Re: [PATCH V4 19/22] LoongArch: Add VDSO and VSYSCALL support

[Huacai Chen]

Hi, Ruoyao,

On Thu, Sep 30, 2021 at 11:43 PM Xi Ruoyao <xry111@xxxxxxxxxxxxxxxx> wrote:
>
> On Mon, 2021-09-27 at 14:42 +0800, Huacai Chen wrote:
> > diff --git a/arch/loongarch/vdso/gen_vdso_offsets.sh
> > b/arch/loongarch/vdso/gen_vdso_offsets.sh
> > new file mode 100755
> > index 000000000000..7da255fea213
> > --- /dev/null
> > +++ b/arch/loongarch/vdso/gen_vdso_offsets.sh
> > @@ -0,0 +1,14 @@
> > +#!/bin/sh
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +#
> > +# Derived from RISC-V and ARM64:
> > +# Author: Will Deacon <will.deacon@xxxxxxx>
> > +#
> > +# Match symbols in the DSO that look like VDSO_*; produce a header
> > file
> > +# of constant offsets into the shared object.
> > +#
> > +
> > +LC_ALL=C
>
> I'm wondering whether this line is really useful... There is no "export"
> here so the variable won't be passed to the environment of the sed
> command below.
Have you encountered some problems with this? It just works for me,
and both ARM64 and RISCV are the same.

Huacai
>
> > +sed -n -e 's/^00*/0/' -e \
> > +'s/^\([0-9a-fA-F]*\) . VDSO_\([a-zA-Z0-9_]*\)$/\#define
> > vdso_offset_\2\t0x\1/p'