* [PATCH] efi/libstub: avoid linking libstub/lib-ksyms.o into vmlinux
@ 2020-03-05 5:50 Masahiro Yamada
2020-03-05 7:20 ` Ard Biesheuvel
0 siblings, 1 reply; 6+ messages in thread
From: Masahiro Yamada @ 2020-03-05 5:50 UTC (permalink / raw)
To: Ard Biesheuvel, linux-efi; +Cc: linux-kernel, Ingo Molnar, Masahiro Yamada
drivers/firmware/efi/libstub/Makefile is supposed to create a static
library, which is not directly linked to vmlinux.
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-$(CONFIG_EFI_TEST) += test/
--
2.17.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] efi/libstub: avoid linking libstub/lib-ksyms.o into vmlinux
2020-03-05 5:50 [PATCH] efi/libstub: avoid linking libstub/lib-ksyms.o into vmlinux Masahiro Yamada
@ 2020-03-05 7:20 ` Ard Biesheuvel
2020-03-05 7:39 ` Masahiro Yamada
0 siblings, 1 reply; 6+ messages in thread
From: Ard Biesheuvel @ 2020-03-05 7:20 UTC (permalink / raw)
To: Masahiro Yamada; +Cc: linux-efi, Linux Kernel Mailing List, Ingo Molnar
On Thu, 5 Mar 2020 at 06:50, Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> drivers/firmware/efi/libstub/Makefile is supposed to create a static
> library, which is not directly linked to vmlinux.
>
This is not true for arm64. Does that matter?
> Since commit 7f2084fa55e6 ("[kbuild] handle exports in lib-y objects
> reliably"), any Makefile using lib-y generates lib-ksyms.o which is
> linked into vmlinux.
>
> In this case, the following garbage object is linked into vmlinux.
>
> drivers/firmware/efi/libstub/lib-ksyms.o
>
> We do not want to link anything from libstub/ directly to vmlinux,
> so using subdir-y instead of obj-y is the correct way to descend into
> this directory.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
>
> drivers/firmware/efi/Makefile | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
> index 554d795270d9..4fd2fa02f549 100644
> --- a/drivers/firmware/efi/Makefile
> +++ b/drivers/firmware/efi/Makefile
> @@ -19,7 +19,7 @@ obj-$(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
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] efi/libstub: avoid linking libstub/lib-ksyms.o into vmlinux
2020-03-05 7:20 ` Ard Biesheuvel
@ 2020-03-05 7:39 ` Masahiro Yamada
2020-03-05 7:47 ` Ard Biesheuvel
0 siblings, 1 reply; 6+ messages in thread
From: Masahiro Yamada @ 2020-03-05 7:39 UTC (permalink / raw)
To: Ard Biesheuvel; +Cc: linux-efi, Linux Kernel Mailing List, Ingo Molnar
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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] efi/libstub: avoid linking libstub/lib-ksyms.o into vmlinux
2020-03-05 7:39 ` Masahiro Yamada
@ 2020-03-05 7:47 ` Ard Biesheuvel
2020-03-05 8:15 ` Masahiro Yamada
0 siblings, 1 reply; 6+ messages in thread
From: Ard Biesheuvel @ 2020-03-05 7:47 UTC (permalink / raw)
To: Masahiro Yamada; +Cc: linux-efi, Linux Kernel Mailing List, Ingo Molnar
On Thu, 5 Mar 2020 at 08:39, Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> 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.
>
How about
"""
drivers/firmware/efi/libstub/Makefile builds a static library, which
is not linked into the main vmlinux target in the ordinary way
[arm64], or at all [ARM, x86]
"""
>
>
>
>
> > > 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,
and
"""
We do not want to follow the default linking rules for static
libraries built under libstub/
"""
If you agree, no need to resend, I'll fix it up when applying
> > > 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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] efi/libstub: avoid linking libstub/lib-ksyms.o into vmlinux
2020-03-05 7:47 ` Ard Biesheuvel
@ 2020-03-05 8:15 ` Masahiro Yamada
2020-03-05 8:21 ` Ard Biesheuvel
0 siblings, 1 reply; 6+ messages in thread
From: Masahiro Yamada @ 2020-03-05 8:15 UTC (permalink / raw)
To: Ard Biesheuvel; +Cc: linux-efi, Linux Kernel Mailing List, Ingo Molnar
Hi Ard,
On Thu, Mar 5, 2020 at 4:47 PM Ard Biesheuvel <ardb@kernel.org> wrote:
>
> If you agree, no need to resend, I'll fix it up when applying
>
I agree.
Please fix it up.
Thanks.
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] efi/libstub: avoid linking libstub/lib-ksyms.o into vmlinux
2020-03-05 8:15 ` Masahiro Yamada
@ 2020-03-05 8:21 ` Ard Biesheuvel
0 siblings, 0 replies; 6+ messages in thread
From: Ard Biesheuvel @ 2020-03-05 8:21 UTC (permalink / raw)
To: Masahiro Yamada; +Cc: linux-efi, Linux Kernel Mailing List, Ingo Molnar
On Thu, 5 Mar 2020 at 09:16, Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> Hi Ard,
>
>
> On Thu, Mar 5, 2020 at 4:47 PM Ard Biesheuvel <ardb@kernel.org> wrote:
> >
> > If you agree, no need to resend, I'll fix it up when applying
> >
>
>
> I agree.
> Please fix it up.
>
Thank you,
Queued in efi/next
^ permalink raw reply [flat|nested] 6+ messages in thread
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2020-03-05 5:50 [PATCH] efi/libstub: avoid linking libstub/lib-ksyms.o into vmlinux Masahiro Yamada
2020-03-05 7:20 ` Ard Biesheuvel
2020-03-05 7:39 ` Masahiro Yamada
2020-03-05 7:47 ` Ard Biesheuvel
2020-03-05 8:15 ` Masahiro Yamada
2020-03-05 8:21 ` Ard Biesheuvel
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