources are freed in the inverted order they had been
> > > allocated, priv->regmap was freed before the spurious fake irq that
> > > CONFIG_DEBUG_SHIRQ adds called the handler.
> > >  
> >
> > Fixes: 3af109131b7eb8 ("iio: adc: meson-saradc: switch from polling to
> > interrupt mode")  
> > > Reported-by: Elie Roudninski <xademax@gmail.com>
> > > Signed-off-by: Remi Pommarel <repk@triplefau.lt>  
> > Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> >
> > thank you for fixing this!  
> The patch fixed the kernel panic I had, i can now successfully boot my
> meson-gxl-s905x-libretech-cc boad using patched linux 5.2.11
> 
> Tested-by: Elie ROUDNINSKI <xademax@gmail.com>
Rather than rush through a quick pull request I'm going to hold this one
until after the merge window.

Applied to the fixes-togreg branch of iio.git (which is now based
on staging-next).

Thanks,

Jonathan

> 
> Elie
> >
> >
> > Martin