[PATCH v2 06/21] riscv: implement elf_apply_relocations() for ELF relocation support

[Sascha Hauer]

Add architecture-specific ELF relocation support for RISC-V,
enabling dynamic relocation of position-independent ELF binaries.
The implemetation reuses the existing relocate_image().

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply at anthropic.com>
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 arch/riscv/lib/reloc.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/arch/riscv/lib/reloc.c b/arch/riscv/lib/reloc.c
index 18b13a7013cff4032c12b999470f265dbda13c51..9a5004cf5b762b39bb98f7f0ab112c204185b33a 100644
--- a/arch/riscv/lib/reloc.c
+++ b/arch/riscv/lib/reloc.c
@@ -75,3 +75,58 @@ void relocate_to_current_adr(void)
 
 	sync_caches_for_execution();
 }
+
+#if __riscv_xlen == 64
+
+/*
+ * Apply RISC-V 64-bit ELF relocations
+ */
+int elf_apply_relocations(struct elf_image *elf, const void *dyn_seg)
+{
+	Elf64_Rela *rela;
+	void *rel_ptr;
+	u64 relasz;
+	phys_addr_t base = (phys_addr_t)elf->reloc_offset;
+	int ret;
+
+	ret = elf_parse_dynamic_section_rela(elf, dyn_seg, &rel_ptr, &relasz);
+	if (ret)
+		return ret;
+
+	rela = (Elf64_Rela *)rel_ptr;
+
+	relocate_image(base, rela, (void *)rela + relasz, NULL, NULL);
+
+	return 0;
+}
+
+#else /* 32-bit RISC-V */
+
+/*
+ * Apply RISC-V 32-bit ELF relocations
+ */
+int elf_apply_relocations(struct elf_image *elf, const void *dyn_seg)
+{
+	Elf32_Rela *rela;
+	void *rel_ptr;
+	u64 relasz;
+	phys_addr_t base = (phys_addr_t)elf->reloc_offset;
+	int ret;
+
+	if (elf->class != ELFCLASS32) {
+		pr_err("Wrong ELF class for RISC-V 32 relocation\n");
+		return -EINVAL;
+	}
+
+	ret = elf_parse_dynamic_section_rela(elf, dyn_seg, &rel_ptr, &relasz);
+	if (ret)
+		return ret;
+
+	rela = (Elf32_Rela *)rel_ptr;
+
+	relocate_image(base, rela, (void *)rela + relasz, NULL, NULL);
+
+	return 0;
+}
+
+#endif

-- 
2.47.3