Messages in this thread | | | Subject | Re: [PATCH v3] err.h: allow IS_ERR_VALUE to handle properly more types | From | Andrzej Hajda <> | Date | Fri, 12 Feb 2016 15:45:38 +0100 |
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On 02/11/2016 05:39 PM, Arnd Bergmann wrote: > On Thursday 11 February 2016 08:00:54 Andrzej Hajda wrote: >>> I think the easiest way to express this would be to ensure that the argument >>> is 'unsigned long', like: >>> >>> #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \ >>> unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO)) >> This way you will limit it only to unsigned long type, which seems too >> strict to me. >> I think the macro should accept all long enough unsigned types, otherwise we >> could end up with bunch of macros IS_ERR_VALUE_U32, IS_ERR_VALUE_ULL... > I think in practice we only care about 'int' and 'unsigned long', which are > the ones that 90% of the existing users pass in today. u32 has never worked > on 64-bit architectures so far, so we don't necessarily have to make it work. > As Al mentioned, most users of IS_ERR_VALUE are wrong anyway and should > just use 'if (err < 0)' or 'if (err)'. > > We could also consider making just 'int' and 'unsigned long' allowed types > for the moment, and then change all users passing 'int' before forbidding them. > > Arnd > >
OK so in short we need to fix 140 usages of the macro? Who should do them? I can create cocci patch for more obvious cases. What about these less obvious? As I understand we do not touch the macro till fixes are merged?
Regards Andrzej
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