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[45.78.64.189]) by smtp.gmail.com with ESMTPSA id 956f58d0204a3-66d247487c6sm382013d50.15.2026.08.25.11.53.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Aug 2026 11:53:20 -0700 (PDT) From: Chengfeng Ye To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Chengfeng Ye Subject: [PATCH net-next] net: pktgen: return bool from __pktgen_NN_threads() Date: Wed, 26 Aug 2026 02:53:13 +0800 Message-ID: <20260825185313.239861-1-nicoyip.dev@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260824152331.216494-1-nicoyip.dev@gmail.com> References: <20260824152331.216494-1-nicoyip.dev@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Callers of __pktgen_NN_threads() only check whether a pktgen_dev was found. After the RCU lookup they never dereference the returned pointer, so returning it past rcu_read_unlock() is confusing. Return bool instead and keep the pktgen_dev pointer local to the RCU critical section. Suggested-by: Paolo Abeni Signed-off-by: Chengfeng Ye --- This is a net-next follow-up to https://lore.kernel.org/netdev/20260824152331.216494-1-nicoyip.dev@gmail.com/ net/core/pktgen.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 4fb1853589b3..9985b30c5a42 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -2024,11 +2024,11 @@ static const struct proc_ops pktgen_thread_proc_ops = { }; /* Think find or remove for NN */ -static struct pktgen_dev *__pktgen_NN_threads(const struct pktgen_net *pn, - const char *ifname, int remove) +static bool __pktgen_NN_threads(const struct pktgen_net *pn, + const char *ifname, int remove) { struct pktgen_thread *t; - struct pktgen_dev *pkt_dev = NULL; + struct pktgen_dev *pkt_dev; bool exact = (remove == FIND); list_for_each_entry(t, &pn->pktgen_threads, th_list) { @@ -2042,9 +2042,9 @@ static struct pktgen_dev *__pktgen_NN_threads(const struct pktgen_net *pn, } rcu_read_unlock(); if (pkt_dev) - break; + return true; } - return pkt_dev; + return false; } /* @@ -2052,7 +2052,6 @@ static struct pktgen_dev *__pktgen_NN_threads(const struct pktgen_net *pn, */ static void pktgen_mark_device(const struct pktgen_net *pn, const char *ifname) { - struct pktgen_dev *pkt_dev = NULL; const int max_tries = 10, msec_per_try = 125; int i = 0; @@ -2061,8 +2060,7 @@ static void pktgen_mark_device(const struct pktgen_net *pn, const char *ifname) while (1) { - pkt_dev = __pktgen_NN_threads(pn, ifname, REMOVE); - if (pkt_dev == NULL) + if (!__pktgen_NN_threads(pn, ifname, REMOVE)) break; /* success */ mutex_unlock(&pktgen_thread_lock); @@ -3836,8 +3834,7 @@ static int pktgen_add_device(struct pktgen_thread *t, const char *ifname) /* We don't allow a device to be on several threads */ - pkt_dev = __pktgen_NN_threads(t->net, ifname, FIND); - if (pkt_dev) { + if (__pktgen_NN_threads(t->net, ifname, FIND)) { pr_err("ERROR: interface already used\n"); return -EBUSY; } -- 2.43.0