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McKenney" , Peter Zijlstra , Randy Dunlap , Rasmus Villemoes , Sebastian Andrzej Siewior , Song Liu , Steven Rostedt , Tejun Heo , Thomas Gleixner , Valentin Schneider , Vincent Guittot , Vlastimil Babka , Yonghong Song , Yury Norov , linux-mm@kvack.org, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH 02/16] lib/bitmap: don't call bitmap_set() with len == 0 Date: Mon, 18 Jul 2022 12:28:30 -0700 Message-Id: <20220718192844.1805158-3-yury.norov@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220718192844.1805158-1-yury.norov@gmail.com> References: <20220718192844.1805158-1-yury.norov@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1658172530; a=rsa-sha256; cv=none; b=K/nw91sc3pQ16PQ4O1DY+zVtzYISClkxTEqV3GUJPdW/WHadMGzJsEYDrC5V9rW8355ThG ltUdPPCxkx/YcVArBO2wqqMtj3R2+W4Mv/4WqoQJoQegmmmcjYtY0Ph+diipKErT3LuYax P2xV43Gx1Ndec6tnkzwOBAfbs51MA8k= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=K+OO8GlS; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf25.hostedemail.com: domain of yury.norov@gmail.com designates 209.85.222.181 as permitted sender) smtp.mailfrom=yury.norov@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1658172530; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=mds6TiJm2i/ciGRewHyQeRgrE3/eBxBJskgGjRCv8jE=; b=FuW8YN1w/5XXtUvx79TvFHVZByAl2B0CxFwLQ97WVdFLb0Vat0kRdxBoXbEFuDWu78u7m7 At9K0d1Q9jN4uWNMtFPfNOJfaaO43r0+Fmka2EsG1Ov40x2GJcNFpDrbUX9o4mrw6xjNPZ xW4yBUCW43xqV2ED3bnzoWPk2kmoeL0= X-Rspamd-Queue-Id: 040DFA009A X-Rspam-User: Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=K+OO8GlS; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf25.hostedemail.com: domain of yury.norov@gmail.com designates 209.85.222.181 as permitted sender) smtp.mailfrom=yury.norov@gmail.com X-Rspamd-Server: rspam08 X-Stat-Signature: wigmximomq5mp8k6e714bkeciyduzgbj X-HE-Tag: 1658172529-848987 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: bitmap_parselist() format allows passing 0-length regions, but because len == 0 is not covered by small_const_nbits() macro, we have to call __bitmap_set() and do some prologue calculations just for nothing. Signed-off-by: Yury Norov --- lib/bitmap.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index cd4dd848ea6a..790df2ea02df 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -712,10 +712,13 @@ struct region { static void bitmap_set_region(const struct region *r, unsigned long *bitmap) { - unsigned int start; + unsigned int start, len; - for (start = r->start; start <= r->end; start += r->group_len) - bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); + for (start = r->start; start <= r->end; start += r->group_len) { + len = min(r->end - start + 1, r->off); + if (len > 0) + bitmap_set(bitmap, start, len); + } } static int bitmap_check_region(const struct region *r) -- 2.34.1