diff mbox series

arm: Fix build issue with LD_DEAD_CODE_DATA_ELIMINATION

Message ID 20240808123556.681609-1-liuyuntao12@huawei.com (mailing list archive)
State New, archived
Headers show
Series arm: Fix build issue with LD_DEAD_CODE_DATA_ELIMINATION | expand

Commit Message

liuyuntao (F) Aug. 8, 2024, 12:35 p.m. UTC 
There is a build issue with LD segmentation fault, while
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled, as bellow.

scripts/link-vmlinux.sh: line 49:  3796 Segmentation fault
 (core dumped) ${ld} ${ldflags} -o ${output} ${wl}--whole-archive
 ${objs} ${wl}--no-whole-archive ${wl}--start-group
 ${libs} ${wl}--end-group ${kallsymso} ${btf_vmlinux_bin_o} ${ldlibs}

The error occurs in older versions of the GNU ld with version earlier
than 2.36. It makes most sense to have a minimum LD version as
a dependency for HAVE_LD_DEAD_CODE_DATA_ELIMINATION and eliminate
the impact of ".reloc  .text, R_ARM_NONE, ." when
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled.

Fixes: ed0f94102251 ("ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION")
Reported-by: Harith George <mail2hgg@gmail.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com>
Link: https://lore.kernel.org/all/14e9aefb-88d1-4eee-8288-ef15d4a9b059@gmail.com/
---
 arch/arm/Kconfig             |  2 +-
 arch/arm/kernel/entry-armv.S | 12 +++++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

Comments

Arnd Bergmann Aug. 9, 2024, 2:47 p.m. UTC | #1 
On Thu, Aug 8, 2024, at 14:35, Yuntao Liu wrote:
> There is a build issue with LD segmentation fault, while
> CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled, as bellow.
>
> scripts/link-vmlinux.sh: line 49:  3796 Segmentation fault
>  (core dumped) ${ld} ${ldflags} -o ${output} ${wl}--whole-archive
>  ${objs} ${wl}--no-whole-archive ${wl}--start-group
>  ${libs} ${wl}--end-group ${kallsymso} ${btf_vmlinux_bin_o} ${ldlibs}
>
> The error occurs in older versions of the GNU ld with version earlier
> than 2.36. It makes most sense to have a minimum LD version as
> a dependency for HAVE_LD_DEAD_CODE_DATA_ELIMINATION and eliminate
> the impact of ".reloc  .text, R_ARM_NONE, ." when
> CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled.
>
> Fixes: ed0f94102251 ("ARM: 9404/1: arm32: enable 
> HAVE_LD_DEAD_CODE_DATA_ELIMINATION")
> Reported-by: Harith George <mail2hgg@gmail.com>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com>
> Link: 
> https://lore.kernel.org/all/14e9aefb-88d1-4eee-8288-ef15d4a9b059@gmail.com/

Looks good to me,

Acked-by: Arnd Bergmann <arnd@arndb.de>
Harith George Aug. 12, 2024, 7:51 a.m. UTC | #2 
On 08-08-2024 18:05, Yuntao Liu wrote:
> There is a build issue with LD segmentation fault, while
> CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled, as bellow.
> 
> scripts/link-vmlinux.sh: line 49:  3796 Segmentation fault
>   (core dumped) ${ld} ${ldflags} -o ${output} ${wl}--whole-archive
>   ${objs} ${wl}--no-whole-archive ${wl}--start-group
>   ${libs} ${wl}--end-group ${kallsymso} ${btf_vmlinux_bin_o} ${ldlibs}
> 
> The error occurs in older versions of the GNU ld with version earlier
> than 2.36. It makes most sense to have a minimum LD version as
> a dependency for HAVE_LD_DEAD_CODE_DATA_ELIMINATION and eliminate
> the impact of ".reloc  .text, R_ARM_NONE, ." when
> CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled.
> 
> Fixes: ed0f94102251 ("ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION")
> Reported-by: Harith George <mail2hgg@gmail.com>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com>
> Link: https://lore.kernel.org/all/14e9aefb-88d1-4eee-8288-ef15d4a9b059@gmail.com/
> ---
>   arch/arm/Kconfig             |  2 +-
>   arch/arm/kernel/entry-armv.S | 12 +++++++++---
>   2 files changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 54b2bb817a7f..173159e93c99 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -117,7 +117,7 @@ config ARM
>   	select HAVE_KERNEL_XZ
>   	select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
>   	select HAVE_KRETPROBES if HAVE_KPROBES
> -	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
> +	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_IS_LLD)
>   	select HAVE_MOD_ARCH_SPECIFIC
>   	select HAVE_NMI
>   	select HAVE_OPTPROBES if !THUMB2_KERNEL
> diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
> index f01d23a220e6..cd443faf8645 100644
> --- a/arch/arm/kernel/entry-armv.S
> +++ b/arch/arm/kernel/entry-armv.S
> @@ -29,6 +29,12 @@
>   #include "entry-header.S"
>   #include <asm/probes.h>
>   
> +#ifdef CONFIG_HAVE_LD_DEAD_CODE_DATA_ELIMINATION
> +#define RELOC_TEXT_NONE (.reloc  .text, R_ARM_NONE, .)
> +#else
> +#define RELOC_TEXT_NONE
> +#endif
> +
>   /*
>    * Interrupt handling.
>    */
> @@ -1065,7 +1071,7 @@ vector_addrexcptn:
>   	.globl	vector_fiq
>   
>   	.section .vectors, "ax", %progbits
> -	.reloc  .text, R_ARM_NONE, .
> +	RELOC_TEXT_NONE
>   	W(b)	vector_rst
>   	W(b)	vector_und
>   ARM(	.reloc	., R_ARM_LDR_PC_G0, .L__vector_swi		)
> @@ -1079,7 +1085,7 @@ THUMB(	.reloc	., R_ARM_THM_PC12, .L__vector_swi		)
>   
>   #ifdef CONFIG_HARDEN_BRANCH_HISTORY
>   	.section .vectors.bhb.loop8, "ax", %progbits
> -	.reloc  .text, R_ARM_NONE, .
> +	RELOC_TEXT_NONE
>   	W(b)	vector_rst
>   	W(b)	vector_bhb_loop8_und
>   ARM(	.reloc	., R_ARM_LDR_PC_G0, .L__vector_bhb_loop8_swi	)
> @@ -1092,7 +1098,7 @@ THUMB(	.reloc	., R_ARM_THM_PC12, .L__vector_bhb_loop8_swi	)
>   	W(b)	vector_bhb_loop8_fiq
>   
>   	.section .vectors.bhb.bpiall, "ax", %progbits
> -	.reloc  .text, R_ARM_NONE, .
> +	RELOC_TEXT_NONE
>   	W(b)	vector_rst
>   	W(b)	vector_bhb_bpiall_und
>   ARM(	.reloc	., R_ARM_LDR_PC_G0, .L__vector_bhb_bpiall_swi	)
Build tested. Solves the earlier build issue I was seeing.
fwiw, you can add my tested by tag if needed.

Tested-by: Harith George <mail2hgg@gmail.com>
Russell King (Oracle) Aug. 12, 2024, 3:06 p.m. UTC | #3 
On Mon, Aug 12, 2024 at 01:21:59PM +0530, Harith George wrote:
> On 08-08-2024 18:05, Yuntao Liu wrote:
> > There is a build issue with LD segmentation fault, while
> > CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled, as bellow.
> > 
> > scripts/link-vmlinux.sh: line 49:  3796 Segmentation fault
> >   (core dumped) ${ld} ${ldflags} -o ${output} ${wl}--whole-archive
> >   ${objs} ${wl}--no-whole-archive ${wl}--start-group
> >   ${libs} ${wl}--end-group ${kallsymso} ${btf_vmlinux_bin_o} ${ldlibs}
> > 
> > The error occurs in older versions of the GNU ld with version earlier
> > than 2.36. It makes most sense to have a minimum LD version as
> > a dependency for HAVE_LD_DEAD_CODE_DATA_ELIMINATION and eliminate
> > the impact of ".reloc  .text, R_ARM_NONE, ." when
> > CONFIG_LD_DEAD_CODE_DATA_ELIMINATION is not enabled.
> > 
> > Fixes: ed0f94102251 ("ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION")
> > Reported-by: Harith George <mail2hgg@gmail.com>
> > Suggested-by: Arnd Bergmann <arnd@arndb.de>
> > Signed-off-by: Yuntao Liu <liuyuntao12@huawei.com>
> > Link: https://lore.kernel.org/all/14e9aefb-88d1-4eee-8288-ef15d4a9b059@gmail.com/
> 
> Build tested. Solves the earlier build issue I was seeing.
> fwiw, you can add my tested by tag if needed.
> 
> Tested-by: Harith George <mail2hgg@gmail.com>

(a) please see the note in my signature below.
(b) this tested-by needs to be collected by the submitter before it gets
    into the patch system.
(c) it needs to get into the patch system.

Bear in mind that as a result of (a), it's going to be better to get it
into the patch system sooner rather than later - I am expecting there to
be a period of time (weeks) where it will be impossible for me to read
the screen...
diff mbox series

Patch

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 54b2bb817a7f..173159e93c99 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -117,7 +117,7 @@  config ARM
 	select HAVE_KERNEL_XZ
 	select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
 	select HAVE_KRETPROBES if HAVE_KPROBES
-	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+	select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if (LD_VERSION >= 23600 || LD_IS_LLD)
 	select HAVE_MOD_ARCH_SPECIFIC
 	select HAVE_NMI
 	select HAVE_OPTPROBES if !THUMB2_KERNEL
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index f01d23a220e6..cd443faf8645 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -29,6 +29,12 @@ 
 #include "entry-header.S"
 #include <asm/probes.h>
 
+#ifdef CONFIG_HAVE_LD_DEAD_CODE_DATA_ELIMINATION
+#define RELOC_TEXT_NONE (.reloc  .text, R_ARM_NONE, .)
+#else
+#define RELOC_TEXT_NONE
+#endif
+
 /*
  * Interrupt handling.
  */
@@ -1065,7 +1071,7 @@  vector_addrexcptn:
 	.globl	vector_fiq
 
 	.section .vectors, "ax", %progbits
-	.reloc  .text, R_ARM_NONE, .
+	RELOC_TEXT_NONE
 	W(b)	vector_rst
 	W(b)	vector_und
 ARM(	.reloc	., R_ARM_LDR_PC_G0, .L__vector_swi		)
@@ -1079,7 +1085,7 @@  THUMB(	.reloc	., R_ARM_THM_PC12, .L__vector_swi		)
 
 #ifdef CONFIG_HARDEN_BRANCH_HISTORY
 	.section .vectors.bhb.loop8, "ax", %progbits
-	.reloc  .text, R_ARM_NONE, .
+	RELOC_TEXT_NONE
 	W(b)	vector_rst
 	W(b)	vector_bhb_loop8_und
 ARM(	.reloc	., R_ARM_LDR_PC_G0, .L__vector_bhb_loop8_swi	)
@@ -1092,7 +1098,7 @@  THUMB(	.reloc	., R_ARM_THM_PC12, .L__vector_bhb_loop8_swi	)
 	W(b)	vector_bhb_loop8_fiq
 
 	.section .vectors.bhb.bpiall, "ax", %progbits
-	.reloc  .text, R_ARM_NONE, .
+	RELOC_TEXT_NONE
 	W(b)	vector_rst
 	W(b)	vector_bhb_bpiall_und
 ARM(	.reloc	., R_ARM_LDR_PC_G0, .L__vector_bhb_bpiall_swi	)