diff mbox series

package/uclibc: Fix build when RVA is disabled

Message ID 20240902175956.2837858-1-Mr.Bossman075@gmail.com
State Changes Requested
Headers show
Series package/uclibc: Fix build when RVA is disabled | expand

Commit Message

Jesse T Sept. 2, 2024, 5:59 p.m. UTC
If the RVA option is disabled uclibc won't build with Shared libraries
enabled or Threads enabled. Add guards against this.

When the RVA option is disabled, the build fails with the
following errors:
With Threads enabled:

  LD libuClibc-1.0.48.so
riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(err.os): in function `.L0 ':
err.c:(.text+0xa0): undefined reference to `__atomic_compare_exchange_4'
riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(err.os): in function `.L6':
err.c:(.text+0x138): undefined reference to `__atomic_exchange_4'
riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(__cxa_finalize.os): in function `.L3':
__cxa_finalize.c:(.text+0xac): undefined reference to `__atomic_compare_exchange_8'
riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(fork.oS): in function `.L23':
fork.c:(.text+0x130): undefined reference to `__atomic_fetch_add_4'
riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(sem_timedwait.oS): in function `.L5':
sem_timedwait.c:(.text+0xe0): undefined reference to `__atomic_fetch_add_8'

With Shared libraries enabled:

  LD libuClibc-1.0.48.so
riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(__cxa_finalize.os): in function `.L3':
__cxa_finalize.c:(.text+0xa4): undefined reference to `__atomic_compare_exchange_8'

Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com>
---
 arch/Config.in           | 2 +-
 package/uclibc/Config.in | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

Comments

Thomas Petazzoni Sept. 3, 2024, 6:55 p.m. UTC | #1
Hello,

+Waldemar in Cc, uclibc stuff :-)

On Mon,  2 Sep 2024 13:59:56 -0400
Jesse Taube <mr.bossman075@gmail.com> wrote:

> If the RVA option is disabled uclibc won't build with Shared libraries
> enabled or Threads enabled. Add guards against this.

Meh, this looks weird to me, and I'd like some better understanding
before adding "random" guards.

> When the RVA option is disabled, the build fails with the
> following errors:
> With Threads enabled:
> 
>   LD libuClibc-1.0.48.so
> riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(err.os): in function `.L0 ':
> err.c:(.text+0xa0): undefined reference to `__atomic_compare_exchange_4'
> riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(err.os): in function `.L6':
> err.c:(.text+0x138): undefined reference to `__atomic_exchange_4'
> riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(__cxa_finalize.os): in function `.L3':
> __cxa_finalize.c:(.text+0xac): undefined reference to `__atomic_compare_exchange_8'
> riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(fork.oS): in function `.L23':
> fork.c:(.text+0x130): undefined reference to `__atomic_fetch_add_4'
> riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(sem_timedwait.oS): in function `.L5':
> sem_timedwait.c:(.text+0xe0): undefined reference to `__atomic_fetch_add_8'
> 
> With Shared libraries enabled:
> 
>   LD libuClibc-1.0.48.so
> riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(__cxa_finalize.os): in function `.L3':
> __cxa_finalize.c:(.text+0xa4): undefined reference to `__atomic_compare_exchange_8'
> 
> Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com>
> ---
>  arch/Config.in           | 2 +-
>  package/uclibc/Config.in | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/Config.in b/arch/Config.in
> index f39c33ef7f..d0052782be 100644
> --- a/arch/Config.in
> +++ b/arch/Config.in
> @@ -431,7 +431,7 @@ choice
>  config BR2_BINFMT_ELF
>  	bool "ELF"
>  	depends on BR2_USE_MMU
> -	select BR2_BINFMT_SUPPORTS_SHARED
> +	select BR2_BINFMT_SUPPORTS_SHARED if !BR2_riscv || BR2_RISCV_ISA_RVA

Why this? This is no covered in your commit log.

>  	help
>  	  ELF (Executable and Linkable Format) is a format for libraries
>  	  and executables used across different architectures and
> diff --git a/package/uclibc/Config.in b/package/uclibc/Config.in
> index 73ddd5ef58..f7edd417c6 100644
> --- a/package/uclibc/Config.in
> +++ b/package/uclibc/Config.in
> @@ -78,13 +78,13 @@ choice
>  
>  config BR2_PTHREADS_NATIVE
>  	bool "Native POSIX Threading (NPTL)"
> -	depends on BR2_USE_MMU
> +	depends on BR2_USE_MMU && (!BR2_riscv || BR2_RISCV_ISA_RVA)
>  	select BR2_TOOLCHAIN_HAS_THREADS
>  	select BR2_TOOLCHAIN_HAS_THREADS_NPTL
>  
>  config BR2_PTHREADS
>  	bool "linuxthreads"
> -	depends on !BR2_aarch64 && !BR2_aarch64_be
> +	depends on !BR2_aarch64 && !BR2_aarch64_be && (!BR2_riscv || BR2_RISCV_ISA_RVA)
>  	select BR2_TOOLCHAIN_HAS_THREADS

I would really like to hear back from Waldemar on this.

uClibc supports architectures that don't have atomic support (such as
ARC750/ARC770), so it is somewhat surprising that it wouldn't support
RISC-V without atomics. So let's try to understand the real problem and
find the correct solution rather than papering over the problem in a
very custom/architecture-specific way.

Thanks!

Thomas
Waldemar Brodkorb Sept. 5, 2024, 10:39 a.m. UTC | #2
Hi Thomas,
Thomas Petazzoni wrote,

> Hello,
> 
> +Waldemar in Cc, uclibc stuff :-)
> 
> On Mon,  2 Sep 2024 13:59:56 -0400
> Jesse Taube <mr.bossman075@gmail.com> wrote:
> 
> > If the RVA option is disabled uclibc won't build with Shared libraries
> > enabled or Threads enabled. Add guards against this.
> 
> Meh, this looks weird to me, and I'd like some better understanding
> before adding "random" guards.
> 
> > When the RVA option is disabled, the build fails with the
> > following errors:
> > With Threads enabled:
> > 
> >   LD libuClibc-1.0.48.so
> > riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(err.os): in function `.L0 ':
> > err.c:(.text+0xa0): undefined reference to `__atomic_compare_exchange_4'
> > riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(err.os): in function `.L6':
> > err.c:(.text+0x138): undefined reference to `__atomic_exchange_4'
> > riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(__cxa_finalize.os): in function `.L3':
> > __cxa_finalize.c:(.text+0xac): undefined reference to `__atomic_compare_exchange_8'
> > riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(fork.oS): in function `.L23':
> > fork.c:(.text+0x130): undefined reference to `__atomic_fetch_add_4'
> > riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(sem_timedwait.oS): in function `.L5':
> > sem_timedwait.c:(.text+0xe0): undefined reference to `__atomic_fetch_add_8'
> > 
> > With Shared libraries enabled:
> > 
> >   LD libuClibc-1.0.48.so
> > riscv64-buildroot-linux-uclibc/bin/ld: libc/libc_so.a(__cxa_finalize.os): in function `.L3':
> > __cxa_finalize.c:(.text+0xa4): undefined reference to `__atomic_compare_exchange_8'
> > 
> > Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com>
> > ---
> >  arch/Config.in           | 2 +-
> >  package/uclibc/Config.in | 4 ++--
> >  2 files changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/arch/Config.in b/arch/Config.in
> > index f39c33ef7f..d0052782be 100644
> > --- a/arch/Config.in
> > +++ b/arch/Config.in
> > @@ -431,7 +431,7 @@ choice
> >  config BR2_BINFMT_ELF
> >  	bool "ELF"
> >  	depends on BR2_USE_MMU
> > -	select BR2_BINFMT_SUPPORTS_SHARED
> > +	select BR2_BINFMT_SUPPORTS_SHARED if !BR2_riscv || BR2_RISCV_ISA_RVA
> 
> Why this? This is no covered in your commit log.
> 
> >  	help
> >  	  ELF (Executable and Linkable Format) is a format for libraries
> >  	  and executables used across different architectures and
> > diff --git a/package/uclibc/Config.in b/package/uclibc/Config.in
> > index 73ddd5ef58..f7edd417c6 100644
> > --- a/package/uclibc/Config.in
> > +++ b/package/uclibc/Config.in
> > @@ -78,13 +78,13 @@ choice
> >  
> >  config BR2_PTHREADS_NATIVE
> >  	bool "Native POSIX Threading (NPTL)"
> > -	depends on BR2_USE_MMU
> > +	depends on BR2_USE_MMU && (!BR2_riscv || BR2_RISCV_ISA_RVA)
> >  	select BR2_TOOLCHAIN_HAS_THREADS
> >  	select BR2_TOOLCHAIN_HAS_THREADS_NPTL
> >  
> >  config BR2_PTHREADS
> >  	bool "linuxthreads"
> > -	depends on !BR2_aarch64 && !BR2_aarch64_be
> > +	depends on !BR2_aarch64 && !BR2_aarch64_be && (!BR2_riscv || BR2_RISCV_ISA_RVA)
> >  	select BR2_TOOLCHAIN_HAS_THREADS
> 
> I would really like to hear back from Waldemar on this.
> 
> uClibc supports architectures that don't have atomic support (such as
> ARC750/ARC770), so it is somewhat surprising that it wouldn't support
> RISC-V without atomics. So let's try to understand the real problem and
> find the correct solution rather than papering over the problem in a
> very custom/architecture-specific way.

It seems indeed that uClibc-ng depends on RV-A extension. Gcc emits
the calls to some atomic functions when RV-A is disabled in the
compiler. It is not uClibc-ng itself. We don't use atomic functions.
I haven't found a way to disable this behaviour in GCC.

best regards
 Waldemar
diff mbox series

Patch

diff --git a/arch/Config.in b/arch/Config.in
index f39c33ef7f..d0052782be 100644
--- a/arch/Config.in
+++ b/arch/Config.in
@@ -431,7 +431,7 @@  choice
 config BR2_BINFMT_ELF
 	bool "ELF"
 	depends on BR2_USE_MMU
-	select BR2_BINFMT_SUPPORTS_SHARED
+	select BR2_BINFMT_SUPPORTS_SHARED if !BR2_riscv || BR2_RISCV_ISA_RVA
 	help
 	  ELF (Executable and Linkable Format) is a format for libraries
 	  and executables used across different architectures and
diff --git a/package/uclibc/Config.in b/package/uclibc/Config.in
index 73ddd5ef58..f7edd417c6 100644
--- a/package/uclibc/Config.in
+++ b/package/uclibc/Config.in
@@ -78,13 +78,13 @@  choice
 
 config BR2_PTHREADS_NATIVE
 	bool "Native POSIX Threading (NPTL)"
-	depends on BR2_USE_MMU
+	depends on BR2_USE_MMU && (!BR2_riscv || BR2_RISCV_ISA_RVA)
 	select BR2_TOOLCHAIN_HAS_THREADS
 	select BR2_TOOLCHAIN_HAS_THREADS_NPTL
 
 config BR2_PTHREADS
 	bool "linuxthreads"
-	depends on !BR2_aarch64 && !BR2_aarch64_be
+	depends on !BR2_aarch64 && !BR2_aarch64_be && (!BR2_riscv || BR2_RISCV_ISA_RVA)
 	select BR2_TOOLCHAIN_HAS_THREADS
 
 config BR2_PTHREADS_NONE