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From:   Kangmin Park <l4stpr0gr4m@gmail.com>
To:     "Eric W. Biederman" <ebiederm@xmission.com>
Cc:     Kees Cook <keescook@chromium.org>, Oleg Nesterov <oleg@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH] signal: Remove duplicate code in do_tkill
Date:   Tue,  2 Aug 2022 00:06:47 +0900
Message-Id: <20220801150647.70207-1-l4stpr0gr4m@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

do_tkill() prepares kernel_siginfo with the same logic as the
prepare_kill_siginfo() except to set si_code.

So, add si_code parameter to the prepare_kill_siginfo(), and call
the function in do_tkill() to remove the duplicate code.

Signed-off-by: Kangmin Park <l4stpr0gr4m@gmail.com>
---
 kernel/signal.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 6f86fda5e432..a71f4d69dd54 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3752,12 +3752,12 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time32, compat_sigset_t __user *, uthese,
 #endif
 #endif
 
-static inline void prepare_kill_siginfo(int sig, struct kernel_siginfo *info)
+static inline void prepare_kill_siginfo(int sig, int si_code, struct kernel_siginfo *info)
 {
 	clear_siginfo(info);
 	info->si_signo = sig;
 	info->si_errno = 0;
-	info->si_code = SI_USER;
+	info->si_code = si_code;
 	info->si_pid = task_tgid_vnr(current);
 	info->si_uid = from_kuid_munged(current_user_ns(), current_uid());
 }
@@ -3771,7 +3771,7 @@ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig)
 {
 	struct kernel_siginfo info;
 
-	prepare_kill_siginfo(sig, &info);
+	prepare_kill_siginfo(sig, SI_USER, &info);
 
 	return kill_something_info(sig, &info, pid);
 }
@@ -3884,7 +3884,7 @@ SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig,
 		    (kinfo.si_code >= 0 || kinfo.si_code == SI_TKILL))
 			goto err;
 	} else {
-		prepare_kill_siginfo(sig, &kinfo);
+		prepare_kill_siginfo(sig, SI_USER, &kinfo);
 	}
 
 	ret = kill_pid_info(sig, &kinfo, pid);
@@ -3928,12 +3928,7 @@ static int do_tkill(pid_t tgid, pid_t pid, int sig)
 {
 	struct kernel_siginfo info;
 
-	clear_siginfo(&info);
-	info.si_signo = sig;
-	info.si_errno = 0;
-	info.si_code = SI_TKILL;
-	info.si_pid = task_tgid_vnr(current);
-	info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
+	prepare_kill_siginfo(sig, SI_TKILL, &info);
 
 	return do_send_specific(tgid, pid, sig, &info);
 }
-- 
2.26.3