* [PATCH] [MIPS] Place __kernel_entry at the beginning of text section
@ 2024-11-25 23:09 Rong Xu
2024-11-25 23:42 ` Chris Packham
0 siblings, 1 reply; 4+ messages in thread
From: Rong Xu @ 2024-11-25 23:09 UTC (permalink / raw)
To: Thomas Bogendoerfer, Masahiro Yamada, Klara Modin, Rong Xu,
Christophe Leroy, Michael Ellerman, Nicolas Schier,
Chris Packham, Maciej W. Rozycki, linux-mips, linux-kernel
Mark __kernel_entry as ".head.text" and place HEAD_TEXT before
TEXT_TEXT in the linker script. This ensures that __kernel_entry
will be placed at the beginning of text section.
Drop mips from scripts/head-object-list.txt.
Signed-off-by: Rong Xu <xur@google.com>
Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
arch/mips/kernel/head.S | 1 +
arch/mips/kernel/vmlinux.lds.S | 1 +
scripts/head-object-list.txt | 1 -
3 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index e90695b2b60e..6d5fc498c6f9 100644
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -26,6 +26,7 @@
#include <kernel-entry-init.h>
+ __HEAD
/*
* For the moment disable interrupts, mark the kernel mode and
* set ST0_KX so that the CPU does not spit fire when using
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index d575f945d422..c9c1ba85ac7b 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -62,6 +62,7 @@ SECTIONS
_text = .; /* Text and read-only data */
_stext = .;
.text : {
+ HEAD_TEXT
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
diff --git a/scripts/head-object-list.txt b/scripts/head-object-list.txt
index fd5d00bac447..f12b4a7b8406 100644
--- a/scripts/head-object-list.txt
+++ b/scripts/head-object-list.txt
@@ -23,7 +23,6 @@ arch/m68k/coldfire/head.o
arch/m68k/kernel/head.o
arch/m68k/kernel/sun3-head.o
arch/microblaze/kernel/head.o
-arch/mips/kernel/head.o
arch/nios2/kernel/head.o
arch/openrisc/kernel/head.o
arch/parisc/kernel/head.o
base-commit: 3596c721c4348b2a964e43f9296a0c01509ba927
--
2.47.0.338.g60cca15819-goog
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] [MIPS] Place __kernel_entry at the beginning of text section
2024-11-25 23:09 [PATCH] [MIPS] Place __kernel_entry at the beginning of text section Rong Xu
@ 2024-11-25 23:42 ` Chris Packham
2024-11-26 3:42 ` Masahiro Yamada
0 siblings, 1 reply; 4+ messages in thread
From: Chris Packham @ 2024-11-25 23:42 UTC (permalink / raw)
To: Rong Xu, Thomas Bogendoerfer, Masahiro Yamada, Klara Modin,
Christophe Leroy, Michael Ellerman, Nicolas Schier,
Maciej W. Rozycki, linux-mips, linux-kernel
On 26/11/24 12:09, Rong Xu wrote:
> Mark __kernel_entry as ".head.text" and place HEAD_TEXT before
> TEXT_TEXT in the linker script. This ensures that __kernel_entry
> will be placed at the beginning of text section.
>
> Drop mips from scripts/head-object-list.txt.
>
> Signed-off-by: Rong Xu <xur@google.com>
> Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Works for me on my RTL9302C based board
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
> arch/mips/kernel/head.S | 1 +
> arch/mips/kernel/vmlinux.lds.S | 1 +
> scripts/head-object-list.txt | 1 -
> 3 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
> index e90695b2b60e..6d5fc498c6f9 100644
> --- a/arch/mips/kernel/head.S
> +++ b/arch/mips/kernel/head.S
> @@ -26,6 +26,7 @@
>
> #include <kernel-entry-init.h>
>
> + __HEAD
I'm not and expert on any of this but... should this go below the
setup_c0_status_* macros (just before the CONFIG_NO_EXCEPT_FILL) line? I
don't think it makes any actual difference but as a reader it feels more
logical that the __HEAD annotation is applying to the .fill and
__kernel_entry.
> /*
> * For the moment disable interrupts, mark the kernel mode and
> * set ST0_KX so that the CPU does not spit fire when using
> diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
> index d575f945d422..c9c1ba85ac7b 100644
> --- a/arch/mips/kernel/vmlinux.lds.S
> +++ b/arch/mips/kernel/vmlinux.lds.S
> @@ -62,6 +62,7 @@ SECTIONS
> _text = .; /* Text and read-only data */
> _stext = .;
> .text : {
> + HEAD_TEXT
> TEXT_TEXT
> SCHED_TEXT
> LOCK_TEXT
> diff --git a/scripts/head-object-list.txt b/scripts/head-object-list.txt
> index fd5d00bac447..f12b4a7b8406 100644
> --- a/scripts/head-object-list.txt
> +++ b/scripts/head-object-list.txt
> @@ -23,7 +23,6 @@ arch/m68k/coldfire/head.o
> arch/m68k/kernel/head.o
> arch/m68k/kernel/sun3-head.o
> arch/microblaze/kernel/head.o
> -arch/mips/kernel/head.o
> arch/nios2/kernel/head.o
> arch/openrisc/kernel/head.o
> arch/parisc/kernel/head.o
>
> base-commit: 3596c721c4348b2a964e43f9296a0c01509ba927
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] [MIPS] Place __kernel_entry at the beginning of text section
2024-11-25 23:42 ` Chris Packham
@ 2024-11-26 3:42 ` Masahiro Yamada
2024-11-26 17:36 ` Rong Xu
0 siblings, 1 reply; 4+ messages in thread
From: Masahiro Yamada @ 2024-11-26 3:42 UTC (permalink / raw)
To: Chris Packham, Rong Xu
Cc: Thomas Bogendoerfer, Klara Modin, Christophe Leroy,
Michael Ellerman, Nicolas Schier, Maciej W. Rozycki, linux-mips,
linux-kernel
On Tue, Nov 26, 2024 at 8:42 AM Chris Packham
<chris.packham@alliedtelesis.co.nz> wrote:
>
>
> On 26/11/24 12:09, Rong Xu wrote:
> > Mark __kernel_entry as ".head.text" and place HEAD_TEXT before
> > TEXT_TEXT in the linker script. This ensures that __kernel_entry
> > will be placed at the beginning of text section.
> >
> > Drop mips from scripts/head-object-list.txt.
> >
> > Signed-off-by: Rong Xu <xur@google.com>
> > Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
>
> Works for me on my RTL9302C based board
>
> Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
>
> > ---
> > arch/mips/kernel/head.S | 1 +
> > arch/mips/kernel/vmlinux.lds.S | 1 +
> > scripts/head-object-list.txt | 1 -
> > 3 files changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
> > index e90695b2b60e..6d5fc498c6f9 100644
> > --- a/arch/mips/kernel/head.S
> > +++ b/arch/mips/kernel/head.S
> > @@ -26,6 +26,7 @@
> >
> > #include <kernel-entry-init.h>
> >
> > + __HEAD
>
> I'm not and expert on any of this but... should this go below the
> setup_c0_status_* macros (just before the CONFIG_NO_EXCEPT_FILL) line? I
> don't think it makes any actual difference but as a reader it feels more
> logical that the __HEAD annotation is applying to the .fill and
> __kernel_entry.
Agree.
Having __HEAD right before the allocated code would be better.
We have one more section marker, __REF, some lines below.
This is placed right before the affected code.
Rong, could please send v2 as Chris suggested?
Then, I will insert this to my tree to avoid regression.
I will drop the previous commit
(MIPS: move _stext definition to vmlinux.lds.S).
It changed the location of _stext when
CONFIG_NO_EXCEPT_FILL is disabled.
Thanks.
>
> > /*
> > * For the moment disable interrupts, mark the kernel mode and
> > * set ST0_KX so that the CPU does not spit fire when using
> > diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
> > index d575f945d422..c9c1ba85ac7b 100644
> > --- a/arch/mips/kernel/vmlinux.lds.S
> > +++ b/arch/mips/kernel/vmlinux.lds.S
> > @@ -62,6 +62,7 @@ SECTIONS
> > _text = .; /* Text and read-only data */
> > _stext = .;
> > .text : {
> > + HEAD_TEXT
> > TEXT_TEXT
> > SCHED_TEXT
> > LOCK_TEXT
> > diff --git a/scripts/head-object-list.txt b/scripts/head-object-list.txt
> > index fd5d00bac447..f12b4a7b8406 100644
> > --- a/scripts/head-object-list.txt
> > +++ b/scripts/head-object-list.txt
> > @@ -23,7 +23,6 @@ arch/m68k/coldfire/head.o
> > arch/m68k/kernel/head.o
> > arch/m68k/kernel/sun3-head.o
> > arch/microblaze/kernel/head.o
> > -arch/mips/kernel/head.o
> > arch/nios2/kernel/head.o
> > arch/openrisc/kernel/head.o
> > arch/parisc/kernel/head.o
> >
> > base-commit: 3596c721c4348b2a964e43f9296a0c01509ba927
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] [MIPS] Place __kernel_entry at the beginning of text section
2024-11-26 3:42 ` Masahiro Yamada
@ 2024-11-26 17:36 ` Rong Xu
0 siblings, 0 replies; 4+ messages in thread
From: Rong Xu @ 2024-11-26 17:36 UTC (permalink / raw)
To: Masahiro Yamada
Cc: Chris Packham, Thomas Bogendoerfer, Klara Modin,
Christophe Leroy, Michael Ellerman, Nicolas Schier,
Maciej W. Rozycki, linux-mips, linux-kernel
Thanks Masahiro and Chris for the review!
I just sent out patch v2. I verified that v2 has pretty much the same
layout (except for
some debug info caused layout changes).
-Rong
On Mon, Nov 25, 2024 at 7:43 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> On Tue, Nov 26, 2024 at 8:42 AM Chris Packham
> <chris.packham@alliedtelesis.co.nz> wrote:
> >
> >
> > On 26/11/24 12:09, Rong Xu wrote:
> > > Mark __kernel_entry as ".head.text" and place HEAD_TEXT before
> > > TEXT_TEXT in the linker script. This ensures that __kernel_entry
> > > will be placed at the beginning of text section.
> > >
> > > Drop mips from scripts/head-object-list.txt.
> > >
> > > Signed-off-by: Rong Xu <xur@google.com>
> > > Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> >
> > Works for me on my RTL9302C based board
> >
> > Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> >
> > > ---
> > > arch/mips/kernel/head.S | 1 +
> > > arch/mips/kernel/vmlinux.lds.S | 1 +
> > > scripts/head-object-list.txt | 1 -
> > > 3 files changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
> > > index e90695b2b60e..6d5fc498c6f9 100644
> > > --- a/arch/mips/kernel/head.S
> > > +++ b/arch/mips/kernel/head.S
> > > @@ -26,6 +26,7 @@
> > >
> > > #include <kernel-entry-init.h>
> > >
> > > + __HEAD
> >
> > I'm not and expert on any of this but... should this go below the
> > setup_c0_status_* macros (just before the CONFIG_NO_EXCEPT_FILL) line? I
> > don't think it makes any actual difference but as a reader it feels more
> > logical that the __HEAD annotation is applying to the .fill and
> > __kernel_entry.
>
>
> Agree.
>
> Having __HEAD right before the allocated code would be better.
>
>
> We have one more section marker, __REF, some lines below.
> This is placed right before the affected code.
>
>
> Rong, could please send v2 as Chris suggested?
>
> Then, I will insert this to my tree to avoid regression.
>
> I will drop the previous commit
> (MIPS: move _stext definition to vmlinux.lds.S).
> It changed the location of _stext when
> CONFIG_NO_EXCEPT_FILL is disabled.
>
> Thanks.
>
>
>
>
> >
> > > /*
> > > * For the moment disable interrupts, mark the kernel mode and
> > > * set ST0_KX so that the CPU does not spit fire when using
> > > diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
> > > index d575f945d422..c9c1ba85ac7b 100644
> > > --- a/arch/mips/kernel/vmlinux.lds.S
> > > +++ b/arch/mips/kernel/vmlinux.lds.S
> > > @@ -62,6 +62,7 @@ SECTIONS
> > > _text = .; /* Text and read-only data */
> > > _stext = .;
> > > .text : {
> > > + HEAD_TEXT
> > > TEXT_TEXT
> > > SCHED_TEXT
> > > LOCK_TEXT
> > > diff --git a/scripts/head-object-list.txt b/scripts/head-object-list.txt
> > > index fd5d00bac447..f12b4a7b8406 100644
> > > --- a/scripts/head-object-list.txt
> > > +++ b/scripts/head-object-list.txt
> > > @@ -23,7 +23,6 @@ arch/m68k/coldfire/head.o
> > > arch/m68k/kernel/head.o
> > > arch/m68k/kernel/sun3-head.o
> > > arch/microblaze/kernel/head.o
> > > -arch/mips/kernel/head.o
> > > arch/nios2/kernel/head.o
> > > arch/openrisc/kernel/head.o
> > > arch/parisc/kernel/head.o
> > >
> > > base-commit: 3596c721c4348b2a964e43f9296a0c01509ba927
>
>
>
> --
> Best Regards
> Masahiro Yamada
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2024-11-26 17:37 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2024-11-25 23:09 [PATCH] [MIPS] Place __kernel_entry at the beginning of text section Rong Xu
2024-11-25 23:42 ` Chris Packham
2024-11-26 3:42 ` Masahiro Yamada
2024-11-26 17:36 ` Rong Xu
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