[PATCH v3 05/23] ARM: implement elf_apply_relocations() for ELF relocation support

[Sascha Hauer]

Implement architecture-specific ELF relocation handlers for ARM32 and ARM64.
The implementation reuses the existing relocate_image().

Co-Authored-By: Claude Sonnet 4.5 <noreply at anthropic.com>
Reviewed-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 arch/arm/include/asm/elf.h |  7 +++++++
 arch/arm/lib32/reloc.c     | 19 +++++++++++++++++++
 arch/arm/lib64/reloc.c     | 21 +++++++++++++++++++--
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index 0b4704a4a5615e648f67705ad9daf8dea9f41bab..630c85f2b421cba7e37ea7147c047be948ecdc7e 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -36,6 +36,13 @@ typedef struct user_fp elf_fpregset_t;
 #define R_ARM_THM_CALL		10
 #define R_ARM_THM_JUMP24	30
 
+/* Additional relocation types for dynamic linking */
+#define R_ARM_RELATIVE		23
+
+#define R_AARCH64_NONE		0
+#define R_AARCH64_ABS64		257
+#define R_AARCH64_RELATIVE	1027
+
 /*
  * These are used to set parameters in the core dumps.
  */
diff --git a/arch/arm/lib32/reloc.c b/arch/arm/lib32/reloc.c
index 378ba95b2ffd455436e704a803f5448fc2c2b18c..edd3d7eb486649d70a3ce5a77c25ad52ccd12bc1 100644
--- a/arch/arm/lib32/reloc.c
+++ b/arch/arm/lib32/reloc.c
@@ -54,3 +54,22 @@ void __prereloc relocate_image(unsigned long offset,
 	if (dynend)
 		__memset(dynsym, 0, (unsigned long)dynend - (unsigned long)dynsym);
 }
+
+/*
+ * Apply ARM32 ELF relocations
+ */
+int elf_apply_relocations(struct elf_image *elf, const void *dyn_seg)
+{
+	void *rel_ptr = NULL, *symtab = NULL;
+	u64 relsz;
+	phys_addr_t base = (phys_addr_t)elf->reloc_offset;
+	int ret;
+
+	ret = elf_parse_dynamic_section_rel(elf, dyn_seg, &rel_ptr, &relsz, &symtab);
+	if (ret)
+		return ret;
+
+	relocate_image(base, rel_ptr, rel_ptr + relsz, symtab, NULL);
+
+	return 0;
+}
diff --git a/arch/arm/lib64/reloc.c b/arch/arm/lib64/reloc.c
index 2288f9e2e336887c5edfbf6b080f487394754113..b4981578747007c84eca643db327807ce15ba7c9 100644
--- a/arch/arm/lib64/reloc.c
+++ b/arch/arm/lib64/reloc.c
@@ -8,8 +8,6 @@
 #include <debug_ll.h>
 #include <asm/reloc.h>
 
-#define R_AARCH64_RELATIVE 1027
-
 /*
  * relocate binary to the currently running address
  */
@@ -45,3 +43,22 @@ void __prereloc relocate_image(unsigned long offset,
 		dstart += sizeof(*rel);
 	}
 }
+
+/*
+ * Apply ARM64 ELF relocations
+ */
+int elf_apply_relocations(struct elf_image *elf, const void *dyn_seg)
+{
+	void *rela_ptr = NULL, *symtab = NULL;
+	u64 relasz;
+	phys_addr_t base = (phys_addr_t)elf->reloc_offset;
+	int ret;
+
+	ret = elf_parse_dynamic_section_rela(elf, dyn_seg, &rela_ptr, &relasz, &symtab);
+	if (ret)
+		return ret;
+
+	relocate_image(base, rela_ptr, rela_ptr + relasz, symtab, NULL);
+
+	return 0;
+}

-- 
2.47.3