Re: [Xen-devel] [PATCH] libelf: Fix div0 issues in elf_{shdr, phdr}_count()

[Ian Jackson <ian.jackson@xxxxxxxxxxxxx>]

Jan Beulich writes ("Re: [PATCH] libelf: Fix div0 issues in 
elf_{shdr,phdr}_count()"):
> On 08.12.16 at 15:18, <andrew.cooper3@xxxxxxxxxx> wrote:
> > Spotted by Coverity.
> 
> And wrongly so, imo.
...
> > @@ -148,11 +154,17 @@ unsigned elf_shdr_count(struct elf_binary *elf)
> >  unsigned elf_phdr_count(struct elf_binary *elf)
> >  {
> >      unsigned count = elf_uval(elf, elf->ehdr, e_phnum);
> > +    unsigned entsize = elf_uval(elf, elf->ehdr, e_phentsize);
...
> ... this would end up being dead code, due to the checks the same
> patch you refer to introduced in elf_init().

I think I would prefer code that is obviously correct from local
inspection.  There is no performance implication here.

Maybe what we want is elf_divide() which implments anything/0 as 0.

Ian.

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