Hi Dave, On Thu, 05 Dec 2019 14:57:39 -0800 (PST) David Miller <davem@xxxxxxxxxxxxx> wrote: > > I think it is a false positive as well. It looks like the compiler > has trouble seeing through ptr error guards. > > In the new code the compiler can only see that the return value in the > error case is non-zero, not necessarily that it is < 0 which is the > guard against uninitialized accesses of 'obj'. > > It will satisfy this property, but through the various casts and > implicit demotions, this information is lost on the compiler. > > My compiler didn't emit this warning FWIW. > > gcc (GCC) 8.3.1 20190223 (Red Hat 8.3.1-2) > > I'm unsure how to handle this, setting 'n' to explicitly be NULL > is bogus because the compiler now will think that a NULL deref > happens since the guard isn't guarding the existing assignment. Yeah, not much we can do. x86_64-linux-gnu-gcc (Debian 9.2.1-19) 9.2.1 20191109 -- Cheers, Stephen Rothwell
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