[PATCH 1/3] objtool: Constify 'struct elf *' parameters

From: Ingo Molnar
Date: Wed Apr 22 2020 - 06:32:43 EST


In preparation to parallelize certain parts of objtool, map out which uses
of various data structures are read-only vs. read-write.

As a first step constify 'struct elf' pointer passing, most of the secondary
uses of it in find_symbol_*() methods are read-only.

Also, while at it, better group the 'struct elf' handling methods in elf.h.

Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
tools/objtool/elf.c | 10 +++++-----
tools/objtool/elf.h | 20 ++++++++++----------
2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index f26bb3e8db7b..fab5534c3365 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -127,7 +127,7 @@ static int symbol_by_offset(const void *key, const struct rb_node *node)
return 0;
}

-struct section *find_section_by_name(struct elf *elf, const char *name)
+struct section *find_section_by_name(const struct elf *elf, const char *name)
{
struct section *sec;

@@ -217,7 +217,7 @@ struct symbol *find_func_containing(struct section *sec, unsigned long offset)
return NULL;
}

-struct symbol *find_symbol_by_name(struct elf *elf, const char *name)
+struct symbol *find_symbol_by_name(const struct elf *elf, const char *name)
{
struct symbol *sym;

@@ -228,7 +228,7 @@ struct symbol *find_symbol_by_name(struct elf *elf, const char *name)
return NULL;
}

-struct rela *find_rela_by_dest_range(struct elf *elf, struct section *sec,
+struct rela *find_rela_by_dest_range(const struct elf *elf, struct section *sec,
unsigned long offset, unsigned int len)
{
struct rela *rela, *r = NULL;
@@ -257,7 +257,7 @@ struct rela *find_rela_by_dest_range(struct elf *elf, struct section *sec,
return NULL;
}

-struct rela *find_rela_by_dest(struct elf *elf, struct section *sec, unsigned long offset)
+struct rela *find_rela_by_dest(const struct elf *elf, struct section *sec, unsigned long offset)
{
return find_rela_by_dest_range(elf, sec, offset, 1);
}
@@ -769,7 +769,7 @@ int elf_rebuild_rela_section(struct section *sec)
return 0;
}

-int elf_write(struct elf *elf)
+int elf_write(const struct elf *elf)
{
struct section *sec;
Elf_Scn *s;
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index 2811d04346c9..a55bcde9f1b1 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -114,22 +114,22 @@ static inline u32 rela_hash(struct rela *rela)
}

struct elf *elf_read(const char *name, int flags);
-struct section *find_section_by_name(struct elf *elf, const char *name);
+struct section *elf_create_section(struct elf *elf, const char *name, 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);
+void elf_close(struct elf *elf);
+
+struct section *find_section_by_name(const struct elf *elf, const char *name);
struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
-struct symbol *find_symbol_by_name(struct elf *elf, const char *name);
+struct symbol *find_symbol_by_name(const struct elf *elf, const char *name);
struct symbol *find_symbol_containing(struct section *sec, unsigned long offset);
-struct rela *find_rela_by_dest(struct elf *elf, struct section *sec, unsigned long offset);
-struct rela *find_rela_by_dest_range(struct elf *elf, struct section *sec,
+struct rela *find_rela_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);
+struct rela *find_rela_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);
-struct section *elf_create_section(struct elf *elf, const char *name, size_t
- entsize, int nr);
-struct section *elf_create_rela_section(struct elf *elf, struct section *base);
int elf_rebuild_rela_section(struct section *sec);
-int elf_write(struct elf *elf);
-void elf_close(struct elf *elf);
-void elf_add_rela(struct elf *elf, struct rela *rela);

#define for_each_sec(file, sec) \
list_for_each_entry(sec, &file->elf->sections, list)
--
2.20.1