lkml.org 
[lkml]   [2020]   [Mar]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] efi/libstub: avoid linking libstub/lib-ksyms.o into vmlinux
On Thu, Mar 5, 2020 at 4:21 PM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> On Thu, 5 Mar 2020 at 06:50, Masahiro Yamada <masahiroy@kernel.org> wrote:
> >
> > drivers/firmware/efi/libstub/Makefile is supposed to create a static
> > library, which is not directly linked to vmlinux.
> >
>
> This is not true for arm64. Does that matter?



Yeah, I know. arm64 vmlinux links it
(but in a different manner from normal lib.a )


Shall I rephrase this paragraph as follows?

drivers/firmware/efi/libstub/Makefile is supposed to create a static
library, which is not directly linked to vmlinux on ARCH=arm, x86.



This is just a matter of whether linking
unneeded lib-ksyms.o or not.





> > Since commit 7f2084fa55e6 ("[kbuild] handle exports in lib-y objects
> > reliably"), any Makefile using lib-y generates lib-ksyms.o which is
> > linked into vmlinux.
> >
> > In this case, the following garbage object is linked into vmlinux.
> >
> > drivers/firmware/efi/libstub/lib-ksyms.o
> >
> > We do not want to link anything from libstub/ directly to vmlinux,
> > so using subdir-y instead of obj-y is the correct way to descend into
> > this directory.
> >
> > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> > ---
> >
> > drivers/firmware/efi/Makefile | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
> > index 554d795270d9..4fd2fa02f549 100644
> > --- a/drivers/firmware/efi/Makefile
> > +++ b/drivers/firmware/efi/Makefile
> > @@ -19,7 +19,7 @@ obj-$(CONFIG_EFI_VARS_PSTORE) += efi-pstore.o
> > obj-$(CONFIG_UEFI_CPER) += cper.o
> > obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o
> > obj-$(CONFIG_EFI_RUNTIME_WRAPPERS) += runtime-wrappers.o
> > -obj-$(CONFIG_EFI_STUB) += libstub/
> > +subdir-$(CONFIG_EFI_STUB) += libstub
> > obj-$(CONFIG_EFI_FAKE_MEMMAP) += fake_map.o
> > obj-$(CONFIG_EFI_BOOTLOADER_CONTROL) += efibc.o
> > obj-$(CONFIG_EFI_TEST) += test/
> > --
> > 2.17.1
> >



--
Best Regards
Masahiro Yamada

\
 
 \ /
  Last update: 2020-03-05 08:40    [W:0.061 / U:14.832 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site