refactor to remove arch-specific relocation code from dynamic linker

this was one of the main instances of ugly code duplication: all archs
use basically the same types of relocations, but roughly equivalent
logic was duplicated for each arch to account for the different naming
and numbering of relocation types and variation in whether REL or RELA
records are used.

as an added bonus, both REL and RELA are now supported on all archs,
regardless of which is used by the standard toolchain.

1 files changed, 12 insertions, 29 deletions

diff --git a/arch/x86_64/reloc.h b/arch/x86_64/reloc.h
index 30f65614..ffab5566 100644
--- a/arch/x86_64/reloc.h
+++ b/arch/x86_64/reloc.h
@@ -4,44 +4,27 @@
 
 #define LDSO_ARCH "x86_64"
 
-#define IS_COPY(x) ((x)==R_X86_64_COPY)
-#define IS_PLT(x) ((x)==R_X86_64_JUMP_SLOT)
-
-static inline int do_single_reloc(
-	struct dso *self, unsigned char *base_addr,
-	size_t *reloc_addr, int type, size_t addend,
-	Sym *sym, size_t sym_size,
-	struct symdef def, size_t sym_val)
+static int remap_rel(int type)
 {
 	switch(type) {
-	case R_X86_64_GLOB_DAT:
-	case R_X86_64_JUMP_SLOT:
 	case R_X86_64_64:
-		*reloc_addr = sym_val + addend;
-		break;
-	case R_X86_64_32:
-		*(uint32_t *)reloc_addr = sym_val + addend;
-		break;
+		return REL_SYMBOLIC;
 	case R_X86_64_PC32:
-		*reloc_addr = sym_val + addend - (size_t)reloc_addr + (size_t)base_addr;
-		break;
+		return REL_OFFSET32;
+	case R_X86_64_GLOB_DAT:
+		return REL_GOT;
+	case R_X86_64_JUMP_SLOT:
+		return REL_PLT;
 	case R_X86_64_RELATIVE:
-		*reloc_addr = (size_t)base_addr + addend;
-		break;
+		return REL_RELATIVE;
 	case R_X86_64_COPY:
-		memcpy(reloc_addr, (void *)sym_val, sym_size);
-		break;
+		return REL_COPY;
 	case R_X86_64_DTPMOD64:
-		*reloc_addr = def.dso ? def.dso->tls_id : self->tls_id;
-		break;
+		return REL_DTPMOD;
 	case R_X86_64_DTPOFF64:
-		*reloc_addr = def.sym->st_value + addend;
-		break;
+		return REL_DTPOFF;
 	case R_X86_64_TPOFF64:
-		*reloc_addr = (def.sym
-			? def.sym->st_value - def.dso->tls_offset
-			: 0 - self->tls_offset) + addend;
-		break;
+		return REL_TPOFF;
 	}
 	return 0;
 }