From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by passt.top (Postfix, from userid 1000) id 4377F5A026A; Sat, 25 Feb 2023 14:49:44 +0100 (CET) From: Stefano Brivio To: passt-dev@passt.top Subject: [PATCH] tcp: Suppress knownConditionTrueFalse cppcheck false positive Date: Sat, 25 Feb 2023 14:49:44 +0100 Message-Id: <20230225134944.4160065-1-sbrivio@redhat.com> X-Mailer: git-send-email 2.39.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: WGG64DQQ4FO5OZGK4F46FD7I2VSNZQRA X-Message-ID-Hash: WGG64DQQ4FO5OZGK4F46FD7I2VSNZQRA X-MailFrom: sbrivio@passt.top X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: cppcheck 2.10 reports: tcp.c:1815:12: style: Condition 'wnd>prev_scaled' is always false [knownConditionTrueFalse] if ((wnd > prev_scaled && wnd * 99 / 100 < prev_scaled) || ^ tcp.c:1808:8: note: Assignment 'wnd=((1<<(16+8))<(wnd))?(1<<(16+8)):(wnd)', assigned value is less than 1 wnd = MIN(MAX_WINDOW, wnd); ^ tcp.c:1811:19: note: Assuming condition is false if (prev_scaled == wnd) ^ tcp.c:1815:12: note: Condition 'wnd>prev_scaled' is always false if ((wnd > prev_scaled && wnd * 99 / 100 < prev_scaled) || ^ but this is not actually the case: wnd is typically greater than 1, and might very well be greater than prev_scaled as well. I bisected this down to cppcheck commit b4d455df487c ("Fix 11349: FP negativeIndex for clamped array index (#4627)") and reported findings at https://github.com/danmar/cppcheck/pull/4627. Suppress the warning for the moment being. Signed-off-by: Stefano Brivio --- tcp.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/tcp.c b/tcp.c index 803c2c4..21c319d 100644 --- a/tcp.c +++ b/tcp.c @@ -1812,6 +1812,15 @@ static void tcp_clamp_window(const struct ctx *c, struct tcp_tap_conn *conn, return; /* Discard +/- 1% updates to spare some syscalls. */ + /* TODO: cppcheck, starting from commit b4d455df487c ("Fix + * 11349: FP negativeIndex for clamped array index (#4627)"), + * reports wnd > prev_scaled as always being true, see also: + * + * https://github.com/danmar/cppcheck/pull/4627 + * + * drop this suppression once that's resolved. + */ + /* cppcheck-suppress knownConditionTrueFalse */ if ((wnd > prev_scaled && wnd * 99 / 100 < prev_scaled) || (wnd < prev_scaled && wnd * 101 / 100 > prev_scaled)) return; -- 2.39.1