From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.11 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794489023; b=n2kI+63KTnYbbABv//uWSlNEGyvGGguioWIHIXCGS6Wk2QcfmZ4f2SgKDQKpReyMxH7k yFH/Zxd7Mul0IYlb9NG3Dm+1laOR66myjkm4U5cSaPrAAltvO52h9yyqUuuZE55QWmPh6 uN6iu+JyT3ulAoTuQyYSW5zTWYpJlKXlkd1yhIddTl0dvJHt/P9cjCVLlC83pu5II2UwQ FhdsWWu0G9Gd64C6Hb9GQG8sb9DxdQhlIesgVxJb2AsUSDK71Qaqw4bXo9et9dQ0U5y9h sGGl2l7FgqRuusHwFAz4d6zAveLodVr7QIFB13fEuHanBr+AFmwgK9uHeStaft4BkIg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794489023; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=/ScJysAfHU/3UcDNAAYnWlZ68uEE/9WuK+T2tCuHaVA=; b=Uwiopv2DYjmmSbE6o0dow/NpPRC/fccVyimtaFw8ZJOnEr7QNKKD66myn7E8OYAV7pLJ nDJcygUKTOEIa2UBCfP37bxWy0DPxmfHmA4jYNPIXWzbGWllv7RXl6U5FQ2D4E8R197fX Mu4azlA+eGSilcJ2GWKYyNwFzV915KaKhpwfSUhMNHCOEnN21bhMLwwaWW+skUsDVZiZK dnchwqMig6yBQCrA7w01IpNttU3b1AlfkuMexpOqzsQ5PkFyRUbLdrd4LWxh96nKMyjqb wU60i3q9+8+/Yp6lwW3nteniFef+8Zz4Kt5rxnlBPdRLaxwIIvgs1+nX3rYbbOnA/SQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=sSC54di3; arc=none smtp.remote-ip=95.215.58.11 Received: from mta1.migadu.com (out-11.mta1.migadu.com [95.215.58.11]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A3B8606A33E for ; Thu, 12 Nov 2026 13:10:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 8A3B8606A33E Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=sSC54di3 X-Envelope-To: bpf@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=Khvjz3OMMUyRYmhS0+smYP9TQ+oix+8/Op5iUO6ggxk=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794489020; v=1; x=1795093820; b=sSC54di3GgxMKWcYF2sSz/O0xlW8ZapetPfB185w55XaPUrxYTxmnsq1q7z2OKmPXlczUrBp N+e7mA+F8zvvZSV6U7M+EjV5GgZqBIypCf7FmRr77XgHWYqopk6nFS7hiW3QBfDWDximHNd2ovj 4QNEu8eHP1y3frIV8evzTZmI= X-Envelope-To: bpf@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 6a1e810a2867f43e; Thu, 12 Nov 2026 13:10:19 +0000 X-Mizu-Trace-ID: 6a1e810a2867f43e X-Migadu-Flow: FLOW_OUT From: Tao Cui To: tj@kernel.org Cc: void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, liwanwu@kylinos.cn, usama.arif@linux.dev, sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, cui.tao@linux.dev, Tao Cui Subject: [PATCH 2/6] sched_ext: Make scx_bpf_cid_node() a benign lookup for invalid cids Date: Thu, 12 Nov 2026 21:09:30 +0800 Message-ID: <20261112130934.563321-3-cui.tao@linux.dev> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261112130934.563321-1-cui.tao@linux.dev> References: <20261112130934.563321-1-cui.tao@linux.dev> X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Tao Cui scx_bpf_cid_node() is documented to return NUMA_NO_NODE when @cid is invalid or there is no scheduler. Its implementation goes through scx_cid_to_cpu(), whose cid_valid() calls scx_error() on an invalid value, so an invalid @cid does end at NUMA_NO_NODE, but only after flagging the whole scheduler for exit. Bounds-check @cid in the kfunc instead, keeping the documented benign return and leaving the aborting validation to the paths whose contracts call for it. Fixes: 5cadf7545cc6 ("sched_ext: Add a CID NUMA node lookup kfunc") Signed-off-by: Tao Cui --- kernel/sched/ext/cid.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/kernel/sched/ext/cid.c b/kernel/sched/ext/cid.c index 8e04a8494e11..b09b2c73ccec 100644 --- a/kernel/sched/ext/cid.c +++ b/kernel/sched/ext/cid.c @@ -690,6 +690,16 @@ __bpf_kfunc s32 scx_bpf_cid_node(s32 cid, const struct bpf_prog_aux *aux) sch = scx_prog_sched(aux); if (unlikely(!sch)) return NUMA_NO_NODE; + + /* + * Bounds-check @cid here rather than letting scx_cid_to_cpu() do it: + * its cid_valid() aborts the scheduler on an invalid value, while + * this kfunc is documented as a benign lookup that returns + * NUMA_NO_NODE. + */ + if (cid < 0 || cid >= num_possible_cpus()) + return NUMA_NO_NODE; + cpu = scx_cid_to_cpu(sch, cid); return cpu < 0 ? NUMA_NO_NODE : cpu_to_node(cpu); } -- 2.53.0 base-commit: 5b740a72b55c4267ba4d8010f17dde26b26f52d3