[PATCH 0/2] sparc/module: R_SPARC_UA64 handling to help with LLVM IAS enablement

[PATCH 0/2] sparc/module: R_SPARC_UA64 handling to help with LLVM IAS enablement

[Koakuma via B4 Relay]

Hello~

This series lets the module loader handle R_SPARC_UA64, which is emitted
by LLVM's IAS in certain conditions. Additionally, I put on a small change
to the error log to make it clearer that the printed relocation number
is in hex.

The intention is to get both the kernel and LLVM in a state where
doing a clang+IAS build is possible.

As with before, on the LLVM side the project is tracked here:
https://github.com/llvm/llvm-project/issues/40792

Signed-off-by: Koakuma <koachan@protonmail.com>
---
Koakuma (2):
      sparc/module: Add R_SPARC_UA64 relocation handling
      sparc/module: Make it clear that relocation numbers are shown in hex

 arch/sparc/include/asm/elf_64.h | 1 +
 arch/sparc/kernel/module.c      | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)
---
base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
change-id: 20250305-b4-sparc-relocs-65ac77ca8920

Best regards,
-- 
Koakuma <koachan@protonmail.com>

[PATCH 1/2] sparc/module: Add R_SPARC_UA64 relocation handling

[Koakuma via B4 Relay]

From: Koakuma <koachan@protonmail.com>

This is needed so that the kernel can handle R_SPARC_UA64 relocations,
which is emitted by LLVM's IAS.

Signed-off-by: Koakuma <koachan@protonmail.com>
---
 arch/sparc/include/asm/elf_64.h | 1 +
 arch/sparc/kernel/module.c      | 1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/sparc/include/asm/elf_64.h b/arch/sparc/include/asm/elf_64.h
index 8fb09eec8c3e796a9a79aa0a7877842ceb7ea6d3..694ed081cf8d99adf70be25e5dc0e30a45f70398 100644
--- a/arch/sparc/include/asm/elf_64.h
+++ b/arch/sparc/include/asm/elf_64.h
@@ -58,6 +58,7 @@
 #define R_SPARC_7		43
 #define R_SPARC_5		44
 #define R_SPARC_6		45
+#define R_SPARC_UA64		54
 
 /* Bits present in AT_HWCAP, primarily for Sparc32.  */
 #define HWCAP_SPARC_FLUSH       0x00000001
diff --git a/arch/sparc/kernel/module.c b/arch/sparc/kernel/module.c
index b8c51cc23d96944037494f13d2d65a43bb187729..6e3d4dde4f9ab33040b300c40d5fd5d0584e166d 100644
--- a/arch/sparc/kernel/module.c
+++ b/arch/sparc/kernel/module.c
@@ -87,6 +87,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 			break;
 #ifdef CONFIG_SPARC64
 		case R_SPARC_64:
+		case R_SPARC_UA64:
 			location[0] = v >> 56;
 			location[1] = v >> 48;
 			location[2] = v >> 40;

-- 
2.49.0

[PATCH 2/2] sparc/module: Make it clear that relocation numbers are shown in hex

[Koakuma via B4 Relay]

From: Koakuma <koachan@protonmail.com>

This is to ease debugging by removing the ambiguity of the shown
number base.

Signed-off-by: Koakuma <koachan@protonmail.com>
---
 arch/sparc/kernel/module.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/sparc/kernel/module.c b/arch/sparc/kernel/module.c
index 6e3d4dde4f9ab33040b300c40d5fd5d0584e166d..49740450a6859fda566459ee4679869f9854b760 100644
--- a/arch/sparc/kernel/module.c
+++ b/arch/sparc/kernel/module.c
@@ -142,7 +142,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
 			break;
 
 		default:
-			printk(KERN_ERR "module %s: Unknown relocation: %x\n",
+			printk(KERN_ERR "module %s: Unknown relocation: 0x%x\n",
 			       me->name,
 			       (int) (ELF_R_TYPE(rel[i].r_info) & 0xff));
 			return -ENOEXEC;

-- 
2.49.0

Re: [PATCH 1/2] sparc/module: Add R_SPARC_UA64 relocation handling

[Koakuma]

Koakuma via B4 Relay <devnull+koachan.protonmail.com@kernel.org> wrote:

> From: Koakuma koachan@protonmail.com
> 
> 
> This is needed so that the kernel can handle R_SPARC_UA64 relocations,
> which is emitted by LLVM's IAS.
> 
> Signed-off-by: Koakuma koachan@protonmail.com
> 
> ---
> arch/sparc/include/asm/elf_64.h | 1 +
> arch/sparc/kernel/module.c | 1 +
> 2 files changed, 2 insertions(+)
> 
> diff --git a/arch/sparc/include/asm/elf_64.h b/arch/sparc/include/asm/elf_64.h
> index 8fb09eec8c3e796a9a79aa0a7877842ceb7ea6d3..694ed081cf8d99adf70be25e5dc0e30a45f70398 100644
> --- a/arch/sparc/include/asm/elf_64.h
> +++ b/arch/sparc/include/asm/elf_64.h
> @@ -58,6 +58,7 @@
> #define R_SPARC_7 43
> #define R_SPARC_5 44
> #define R_SPARC_6 45
> +#define R_SPARC_UA64 54
> 
> /* Bits present in AT_HWCAP, primarily for Sparc32. */
> #define HWCAP_SPARC_FLUSH 0x00000001
> diff --git a/arch/sparc/kernel/module.c b/arch/sparc/kernel/module.c
> index b8c51cc23d96944037494f13d2d65a43bb187729..6e3d4dde4f9ab33040b300c40d5fd5d0584e166d 100644
> --- a/arch/sparc/kernel/module.c
> +++ b/arch/sparc/kernel/module.c
> @@ -87,6 +87,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
> break;
> #ifdef CONFIG_SPARC64
> case R_SPARC_64:
> + case R_SPARC_UA64:
> location[0] = v >> 56;
> 
> location[1] = v >> 48;
> 
> location[2] = v >> 40;
> 
> 
> --
> 2.49.0

Ping. Is there anything else I should do for this?

Re: [PATCH 1/2] sparc/module: Add R_SPARC_UA64 relocation handling

[Nathan Chancellor]

On Sun, Aug 03, 2025 at 01:15:02AM +0000, Koakuma wrote:
> Koakuma via B4 Relay <devnull+koachan.protonmail.com@kernel.org> wrote:
> 
> > From: Koakuma koachan@protonmail.com
> > 
> > 
> > This is needed so that the kernel can handle R_SPARC_UA64 relocations,
> > which is emitted by LLVM's IAS.
> > 
> > Signed-off-by: Koakuma koachan@protonmail.com
> > 
> > ---
> > arch/sparc/include/asm/elf_64.h | 1 +
> > arch/sparc/kernel/module.c | 1 +
> > 2 files changed, 2 insertions(+)
> > 
> > diff --git a/arch/sparc/include/asm/elf_64.h b/arch/sparc/include/asm/elf_64.h
> > index 8fb09eec8c3e796a9a79aa0a7877842ceb7ea6d3..694ed081cf8d99adf70be25e5dc0e30a45f70398 100644
> > --- a/arch/sparc/include/asm/elf_64.h
> > +++ b/arch/sparc/include/asm/elf_64.h
> > @@ -58,6 +58,7 @@
> > #define R_SPARC_7 43
> > #define R_SPARC_5 44
> > #define R_SPARC_6 45
> > +#define R_SPARC_UA64 54
> > 
> > /* Bits present in AT_HWCAP, primarily for Sparc32. */
> > #define HWCAP_SPARC_FLUSH 0x00000001
> > diff --git a/arch/sparc/kernel/module.c b/arch/sparc/kernel/module.c
> > index b8c51cc23d96944037494f13d2d65a43bb187729..6e3d4dde4f9ab33040b300c40d5fd5d0584e166d 100644
> > --- a/arch/sparc/kernel/module.c
> > +++ b/arch/sparc/kernel/module.c
> > @@ -87,6 +87,7 @@ int apply_relocate_add(Elf_Shdr *sechdrs,
> > break;
> > #ifdef CONFIG_SPARC64
> > case R_SPARC_64:
> > + case R_SPARC_UA64:
> > location[0] = v >> 56;
> > 
> > location[1] = v >> 48;
> > 
> > location[2] = v >> 40;
> > 
> > 
> > --
> > 2.49.0
> 
> Ping. Is there anything else I should do for this?
> 

This seems reasonable to me, sorry for the delay in commenting. I would
expect this to go via the SPARC tree but if they are too busy or
unavailable to pick this up, we would try to route it via Andrew Morton.
Is there more work needed for the integrated assembler other than this
series?

Cheers,
Nathan

Re: [PATCH 1/2] sparc/module: Add R_SPARC_UA64 relocation handling

[Andreas Larsson]

On 2025-08-15 00:40, Nathan Chancellor wrote:
>> Ping. Is there anything else I should do for this?
>>
> 
> This seems reasonable to me, sorry for the delay in commenting. I would
> expect this to go via the SPARC tree but if they are too busy or
> unavailable to pick this up, we would try to route it via Andrew Morton.
> Is there more work needed for the integrated assembler other than this
> series?
I'll take it through the SPARC tree.

Cheers,
Andreas

Re: [PATCH 1/2] sparc/module: Add R_SPARC_UA64 relocation handling

[Koakuma]

Nathan Chancellor <nathan@kernel.org> wrote:

> Is there more work needed for the integrated assembler other than this
> series?

Yep~ it should be enough. The rest of the work will have to be done in
the LLVM side.