linux-kernel - [PATCH v3 06/17] signal: make kill_ok_by

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Message-Id: <20180602103653.18181-7-christian@brauner.io>
Date:   Sat,  2 Jun 2018 12:36:42 +0200
From:   Christian Brauner <christian@...uner.io>
To:     linux-kernel@...r.kernel.org
Cc:     ebiederm@...ssion.com, gregkh@...uxfoundation.org,
        mingo@...nel.org, james.morris@...rosoft.com,
        keescook@...omium.org, peterz@...radead.org, sds@...ho.nsa.gov,
        viro@...iv.linux.org.uk, akpm@...ux-foundation.org,
        oleg@...hat.com, Christian Brauner <christian@...uner.io>
Subject: [PATCH v3 06/17] signal: make kill_ok_by_cred() return bool

kill_ok_by_cred() already behaves like a boolean function. Let's actually
declare it as such too.

Signed-off-by: Christian Brauner <christian@...uner.io>
---
v2->v3:
* unchanged
v1->v2:
* unchanged
v0->v1:
* unchanged
---
 kernel/signal.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 21508900805b..dd239a8d7d2c 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -717,21 +717,16 @@ static inline bool si_fromuser(const struct siginfo *info)
 /*
  * called with RCU read lock from check_kill_permission()
  */
-static int kill_ok_by_cred(struct task_struct *t)
+static bool kill_ok_by_cred(struct task_struct *t)
 {
 	const struct cred *cred = current_cred();
 	const struct cred *tcred = __task_cred(t);
 
-	if (uid_eq(cred->euid, tcred->suid) ||
-	    uid_eq(cred->euid, tcred->uid)  ||
-	    uid_eq(cred->uid,  tcred->suid) ||
-	    uid_eq(cred->uid,  tcred->uid))
-		return 1;
-
-	if (ns_capable(tcred->user_ns, CAP_KILL))
-		return 1;
-
-	return 0;
+	return uid_eq(cred->euid, tcred->suid) ||
+	       uid_eq(cred->euid, tcred->uid) ||
+	       uid_eq(cred->uid, tcred->suid) ||
+	       uid_eq(cred->uid, tcred->uid) ||
+	       ns_capable(tcred->user_ns, CAP_KILL);
 }
 
 /*
-- 
2.17.0