From: Christian Brauner <christian@xxxxxxxxxx> Subject: 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. Link: http://lkml.kernel.org/r/20180602103653.18181-7-christian@xxxxxxxxxx Signed-off-by: Christian Brauner <christian@xxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: James Morris <james.morris@xxxxxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Stephen Smalley <sds@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/signal.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) --- a/kernel/signal.c~signal-make-kill_ok_by_cred-return-bool +++ a/kernel/signal.c @@ -717,21 +717,16 @@ static inline bool si_fromuser(const str /* * 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); } /* _
