[tip:core/urgent] objtool: Change dead_end_function() to return boolean

From: tip-bot for Josh Poimboeuf
Date: Thu Jul 18 2019 - 15:18:02 EST


Commit-ID: 8e25c9f8b482ea8d8b6fb4f6f5c09bcc5ee18663
Gitweb: https://git.kernel.org/tip/8e25c9f8b482ea8d8b6fb4f6f5c09bcc5ee18663
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Wed, 17 Jul 2019 20:36:50 -0500
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Thu, 18 Jul 2019 21:01:08 +0200

objtool: Change dead_end_function() to return boolean

dead_end_function() can no longer return an error. Simplify its
interface by making it return boolean.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/9e6679610768fb6e6c51dca23f7d4d0c03b0c910.1563413318.git.jpoimboe@xxxxxxxxxx

---
tools/objtool/check.c | 36 ++++++++++++++----------------------
1 file changed, 14 insertions(+), 22 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index dece3253ff6a..d9d1c9b54947 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -105,14 +105,9 @@ static struct instruction *next_insn_same_func(struct objtool_file *file,
*
* For local functions, we have to detect them manually by simply looking for
* the lack of a return instruction.
- *
- * Returns:
- * -1: error
- * 0: no dead end
- * 1: dead end
*/
-static int __dead_end_function(struct objtool_file *file, struct symbol *func,
- int recursion)
+static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
+ int recursion)
{
int i;
struct instruction *insn;
@@ -139,29 +134,29 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
};

if (func->bind == STB_WEAK)
- return 0;
+ return false;

if (func->bind == STB_GLOBAL)
for (i = 0; i < ARRAY_SIZE(global_noreturns); i++)
if (!strcmp(func->name, global_noreturns[i]))
- return 1;
+ return true;

if (!func->len)
- return 0;
+ return false;

insn = find_insn(file, func->sec, func->offset);
if (!insn->func)
- return 0;
+ return false;

func_for_each_insn_all(file, func, insn) {
empty = false;

if (insn->type == INSN_RETURN)
- return 0;
+ return false;
}

if (empty)
- return 0;
+ return false;

/*
* A function can have a sibling call instead of a return. In that
@@ -174,7 +169,7 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,

if (!dest)
/* sibling call to another file */
- return 0;
+ return false;

if (dest->func && dest->func->pfunc != insn->func->pfunc) {

@@ -186,7 +181,7 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
* This is a very rare case. It means
* they aren't dead ends.
*/
- return 0;
+ return false;
}

return __dead_end_function(file, dest->func,
@@ -196,13 +191,13 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,

if (insn->type == INSN_JUMP_DYNAMIC && list_empty(&insn->alts))
/* sibling call */
- return 0;
+ return false;
}

- return 1;
+ return true;
}

-static int dead_end_function(struct objtool_file *file, struct symbol *func)
+static bool dead_end_function(struct objtool_file *file, struct symbol *func)
{
return __dead_end_function(file, func, 0);
}
@@ -2080,11 +2075,8 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
if (is_fentry_call(insn))
break;

- ret = dead_end_function(file, insn->call_dest);
- if (ret == 1)
+ if (dead_end_function(file, insn->call_dest))
return 0;
- if (ret == -1)
- return 1;
}

if (!no_fp && func && !has_valid_stack_frame(&state)) {