Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1475361

Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit.

Show all headers | View raw

[Multipart message — attachments visible in raw view] - view raw

On 8/27/2016 1:25 AM, Christophe JAILLET wrote:
> Le 26/08/2016 à 15:35, Doug Ledford a écrit :
>> On 8/26/2016 12:49 AM, Christophe JAILLET wrote:
>>> The 2nd parameter of 'find_first_bit' is the number of bits to search.
>>> In this case, we are passing 'sizeof(unsigned long)' which is likely to
>>> be 4 or 8.
>> If the size can be 4 or 8, then using 64 universally is not correct.
>> Why not use sizeof() * 8 (or << 3)?
> I agree with you...
> 
> BTW, the log message is wrong. 'port_mask' is a u64. (not an unsigned
> long). So the sizeof should always be 8.
> (cut and paste error from another patch, sorry)

Log message modified, then patch modified to use sizeof() * 8, result
applied.  Thanks.

>>
>>> It is likely that the number of bits of 'port_mask' was expected
>>> here. This
>>> variable is a 'u64', so use 64 instead.
>>>
>>> It has been spotted by the following coccinelle script:
>>> @@
>>> expression ret, x;
>>>
>>> @@
>>> *  ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...));
>>>
>>> Signed-off-by: Christophe JAILLET
>>> <christophe.jaillet-39ZsbGIQGT5GWvitb5QawA@public.gmane.org>
>>> ---
>>> Not sure that using 64 directly is the best option.
>>> Maybe '8 * sizeof(port_mask)' as used in the same file for
>>> 'for_each_set_bit' would be better
>>> ---
> ... as noted here
> 
> Would you like a v2 patch or, will you update it by yourself?
> 
> Best regards,
> CJ
> 
> ---
> L'absence de virus dans ce courrier électronique a été vérifiée par le
> logiciel antivirus Avast.
> https://www.avast.com/antivirus
> 


-- 
Doug Ledford <dledford@redhat.com>
    GPG Key ID: 0E572FDD

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2016-08-26 07:00 +0200
  Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-08-26 15:40 +0200
    Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-08-26 20:10 +0200
      Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-08-26 21:40 +0200
        Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Leon Romanovsky <leon@kernel.org> - 2016-08-28 08:10 +0200
          Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-09-02 16:40 +0200
            Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Leon Romanovsky <leon@kernel.org> - 2016-09-04 11:10 +0200
      Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Leon Romanovsky <leon@kernel.org> - 2016-08-26 21:40 +0200
    Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2016-08-27 07:30 +0200
      Re: [PATCH 1/2] IB/hfi1: Fix a parameter of find_first_bit. Doug Ledford <dledford@redhat.com> - 2016-09-02 19:20 +0200

csiph-web