My pleasure.
I am very new to sparse.
I guess the warning is caused by the macro min.
Then I submitted my changes.
Thanks for code review.
-----邮件原件-----
发件人: Frank Rowand [mailto:[email protected]]
发送时间: 2019年4月11日 2:50
收件人: xiaojiangfeng <[email protected]>; [email protected]; [email protected]
抄送: [email protected]; [email protected]
主题: Re: [PATCH] of: del redundant type conversion
On 4/10/19 1:29 AM, xiaojiangfeng wrote:
> The type of variable l in early_init_dt_scan_chosen is int, there is
> no need to convert to int.
>
> Signed-off-by: xiaojiangfeng <[email protected]>
> ---
> drivers/of/fdt.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index
> 4734223..de893c9 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -1091,7 +1091,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
> /* Retrieve command line */
> p = of_get_flat_dt_prop(node, "bootargs", &l);
> if (p != NULL && l > 0)
> - strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
> + strlcpy(data, p, min(l, COMMAND_LINE_SIZE));
>
> /*
> * CONFIG_CMDLINE is meant to be a default in case nothing else
>
Thanks for catching the redundant cast.
There is a second problem detected by sparse on that line:
drivers/of/fdt.c:1094:34: warning: expression using sizeof(void)
Can you please fix both issues?
Thanks,
Frank
On 4/10/19 6:51 PM, xiaojiangfeng wrote:
> My pleasure.
>
> I am very new to sparse.
>
> I guess the warning is caused by the macro min.
I think the warning is likely because the type of data is 'void *'.
Removing the (int) cast is a good fix, but does not resolve
the sparse warning.
-Frank
> Then I submitted my changes.
>
> Thanks for code review.
>
>
> -----邮件原件-----
> 发件人: Frank Rowand [mailto:[email protected]]
> 发送时间: 2019年4月11日 2:50
> 收件人: xiaojiangfeng <[email protected]>; [email protected]; [email protected]
> 抄送: [email protected]; [email protected]
> 主题: Re: [PATCH] of: del redundant type conversion
>
> On 4/10/19 1:29 AM, xiaojiangfeng wrote:
>> The type of variable l in early_init_dt_scan_chosen is int, there is
>> no need to convert to int.
>>
>> Signed-off-by: xiaojiangfeng <[email protected]>
>> ---
>> drivers/of/fdt.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index
>> 4734223..de893c9 100644
>> --- a/drivers/of/fdt.c
>> +++ b/drivers/of/fdt.c
>> @@ -1091,7 +1091,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
>> /* Retrieve command line */
>> p = of_get_flat_dt_prop(node, "bootargs", &l);
>> if (p != NULL && l > 0)
>> - strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
>> + strlcpy(data, p, min(l, COMMAND_LINE_SIZE));
>>
>> /*
>> * CONFIG_CMDLINE is meant to be a default in case nothing else
>>
>
> Thanks for catching the redundant cast.
>
> There is a second problem detected by sparse on that line:
>
> drivers/of/fdt.c:1094:34: warning: expression using sizeof(void)
>
> Can you please fix both issues?
>
> Thanks,
>
> Frank
>
On 4/10/19 9:13 PM, Frank Rowand wrote:
> On 4/10/19 6:51 PM, xiaojiangfeng wrote:
>> My pleasure.
>>
>> I am very new to sparse.
>>
>> I guess the warning is caused by the macro min.
>
> I think the warning is likely because the type of data is 'void *'.
>
> Removing the (int) cast is a good fix, but does not resolve
> the sparse warning.
Let me correct myself. When I ran sparse, I see the removing min() does
eliminate the sparse warning. I'm not sure why, so I'll go dig a little
deeper.
-Frank
>
> -Frank
>
>
>> Then I submitted my changes.
>>
>> Thanks for code review.
>>
>>
>> -----邮件原件-----
>> 发件人: Frank Rowand [mailto:[email protected]]
>> 发送时间: 2019年4月11日 2:50
>> 收件人: xiaojiangfeng <[email protected]>; [email protected]; [email protected]
>> 抄送: [email protected]; [email protected]
>> 主题: Re: [PATCH] of: del redundant type conversion
>>
>> On 4/10/19 1:29 AM, xiaojiangfeng wrote:
>>> The type of variable l in early_init_dt_scan_chosen is int, there is
>>> no need to convert to int.
>>>
>>> Signed-off-by: xiaojiangfeng <[email protected]>
>>> ---
>>> drivers/of/fdt.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index
>>> 4734223..de893c9 100644
>>> --- a/drivers/of/fdt.c
>>> +++ b/drivers/of/fdt.c
>>> @@ -1091,7 +1091,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
>>> /* Retrieve command line */
>>> p = of_get_flat_dt_prop(node, "bootargs", &l);
>>> if (p != NULL && l > 0)
>>> - strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
>>> + strlcpy(data, p, min(l, COMMAND_LINE_SIZE));
>>>
>>> /*
>>> * CONFIG_CMDLINE is meant to be a default in case nothing else
>>>
>>
>> Thanks for catching the redundant cast.
>>
>> There is a second problem detected by sparse on that line:
>>
>> drivers/of/fdt.c:1094:34: warning: expression using sizeof(void)
>>
>> Can you please fix both issues?
>>
>> Thanks,
>>
>> Frank
>>
>
>
On 4/10/19 9:21 PM, Frank Rowand wrote:
> On 4/10/19 9:13 PM, Frank Rowand wrote:
>> On 4/10/19 6:51 PM, xiaojiangfeng wrote:
>>> My pleasure.
>>>
>>> I am very new to sparse.
>>>
>>> I guess the warning is caused by the macro min.
>>
>> I think the warning is likely because the type of data is 'void *'.
>>
>> Removing the (int) cast is a good fix, but does not resolve
>> the sparse warning.
>
> Let me correct myself. When I ran sparse, I see the removing min() does
> eliminate the sparse warning. I'm not sure why, so I'll go dig a little
> deeper.
Digging leaves me with more information, but still not sure of the actual
underlying cause. min() is defined in include/linux/kernel.h. Unraveling
the defines, the code that sparse is complaining about is in
__no_side_effects(), which is:
#define __no_side_effects(x, y) \
(__is_constexpr(x) && __is_constexpr(y))
and __is_constexpr() is:
#define __is_constexpr(x) \
(sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
The compiler warning points to the second sizeof() in the __is_constexpr() for
'l', which expands as:
(sizeof(int) == sizeof(*(8 ? ((void *)((long)( l) * 0l)) : (int *)8)))
I'll dig into this a little more, to see if maybe the problem is related to
my compiler version or sparse version. Or if the reason lies elsewhere.
-Frank
>
> -Frank
>
>>
>> -Frank
>>
>>
>>> Then I submitted my changes.
>>>
>>> Thanks for code review.
>>>
>>>
>>> -----邮件原件-----
>>> 发件人: Frank Rowand [mailto:[email protected]]
>>> 发送时间: 2019年4月11日 2:50
>>> 收件人: xiaojiangfeng <[email protected]>; [email protected]; [email protected]
>>> 抄送: [email protected]; [email protected]
>>> 主题: Re: [PATCH] of: del redundant type conversion
>>>
>>> On 4/10/19 1:29 AM, xiaojiangfeng wrote:
>>>> The type of variable l in early_init_dt_scan_chosen is int, there is
>>>> no need to convert to int.
>>>>
>>>> Signed-off-by: xiaojiangfeng <[email protected]>
>>>> ---
>>>> drivers/of/fdt.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index
>>>> 4734223..de893c9 100644
>>>> --- a/drivers/of/fdt.c
>>>> +++ b/drivers/of/fdt.c
>>>> @@ -1091,7 +1091,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
>>>> /* Retrieve command line */
>>>> p = of_get_flat_dt_prop(node, "bootargs", &l);
>>>> if (p != NULL && l > 0)
>>>> - strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
>>>> + strlcpy(data, p, min(l, COMMAND_LINE_SIZE));
>>>>
>>>> /*
>>>> * CONFIG_CMDLINE is meant to be a default in case nothing else
>>>>
>>>
>>> Thanks for catching the redundant cast.
>>>
>>> There is a second problem detected by sparse on that line:
>>>
>>> drivers/of/fdt.c:1094:34: warning: expression using sizeof(void)
>>>
>>> Can you please fix both issues?
>>>
>>> Thanks,
>>>
>>> Frank
>>>
>>
>>
>
>