Re:size_t-to-int vulnerability in Linux’s filesystem layer
by xeeeeeeeeeeenu on Tuesday July 20, 2021 @11:37AM
(#27895049)
It warns if you add -Wconversion. Unfortunately, that flag generates lots of false positives (at least in gcc), so using it isn't always a good idea.
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Re:size_t-to-int vulnerability in Linux’s filesystem layer
by morio on Tuesday July 20, 2021 @12:18PM
(#27895720)
What kind of false positives are you seeing with gcc?
Personally I have never seen gcc spitting out a false positive. IMO it's always a good idea to explicitly downcast even if you know that it's 'safe'. That way someone else will see instantly what's going on. The fact that Rust requires it should tell us something.
Re:size_t-to-int vulnerability in Linux’s filesystem layer
by xeeeeeeeeeeenu on Tuesday July 20, 2021 @02:00PM
(#27897025)
For example, I've just reported this: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101537
You can find more cases in the bugtracker. To be fair, it seems many of them were fixed in recent releases.
Re:size_t-to-int vulnerability in Linux’s filesystem layer
by Cloudef on Wednesday July 21, 2021 @12:38AM
(#27902395)
The 1 and 0 are ints. It most likely complaints because the sign isn't same.
Re:size_t-to-int vulnerability in Linux’s filesystem layer
by jeffbee on Tuesday July 20, 2021 @12:01PM
(#27895409)
It isn't ever a good idea. C programmers are just supposed to know about the conversion and promotion rules, every time they add a line, even though the rules are actually insanely complicated. Compiler warnings can't overcome this because programmers have no way of just discovering one of GCC's 726 warning flags, only a few of which are enabled by -Wall and -Wextra, most of which are way too noisy to serve a useful purpose.