[PATCH 5.10 027/130] objtool: Create reloc sections implicitly

[Greg Kroah-Hartman]

From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

commit d0c5c4cc73da0b05b0d9e5f833f2d859e1b45f8e upstream.

Have elf_add_reloc() create the relocation section implicitly.

Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Reviewed-by: Miroslav Benes <mbenes@xxxxxxx>
Link: https://lkml.kernel.org/r/20210326151259.880174448@xxxxxxxxxxxxx
[bwh: Backported to 5.10: drop changes in create_mcount_loc_sections()]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 tools/objtool/check.c   |    3 ---
 tools/objtool/elf.c     |    9 ++++++++-
 tools/objtool/elf.h     |    1 -
 tools/objtool/orc_gen.c |    2 --
 4 files changed, 8 insertions(+), 7 deletions(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -459,9 +459,6 @@ static int create_static_call_sections(s
 	if (!sec)
 		return -1;
 
-	if (!elf_create_reloc_section(file->elf, sec, SHT_RELA))
-		return -1;
-
 	idx = 0;
 	list_for_each_entry(insn, &file->static_call_list, static_call_node) {
 
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -498,11 +498,18 @@ err:
 	return -1;
 }
 
+static struct section *elf_create_reloc_section(struct elf *elf,
+						struct section *base,
+						int reltype);
+
 int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset,
 		  unsigned int type, struct symbol *sym, int addend)
 {
 	struct reloc *reloc;
 
+	if (!sec->reloc && !elf_create_reloc_section(elf, sec, SHT_RELA))
+		return -1;
+
 	reloc = malloc(sizeof(*reloc));
 	if (!reloc) {
 		perror("malloc");
@@ -880,7 +887,7 @@ static struct section *elf_create_rela_r
 	return sec;
 }
 
-struct section *elf_create_reloc_section(struct elf *elf,
+static struct section *elf_create_reloc_section(struct elf *elf,
 					 struct section *base,
 					 int reltype)
 {
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -122,7 +122,6 @@ static inline u32 reloc_hash(struct relo
 
 struct elf *elf_open_read(const char *name, int flags);
 struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr);
-struct section *elf_create_reloc_section(struct elf *elf, struct section *base, int reltype);
 
 int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset,
 		  unsigned int type, struct symbol *sym, int addend);
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -222,8 +222,6 @@ int orc_create(struct objtool_file *file
 	sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), nr);
 	if (!sec)
 		return -1;
-	if (!elf_create_reloc_section(file->elf, sec, SHT_RELA))
-		return -1;
 
 	/* Write ORC entries to sections: */
 	list_for_each_entry(entry, &orc_list, list) {