Re: [PATCH v4 09/39] x86/vdso: Enable sframe generation in VDSO

Josh Poimboeuf
2025-01-24T16:43:35Z

On Fri, Jan 24, 2025 at 05:00:27PM +0100, Jens Remus wrote:
> On 22.01.2025 03:31, Josh Poimboeuf wrote:
> > diff --git a/arch/x86/include/asm/dwarf2.h b/arch/x86/include/asm/dwarf2.h
> > index b195b3c8677e..1c354f648505 100644
> > --- a/arch/x86/include/asm/dwarf2.h
> > +++ b/arch/x86/include/asm/dwarf2.h
> > @@ -12,8 +12,11 @@
> > * For the vDSO, emit both runtime unwind information and debug
> > * symbols for the .dbg file.
> > */
> > -
>
> Nit: Deleted blank line you introduced in "[PATCH v4 05/39] x86/asm:
> Avoid emitting DWARF CFI for non-VDSO".

Indeed.

> > +#ifdef __x86_64__
>
> #if defined(__x86_64__) && defined(CONFIG_AS_SFRAME)
>
> AFAIK the kernel has a minimum binutils requirement of 2.25 [1]
> and assembler option "--gsframe" as well as directive
> ".cfi_sections .sframe" were introduced with 2.40.

True, I'll change it to just '#ifdef CONFIG_AS_SFRAME' since that's what
really matters (and 32-bit doesn't support it anyway).

> > + .cfi_sections .eh_frame, .debug_frame, .sframe
> > +#else
> > .cfi_sections .eh_frame, .debug_frame
> > +#endif
> > #define CFI_STARTPROC .cfi_startproc
> > #define CFI_ENDPROC .cfi_endproc

--
Josh