* [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
end of thread, other threads:[~2020-03-05 8:21 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 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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