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

[Palmer Dabbelt]

On Tue, 03 Jun 2025 14:52:18 PDT (-0700), nathan@xxxxxxxxxx wrote:
> 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@xxxxxxxxxx>
> > Closes: https://github.com/ClangBuiltLinux/linux/issues/2093
> > Signed-off-by: Fangrui Song <i@xxxxxxxxxx>
>
> Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx>

Thanks, I'll pick it up (might take a bit to show up on fixes, I'm 
trying to sort out another amdgpu stack warning...)

> > ---
> >  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@xxxxxxxxxx>