[PATCH 06/22] objtool: Add mark_sec_changed()

From: Josh Poimboeuf
Date: Tue May 30 2023 - 13:21:59 EST


Ensure elf->changed always gets set when sec->changed gets set.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/elf.c | 31 +++++++++++++++--------------
tools/objtool/include/objtool/elf.h | 14 ++++++++++++-
2 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index f72ec6d8fb14..67967c231972 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -562,7 +562,8 @@ int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset,
elf_hash_add(reloc, &reloc->hash, reloc_hash(reloc));

sec->rsec->sh.sh_size += sec->rsec->sh.sh_entsize;
- sec->rsec->changed = true;
+
+ mark_sec_changed(elf, sec->rsec, true);

return 0;
}
@@ -577,7 +578,7 @@ static void elf_dirty_reloc_sym(struct elf *elf, struct symbol *sym)
struct reloc *reloc;

list_for_each_entry(reloc, &sym->reloc_list, sym_reloc_entry)
- reloc->sec->changed = true;
+ mark_sec_changed(elf, reloc->sec, true);
}

/*
@@ -654,7 +655,7 @@ static int elf_update_symbol(struct elf *elf, struct section *symtab,
symtab_data->d_align = 1;
symtab_data->d_type = ELF_T_SYM;

- symtab->changed = true;
+ mark_sec_changed(elf, symtab, true);
symtab->truncate = true;

if (t) {
@@ -669,7 +670,7 @@ static int elf_update_symbol(struct elf *elf, struct section *symtab,
shndx_data->d_align = sizeof(Elf32_Word);
shndx_data->d_type = ELF_T_WORD;

- symtab_shndx->changed = true;
+ mark_sec_changed(elf, symtab_shndx, true);
symtab_shndx->truncate = true;
}

@@ -773,11 +774,11 @@ __elf_create_symbol(struct elf *elf, struct symbol *sym)
}

symtab->sh.sh_size += symtab->sh.sh_entsize;
- symtab->changed = true;
+ mark_sec_changed(elf, symtab, true);

if (symtab_shndx) {
symtab_shndx->sh.sh_size += sizeof(Elf32_Word);
- symtab_shndx->changed = true;
+ mark_sec_changed(elf, symtab_shndx, true);
}

return sym;
@@ -1040,7 +1041,8 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str)

len = strtab->sh.sh_size;
strtab->sh.sh_size += data->d_size;
- strtab->changed = true;
+
+ mark_sec_changed(elf, strtab, true);

return len;
}
@@ -1075,7 +1077,6 @@ struct section *elf_create_section(struct elf *elf, const char *name,
}

sec->idx = elf_ndxscn(s);
- sec->changed = true;

sec->data = elf_newdata(s);
if (!sec->data) {
@@ -1122,7 +1123,7 @@ struct section *elf_create_section(struct elf *elf, const char *name,
elf_hash_add(section, &sec->hash, sec->idx);
elf_hash_add(section_name, &sec->name_hash, str_hash(sec->name));

- elf->changed = true;
+ mark_sec_changed(elf, sec, true);

return sec;
}
@@ -1208,9 +1209,8 @@ int elf_write_insn(struct elf *elf, struct section *sec,
}

memcpy(data->d_buf + offset, insn, len);
- elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY);

- elf->changed = true;
+ mark_sec_changed(elf, sec, true);

return 0;
}
@@ -1235,7 +1235,7 @@ int elf_write_reloc(struct elf *elf, struct reloc *reloc)
return -1;
}

- elf->changed = true;
+ mark_sec_changed(elf, rsec, true);

return 0;
}
@@ -1307,12 +1307,14 @@ int elf_write(struct elf *elf)
if (sec->truncate)
elf_truncate_section(elf, sec);

- if (sec->changed) {
+ if (sec_changed(sec)) {
s = elf_getscn(elf->elf, sec->idx);
if (!s) {
WARN_ELF("elf_getscn");
return -1;
}
+
+ /* Note this also flags the section dirty */
if (!gelf_update_shdr(s, &sec->sh)) {
WARN_ELF("gelf_update_shdr");
return -1;
@@ -1324,8 +1326,7 @@ int elf_write(struct elf *elf)
return -1;
}

- sec->changed = false;
- elf->changed = true;
+ mark_sec_changed(elf, sec, false);
}
}

diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
index b81d78b35126..56b66ff91943 100644
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -39,7 +39,7 @@ struct section {
Elf_Data *data;
char *name;
int idx;
- bool changed, text, rodata, noinstr, init, truncate;
+ bool _changed, text, rodata, noinstr, init, truncate;
struct reloc *reloc_data;
};

@@ -164,6 +164,18 @@ static inline bool is_reloc_sec(struct section *sec)
return sec->sh.sh_type == SHT_RELA || sec->sh.sh_type == SHT_REL;
}

+static inline bool sec_changed(struct section *sec)
+{
+ return sec->_changed;
+}
+
+static inline void mark_sec_changed(struct elf *elf, struct section *sec,
+ bool changed)
+{
+ sec->_changed = changed;
+ elf->changed |= changed;
+}
+
#define for_each_sec(file, sec) \
list_for_each_entry(sec, &file->elf->sections, list)

--
2.40.1