[PATCH v3 09/16] objtool: Implicitly create reloc sections

From: Peter Zijlstra
Date: Fri Mar 26 2021 - 11:16:17 EST


Have elf_add_reloc() create the relocation section implicity.

Suggested-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
tools/objtool/check.c | 6 ------
tools/objtool/elf.c | 9 ++++++++-
tools/objtool/include/objtool/elf.h | 1 -
tools/objtool/orc_gen.c | 2 --
4 files changed, 8 insertions(+), 10 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) {

@@ -547,9 +544,6 @@ static int create_mcount_loc_sections(st
if (!sec)
return -1;

- if (!elf_create_reloc_section(file->elf, sec, SHT_RELA))
- return -1;
-
idx = 0;
list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node) {

--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -447,11 +447,18 @@ static int read_symbols(struct elf *elf)
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");
@@ -829,7 +836,7 @@ 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/include/objtool/elf.h
+++ b/tools/objtool/include/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
@@ -225,8 +225,6 @@ 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) {