In the most cases, the entry size of rodata is 8 bytes because the
relocation type is 64 bit. There are also 32 bit relocation types,
the entry size of rodata should be 4 bytes in this case.

Add an arch-specific function arch_reloc_size() to assign the entry
size of rodata for x86, powerpc and LoongArch.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 tools/objtool/arch/loongarch/decode.c | 11 +++++++++++
 tools/objtool/arch/powerpc/decode.c   | 15 +++++++++++++++
 tools/objtool/arch/x86/decode.c       | 13 +++++++++++++
 tools/objtool/check.c                 |  2 +-
 tools/objtool/include/objtool/arch.h  |  2 ++
 5 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c
index 69b66994f2a1..b64205b89f6b 100644
--- a/tools/objtool/arch/loongarch/decode.c
+++ b/tools/objtool/arch/loongarch/decode.c
@@ -363,3 +363,14 @@ void arch_initial_func_cfi_state(struct cfi_init_state *state)
 	state->cfa.base = CFI_SP;
 	state->cfa.offset = 0;
 }
+
+unsigned int arch_reloc_size(struct reloc *reloc)
+{
+	switch (reloc_type(reloc)) {
+	case R_LARCH_32:
+	case R_LARCH_32_PCREL:
+		return 4;
+	default:
+		return 8;
+	}
+}
diff --git a/tools/objtool/arch/powerpc/decode.c b/tools/objtool/arch/powerpc/decode.c
index 53b55690f320..3c95dd74fca0 100644
--- a/tools/objtool/arch/powerpc/decode.c
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -106,3 +106,18 @@ void arch_initial_func_cfi_state(struct cfi_init_state *state)
 	state->regs[CFI_RA].base = CFI_CFA;
 	state->regs[CFI_RA].offset = 0;
 }
+
+unsigned int arch_reloc_size(struct reloc *reloc)
+{
+	switch (reloc_type(reloc)) {
+	case R_PPC_REL32:
+	case R_PPC64_REL32:
+	case R_PPC_ADDR32:
+	case R_PPC_UADDR32:
+	case R_PPC_PLT32:
+	case R_PPC_PLTREL32:
+		return 4;
+	default:
+		return 8;
+	}
+}
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index fe1362c34564..fb9691a34d92 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -852,3 +852,16 @@ bool arch_is_embedded_insn(struct symbol *sym)
 	return !strcmp(sym->name, "retbleed_return_thunk") ||
 	       !strcmp(sym->name, "srso_safe_ret");
 }
+
+unsigned int arch_reloc_size(struct reloc *reloc)
+{
+	switch (reloc_type(reloc)) {
+	case R_X86_64_32:
+	case R_X86_64_32S:
+	case R_X86_64_PC32:
+	case R_X86_64_PLT32:
+		return 4;
+	default:
+		return 8;
+	}
+}
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index f64435ad3514..d8668ae0f599 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1968,7 +1968,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
 			break;
 
 		/* Make sure the table entries are consecutive: */
-		if (prev_offset && reloc_offset(reloc) != prev_offset + 8)
+		if (prev_offset && reloc_offset(reloc) != prev_offset + arch_reloc_size(reloc))
 			break;
 
 		sym_offset = reloc->sym->offset + reloc_addend(reloc);
diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h
index d63b46a19f39..396f7c6c81c0 100644
--- a/tools/objtool/include/objtool/arch.h
+++ b/tools/objtool/include/objtool/arch.h
@@ -97,4 +97,6 @@ int arch_rewrite_retpolines(struct objtool_file *file);
 
 bool arch_pc_relative_reloc(struct reloc *reloc);
 
+unsigned int arch_reloc_size(struct reloc *reloc);
+
 #endif /* _ARCH_H */
-- 
2.42.0

In arch/powerpc/include/uapi/asm/elf.h, R_PPC64_REL32 is defined as a
macro to R_PPC_REL32, makes the case value here being duplicate and
creates the following error...

arch/powerpc/decode.c: In function ‘arch_reloc_size’:
arch/powerpc/decode.c:114:9: error: duplicate case value
  114 |         case R_PPC64_REL32:
      |         ^~~~
arch/powerpc/decode.c:113:9: note: previously used here
  113 |         case R_PPC_REL32:
      |         ^~~~

Remove the duplicate case value to fix the error.

Fixes: "FROMLIST: objtool: Handle different entry size of rodata"
Signed-off-by: Kexy Biscuit <kexybiscuit@aosc.io>
---
This patch is required for this series to build on powerpc, however I'm
not sure if it's the preferred way... Please advise.

 tools/objtool/arch/powerpc/decode.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/objtool/arch/powerpc/decode.c b/tools/objtool/arch/powerpc/decode.c
index 3c95dd74fca0..7c0bf2429067 100644
--- a/tools/objtool/arch/powerpc/decode.c
+++ b/tools/objtool/arch/powerpc/decode.c
@@ -111,7 +111,6 @@ unsigned int arch_reloc_size(struct reloc *reloc)
 {
 	switch (reloc_type(reloc)) {
 	case R_PPC_REL32:
-	case R_PPC64_REL32:
 	case R_PPC_ADDR32:
 	case R_PPC_UADDR32:
 	case R_PPC_PLT32:
-- 
2.48.1

On Tue, Feb 11, 2025 at 10:19:57PM +0800, Kexy Biscuit wrote:
> In arch/powerpc/include/uapi/asm/elf.h, R_PPC64_REL32 is defined as a
> macro to R_PPC_REL32, makes the case value here being duplicate and
> creates the following error...
> 
> arch/powerpc/decode.c: In function ‘arch_reloc_size’:
> arch/powerpc/decode.c:114:9: error: duplicate case value
>   114 |         case R_PPC64_REL32:
>       |         ^~~~
> arch/powerpc/decode.c:113:9: note: previously used here
>   113 |         case R_PPC_REL32:
>       |         ^~~~
> 
> Remove the duplicate case value to fix the error.
> 
> Fixes: "FROMLIST: objtool: Handle different entry size of rodata"
> Signed-off-by: Kexy Biscuit <kexybiscuit@aosc.io>
> ---
> This patch is required for this series to build on powerpc, however I'm
> not sure if it's the preferred way... Please advise.

If there are no objections, I'll squash this into the original patch to
avoid breaking bisection.

-- 
Josh