From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f54.google.com (mail-ej1-f54.google.com [209.85.218.54]) (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 04907286A2 for ; Wed, 14 Aug 2024 05:00:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723611625; cv=none; b=qFfo7K1KINn0FrDpq3S8e89T3ShXLWm4hujmxjHwNEKtU4f2r7YB8ZhQ40svuuAnixlMbPHaGflxBAvyiHYCHtF86uaGA9zFlDBvy3clTB08hpfohCBBV4HPmM80JyE4P0EG8iV+nLbSIvXfR3CKnnAcMoj4dgxAnlzlAFOGJSw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723611625; c=relaxed/simple; bh=9BNXSKP/aqgDEv5pgWnt0nOgPlpcmupJ3ccD2GqVxF0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GadU5JJ3jWxXDgbbLZhV/V6MjyI3aRnu2025gUn+1EPxEBUf2l28x67bR+9pQQ2U4FK+1c9D2taxfQ3HkxAMBJMnbWlr4+m0xNZyMcXLG/++e7LlfXib4K6ScXixsGKzJIbL8960LB7cbcq+20gASVZ8EvkI+LnYesimOvOXxOg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.218.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-ej1-f54.google.com with SMTP id a640c23a62f3a-a7aac70e30dso689181566b.1 for ; Tue, 13 Aug 2024 22:00:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723611622; x=1724216422; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=tYUCmWL8Hkl6zsFmwTAECInMtiFeosdeg5txclz9CL0=; b=Q8QoWaAQjBcS2TURj4W7pyawwPjux1N0vv4wPB+DF34Mq22vCDN0BKoLavzvFH9iVj fsdueT9UfIYlfC7Xc4Pxt8QjADuaL3dHt6hkm5ddvYaom2P693ntlJwRsn5mgxEjQJE1 5bVWxfUwerCIDaBy0VdXGhSQjVSlhdpYZdLy3quAtu621opAYtsSNm8bIBEBSj2tHqpO Iui5lVQAN4gO4/lrs2EWdCFlpzgVi0S5O4kTppXn8cuTsRD5ciGEkZRTdfVLKYGeov0I fM0xop8VBwD7Kyfj5x/+vPZiXFT3O7CknlhO+3255WHeAu3l587JTnlypOwLy3BjSR0V M2FA== X-Forwarded-Encrypted: i=1; AJvYcCWE50NBmbIitpZcfsV/tPkGYZX2eJMiZitlbDRh8JRxjTTBT3O+xMRMVYWYQhx0gP3gdiuxJvY=@vger.kernel.org X-Gm-Message-State: AOJu0YxO6/hvptCHZ9hdx9UzmQXTGaDV/FHmvcl/5VCY+H5S+lydG5yi 5vozqU2gtVp6k2EkAzMXhk1QpA8HLOkGyR2BWMPunYgHdVnePlMz X-Google-Smtp-Source: AGHT+IHOmtZ8AR/RyZGoiRm3RpnFl+CmXo1XwXVZToUyAUzLRXhHwpeDwfjZWPvTdcIHxNERtleHeQ== X-Received: by 2002:a17:907:f76a:b0:a80:7ce0:8b2a with SMTP id a640c23a62f3a-a8366d37f3emr100601666b.19.1723611621654; Tue, 13 Aug 2024 22:00:21 -0700 (PDT) Received: from ?IPV6:2a0b:e7c0:0:107::aaaa:69? ([2a0b:e7c0:0:107::aaaa:69]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a80f411bdf0sm127624766b.114.2024.08.13.22.00.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 13 Aug 2024 22:00:20 -0700 (PDT) Message-ID: Date: Wed, 14 Aug 2024 07:00:19 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net v2 1/2] ptp: ocp: adjust sysfs entries to expose tty information To: Vadim Fedorenko , Greg Kroah-Hartman , Vadim Fedorenko Cc: Jakub Kicinski , Jonathan Lemon , netdev@vger.kernel.org References: <20240805220500.1808797-1-vadfed@meta.com> <2024081350-tingly-coming-a74d@gregkh> Content-Language: en-US From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; keydata= xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSFKaXJpIFNsYWJ5 IDxqaXJpc2xhYnlAa2VybmVsLm9yZz7CwXcEEwEIACEFAlW3RUwCGwMFCwkIBwIGFQgJCgsC BBYCAwECHgECF4AACgkQvSWxBAa0cEnVTg//TQpdIAr8Tn0VAeUjdVIH9XCFw+cPSU+zMSCH eCZoA/N6gitEcnvHoFVVM7b3hK2HgoFUNbmYC0RdcSc80pOF5gCnACSP9XWHGWzeKCARRcQR 4s5YD8I4VV5hqXcKo2DFAtIOVbHDW+0okOzcecdasCakUTr7s2fXz97uuoc2gIBB7bmHUGAH XQXHvdnCLjDjR+eJN+zrtbqZKYSfj89s/ZHn5Slug6w8qOPT1sVNGG+eWPlc5s7XYhT9z66E l5C0rG35JE4PhC+tl7BaE5IwjJlBMHf/cMJxNHAYoQ1hWQCKOfMDQ6bsEr++kGUCbHkrEFwD UVA72iLnnnlZCMevwE4hc0zVhseWhPc/KMYObU1sDGqaCesRLkE3tiE7X2cikmj/qH0CoMWe gjnwnQ2qVJcaPSzJ4QITvchEQ+tbuVAyvn9H+9MkdT7b7b2OaqYsUP8rn/2k1Td5zknUz7iF oJ0Z9wPTl6tDfF8phaMIPISYrhceVOIoL+rWfaikhBulZTIT5ihieY9nQOw6vhOfWkYvv0Dl o4GRnb2ybPQpfEs7WtetOsUgiUbfljTgILFw3CsPW8JESOGQc0Pv8ieznIighqPPFz9g+zSu Ss/rpcsqag5n9rQp/H3WW5zKUpeYcKGaPDp/vSUovMcjp8USIhzBBrmI7UWAtuedG9prjqfO wU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02XFTI t4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P+nJW YIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYVnZAK DiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNeLuS8 f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+BavGQ 8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUFBqgk 3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpotgK4 /57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPDGHo7 39Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBKHQxz 1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkFAk6S 54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH/1ld wRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+Kzdr 90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj9YLx jhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbcezWI wZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+dyTKL wLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330mkR4g W6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/tJ98 f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCujlYQ DFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmffaK/ S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 13. 08. 24, 20:24, Vadim Fedorenko wrote: > On 13/08/2024 10:33, Greg Kroah-Hartman wrote: >> On Mon, Aug 05, 2024 at 03:04:59PM -0700, Vadim Fedorenko wrote: >>> Starting v6.8 the serial port subsystem changed the hierarchy of devices >>> and symlinks are not working anymore. Previous discussion made it clear >>> that the idea of symlinks for tty devices was wrong by design. Implement >>> additional attributes to expose the information. Fixes tag points to the >>> commit which introduced the change. >>> >>> Fixes: b286f4e87e32 ("serial: core: Move tty and serdev to be >>> children of serial core port device") >>> Signed-off-by: Vadim Fedorenko >>> --- >>>   drivers/ptp/ptp_ocp.c | 68 +++++++++++++++++++++++++++++++++---------- >>>   1 file changed, 52 insertions(+), 16 deletions(-) >>> >>> diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c >>> index ee2ced88ab34..7a5026656452 100644 >>> --- a/drivers/ptp/ptp_ocp.c >>> +++ b/drivers/ptp/ptp_ocp.c >>> @@ -3346,6 +3346,55 @@ static EXT_ATTR_RO(freq, frequency, 1); >>>   static EXT_ATTR_RO(freq, frequency, 2); >>>   static EXT_ATTR_RO(freq, frequency, 3); >>> +static ssize_t >>> +ptp_ocp_tty_show(struct device *dev, struct device_attribute *attr, >>> char *buf) >>> +{ >>> +    struct dev_ext_attribute *ea = to_ext_attr(attr); >>> +    struct ptp_ocp *bp = dev_get_drvdata(dev); >>> +    struct ptp_ocp_serial_port *port; >>> + >>> +    port = (void *)((uintptr_t)bp + (uintptr_t)ea->var); >> >> That's insane pointer math, how do we know this is correct? >> >>> +    return sysfs_emit(buf, "ttyS%d", port->line); >>> +} >>> + >>> +static umode_t >>> +ptp_ocp_timecard_tty_is_visible(struct kobject *kobj, struct >>> attribute *attr, int n) >>> +{ >>> +    struct ptp_ocp *bp = dev_get_drvdata(kobj_to_dev(kobj)); >>> +    struct ptp_ocp_serial_port *port; >>> +    struct device_attribute *dattr; >>> +    struct dev_ext_attribute *ea; >>> + >>> +    if (strncmp(attr->name, "tty", 3)) >>> +        return attr->mode; >>> + >>> +    dattr = container_of(attr, struct device_attribute, attr); >>> +    ea = container_of(dattr, struct dev_ext_attribute, attr); >>> +    port = (void *)((uintptr_t)bp + (uintptr_t)ea->var); >> >> That's crazy pointer math, how are you ensured that it is correct?  Why >> isn't there a container_of() thing here instead? > > Well, container_of cannot be used here because the attributes are static > while the function reads dynamic instance. The only values that are > populated into the attributes of the group are offsets. > But I can convert it to a helper which will check that the offset > provided is the real offset of the structure we expect. And it could be > reused in both "is_visible" and "show" functions. Strong NACK against this approach. What about converting those 4 ports into an array and adding an enum { PORT_GNSS, POTR_GNSS2, PORT_MAC, PORT_NMEA }? thanks, -- js suse labs