linux-kernel - Re: [PATCH v6 4/4] risc/purgatory: Add linker script

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Message-ID: <20230501-griminess-defiling-73b367bb2e47@spud>
Date:   Mon, 1 May 2023 18:28:39 +0100
From:   Conor Dooley <conor@...nel.org>
To:     Ricardo Ribalda <ribalda@...omium.org>
Cc:     Nick Desaulniers <ndesaulniers@...gle.com>,
        Eric Biederman <ebiederm@...ssion.com>,
        Philipp Rudo <prudo@...ux.vnet.ibm.com>,
        Dave Young <dyoung@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        "H. Peter Anvin" <hpa@...or.com>,
        Nathan Chancellor <nathan@...nel.org>,
        Tom Rix <trix@...hat.com>,
        Michael Ellerman <mpe@...erman.id.au>,
        Nicholas Piggin <npiggin@...il.com>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>, Baoquan He <bhe@...hat.com>,
        Philipp Rudo <prudo@...hat.com>, kexec@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Ross Zwisler <zwisler@...gle.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Simon Horman <horms@...nel.org>, llvm@...ts.linux.dev,
        linuxppc-dev@...ts.ozlabs.org, linux-riscv@...ts.infradead.org,
        stable@...r.kernel.org
Subject: Re: [PATCH v6 4/4] risc/purgatory: Add linker script

On Mon, May 01, 2023 at 07:18:12PM +0200, Ricardo Ribalda wrote:
> On Mon, 1 May 2023 at 18:19, Nick Desaulniers <ndesaulniers@...gle.com> wrote:
> >
> > On Mon, May 1, 2023 at 5:39 AM Ricardo Ribalda <ribalda@...omium.org> wrote:
> > >
> > > If PGO is enabled, the purgatory ends up with multiple .text sections.
> > > This is not supported by kexec and crashes the system.
> > >
> > > Cc: stable@...r.kernel.org
> > > Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
> > > Signed-off-by: Ricardo Ribalda <ribalda@...omium.org>
> >
> > Hi Ricardo,
> > Thanks for the series.  Does this patch 4/4 need a new online commit
> > description? It's not adding a linker script (maybe an earlier version
> > was).

> Thanks for catching this. It should have said
> 
> risc/purgatory: Remove profile optimization flags
     ^^
Perhaps with the omitted v added too?

Also while playing the $subject nitpicking game, is it not called
"profile**-guided** optimisation" (and ditto in the comments)?

Cheers,
Conor.

> Will fix it on my local branch in case there is a next version of the
> series. Otherwise, please the maintainer fix the subject.

> > > ---
> > >  arch/riscv/purgatory/Makefile | 5 +++++
> > >  1 file changed, 5 insertions(+)
> > >
> > > diff --git a/arch/riscv/purgatory/Makefile b/arch/riscv/purgatory/Makefile
> > > index 5730797a6b40..cf3a44121a90 100644
> > > --- a/arch/riscv/purgatory/Makefile
> > > +++ b/arch/riscv/purgatory/Makefile
> > > @@ -35,6 +35,11 @@ CFLAGS_sha256.o := -D__DISABLE_EXPORTS
> > >  CFLAGS_string.o := -D__DISABLE_EXPORTS
> > >  CFLAGS_ctype.o := -D__DISABLE_EXPORTS
> > >
> > > +# When profile optimization is enabled, llvm emits two different overlapping
> > > +# text sections, which is not supported by kexec. Remove profile optimization
> > > +# flags.
> > > +KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%,$(KBUILD_CFLAGS))
> > > +
> > >  # When linking purgatory.ro with -r unresolved symbols are not checked,
> > >  # also link a purgatory.chk binary without -r to check for unresolved symbols.
> > >  PURGATORY_LDFLAGS := -e purgatory_start -z nodefaultlib
> > >
> > > --
> > > 2.40.1.495.gc816e09b53d-goog
> > >
> >
> >
> > --
> > Thanks,
> > ~Nick Desaulniers
> 
> 
> 
> -- 
> Ricardo Ribalda
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

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