Messages in this thread | | | Date | Wed, 18 Oct 2023 16:08:31 -0700 | From | Kees Cook <> | Subject | Re: [PATCH] bcachefs: Refactor bkey_i to use a flexible array |
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On Wed, Oct 18, 2023 at 03:36:00PM -0700, Kees Cook wrote: > On Wed, Oct 18, 2023 at 06:04:07PM -0400, Kent Overstreet wrote: > > On Fri, Oct 13, 2023 at 04:44:21PM -0700, Kees Cook wrote: > > > On Fri, Oct 13, 2023 at 07:26:11AM -0400, Brian Foster wrote: > > > > Hi Kees, > > > > > > > > I'm curious if this is something that could be buried in bch_val given > > > > it's already kind of a fake structure..? If not, my only nitty comment > > > > > > I was thinking it would be best to keep the flexible array has "high" in > > > the struct as possible, as in the future more refactoring will be needed > > > to avoid having flex arrays overlap with other members in composite > > > structures. So instead of pushing into bch_val, I left it at the highest > > > level possible, bch_i, as that's the struct being used by the memcpy(). > > > > I agree with Brian here - I'd like this buried in bch_val, if possible. > > > > I also went with unsafe_memcpy() for now - that's now in my for-next > > tree. I'm not seeing any advantage of DECLARE_FLEX_ARRAY over that - > > perhaps later if we could use __counted_by that would make more sense. > > This won't help here because of the combination of -fstrict-flex-arrays=3 > and -Wstringop-overflow (the latter is in W=1 builds). The builtin memcpy > still complains about the 0-sized destination. I'll send a v3 with this > in bch_val.
Actually, I've sent a v3 that totally replaces the memcpy with a direct assignment instead. No struct changes needed!
-- Kees Cook
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