From patchwork Wed Dec 20 21:40:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Mikityanskiy X-Patchwork-Id: 13500467 Received: from mail-ej1-f46.google.com (mail-ej1-f46.google.com [209.85.218.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 008C54C3DC; Wed, 20 Dec 2023 21:40:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fG68nxr1" Received: by mail-ej1-f46.google.com with SMTP id a640c23a62f3a-a2356bb40e3so8865466b.1; Wed, 20 Dec 2023 13:40:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1703108435; x=1703713235; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=CD7VeMnjKAxyZj8mbMwt4mJMl93BY6cO6FMg2JTnA74=; b=fG68nxr1hIC/vqCaABoYJ4jQgTg3zdtHrBewyxENw+WXb/F2tmqvcw+UYwqvgmVre9 eKYqw7/BgtMmhWkXiYylvKAq1eVCqMCQiSrwKEcV3dTFjvVkviphUm+tYZ9hCjpIAp0a pY8oe7VG4H/vqNFbYyZSr+246pyFp70wWWdA2VZDxzlkR1dwlMGB3smvrKXpK20eAbz1 ozD0yfnvs3RY7Iz4Vh2swhYK1AjGo2NSX2mYdfLjUjix44lXKmDWVWqtTMNx/Y5SbHKq sX0/ovkZeI3f41vgzIzF20h67VVLR1pJpMlRADXJqlEDr3DQD53MqGcojJ7GpQfNQtie 9r5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1703108435; x=1703713235; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=CD7VeMnjKAxyZj8mbMwt4mJMl93BY6cO6FMg2JTnA74=; b=EzQ507Wv0a8wv0BSZJtMy631J2xTkVNkhO7GCSL1qCRti06I4iYONvUAvQZBxIV1p+ jRNlJCygQQECg/eYPlOt41IL5W6aFfsK7f1TFXO7SedM/i7HOxnzhQtiWCyTgAgrvwIx /z8EIk+OjvZ116AqRfwvAl6t4fBZLRqHyvyTm0q+PCxyTsoNj7+lpybfJkfjhd5F/j/H evqU+laHDaUHjbKJAx2kVIiHlE49H30c02MVlXCYOCsIkZ7EKSbwwTzIhaoax5w4wZDp DubY9a7jyIw6Ma00y3dqRKRZKezYxcQ2bz37pNw7LSpB3qVTPS6O+xdeDGTeMFNJdv9Q Y1+Q== X-Gm-Message-State: AOJu0YwGJx29ujtabsppTlBCq2xN2gJ5XocDv/exQiC5AfdrTXqsPAxc O9z05gSzds0I5Vm+1RPn8Pk= X-Google-Smtp-Source: AGHT+IFOZ5KB1f8BKZKidNyLx56gZSqFtkxELjQ1V4ZwxFmpE05JVQpdm3NS3JKmInS9cV/9gheIqA== X-Received: by 2002:a17:906:5657:b0:a26:88f4:3fae with SMTP id v23-20020a170906565700b00a2688f43faemr1389315ejr.67.1703108435174; Wed, 20 Dec 2023 13:40:35 -0800 (PST) Received: from localhost ([185.220.101.166]) by smtp.gmail.com with ESMTPSA id wl1-20020a170907310100b00a236378a43fsm241250ejb.62.2023.12.20.13.40.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Dec 2023 13:40:34 -0800 (PST) From: Maxim Mikityanskiy To: Eduard Zingerman , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: John Fastabend , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Mykola Lysenko , Shuah Khan , "David S. Miller" , Jakub Kicinski , Jesper Dangaard Brouer , bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, netdev@vger.kernel.org, Maxim Mikityanskiy Subject: [PATCH bpf-next 05/15] selftests/bpf: Add a test case for 32-bit spill tracking Date: Wed, 20 Dec 2023 23:40:03 +0200 Message-ID: <20231220214013.3327288-6-maxtram95@gmail.com> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231220214013.3327288-1-maxtram95@gmail.com> References: <20231220214013.3327288-1-maxtram95@gmail.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Maxim Mikityanskiy When a range check is performed on a register that was 32-bit spilled to the stack, the IDs of the two instances of the register are the same, so the range should also be the same. Signed-off-by: Maxim Mikityanskiy --- .../selftests/bpf/progs/verifier_spill_fill.c | 31 +++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c index 84eccab36582..f2c1fe5b1dba 100644 --- a/tools/testing/selftests/bpf/progs/verifier_spill_fill.c +++ b/tools/testing/selftests/bpf/progs/verifier_spill_fill.c @@ -737,4 +737,35 @@ __naked void stack_load_preserves_const_precision_subreg(void) : __clobber_common); } +SEC("xdp") +__description("32-bit spilled reg range should be tracked") +__success __retval(0) +__naked void spill_32bit_range_track(void) +{ + asm volatile(" \ + call %[bpf_ktime_get_ns]; \ + /* Make r0 bounded. */ \ + r0 &= 65535; \ + /* Assign an ID to r0. */ \ + r1 = r0; \ + /* 32-bit spill r0 to stack. */ \ + *(u32*)(r10 - 8) = r0; \ + /* Boundary check on r0. */ \ + if r0 < 1 goto l0_%=; \ + /* 32-bit fill r1 from stack. */ \ + r1 = *(u32*)(r10 - 8); \ + /* r1 == r0 => r1 >= 1 always. */ \ + if r1 >= 1 goto l0_%=; \ + /* Dead branch: the verifier should prune it. \ + * Do an invalid memory access if the verifier \ + * follows it. \ + */ \ + r0 = *(u64*)(r9 + 0); \ +l0_%=: r0 = 0; \ + exit; \ +" : + : __imm(bpf_ktime_get_ns) + : __clobber_all); +} + char _license[] SEC("license") = "GPL";