Re: [PATCH 11/13] fs: fix unsigned enum warning with gcc-4.2

Brendan Gregg
2017-02-28T21:53:10Z

On Tue, Jan 3, 2017 at 2:47 PM, Brendan Gregg <brendan.d.gregg@gmail.com> wrote:
>
> On Fri, Dec 16, 2016 at 2:56 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> >
> > With arm-linux-gcc-4.2, almost every file we build in the kernel ends
> > up with this warning:
> >
> > include/linux/fs.h:2648: warning: comparison of unsigned expression < 0 is always false
> >
>
> Thanks, I'd like to see this fixed as a similar warning gets printed
> whenever running many of the bcc/BPF tools, which gets annoying and is
> user-visible. eg:
>
> # /usr/share/bcc/tools/xfsslower 1
> In file included from /virtual/main.c:3:
> /lib/modules/4.8.6-300.fc25.x86_64/build/include/linux/fs.h:2677:9:
> warning: comparison of unsigned enum expression < 0 is always false
> [-Wtautological-compare]
> if (id < 0 || id >= READING_MAX_ID)
> ~~ ^ ~
> 1 warning generated.
> Tracing XFS operations slower than 1 ms
> TIME COMM PID T BYTES OFF_KB LAT(ms) FILENAME
> 14:44:27 cksum 4414 R 65536 0 1.02 chcon
> 14:44:27 cksum 4414 R 65536 0 1.20 cpio
> 14:44:27 cksum 4414 R 65536 0 1.01 diff
> 14:44:27 cksum 4414 R 65536 0 1.15 dir
> [...]
>
> This patch fixes the warning.
>

What's the status of this patch? I still get these warnings on latest. Thanks,

Brendan