Re: [PATCH v6 4/4] risc/purgatory: Add linker script
On Mon, May 01, 2023 at 09:54:43PM +0200, Ricardo Ribalda wrote:
> On Mon, 1 May 2023 at 19:41, Conor Dooley wrote:
> > On Mon, May 01, 2023 at 02:38:22PM +0200, Ricardo Ribalda wrote:
> > > If PGO is enabled, the purgatory ends up with multiple .text sections.
> > > This is not supported by kexec and crashes the system.
> > >
> > > Cc: sta...@vger.kernel.org
> > > Fixes: 930457057abe ("kernel/kexec_file.c: split up
> > > __kexec_load_puragory")
> > > Signed-off-by: Ricardo Ribalda
> > > ---
> > > 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))
> >
> > With the caveat of not being au fait with the workings of either PGO or
> > of purgatory, how come you modify KBUILD_CFLAGS here rather than the
> > purgatory specific PURGATORY_CFLAGS that are used later in the file?
>
> Definitely, not a Makefile expert here, but when I tried this:
>
> @@ -35,6 +40,7 @@ PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel
> PURGATORY_CFLAGS := -mcmodel=large -ffreestanding
> -fno-zero-initialized-in-bss -g0
> PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING
> PURGATORY_CFLAGS += -fno-stack-protector
> +PURGATORY_CFLAGS := $(filter-out -fprofile-sample-use=%
> -fprofile-use=%,$(KBUILD_CFLAGS))
>
> It did not work.
Unfortunately I am oh-so-far from an expert on this kind of thing, but I
had thought that PURGATORY_CFLAGS_REMOVE was intended for this sort of
purpose.
> Fixes: bde971a83bbf ("KVM: arm64: nvhe: Fix build with profile optimization")
>
> does this approach, so this is what I tried and worked.
That doesn't have a specific CFLAGS though afaict.
Perhaps Nick etc have a more informed opinion here than I do, sorry.
Thanks,
Conor.
> > > +
> > > # 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
> > >
> > >
> > > ___
> > > linux-riscv mailing list
> > > linux-ri...@lists.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/linux-riscv
>
>
>
> --
> Ricardo Ribalda
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Re: [PATCH v6 4/4] risc/purgatory: Add linker script
Hi Conor
On Mon, 1 May 2023 at 19:41, Conor Dooley wrote:
>
> Hey Ricardo,
>
> On Mon, May 01, 2023 at 02:38:22PM +0200, Ricardo Ribalda wrote:
> > If PGO is enabled, the purgatory ends up with multiple .text sections.
> > This is not supported by kexec and crashes the system.
> >
> > Cc: sta...@vger.kernel.org
> > Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
> > Signed-off-by: Ricardo Ribalda
> > ---
> > 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))
>
> With the caveat of not being au fait with the workings of either PGO or
> of purgatory, how come you modify KBUILD_CFLAGS here rather than the
> purgatory specific PURGATORY_CFLAGS that are used later in the file?
Definitely, not a Makefile expert here, but when I tried this:
@@ -35,6 +40,7 @@ PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel
PURGATORY_CFLAGS := -mcmodel=large -ffreestanding
-fno-zero-initialized-in-bss -g0
PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING
PURGATORY_CFLAGS += -fno-stack-protector
+PURGATORY_CFLAGS := $(filter-out -fprofile-sample-use=%
-fprofile-use=%,$(KBUILD_CFLAGS))
It did not work.
Fixes: bde971a83bbf ("KVM: arm64: nvhe: Fix build with profile optimization")
does this approach, so this is what I tried and worked.
Thanks!
>
> Cheers,
> Conor.
>
> > +
> > # 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
> >
> >
> > ___
> > linux-riscv mailing list
> > linux-ri...@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv
--
Ricardo Ribalda
Re: [PATCH v6 4/4] risc/purgatory: Add linker script
Hey Ricardo,
On Mon, May 01, 2023 at 02:38:22PM +0200, Ricardo Ribalda wrote:
> If PGO is enabled, the purgatory ends up with multiple .text sections.
> This is not supported by kexec and crashes the system.
>
> Cc: sta...@vger.kernel.org
> Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
> Signed-off-by: Ricardo Ribalda
> ---
> 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))
With the caveat of not being au fait with the workings of either PGO or
of purgatory, how come you modify KBUILD_CFLAGS here rather than the
purgatory specific PURGATORY_CFLAGS that are used later in the file?
Cheers,
Conor.
> +
> # 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
>
>
> ___
> linux-riscv mailing list
> linux-ri...@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
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Re: [PATCH v6 4/4] risc/purgatory: Add linker script
Hi Conor
Fixed on my branch
https://git.kernel.org/pub/scm/linux/kernel/git/ribalda/linux.git/commit/?h=b4/kexec_clang16=1e9cda9fa638cc72581986f60b490cc069a38f75
Will submit a new version after a while :)
Thanks!
On Mon, 1 May 2023 at 19:28, Conor Dooley wrote:
>
> On Mon, May 01, 2023 at 07:18:12PM +0200, Ricardo Ribalda wrote:
> > On Mon, 1 May 2023 at 18:19, Nick Desaulniers
> > wrote:
> > >
> > > On Mon, May 1, 2023 at 5:39 AM Ricardo Ribalda
> > > wrote:
> > > >
> > > > If PGO is enabled, the purgatory ends up with multiple .text sections.
> > > > This is not supported by kexec and crashes the system.
> > > >
> > > > Cc: sta...@vger.kernel.org
> > > > Fixes: 930457057abe ("kernel/kexec_file.c: split up
> > > > __kexec_load_puragory")
> > > > Signed-off-by: Ricardo Ribalda
> > >
> > > 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-ri...@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv
--
Ricardo Ribalda
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 wrote:
> >
> > On Mon, May 1, 2023 at 5:39 AM Ricardo Ribalda wrote:
> > >
> > > If PGO is enabled, the purgatory ends up with multiple .text sections.
> > > This is not supported by kexec and crashes the system.
> > >
> > > Cc: sta...@vger.kernel.org
> > > Fixes: 930457057abe ("kernel/kexec_file.c: split up
> > > __kexec_load_puragory")
> > > Signed-off-by: Ricardo Ribalda
> >
> > 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-ri...@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
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Re: [PATCH v6 4/4] risc/purgatory: Add linker script
Hi Nick
Thanks for catching this. It should have said
risc/purgatory: Remove profile optimization flags
Will fix it on my local branch in case there is a next version of the
series. Otherwise, please the maintainer fix the subject.
Thanks!
On Mon, 1 May 2023 at 18:19, Nick Desaulniers wrote:
>
> On Mon, May 1, 2023 at 5:39 AM Ricardo Ribalda wrote:
> >
> > If PGO is enabled, the purgatory ends up with multiple .text sections.
> > This is not supported by kexec and crashes the system.
> >
> > Cc: sta...@vger.kernel.org
> > Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
> > Signed-off-by: Ricardo Ribalda
>
> 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).
>
> > ---
> > 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
Re: [PATCH v6 4/4] risc/purgatory: Add linker script
On Mon, May 1, 2023 at 5:39 AM Ricardo Ribalda wrote:
>
> If PGO is enabled, the purgatory ends up with multiple .text sections.
> This is not supported by kexec and crashes the system.
>
> Cc: sta...@vger.kernel.org
> Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
> Signed-off-by: Ricardo Ribalda
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).
> ---
> 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
Re: [PATCH v6 4/4] risc/purgatory: Add linker script
On Mon, 01 May 2023 05:38:22 PDT (-0700), riba...@chromium.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: sta...@vger.kernel.org
Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
Signed-off-by: Ricardo Ribalda
---
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
Acked-by: Palmer Dabbelt
[PATCH v6 4/4] risc/purgatory: Add linker script
If PGO is enabled, the purgatory ends up with multiple .text sections.
This is not supported by kexec and crashes the system.
Cc: sta...@vger.kernel.org
Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
Signed-off-by: Ricardo Ribalda
---
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
