[PATCH] riscv: vdso: Exclude .rodata from the PT_DYNAMIC segment

[Nathan Chancellor]

On Mon, Jun 02, 2025 at 08:48:44PM -0700, Fangrui Song wrote:
> .rodata is implicitly included in the PT_DYNAMIC segment due to
> inheriting the segment of the preceding .dynamic section (in both GNU ld
> and LLD).  When the .rodata section's size is not a multiple of 16
> bytes on riscv64, llvm-readelf will report a "PT_DYNAMIC dynamic table
> is invalid" warning.  Note: in the presence of the .dynamic section, GNU
> readelf and llvm-readelf's -d option decodes the dynamic section using
> the section.
> 
> This issue arose after commit 8f8c1ff879fab60f80f3a7aec3000f47e5b03ba9
> ("riscv: vdso.lds.S: remove hardcoded 0x800 .text start addr"), which
> placed .rodata directly after .dynamic by removing .eh_frame.
> 
> This patch resolves the implicit inclusion into PT_DYNAMIC by explicitly
> specifying the :text output section phdr.
> 
> Reported-by: Nathan Chancellor <nathan at kernel.org>
> Closes: https://github.com/ClangBuiltLinux/linux/issues/2093
> Signed-off-by: Fangrui Song <i at maskray.me>

Tested-by: Nathan Chancellor <nathan at kernel.org>

> ---
>  arch/riscv/kernel/vdso/vdso.lds.S | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vdso.lds.S
> index abc69cda0445b1f500a89b47deefa31349103f08..62e0410f69f09e2bbf27101c000d604193f525cb 100644
> --- a/arch/riscv/kernel/vdso/vdso.lds.S
> +++ b/arch/riscv/kernel/vdso/vdso.lds.S
> @@ -30,7 +30,7 @@ SECTIONS
>  		*(.data .data.* .gnu.linkonce.d.*)
>  		*(.dynbss)
>  		*(.bss .bss.* .gnu.linkonce.b.*)
> -	}
> +	}						:text
>  
>  	.note		: { *(.note.*) }		:text	:note
>  
> 
> ---
> base-commit: 1a3f6980889df3fc90ad3e4a525061d2c138adba
> change-id: 20250602-riscv-vdso-13efdee34a24
> 
> Best regards,
> -- 
> Fangrui Song <i at maskray.me>
>