2020-11-22 12:12:59

by Alexey Dobriyan

Subject: [PATCH] driver core: cleanup kstrto*() usage

kstrto*() functions can write result directly to target memory
if no additional checks needs to be done.

Signed-off-by: Alexey Dobriyan <[email protected]>
---

drivers/base/core.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1701,12 +1701,10 @@ ssize_t device_store_ulong(struct device *dev,
{
struct dev_ext_attribute *ea = to_ext_attr(attr);
int ret;
- unsigned long new;

- ret = kstrtoul(buf, 0, &new);
+ ret = kstrtoul(buf, 0, (unsigned long *)ea->var);
if (ret)
return ret;
- *(unsigned long *)(ea->var) = new;
/* Always return full write size even if we didn't consume all */
return size;
}
@@ -1726,16 +1724,12 @@ ssize_t device_store_int(struct device *dev,
const char *buf, size_t size)
{
struct dev_ext_attribute *ea = to_ext_attr(attr);
+ int val;
int ret;
- long new;

- ret = kstrtol(buf, 0, &new);
+ ret = kstrtoint(buf, 0, (int *)ea->var);
if (ret)
return ret;
-
- if (new > INT_MAX || new < INT_MIN)
- return -EINVAL;
- *(int *)(ea->var) = new;
/* Always return full write size even if we didn't consume all */
return size;
}

2020-11-23 00:35:33

by Chen, Rong A

Subject: Re: [PATCH] driver core: cleanup kstrto*() usage

Hi Alexey,

I love your patch! Perhaps something to improve:

[auto build test WARNING on driver-core/driver-core-testing]
[also build test WARNING on v5.10-rc4]
[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]

url: https://github.com/0day-ci/linux/commits/Alexey-Dobriyan/driver-core-cleanup-kstrto-usage/20201122-201458
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git 33c0c9bdf7a59051a654cd98b7d2b48ce0080967
compiler: riscv64-linux-gcc (GCC) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>


cppcheck possible warnings: (new ones prefixed by >>, may not real problems)

drivers/base/core.c:3196:10: warning: Identical inner 'return' condition is always true. [identicalInnerCondition]
return *tmp;
^
drivers/base/core.c:3195:6: note: outer condition: *tmp
if (*tmp)
^
drivers/base/core.c:3196:10: note: identical inner condition: *tmp
return *tmp;
^
drivers/base/core.c:3202:10: warning: Identical inner 'return' condition is always true. [identicalInnerCondition]
return *tmp;
^
drivers/base/core.c:3201:6: note: outer condition: *tmp
if (*tmp)
^
drivers/base/core.c:3202:10: note: identical inner condition: *tmp
return *tmp;
^
>> drivers/base/core.c:1725:6: warning: Unused variable: val [unusedVariable]
int val;
^

vim +1725 drivers/base/core.c

ca22e56debc57b Kay Sievers 2011-12-14 1719
ca22e56debc57b Kay Sievers 2011-12-14 1720 ssize_t device_store_int(struct device *dev,
ca22e56debc57b Kay Sievers 2011-12-14 1721 struct device_attribute *attr,
ca22e56debc57b Kay Sievers 2011-12-14 1722 const char *buf, size_t size)
ca22e56debc57b Kay Sievers 2011-12-14 1723 {
ca22e56debc57b Kay Sievers 2011-12-14 1724 struct dev_ext_attribute *ea = to_ext_attr(attr);
e7443ff26978ad Alexey Dobriyan 2020-11-22 @1725 int val;
f88184bfee48d4 Kaitao cheng 2018-11-06 1726 int ret;
f88184bfee48d4 Kaitao cheng 2018-11-06 1727
e7443ff26978ad Alexey Dobriyan 2020-11-22 1728 ret = kstrtoint(buf, 0, (int *)ea->var);
f88184bfee48d4 Kaitao cheng 2018-11-06 1729 if (ret)
f88184bfee48d4 Kaitao cheng 2018-11-06 1730 return ret;
ca22e56debc57b Kay Sievers 2011-12-14 1731 /* Always return full write size even if we didn't consume all */
ca22e56debc57b Kay Sievers 2011-12-14 1732 return size;
ca22e56debc57b Kay Sievers 2011-12-14 1733 }
ca22e56debc57b Kay Sievers 2011-12-14 1734 EXPORT_SYMBOL_GPL(device_store_int);
ca22e56debc57b Kay Sievers 2011-12-14 1735

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]