[PATCH 5/7] objtool: Clean up elf_write() condition

[Peter Zijlstra]

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

Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
 tools/objtool/check.c   |    4 +++-
 tools/objtool/elf.c     |   13 +++++++++++--
 tools/objtool/elf.h     |    5 +++--
 tools/objtool/orc_gen.c |    2 +-
 4 files changed, 18 insertions(+), 6 deletions(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2740,7 +2740,7 @@ int check(const char *_objname, bool orc
 
        objname = _objname;
 
-       file.elf = elf_open_read(objname, orc ? O_RDWR : O_RDONLY);
+       file.elf = elf_open_read(objname, O_RDWR);
        if (!file.elf)
                return 1;
 
@@ -2801,7 +2801,9 @@ int check(const char *_objname, bool orc
                ret = create_orc_sections(&file);
                if (ret < 0)
                        goto out;
+       }
 
+       if (file.elf->changed) {
                ret = elf_write(file.elf);
                if (ret < 0)
                        goto out;
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -747,6 +747,8 @@ 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;
 }
 
@@ -880,11 +882,14 @@ static int elf_rebuild_rela_reloc_sectio
        return 0;
 }
 
-int elf_rebuild_reloc_section(struct section *sec)
+int elf_rebuild_reloc_section(struct elf *elf, struct section *sec)
 {
        struct reloc *reloc;
        int nr;
 
+       sec->changed = true;
+       elf->changed = true;
+
        nr = 0;
        list_for_each_entry(reloc, &sec->reloc_list, list)
                nr++;
@@ -896,7 +901,7 @@ int elf_rebuild_reloc_section(struct sec
        }
 }
 
-int elf_write(const struct elf *elf)
+int elf_write(struct elf *elf)
 {
        struct section *sec;
        Elf_Scn *s;
@@ -913,6 +918,8 @@ int elf_write(const struct elf *elf)
                                WARN_ELF("gelf_update_shdr");
                                return -1;
                        }
+
+                       sec->changed = false;
                }
        }
 
@@ -925,6 +932,8 @@ int elf_write(const struct elf *elf)
                return -1;
        }
 
+       elf->changed = false;
+
        return 0;
 }
 
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -79,6 +79,7 @@ struct elf {
        Elf *elf;
        GElf_Ehdr ehdr;
        int fd;
+       bool changed;
        char *name;
        struct list_head sections;
        DECLARE_HASHTABLE(symbol_hash, ELF_HASH_BITS);
@@ -121,7 +122,7 @@ struct elf *elf_open_read(const char *na
 struct section *elf_create_section(struct elf *elf, const char *name, size_t 
entsize, int nr);
 struct section *elf_create_reloc_section(struct elf *elf, struct section 
*base, int reltype);
 void elf_add_reloc(struct elf *elf, struct reloc *reloc);
-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);
@@ -133,7 +134,7 @@ struct reloc *find_reloc_by_dest(const s
 struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section 
*sec,
                                     unsigned long offset, unsigned int len);
 struct symbol *find_func_containing(struct section *sec, unsigned long offset);
-int elf_rebuild_reloc_section(struct section *sec);
+int elf_rebuild_reloc_section(struct elf *elf, struct section *sec);
 
 #define for_each_sec(file, sec)                                                
\
        list_for_each_entry(sec, &file->elf->sections, list)
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -222,7 +222,7 @@ int create_orc_sections(struct objtool_f
                }
        }
 
-       if (elf_rebuild_reloc_section(ip_relocsec))
+       if (elf_rebuild_reloc_section(file->elf, ip_relocsec))
                return -1;
 
        return 0;