Commit-ID: 6631e66ca871357181aedaa9c60fe121641a7135
Gitweb: https://git.kernel.org/tip/6631e66ca871357181aedaa9c60fe121641a7135
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Thu, 28 Feb 2019 14:17:50 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 3 Apr 2019 09:41:08 +0200
objtool: Handle function aliases
Function aliases result in different symbols for the same set of
instructions; track a canonical symbol so there is a unique point of
access.
This again prepares the way for function attributes. And in particular
the need for aliases comes from how KASAN uses them.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
tools/objtool/elf.c | 15 +++++++++++----
tools/objtool/elf.h | 2 +-
2 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index b8f3cca8e58b..dd198d53387d 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -219,7 +219,7 @@ static int read_sections(struct elf *elf)
static int read_symbols(struct elf *elf)
{
struct section *symtab, *sec;
- struct symbol *sym, *pfunc;
+ struct symbol *sym, *pfunc, *alias;
struct list_head *entry, *tmp;
int symbols_nr, i;
char *coldstr;
@@ -239,6 +239,7 @@ static int read_symbols(struct elf *elf)
return -1;
}
memset(sym, 0, sizeof(*sym));
+ alias = sym;
sym->idx = i;
@@ -288,11 +289,17 @@ static int read_symbols(struct elf *elf)
break;
}
- if (sym->offset == s->offset && sym->len >= s->len) {
- entry = tmp;
- break;
+ if (sym->offset == s->offset) {
+ if (sym->len == s->len && alias == sym)
+ alias = s;
+
+ if (sym->len >= s->len) {
+ entry = tmp;
+ break;
+ }
}
}
+ sym->alias = alias;
list_add(&sym->list, entry);
hash_add(sym->sec->symbol_hash, &sym->hash, sym->idx);
}
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index bc97ed86b9cd..968265b4b4cd 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -61,7 +61,7 @@ struct symbol {
unsigned char bind, type;
unsigned long offset;
unsigned int len;
- struct symbol *pfunc, *cfunc;
+ struct symbol *pfunc, *cfunc, *alias;
};
struct rela {
|