[PATCH v4 18/18] objtool: Clean up elf_write() condition

Peter Zijlstra
2020-05-01T20:31:20Z

With there being multiple ways to change the ELF data, let's more
concisely track modification.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
tools/objtool/check.c | 2 +-
tools/objtool/elf.c | 8 +++++++-
tools/objtool/elf.h | 3 ++-
3 files changed, 10 insertions(+), 3 deletions(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2904,7 +2904,7 @@ int check(const char *_objname, bool orc
goto out;
}

- if (orc || !list_empty(&file.static_call_list)) {
+ if (file.elf->changed) {
ret = elf_write(file.elf);
if (ret < 0)
goto out;
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -703,6 +703,8 @@ struct section *elf_create_section(struc
elf_hash_add(elf->section_hash, &sec->hash, sec->idx);
elf_hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name));

+ elf->changed = true;
+
return sec;
}

@@ -769,7 +771,7 @@ int elf_rebuild_rela_section(struct sect
return 0;
}

-int elf_write(const struct elf *elf)
+int elf_write(struct elf *elf)
{
struct section *sec;
Elf_Scn *s;
@@ -786,6 +788,8 @@ int elf_write(const struct elf *elf)
WARN_ELF("gelf_update_shdr");
return -1;
}
+
+ sec->changed = false;
}
}

@@ -798,6 +802,8 @@ int elf_write(const struct elf *elf)
return -1;
}

+ elf->changed = false;
+
return 0;
}

--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -77,6 +77,7 @@ struct elf {
Elf *elf;
GElf_Ehdr ehdr;
int fd;
+ bool changed;
char *name;
struct list_head sections;
DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
@@ -118,7 +119,7 @@ struct elf *elf_open_read(const char *na
struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr);
struct section *elf_create_rela_section(struct elf *elf, struct section *base);
void elf_add_rela(struct elf *elf, struct rela *rela);
-int elf_write(const struct elf *elf);
+int elf_write(struct elf *elf);
void elf_close(struct elf *elf);

struct section *find_section_by_name(const struct elf *elf, const char *name);