[PATCH v2] [MIPS] Place __kernel_entry at the beginning of text section

[PATCH v2] [MIPS] Place __kernel_entry at the beginning of text section

[Rong Xu]

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>
Closes: https://lore.kernel.org/lkml/c6719149-8531-4174-824e-a3caf4bc6d0e@alliedtelesis.co.nz/T/
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..c7528d96dd1a 100644
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -59,6 +59,7 @@
 #endif
 	.endm
 
+	__HEAD
 #ifndef CONFIG_NO_EXCEPT_FILL
 	/*
 	 * Reserved space for exception handlers.
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

Re: [PATCH v2] [MIPS] Place __kernel_entry at the beginning of text section

[Rong Xu]

I forgot to add the changelog for this V2: The change was to move __HEAD
down based on Chris Packham's review.

-Rong

On Tue, Nov 26, 2024 at 9:34 AM Rong Xu <xur@google.com> 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>
> Closes: https://lore.kernel.org/lkml/c6719149-8531-4174-824e-a3caf4bc6d0e@alliedtelesis.co.nz/T/
> 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..c7528d96dd1a 100644
> --- a/arch/mips/kernel/head.S
> +++ b/arch/mips/kernel/head.S
> @@ -59,6 +59,7 @@
>  #endif
>         .endm
>
> +       __HEAD
>  #ifndef CONFIG_NO_EXCEPT_FILL
>         /*
>          * Reserved space for exception handlers.
> 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
>

Re: [PATCH v2] [MIPS] Place __kernel_entry at the beginning of text section

[Masahiro Yamada]

On Wed, Nov 27, 2024 at 2:34 AM Rong Xu <xur@google.com> 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>
> Closes: https://lore.kernel.org/lkml/c6719149-8531-4174-824e-a3caf4bc6d0e@alliedtelesis.co.nz/T/
> Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz>


Applied to linux-kbuild.
(Inserted before the offending commit)

Thanks!



-- 
Best Regards
Masahiro Yamada

Re: [PATCH v2] [MIPS] Place __kernel_entry at the beginning of text section

[Maciej W. Rozycki]

On Tue, 26 Nov 2024, Rong Xu wrote:

> diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
> index e90695b2b60e..c7528d96dd1a 100644
> --- a/arch/mips/kernel/head.S
> +++ b/arch/mips/kernel/head.S
> @@ -59,6 +59,7 @@
>  #endif
>  	.endm
>  
> +	__HEAD
>  #ifndef CONFIG_NO_EXCEPT_FILL
>  	/*
>  	 * Reserved space for exception handlers.

 A new line would be preferable afterwards so as to visually separate the 
directive from the conditional part that follows.  It looks messy as it 
stands (and we have prior art further down the file with __REF).  Please 
send a fix.

  Maciej

Re: [PATCH v2] [MIPS] Place __kernel_entry at the beginning of text section

[Rong Xu]

Sure. I'll send a separate patch for this format change (not v3 as
this patch was already submitted).

Thanks!

-Rong

On Mon, Dec 2, 2024 at 9:58 AM Maciej W. Rozycki <macro@orcam.me.uk> wrote:
>
> On Tue, 26 Nov 2024, Rong Xu wrote:
>
> > diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
> > index e90695b2b60e..c7528d96dd1a 100644
> > --- a/arch/mips/kernel/head.S
> > +++ b/arch/mips/kernel/head.S
> > @@ -59,6 +59,7 @@
> >  #endif
> >       .endm
> >
> > +     __HEAD
> >  #ifndef CONFIG_NO_EXCEPT_FILL
> >       /*
> >        * Reserved space for exception handlers.
>
>  A new line would be preferable afterwards so as to visually separate the
> directive from the conditional part that follows.  It looks messy as it
> stands (and we have prior art further down the file with __REF).  Please
> send a fix.
>
>   Maciej