diff mbox series

[soc/renesas] renesas-soc: Add error handling in renesas_soc_init

Message ID 20231129143431.34459-1-liuhaoran14@163.com (mailing list archive)
State Rejected
Delegated to: Geert Uytterhoeven
Headers show
Series [soc/renesas] renesas-soc: Add error handling in renesas_soc_init | expand

Commit Message

Haoran Liu Nov. 29, 2023, 2:34 p.m. UTC 
This patch enhances the renesas_soc_init function in
drivers/soc/renesas/renesas-soc.c by adding error handling for the
of_property_read_string call. Previously, the function did not check
for failure cases of of_property_read_string, which could lead to
improper behavior if the required device tree properties were missing
or incorrect.

Although the error addressed by this patch may not occur in the current
environment, I still suggest implementing these error handling routines
if the function is not highly time-sensitive. As the environment evolves
or the code gets reused in different contexts, there's a possibility that
these errors might occur. Addressing them now can prevent potential
debugging efforts in the future, which could be quite resource-intensive.

Signed-off-by: Haoran Liu <liuhaoran14@163.com>
---
 drivers/soc/renesas/renesas-soc.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

kernel test robot Nov. 30, 2023, 3:54 a.m. UTC | #1 
Hi Haoran,

kernel test robot noticed the following build errors:

[auto build test ERROR on geert-renesas-devel/next]
[also build test ERROR on linus/master v6.7-rc3 next-20231129]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Haoran-Liu/renesas-soc-Add-error-handling-in-renesas_soc_init/20231129-225113
base:   https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel.git next
patch link:    https://lore.kernel.org/r/20231129143431.34459-1-liuhaoran14%40163.com
patch subject: [PATCH] [soc/renesas] renesas-soc: Add error handling in renesas_soc_init
config: powerpc-allmodconfig (https://download.01.org/0day-ci/archive/20231130/202311300814.9jXQLQEU-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231130/202311300814.9jXQLQEU-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311300814.9jXQLQEU-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/soc/renesas/renesas-soc.c:492:11: error: use of undeclared identifier 'dev'
     492 |                 dev_err(dev, "Failed to read model property: %d\n", ret);
         |                         ^
   1 error generated.


vim +/dev +492 drivers/soc/renesas/renesas-soc.c

   447	
   448	static int __init renesas_soc_init(void)
   449	{
   450		struct soc_device_attribute *soc_dev_attr;
   451		unsigned int product, eshi = 0, eslo;
   452		const struct renesas_family *family;
   453		const struct of_device_id *match;
   454		const struct renesas_soc *soc;
   455		const struct renesas_id *id;
   456		void __iomem *chipid = NULL;
   457		const char *rev_prefix = "";
   458		struct soc_device *soc_dev;
   459		struct device_node *np;
   460		const char *soc_id;
   461		int ret;
   462	
   463		match = of_match_node(renesas_socs, of_root);
   464		if (!match)
   465			return -ENODEV;
   466	
   467		soc_id = strchr(match->compatible, ',') + 1;
   468		soc = match->data;
   469		family = soc->family;
   470	
   471		np = of_find_matching_node_and_match(NULL, renesas_ids, &match);
   472		if (np) {
   473			id = match->data;
   474			chipid = of_iomap(np, 0);
   475			of_node_put(np);
   476		} else if (soc->id && family->reg) {
   477			/* Try hardcoded CCCR/PRR fallback */
   478			id = &id_prr;
   479			chipid = ioremap(family->reg, 4);
   480		}
   481	
   482		soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
   483		if (!soc_dev_attr) {
   484			if (chipid)
   485				iounmap(chipid);
   486			return -ENOMEM;
   487		}
   488	
   489		np = of_find_node_by_path("/");
   490		ret = of_property_read_string(np, "model", &soc_dev_attr->machine);
   491		if (ret) {
 > 492			dev_err(dev, "Failed to read model property: %d\n", ret);
Geert Uytterhoeven Nov. 30, 2023, 10:59 a.m. UTC | #2 
Hi Haoran,

Thanks for your patch!

On Wed, Nov 29, 2023 at 3:34 PM Haoran Liu <liuhaoran14@163.com> wrote:
> This patch enhances the renesas_soc_init function in
> drivers/soc/renesas/renesas-soc.c by adding error handling for the
> of_property_read_string call. Previously, the function did not check
> for failure cases of of_property_read_string, which could lead to
> improper behavior if the required device tree properties were missing

Which improper behavior did you encounter? All of the
soc_device_attribute fields are optional, and drivers/base/soc.c
considers that when handling the machine field (sysfs_emit() handles
NULL pointer strings fine).

> or incorrect.

FTR, "model" is a required property of the root node.

> Although the error addressed by this patch may not occur in the current
> environment, I still suggest implementing these error handling routines
> if the function is not highly time-sensitive. As the environment evolves
> or the code gets reused in different contexts, there's a possibility that
> these errors might occur. Addressing them now can prevent potential
> debugging efforts in the future, which could be quite resource-intensive.
>
> Signed-off-by: Haoran Liu <liuhaoran14@163.com>

> --- a/drivers/soc/renesas/renesas-soc.c
> +++ b/drivers/soc/renesas/renesas-soc.c
> @@ -487,7 +487,13 @@ static int __init renesas_soc_init(void)
>         }
>
>         np = of_find_node_by_path("/");
> -       of_property_read_string(np, "model", &soc_dev_attr->machine);
> +       ret = of_property_read_string(np, "model", &soc_dev_attr->machine);
> +       if (ret) {
> +               dev_err(dev, "Failed to read model property: %d\n", ret);

As reported by the kernel test robot:

    error: use of undeclared identifier 'dev'

Please do not submit completely untested patches.

> +               kfree(soc_dev_attr);
> +               return ret;

As the machine field is optional, there is no need for this check,
let alone to make this a fatal error condition.

> +       }
> +
>         of_node_put(np);
>
>         soc_dev_attr->family = kstrdup_const(family->name, GFP_KERNEL);

Gr{oetje,eeting}s,

                        Geert
kernel test robot Dec. 1, 2023, 9:14 a.m. UTC | #3 
Hi Haoran,

kernel test robot noticed the following build errors:

[auto build test ERROR on geert-renesas-devel/next]
[also build test ERROR on linus/master v6.7-rc3 next-20231201]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Haoran-Liu/renesas-soc-Add-error-handling-in-renesas_soc_init/20231129-225113
base:   https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-devel.git next
patch link:    https://lore.kernel.org/r/20231129143431.34459-1-liuhaoran14%40163.com
patch subject: [PATCH] [soc/renesas] renesas-soc: Add error handling in renesas_soc_init
config: openrisc-allyesconfig (https://download.01.org/0day-ci/archive/20231201/202312011703.teVKAipZ-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231201/202312011703.teVKAipZ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202312011703.teVKAipZ-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from include/linux/device.h:15,
                    from include/linux/sys_soc.h:9,
                    from drivers/soc/renesas/renesas-soc.c:13:
   drivers/soc/renesas/renesas-soc.c: In function 'renesas_soc_init':
>> drivers/soc/renesas/renesas-soc.c:492:25: error: 'dev' undeclared (first use in this function); did you mean 'cdev'?
     492 |                 dev_err(dev, "Failed to read model property: %d\n", ret);
         |                         ^~~
   include/linux/dev_printk.h:110:25: note: in definition of macro 'dev_printk_index_wrap'
     110 |                 _p_func(dev, fmt, ##__VA_ARGS__);                       \
         |                         ^~~
   drivers/soc/renesas/renesas-soc.c:492:17: note: in expansion of macro 'dev_err'
     492 |                 dev_err(dev, "Failed to read model property: %d\n", ret);
         |                 ^~~~~~~
   drivers/soc/renesas/renesas-soc.c:492:25: note: each undeclared identifier is reported only once for each function it appears in
     492 |                 dev_err(dev, "Failed to read model property: %d\n", ret);
         |                         ^~~
   include/linux/dev_printk.h:110:25: note: in definition of macro 'dev_printk_index_wrap'
     110 |                 _p_func(dev, fmt, ##__VA_ARGS__);                       \
         |                         ^~~
   drivers/soc/renesas/renesas-soc.c:492:17: note: in expansion of macro 'dev_err'
     492 |                 dev_err(dev, "Failed to read model property: %d\n", ret);
         |                 ^~~~~~~


vim +492 drivers/soc/renesas/renesas-soc.c

   447	
   448	static int __init renesas_soc_init(void)
   449	{
   450		struct soc_device_attribute *soc_dev_attr;
   451		unsigned int product, eshi = 0, eslo;
   452		const struct renesas_family *family;
   453		const struct of_device_id *match;
   454		const struct renesas_soc *soc;
   455		const struct renesas_id *id;
   456		void __iomem *chipid = NULL;
   457		const char *rev_prefix = "";
   458		struct soc_device *soc_dev;
   459		struct device_node *np;
   460		const char *soc_id;
   461		int ret;
   462	
   463		match = of_match_node(renesas_socs, of_root);
   464		if (!match)
   465			return -ENODEV;
   466	
   467		soc_id = strchr(match->compatible, ',') + 1;
   468		soc = match->data;
   469		family = soc->family;
   470	
   471		np = of_find_matching_node_and_match(NULL, renesas_ids, &match);
   472		if (np) {
   473			id = match->data;
   474			chipid = of_iomap(np, 0);
   475			of_node_put(np);
   476		} else if (soc->id && family->reg) {
   477			/* Try hardcoded CCCR/PRR fallback */
   478			id = &id_prr;
   479			chipid = ioremap(family->reg, 4);
   480		}
   481	
   482		soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
   483		if (!soc_dev_attr) {
   484			if (chipid)
   485				iounmap(chipid);
   486			return -ENOMEM;
   487		}
   488	
   489		np = of_find_node_by_path("/");
   490		ret = of_property_read_string(np, "model", &soc_dev_attr->machine);
   491		if (ret) {
 > 492			dev_err(dev, "Failed to read model property: %d\n", ret);
diff mbox series

Patch

diff --git a/drivers/soc/renesas/renesas-soc.c b/drivers/soc/renesas/renesas-soc.c
index c732d4a5b26a..7a5f5c426118 100644
--- a/drivers/soc/renesas/renesas-soc.c
+++ b/drivers/soc/renesas/renesas-soc.c
@@ -487,7 +487,13 @@  static int __init renesas_soc_init(void)
 	}
 
 	np = of_find_node_by_path("/");
-	of_property_read_string(np, "model", &soc_dev_attr->machine);
+	ret = of_property_read_string(np, "model", &soc_dev_attr->machine);
+	if (ret) {
+		dev_err(dev, "Failed to read model property: %d\n", ret);
+		kfree(soc_dev_attr);
+		return ret;
+	}
+
 	of_node_put(np);
 
 	soc_dev_attr->family = kstrdup_const(family->name, GFP_KERNEL);