[PATCH v2 3/7] objtool: Add architecture specific R_REL32 macro

Christophe Leroy christophe.leroy at csgroup.eu
Sat Jul 9 03:31:22 AEST 2022


In order to allow other architectures than x86 to use 32 bits
PC relative relocations (S+A-P), define a R_REL32 macro that each
architecture will define, in the same way as already done for
R_NONE, R_ABS32 and R_ABS64.

For x86 that corresponds to R_X86_64_PC32.
For powerpc it will be R_PPC_REL32/R_PPC64_REL32.

Signed-off-by: Christophe Leroy <christophe.leroy at csgroup.eu>
---
v2: Improved commit message based on feedback from Segher
---
 tools/objtool/arch/x86/include/arch/elf.h |  1 +
 tools/objtool/check.c                     | 10 +++++-----
 tools/objtool/orc_gen.c                   |  2 +-
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/tools/objtool/arch/x86/include/arch/elf.h b/tools/objtool/arch/x86/include/arch/elf.h
index ac14987cf687..e7d228c686db 100644
--- a/tools/objtool/arch/x86/include/arch/elf.h
+++ b/tools/objtool/arch/x86/include/arch/elf.h
@@ -4,5 +4,6 @@
 #define R_NONE R_X86_64_NONE
 #define R_ABS64 R_X86_64_64
 #define R_ABS32 R_X86_64_32
+#define R_REL32	R_X86_64_PC32
 
 #endif /* _OBJTOOL_ARCH_ELF */
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index dec42a226048..ba8fd313372c 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -652,7 +652,7 @@ static int create_static_call_sections(struct objtool_file *file)
 		/* populate reloc for 'addr' */
 		if (elf_add_reloc_to_insn(file->elf, sec,
 					  idx * sizeof(struct static_call_site),
-					  R_X86_64_PC32,
+					  R_REL32,
 					  insn->sec, insn->offset))
 			return -1;
 
@@ -693,7 +693,7 @@ static int create_static_call_sections(struct objtool_file *file)
 		/* populate reloc for 'key' */
 		if (elf_add_reloc(file->elf, sec,
 				  idx * sizeof(struct static_call_site) + 4,
-				  R_X86_64_PC32, key_sym,
+				  R_REL32, key_sym,
 				  is_sibling_call(insn) * STATIC_CALL_SITE_TAIL))
 			return -1;
 
@@ -737,7 +737,7 @@ static int create_retpoline_sites_sections(struct objtool_file *file)
 
 		if (elf_add_reloc_to_insn(file->elf, sec,
 					  idx * sizeof(int),
-					  R_X86_64_PC32,
+					  R_REL32,
 					  insn->sec, insn->offset)) {
 			WARN("elf_add_reloc_to_insn: .retpoline_sites");
 			return -1;
@@ -789,7 +789,7 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file)
 
 		if (elf_add_reloc_to_insn(file->elf, sec,
 					  idx * sizeof(int),
-					  R_X86_64_PC32,
+					  R_REL32,
 					  insn->sec, insn->offset)) {
 			WARN("elf_add_reloc_to_insn: .ibt_endbr_seal");
 			return -1;
@@ -3718,7 +3718,7 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
 			continue;
 
 		off = reloc->sym->offset;
-		if (reloc->type == R_X86_64_PC32 || reloc->type == R_X86_64_PLT32)
+		if (reloc->type == R_REL32 || reloc->type == R_X86_64_PLT32)
 			off += arch_dest_reloc_offset(reloc->addend);
 		else
 			off += reloc->addend;
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index 1f22b7ebae58..49a877b9c879 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -101,7 +101,7 @@ static int write_orc_entry(struct elf *elf, struct section *orc_sec,
 	orc->bp_offset = bswap_if_needed(elf, orc->bp_offset);
 
 	/* populate reloc for ip */
-	if (elf_add_reloc_to_insn(elf, ip_sec, idx * sizeof(int), R_X86_64_PC32,
+	if (elf_add_reloc_to_insn(elf, ip_sec, idx * sizeof(int), R_REL32,
 				  insn_sec, insn_off))
 		return -1;
 
-- 
2.36.1



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