LinuxLists.cc - [PATCH] ARM: fix link warning with XIP + frame-pointer

2021-01-12 15:50:21

Subject: [PATCH] ARM: fix link warning with XIP + frame-pointer

From: Arnd Bergmann <[email protected]>

When frame pointers are used instead of the ARM unwinder,
and the kernel is built using clang with an external assembler
and CONFIG_XIP_KERNEL, every file produces two warnings
like:

arm-linux-gnueabi-ld: warning: orphan section `.ARM.extab' from `net/mac802154/util.o' being placed in section `.ARM.extab'
arm-linux-gnueabi-ld: warning: orphan section `.ARM.exidx' from `net/mac802154/util.o' being placed in section `.ARM.exidx'

The same fix was already merged for the normal (non-XIP)
linker script, with a longer description.

Fixes: c39866f268f8 ("arm/build: Always handle .ARM.exidx and .ARM.extab sections")
Signed-off-by: Arnd Bergmann <[email protected]>
---
arch/arm/kernel/vmlinux-xip.lds.S | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
index 4d0b0cd9222e..ddb70c65d525 100644
--- a/arch/arm/kernel/vmlinux-xip.lds.S
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -43,6 +43,10 @@ SECTIONS
ARM_DISCARD
*(.alt.smp.init)
*(.pv_table)
+#ifndef CONFIG_ARM_UNWIND
+ *(.ARM.exidx) *(.ARM.exidx.*)
+ *(.ARM.extab) *(.ARM.extab.*)
+#endif
}

. = XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR);
--
2.29.2

2021-01-12 16:28:52

by Nathan Chancellor

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Subject: Re: [PATCH] ARM: fix link warning with XIP + frame-pointer

On Tue, Jan 12, 2021 at 04:46:40PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <[email protected]>
>
> When frame pointers are used instead of the ARM unwinder,
> and the kernel is built using clang with an external assembler
> and CONFIG_XIP_KERNEL, every file produces two warnings
> like:
>
> arm-linux-gnueabi-ld: warning: orphan section `.ARM.extab' from `net/mac802154/util.o' being placed in section `.ARM.extab'
> arm-linux-gnueabi-ld: warning: orphan section `.ARM.exidx' from `net/mac802154/util.o' being placed in section `.ARM.exidx'
>
> The same fix was already merged for the normal (non-XIP)
> linker script, with a longer description.
>
> Fixes: c39866f268f8 ("arm/build: Always handle .ARM.exidx and .ARM.extab sections")
> Signed-off-by: Arnd Bergmann <[email protected]>

Reviewed-by: Nathan Chancellor <[email protected]>

> ---
> arch/arm/kernel/vmlinux-xip.lds.S | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
> index 4d0b0cd9222e..ddb70c65d525 100644
> --- a/arch/arm/kernel/vmlinux-xip.lds.S
> +++ b/arch/arm/kernel/vmlinux-xip.lds.S
> @@ -43,6 +43,10 @@ SECTIONS
> ARM_DISCARD
> *(.alt.smp.init)
> *(.pv_table)
> +#ifndef CONFIG_ARM_UNWIND
> + *(.ARM.exidx) *(.ARM.exidx.*)
> + *(.ARM.extab) *(.ARM.extab.*)
> +#endif
> }
>
> . = XIP_VIRT_ADDR(CONFIG_XIP_PHYS_ADDR);
> --
> 2.29.2
>

2021-01-13 02:32:06

by Kees Cook

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