| Message ID | 20220616151901.3989078-1-windhl@126.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] arch: powerpc: platforms: 85xx: Add missing of_node_put in sgy_cts1000.c | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 7 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 23 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
Le 16/06/2022 à 17:19, Liang He a écrit : > In gpio_halt_probe(), of_find_matching_node() will return a node pointer with > refcount incremented. We should use of_node_put() in each fail path or when it > is not used anymore. > > Signed-off-by: Liang He <windhl@126.com> > --- > changelog: > > v2: use goto-label patch style advised by Christophe. > v1: add of_node_put() before each exit. > > arch/powerpc/platforms/85xx/sgy_cts1000.c | 27 +++++++++++++++-------- > 1 file changed, 18 insertions(+), 9 deletions(-) > > diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c > index 98ae64075193..e280f963d88c 100644 > --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c > +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c > @@ -73,6 +73,7 @@ static int gpio_halt_probe(struct platform_device *pdev) > struct device_node *node = pdev->dev.of_node; > int gpio, err, irq; > int trigger; > + int ret; > > if (!node) > return -ENODEV; > @@ -84,20 +85,24 @@ static int gpio_halt_probe(struct platform_device *pdev) > > /* Technically we could just read the first one, but punish > * DT writers for invalid form. */ > - if (of_gpio_count(halt_node) != 1) > - return -EINVAL; > + if (of_gpio_count(halt_node) != 1) { > + ret = -EINVAL; > + goto err_put; > + } > > /* Get the gpio number relative to the dynamic base. */ > gpio = of_get_gpio_flags(halt_node, 0, &flags); > - if (!gpio_is_valid(gpio)) > - return -EINVAL; > + if (!gpio_is_valid(gpio)) { > + ret = -EINVAL; > + gotot err_put; > + } > > err = gpio_request(gpio, "gpio-halt"); > if (err) { > printk(KERN_ERR "gpio-halt: error requesting GPIO %d.\n", > gpio); > - halt_node = NULL; > - return err; > + ret = err; > + goto err_put; > } > > trigger = (flags == OF_GPIO_ACTIVE_LOW); > @@ -112,8 +117,8 @@ static int gpio_halt_probe(struct platform_device *pdev) > printk(KERN_ERR "gpio-halt: error requesting IRQ %d for " > "GPIO %d.\n", irq, gpio); > gpio_free(gpio); > - halt_node = NULL; > - return err; > + ret = err; > + goto err_put; > } > > /* Register our halt function */ > @@ -122,8 +127,12 @@ static int gpio_halt_probe(struct platform_device *pdev) > > printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" > " irq).\n", gpio, trigger, irq); > + ret = 0; > > - return 0; > +err_put: > + of_node_put(halt_node); > + halt_node = NULL; Hi, so now we set 'halt_node' to NULL even in the normal case. This is really spurious. Look at gpio_halt_cb(), but I think that this is just wrong and badly breaks this driver. CJ > + return ret; > } > > static int gpio_halt_remove(struct platform_device *pdev)
Christophe JAILLET <christophe.jaillet@wanadoo.fr> writes: > Le 16/06/2022 à 17:19, Liang He a écrit : >> In gpio_halt_probe(), of_find_matching_node() will return a node pointer with >> refcount incremented. We should use of_node_put() in each fail path or when it >> is not used anymore. >> >> Signed-off-by: Liang He <windhl@126.com> >> --- >> changelog: >> >> v2: use goto-label patch style advised by Christophe. >> v1: add of_node_put() before each exit. >> >> arch/powerpc/platforms/85xx/sgy_cts1000.c | 27 +++++++++++++++-------- >> 1 file changed, 18 insertions(+), 9 deletions(-) >> >> diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c >> index 98ae64075193..e280f963d88c 100644 >> --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c >> +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c >> @@ -73,6 +73,7 @@ static int gpio_halt_probe(struct platform_device *pdev) ... >> @@ -122,8 +127,12 @@ static int gpio_halt_probe(struct platform_device *pdev) >> >> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" >> " irq).\n", gpio, trigger, irq); >> + ret = 0; >> >> - return 0; >> +err_put: >> + of_node_put(halt_node); >> + halt_node = NULL; > > Hi, > so now we set 'halt_node' to NULL even in the normal case. > This is really spurious. > > Look at gpio_halt_cb(), but I think that this is just wrong and badly > breaks this driver. I agree, thanks for reviewing. I think the cleanest solution is to use a local variable for the node in the body of gpio_halt_probe(), and only assign to halt_node once all the checks have passed. So something like: struct device_node *child_node; child_node = of_find_matching_node(node, child_match); ... printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" " irq).\n", gpio, trigger, irq); ret = 0; halt_node = of_node_get(child_node); out_put: of_node_put(child_node); return ret; } cheers
At 2022-06-17 07:37:06, "Michael Ellerman" <mpe@ellerman.id.au> wrote: >Christophe JAILLET <christophe.jaillet@wanadoo.fr> writes: >> Le 16/06/2022 à 17:19, Liang He a écrit : >>> In gpio_halt_probe(), of_find_matching_node() will return a node pointer with >>> refcount incremented. We should use of_node_put() in each fail path or when it >>> is not used anymore. >>> >>> Signed-off-by: Liang He <windhl@126.com> >>> --- >>> changelog: >>> >>> v2: use goto-label patch style advised by Christophe. >>> v1: add of_node_put() before each exit. >>> >>> arch/powerpc/platforms/85xx/sgy_cts1000.c | 27 +++++++++++++++-------- >>> 1 file changed, 18 insertions(+), 9 deletions(-) >>> >>> diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c >>> index 98ae64075193..e280f963d88c 100644 >>> --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c >>> +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c >>> @@ -73,6 +73,7 @@ static int gpio_halt_probe(struct platform_device *pdev) >... >>> @@ -122,8 +127,12 @@ static int gpio_halt_probe(struct platform_device *pdev) >>> >>> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" >>> " irq).\n", gpio, trigger, irq); >>> + ret = 0; >>> >>> - return 0; >>> +err_put: >>> + of_node_put(halt_node); >>> + halt_node = NULL; >> >> Hi, >> so now we set 'halt_node' to NULL even in the normal case. >> This is really spurious. >> >> Look at gpio_halt_cb(), but I think that this is just wrong and badly >> breaks this driver. > >I agree, thanks for reviewing. > >I think the cleanest solution is to use a local variable for the node in >the body of gpio_halt_probe(), and only assign to halt_node once all the >checks have passed. > >So something like: > > struct device_node *child_node; > > child_node = of_find_matching_node(node, child_match); > ... > > printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" > " irq).\n", gpio, trigger, irq); > ret = 0; > halt_node = of_node_get(child_node); > >out_put: > of_node_put(child_node); > > return ret; >} > > >cheers Thanks, Michael and Christophe. I will send a patch based on your reviews. Liang
At 2022-06-17 07:37:06, "Michael Ellerman" <mpe@ellerman.id.au> wrote: >Christophe JAILLET <christophe.jaillet@wanadoo.fr> writes: >> Le 16/06/2022 à 17:19, Liang He a écrit : >>> In gpio_halt_probe(), of_find_matching_node() will return a node pointer with >>> refcount incremented. We should use of_node_put() in each fail path or when it >>> is not used anymore. >>> >>> Signed-off-by: Liang He <windhl@126.com> >>> --- >>> changelog: >>> >>> v2: use goto-label patch style advised by Christophe. >>> v1: add of_node_put() before each exit. >>> >>> arch/powerpc/platforms/85xx/sgy_cts1000.c | 27 +++++++++++++++-------- >>> 1 file changed, 18 insertions(+), 9 deletions(-) >>> >>> diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c >>> index 98ae64075193..e280f963d88c 100644 >>> --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c >>> +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c >>> @@ -73,6 +73,7 @@ static int gpio_halt_probe(struct platform_device *pdev) >... >>> @@ -122,8 +127,12 @@ static int gpio_halt_probe(struct platform_device *pdev) >>> >>> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" >>> " irq).\n", gpio, trigger, irq); >>> + ret = 0; >>> >>> - return 0; >>> +err_put: >>> + of_node_put(halt_node); >>> + halt_node = NULL; >> >> Hi, >> so now we set 'halt_node' to NULL even in the normal case. >> This is really spurious. >> >> Look at gpio_halt_cb(), but I think that this is just wrong and badly >> breaks this driver. > >I agree, thanks for reviewing. > >I think the cleanest solution is to use a local variable for the node in >the body of gpio_halt_probe(), and only assign to halt_node once all the >checks have passed. > >So something like: > > struct device_node *child_node; > > child_node = of_find_matching_node(node, child_match); > ... > > printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" > " irq).\n", gpio, trigger, irq); > ret = 0; > halt_node = of_node_get(child_node); > >out_put: > of_node_put(child_node); > > return ret; >} > > >cheers Hi, Michael and Christophe, I am writing the new patch based on Michael's advice. However, I wonder if there is any place to call of_node_put(halt_node)? As I do not exactly know if gpio_halt_remove() or anyother place can correctly release this global reference？ If not, it is correct that I add a of_node_put(halt_node) in gpio_halt_remove(), right? Thanks and wait for your replies. Liang
"Liang He" <windhl@126.com> writes: > At 2022-06-17 07:37:06, "Michael Ellerman" <mpe@ellerman.id.au> wrote: >>Christophe JAILLET <christophe.jaillet@wanadoo.fr> writes: >>> Le 16/06/2022 à 17:19, Liang He a écrit : >>>> In gpio_halt_probe(), of_find_matching_node() will return a node pointer with >>>> refcount incremented. We should use of_node_put() in each fail path or when it >>>> is not used anymore. >>>> >>>> Signed-off-by: Liang He <windhl@126.com> >>>> --- >>>> changelog: >>>> >>>> v2: use goto-label patch style advised by Christophe. >>>> v1: add of_node_put() before each exit. >>>> >>>> arch/powerpc/platforms/85xx/sgy_cts1000.c | 27 +++++++++++++++-------- >>>> 1 file changed, 18 insertions(+), 9 deletions(-) >>>> >>>> diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c >>>> index 98ae64075193..e280f963d88c 100644 >>>> --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c >>>> +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c >>>> @@ -73,6 +73,7 @@ static int gpio_halt_probe(struct platform_device *pdev) >>... >>>> @@ -122,8 +127,12 @@ static int gpio_halt_probe(struct platform_device *pdev) >>>> >>>> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" >>>> " irq).\n", gpio, trigger, irq); >>>> + ret = 0; >>>> >>>> - return 0; >>>> +err_put: >>>> + of_node_put(halt_node); >>>> + halt_node = NULL; >>> >>> Hi, >>> so now we set 'halt_node' to NULL even in the normal case. >>> This is really spurious. >>> >>> Look at gpio_halt_cb(), but I think that this is just wrong and badly >>> breaks this driver. >> >>I agree, thanks for reviewing. >> >>I think the cleanest solution is to use a local variable for the node in >>the body of gpio_halt_probe(), and only assign to halt_node once all the >>checks have passed. >> >>So something like: >> >> struct device_node *child_node; >> >> child_node = of_find_matching_node(node, child_match); >> ... >> >> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" >> " irq).\n", gpio, trigger, irq); >> ret = 0; >> halt_node = of_node_get(child_node); >> >>out_put: >> of_node_put(child_node); >> >> return ret; >>} >> >> >>cheers > > Hi, Michael and Christophe, > > I am writing the new patch based on Michael's advice. However, I wonder if there is > any place to call of_node_put(halt_node)? As I do not exactly know if gpio_halt_remove() > or anyother place can correctly release this global reference？ > If not, it is correct that I add a of_node_put(halt_node) in gpio_halt_remove(), right? Yes I think so, just before it's set to NULL, eg: diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c index 98ae64075193..7beb3cd420ba 100644 --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c @@ -139,6 +139,7 @@ static int gpio_halt_remove(struct platform_device *pdev) gpio_free(gpio); + of_node_put(halt_node); halt_node = NULL; } cheers
2022-06-17 12:29:02，"Michael Ellerman" <mpe@ellerman.id.au> 写道： >"Liang He" <windhl@126.com> writes: >> At 2022-06-17 07:37:06, "Michael Ellerman" <mpe@ellerman.id.au> wrote: >>>Christophe JAILLET <christophe.jaillet@wanadoo.fr> writes: >>>> Le 16/06/2022 à 17:19, Liang He a écrit : >>>>> In gpio_halt_probe(), of_find_matching_node() will return a node pointer with >>>>> refcount incremented. We should use of_node_put() in each fail path or when it >>>>> is not used anymore. >>>>> >>>>> Signed-off-by: Liang He <windhl@126.com> >>>>> --- >>>>> changelog: >>>>> >>>>> v2: use goto-label patch style advised by Christophe. >>>>> v1: add of_node_put() before each exit. >>>>> >>>>> arch/powerpc/platforms/85xx/sgy_cts1000.c | 27 +++++++++++++++-------- >>>>> 1 file changed, 18 insertions(+), 9 deletions(-) >>>>> >>>>> diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c >>>>> index 98ae64075193..e280f963d88c 100644 >>>>> --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c >>>>> +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c >>>>> @@ -73,6 +73,7 @@ static int gpio_halt_probe(struct platform_device *pdev) >>>... >>>>> @@ -122,8 +127,12 @@ static int gpio_halt_probe(struct platform_device *pdev) >>>>> >>>>> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" >>>>> " irq).\n", gpio, trigger, irq); >>>>> + ret = 0; >>>>> >>>>> - return 0; >>>>> +err_put: >>>>> + of_node_put(halt_node); >>>>> + halt_node = NULL; >>>> >>>> Hi, >>>> so now we set 'halt_node' to NULL even in the normal case. >>>> This is really spurious. >>>> >>>> Look at gpio_halt_cb(), but I think that this is just wrong and badly >>>> breaks this driver. >>> >>>I agree, thanks for reviewing. >>> >>>I think the cleanest solution is to use a local variable for the node in >>>the body of gpio_halt_probe(), and only assign to halt_node once all the >>>checks have passed. >>> >>>So something like: >>> >>> struct device_node *child_node; >>> >>> child_node = of_find_matching_node(node, child_match); >>> ... >>> >>> printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" >>> " irq).\n", gpio, trigger, irq); >>> ret = 0; >>> halt_node = of_node_get(child_node); >>> >>>out_put: >>> of_node_put(child_node); >>> >>> return ret; >>>} >>> >>> >>>cheers >> >> Hi, Michael and Christophe, >> >> I am writing the new patch based on Michael's advice. However, I wonder if there is >> any place to call of_node_put(halt_node)? As I do not exactly know if gpio_halt_remove() >> or anyother place can correctly release this global reference？ >> If not, it is correct that I add a of_node_put(halt_node) in gpio_halt_remove(), right? > >Yes I think so, just before it's set to NULL, eg: > >diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c >index 98ae64075193..7beb3cd420ba 100644 >--- a/arch/powerpc/platforms/85xx/sgy_cts1000.c >+++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c >@@ -139,6 +139,7 @@ static int gpio_halt_remove(struct platform_device *pdev) > > gpio_free(gpio); > >+ of_node_put(halt_node); > halt_node = NULL; > } > > >cheers Ok, I will make the new patch soon.
diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c index 98ae64075193..e280f963d88c 100644 --- a/arch/powerpc/platforms/85xx/sgy_cts1000.c +++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c @@ -73,6 +73,7 @@ static int gpio_halt_probe(struct platform_device *pdev) struct device_node *node = pdev->dev.of_node; int gpio, err, irq; int trigger; + int ret; if (!node) return -ENODEV; @@ -84,20 +85,24 @@ static int gpio_halt_probe(struct platform_device *pdev) /* Technically we could just read the first one, but punish * DT writers for invalid form. */ - if (of_gpio_count(halt_node) != 1) - return -EINVAL; + if (of_gpio_count(halt_node) != 1) { + ret = -EINVAL; + goto err_put; + } /* Get the gpio number relative to the dynamic base. */ gpio = of_get_gpio_flags(halt_node, 0, &flags); - if (!gpio_is_valid(gpio)) - return -EINVAL; + if (!gpio_is_valid(gpio)) { + ret = -EINVAL; + gotot err_put; + } err = gpio_request(gpio, "gpio-halt"); if (err) { printk(KERN_ERR "gpio-halt: error requesting GPIO %d.\n", gpio); - halt_node = NULL; - return err; + ret = err; + goto err_put; } trigger = (flags == OF_GPIO_ACTIVE_LOW); @@ -112,8 +117,8 @@ static int gpio_halt_probe(struct platform_device *pdev) printk(KERN_ERR "gpio-halt: error requesting IRQ %d for " "GPIO %d.\n", irq, gpio); gpio_free(gpio); - halt_node = NULL; - return err; + ret = err; + goto err_put; } /* Register our halt function */ @@ -122,8 +127,12 @@ static int gpio_halt_probe(struct platform_device *pdev) printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d" " irq).\n", gpio, trigger, irq); + ret = 0; - return 0; +err_put: + of_node_put(halt_node); + halt_node = NULL; + return ret; } static int gpio_halt_remove(struct platform_device *pdev)
In gpio_halt_probe(), of_find_matching_node() will return a node pointer with refcount incremented. We should use of_node_put() in each fail path or when it is not used anymore. Signed-off-by: Liang He <windhl@126.com> --- changelog: v2: use goto-label patch style advised by Christophe. v1: add of_node_put() before each exit. arch/powerpc/platforms/85xx/sgy_cts1000.c | 27 +++++++++++++++-------- 1 file changed, 18 insertions(+), 9 deletions(-)