From owner-freebsd-hackers@freebsd.org Tue Dec 18 20:10:01 2018 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 71D73133D9B2 for ; Tue, 18 Dec 2018 20:10:01 +0000 (UTC) (envelope-from amshafer64@gmail.com) Received: from mail-qt1-x82a.google.com (mail-qt1-x82a.google.com [IPv6:2607:f8b0:4864:20::82a]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id A34A485968 for ; Tue, 18 Dec 2018 20:10:00 +0000 (UTC) (envelope-from amshafer64@gmail.com) Received: by mail-qt1-x82a.google.com with SMTP id v11so19715569qtc.2 for ; Tue, 18 Dec 2018 12:10:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:in-reply-to:references:date:message-id :mime-version; bh=NfH1rB+5SfjGgc+6/WfvF3h0rF/tNkjFmzZmeerK+SA=; b=iUl+Ynqqp1SthHQrNyqjrrhuA3LmqQYOiJ+pdy064egOwtZonHyIiVu8aYIHIpwUSg 654jU2XbJFNd5f/2jWvthEL6c9xTcQD7HmWnWMLJct/AE4ah7+oOAsCU8aqj0otCcZq6 tkhloqLmQ3MP3cnkilxvs/Laa4UEZoH5UewvaJNjDkcEv3+1/Z0ZYa7+vPoCRF7oQ8DO vbPR4co7Bj7CpHpXOBypWds5/rjUP3i0vM1Fankw1sd4Io5cQEyTQgQkB0BwFLORYrlw 91daOfbcP2kXqIAQGBIWSk8mNketvr+6WS7VJMGur82kNNBjFLl59tBVVZbUMTrN/SZJ Au3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=NfH1rB+5SfjGgc+6/WfvF3h0rF/tNkjFmzZmeerK+SA=; b=DfJ3YeKn6AOWgF1Xz0QkiT4lOltuXykHlVmDmPHvoiq04oSM7lMzZCmWAHZX4ME3za t1IQEaOgRU/uFgEIelatyEJZew/piyq/E9dR1aAxs8sSPtF8ENzO1aoRfT3/6hKDA9cy AunLskvHmS0DITQmIri2X3EQdrIYqDBUK5Q/6wkorTQQrpSueyaSlPqFIgk09L8kywKe rhlcLhgSmcITOFWQF6WWnLNdvvbQ68qv82bO/m7Lw7V9gYyuSqhCwIuejbC1+RfXaOeD tXQXqTa51MVwIZmL2d70liCnG0FyMWlKcwrQgODTEqY2a76VJKs8bfiV1d6nQN2ekRRS HblQ== X-Gm-Message-State: AA+aEWZ9H+thuTD97FMBq+y6/rFOaoUZN3bf+CkxCbdOrXgIT1r7+Tx9 uH93OwIzdVLvPDJc6+xxCO8= X-Google-Smtp-Source: AFSGD/XXSTcUclgL/Xp43vFERFDjcgPdgRWZ1O0rLEc6Wh/BaVspj9jhkXAhkDhL8kds0Qzx0Y+K4Q== X-Received: by 2002:ac8:4141:: with SMTP id e1mr9231670qtm.96.1545163800108; Tue, 18 Dec 2018 12:10:00 -0800 (PST) Received: from localhost ([178.128.156.9]) by smtp.gmail.com with ESMTPSA id 86sm686790qky.92.2018.12.18.12.09.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Dec 2018 12:09:58 -0800 (PST) From: Austin Shafer To: Ryan Stone Cc: freebsd-hackers@freebsd.org Subject: Re: ENOMEM when calling sysctl_handle_int from custom handler In-Reply-To: References: <861s6fpyua.fsf@triplebuff.com> Date: Tue, 18 Dec 2018 15:08:51 -0500 Message-ID: MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Queue-Id: A34A485968 X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=iUl+Ynqq; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of amshafer64@gmail.com designates 2607:f8b0:4864:20::82a as permitted sender) smtp.mailfrom=amshafer64@gmail.com X-Spamd-Result: default: False [-6.06 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36]; RCVD_COUNT_THREE(0.00)[3]; MX_GOOD(-0.01)[cached: alt3.gmail-smtp-in.l.google.com]; DKIM_TRACE(0.00)[gmail.com:+]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_SHORT(-0.99)[-0.995,0]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; FREEMAIL_TO(0.00)[gmail.com]; FROM_EQ_ENVFROM(0.00)[]; IP_SCORE(-2.06)[ip: (-7.11), ipnet: 2607:f8b0::/32(-1.73), asn: 15169(-1.37), country: US(-0.08)]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; DWL_DNSWL_NONE(0.00)[gmail.com.dwl.dnswl.org : 127.0.5.0]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-hackers@freebsd.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[a.2.8.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; RCVD_TLS_LAST(0.00)[] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Dec 2018 20:10:01 -0000 Ryan Stone writes: > You should not pass arg1 and arg2 to sysctl_handle_int(). You instead > need to pass a pointer to a local value containing the value you want > to return to the sysctl caller. After sysctl_handle_int returns, if > it returned 0 and req->newptr is non-NULL, then the integer value will > contain the new value that was passed to you from userland. You want > something that looks like this: > > int > my_sysctl_handler(SYSCTL_HANDLER_ARGS) > { > int val, error; > > val = 5; /* Or whatever value you want to return from userland. */ > > error = sysctl_handle_int(oidp, &val, 0, req); > if (error != 0 || req->newptr == NULL) > return (error); > > /* val contains the value set by the caller, so do something > interesting with it here. */ > > return (0); > } Hmm yup this seems to be problem. I had originally tried to just pass the handler args directly through to sysctl_handle_int to make sure I was creating the nodes correctly, since I knew sysctl_handle_int worked. Thanks again for all the help on these beginner questions! Austin Shafer