Messages in this thread | | | Date | Mon, 26 Feb 2018 16:17:48 -0600 | From | Segher Boessenkool <> | Subject | Re: [PATCH 06/21] powerpc: Avoid comparison of unsigned long >= 0 in __access_ok |
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On Mon, Feb 26, 2018 at 09:00:09PM +0100, christophe leroy wrote: > Le 26/02/2018 à 18:50, Mathieu Malaterre a écrit : > >On Mon, Feb 26, 2018 at 8:44 AM, Mathieu Malaterre <malat@debian.org> > >wrote: > >>On Mon, Feb 26, 2018 at 7:50 AM, Christophe LEROY > >><christophe.leroy@c-s.fr> wrote: > >>>Note that I already try to submit a fix for this warning 3 years ago > >>>(https://patchwork.ozlabs.org/patch/418075/) and it was rejected with the > >>>following comment: > > > >Tested again today with gcc 6.3.0 and gcc is still producing the > >original warning (treated as error). > > That's right, it seems that recent versions of gcc are not happy anymore > with that change. > > Maybe Segher has a suggestion for that one ?
Your patch:
#define __access_ok(addr, size, segment) \ (((addr) <= (segment).seg) && \ - (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) + (((size) <= 1) || (((size) - 1) <= ((segment).seg - (addr)))))
Is there any reason to write this as a macro? Let's make this more readable:
static inline int __access_ok(unsigned long addr, unsigned long size, mm_segment_t seg) { if (addr > seg.seg) return 0; return (size == 0 || size - 1 <= seg.seg - addr); }
and I think we are done already, or will this warn for any input?
Segher
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