2020-04-16 00:10:41

by Ilie Halip

Subject: [PATCH v2] riscv: fix vdso build with lld

When building with the LLVM linker this error occurrs:
LD arch/riscv/kernel/vdso/vdso-syms.o
ld.lld: error: no input files

This happens because the lld treats -R as an alias to -rpath, as opposed
to ld where -R means --just-symbols.

Use the long option name for compatibility between the two.

Link: https://github.com/ClangBuiltLinux/linux/issues/805
Reported-by: Dmitry Golovin <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Signed-off-by: Ilie Halip <[email protected]>

---
Changed in v2:
* a comment line dropped, another one slightly reworded
* added Nick's Reviewed-by
---
arch/riscv/kernel/vdso/Makefile | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 33b16f4212f7..a4ee3a0e7d20 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -33,15 +33,15 @@ $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold)

# We also create a special relocatable object that should mirror the symbol
-# table and layout of the linked DSO. With ld -R we can then refer to
-# these symbols in the kernel code rather than hand-coded addresses.
+# table and layout of the linked DSO. With ld --just-symbols we can then
+# refer to these symbols in the kernel code rather than hand-coded addresses.

SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
-Wl,--build-id -Wl,--hash-style=both
$(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
$(call if_changed,vdsold)

-LDFLAGS_vdso-syms.o := -r -R
+LDFLAGS_vdso-syms.o := -r --just-symbols
$(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
$(call if_changed,ld)

--
2.17.1

2020-04-16 00:10:52

by Fangrui Song

Subject: Re: [PATCH v2] riscv: fix vdso build with lld

On 2020-04-15, Ilie Halip wrote:
>When building with the LLVM linker this error occurrs:
> LD arch/riscv/kernel/vdso/vdso-syms.o
> ld.lld: error: no input files
>
>This happens because the lld treats -R as an alias to -rpath, as opposed
>to ld where -R means --just-symbols.
>
>Use the long option name for compatibility between the two.
>
>Link: https://github.com/ClangBuiltLinux/linux/issues/805
>Reported-by: Dmitry Golovin <[email protected]>
>Reviewed-by: Nick Desaulniers <[email protected]>
>Signed-off-by: Ilie Halip <[email protected]>
>
>---
>Changed in v2:
> * a comment line dropped, another one slightly reworded
> * added Nick's Reviewed-by
>---
> arch/riscv/kernel/vdso/Makefile | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
>diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
>index 33b16f4212f7..a4ee3a0e7d20 100644
>--- a/arch/riscv/kernel/vdso/Makefile
>+++ b/arch/riscv/kernel/vdso/Makefile
>@@ -33,15 +33,15 @@ $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
> $(call if_changed,vdsold)
>
> # We also create a special relocatable object that should mirror the symbol
>-# table and layout of the linked DSO. With ld -R we can then refer to
>-# these symbols in the kernel code rather than hand-coded addresses.
>+# table and layout of the linked DSO. With ld --just-symbols we can then
>+# refer to these symbols in the kernel code rather than hand-coded addresses.
>
> SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
> -Wl,--build-id -Wl,--hash-style=both
> $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
> $(call if_changed,vdsold)
>
>-LDFLAGS_vdso-syms.o := -r -R
>+LDFLAGS_vdso-syms.o := -r --just-symbols
> $(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
> $(call if_changed,ld)
>
>--
>2.17.1

https://lore.kernel.org/linux-riscv/[email protected]/

Reviewed-by: Fangrui Song <[email protected]>

2020-04-21 22:26:38

by Palmer Dabbelt

Subject: Re: [PATCH v2] riscv: fix vdso build with lld

On Wed, 15 Apr 2020 07:29:58 PDT (-0700), [email protected] wrote:
> When building with the LLVM linker this error occurrs:
> LD arch/riscv/kernel/vdso/vdso-syms.o
> ld.lld: error: no input files
>
> This happens because the lld treats -R as an alias to -rpath, as opposed
> to ld where -R means --just-symbols.
>
> Use the long option name for compatibility between the two.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/805
> Reported-by: Dmitry Golovin <[email protected]>
> Reviewed-by: Nick Desaulniers <[email protected]>
> Signed-off-by: Ilie Halip <[email protected]>
>
> ---
> Changed in v2:
> * a comment line dropped, another one slightly reworded
> * added Nick's Reviewed-by
> ---
> arch/riscv/kernel/vdso/Makefile | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
> index 33b16f4212f7..a4ee3a0e7d20 100644
> --- a/arch/riscv/kernel/vdso/Makefile
> +++ b/arch/riscv/kernel/vdso/Makefile
> @@ -33,15 +33,15 @@ $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
> $(call if_changed,vdsold)
>
> # We also create a special relocatable object that should mirror the symbol
> -# table and layout of the linked DSO. With ld -R we can then refer to
> -# these symbols in the kernel code rather than hand-coded addresses.
> +# table and layout of the linked DSO. With ld --just-symbols we can then
> +# refer to these symbols in the kernel code rather than hand-coded addresses.
>
> SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
> -Wl,--build-id -Wl,--hash-style=both
> $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
> $(call if_changed,vdsold)
>
> -LDFLAGS_vdso-syms.o := -r -R
> +LDFLAGS_vdso-syms.o := -r --just-symbols
> $(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
> $(call if_changed,ld)

Thanks, this is on fixes.