| Message ID | 20201127094446.121277-1-miaoqinglang@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | hwrng: exynos - fix reference leak in exynos_trng_probe | expand |
On Fri, Nov 27, 2020 at 05:44:46PM +0800, Qinglang Miao wrote: > pm_runtime_get_sync will increment pm usage counter even it > failed. Forgetting to putting operation will result in a > reference leak here. > > A new function pm_runtime_resume_and_get is introduced in > [0] to keep usage counter balanced. So We fix the reference > leak by replacing it with new funtion. > > [0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") Do not put such dependencies into the commit message - it does not bring useful information to the history. Store it under '---' separator. > > Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver") > Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> > --- > drivers/char/hw_random/exynos-trng.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c > index 8e1fe3f8d..666246bc8 100644 > --- a/drivers/char/hw_random/exynos-trng.c > +++ b/drivers/char/hw_random/exynos-trng.c > @@ -132,7 +132,7 @@ static int exynos_trng_probe(struct platform_device *pdev) > return PTR_ERR(trng->mem); > > pm_runtime_enable(&pdev->dev); > - ret = pm_runtime_get_sync(&pdev->dev); > + ret = pm_runtime_resume_and_get(&pdev->dev); This cannot be applied. Fix it by replacing err_clock label with this one. Best regards, Krzysztof
It was <2020-11-27 pią 17:44>, when Qinglang Miao wrote: > pm_runtime_get_sync will increment pm usage counter even it > failed. Forgetting to putting operation will result in a > reference leak here. > > A new function pm_runtime_resume_and_get is introduced in > [0] to keep usage counter balanced. So We fix the reference > leak by replacing it with new funtion. > > [0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") > > Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver") > Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> > --- > drivers/char/hw_random/exynos-trng.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c > index 8e1fe3f8d..666246bc8 100644 > --- a/drivers/char/hw_random/exynos-trng.c > +++ b/drivers/char/hw_random/exynos-trng.c > @@ -132,7 +132,7 @@ static int exynos_trng_probe(struct platform_device *pdev) > return PTR_ERR(trng->mem); > > pm_runtime_enable(&pdev->dev); > - ret = pm_runtime_get_sync(&pdev->dev); > + ret = pm_runtime_resume_and_get(&pdev->dev); > if (ret < 0) { > dev_err(&pdev->dev, "Could not get runtime PM.\n"); > goto err_pm_get; Thanks. I suppose you may use the new function exynos_trng_resume(), remove everything and leave only return pm_runtime_resume_and_get(dev);
在 2020/11/27 17:44, Krzysztof Kozlowski 写道: > On Fri, Nov 27, 2020 at 05:44:46PM +0800, Qinglang Miao wrote: >> pm_runtime_get_sync will increment pm usage counter even it >> failed. Forgetting to putting operation will result in a >> reference leak here. >> >> A new function pm_runtime_resume_and_get is introduced in >> [0] to keep usage counter balanced. So We fix the reference >> leak by replacing it with new funtion. >> >> [0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") > > Do not put such dependencies into the commit message - it does not bring > useful information to the history. Store it under '---' separator. > >> >> Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver") >> Reported-by: Hulk Robot <hulkci@huawei.com> >> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> >> --- >> drivers/char/hw_random/exynos-trng.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c >> index 8e1fe3f8d..666246bc8 100644 >> --- a/drivers/char/hw_random/exynos-trng.c >> +++ b/drivers/char/hw_random/exynos-trng.c >> @@ -132,7 +132,7 @@ static int exynos_trng_probe(struct platform_device *pdev) >> return PTR_ERR(trng->mem); >> >> pm_runtime_enable(&pdev->dev); >> - ret = pm_runtime_get_sync(&pdev->dev); >> + ret = pm_runtime_resume_and_get(&pdev->dev); > > This cannot be applied. Fix it by replacing err_clock label with this > one. > > Best regards, > Krzysztof > > . Hi Krzysztof, I realize that there's a mistake in this patch through your reply. There's two way to fix this one: 1) replace err_pm_get with err_clock label when pm_runtime_get_sync fails. 2) replace pm_runtime_get_sync with pm_runtime_resume_and_get and remove redundant label(err_clock). I take 2) on v2 for it makes codes more clearer in a way. Thanks. >
在 2020/11/27 22:26, Lukasz Stelmach 写道: > It was <2020-11-27 pią 17:44>, when Qinglang Miao wrote: >> pm_runtime_get_sync will increment pm usage counter even it >> failed. Forgetting to putting operation will result in a >> reference leak here. >> >> A new function pm_runtime_resume_and_get is introduced in >> [0] to keep usage counter balanced. So We fix the reference >> leak by replacing it with new funtion. >> >> [0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") >> >> Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver") >> Reported-by: Hulk Robot <hulkci@huawei.com> >> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> >> --- >> drivers/char/hw_random/exynos-trng.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c >> index 8e1fe3f8d..666246bc8 100644 >> --- a/drivers/char/hw_random/exynos-trng.c >> +++ b/drivers/char/hw_random/exynos-trng.c >> @@ -132,7 +132,7 @@ static int exynos_trng_probe(struct platform_device *pdev) >> return PTR_ERR(trng->mem); >> >> pm_runtime_enable(&pdev->dev); >> - ret = pm_runtime_get_sync(&pdev->dev); >> + ret = pm_runtime_resume_and_get(&pdev->dev); >> if (ret < 0) { >> dev_err(&pdev->dev, "Could not get runtime PM.\n"); >> goto err_pm_get; > > Thanks. I suppose you may use the new function exynos_trng_resume(), > remove everything and leave only > > return pm_runtime_resume_and_get(dev); Hi, Lukasz I sent a v2 on this one. But I'm not really sure about what does 'remove everything' mean. for example, should I remove exynos_trng_resume in this patch? Thanks. >
diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c index 8e1fe3f8d..666246bc8 100644 --- a/drivers/char/hw_random/exynos-trng.c +++ b/drivers/char/hw_random/exynos-trng.c @@ -132,7 +132,7 @@ static int exynos_trng_probe(struct platform_device *pdev) return PTR_ERR(trng->mem); pm_runtime_enable(&pdev->dev); - ret = pm_runtime_get_sync(&pdev->dev); + ret = pm_runtime_resume_and_get(&pdev->dev); if (ret < 0) { dev_err(&pdev->dev, "Could not get runtime PM.\n"); goto err_pm_get;
pm_runtime_get_sync will increment pm usage counter even it failed. Forgetting to putting operation will result in a reference leak here. A new function pm_runtime_resume_and_get is introduced in [0] to keep usage counter balanced. So We fix the reference leak by replacing it with new funtion. [0] dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> --- drivers/char/hw_random/exynos-trng.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)