Re: Linux 4.19 and GCC 9

[Greg KH]

On Tue, Jun 25, 2019 at 03:50:29PM +0800, Greg KH wrote:
> On Mon, Jun 24, 2019 at 11:42:34AM +0100, Ignat Korchagin wrote:
> > Hi Greg,
> > 
> > > > For us it seems applying the following 4 mainline patches makes 4.19.x
> > > > branch perf compile with GCC-9:
> > > >
> > > > 4d0f16d059ddb91424480d88473f7392f24aebdc: perf ui helpline: Use
> > > > strlcpy() as a shorter form of strncpy() + explicit set nul
> > > > b6313899f4ed2e76b8375cf8069556f5b94fbff0: perf help: Remove needless
> > > > use of strncpy()
> > > > 5192bde7d98c99f2cd80225649e3c2e7493722f7: perf header: Fix unchecked
> > > > usage of strncpy()
> > > > 97acec7df172cd1e450f81f5e293c0aa145a2797: perf data: Fix 'strncat may
> > > > truncate' build failure with recent gcc
> > > >
> > > > I also checked that 4.19.49 compiles fine with GCC 9, although with a
> > > > lot of warnings, mostly from objtool, like "warning: objtool:
> > > > sock_register()+0xd: sibling call from callable instruction with
> > > > modified stack frame". But it's a start.
> > > >
> > > > Can we apply the above-mentioned patches, please?
> > 
> > > I'll look into these after the next round of kernels are released.  I
> > 
> > Did you by any chance forget to queue these patches? :) (the build is
> > still broken for GCC 9.1)
> 
> I am on the road and getting to backports for this stuff is on the
> bottom of my list until next week at the earliest, sorry.

Oh nevermind, I just queued them up now.

If there are any other gcc9 patches that you see that I've missed,
please let me know.

Now, to try to track down the fix for all of those build warnings, those
need to get fixed up...

thanks,

greg k-h