lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Sat, 12 Sep 2020 10:05:02 +0900 From: Sergey Senozhatsky <sergey.senozhatsky@...il.com> To: Wolfram Sang <wsa@...nel.org>, Jean Delvare <jdelvare@...e.de> Cc: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, Mika Westerberg <mika.westerberg@...ux.intel.com>, linux-i2c@...r.kernel.org, linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org, Sergey Senozhatsky <sergey.senozhatsky@...il.com> Subject: Re: [PATCH] i2c: do not acpi/of match device in i2c_device_probe() On (20/08/26 23:49), Sergey Senozhatsky wrote: > i2c, apparently, can match the same device twice - the first > time in ->match bus hook (i2c_device_match()), and the second > one in ->probe (i2c_device_probe()) bus hook. > > To make things more complicated, the second matching does not > do exactly same checks as the first one. Namely, i2c_device_match() > calls acpi_driver_match_device() which considers devices that > provide of_match_table and performs of_compatible() matching for > such devices. One important thing to note here is that ACPI > of_compatible() matching (acpi_of_match_device()) is part of ACPI > and does not depend on CONFIG_OF. > > i2c_device_probe(), on the other hand, calls acpi_match_device() > which does not perform of_compatible() matching, but instead > i2c_device_probe() relies on CONFIG_OF API to perform of_match_table > matching, IOW ->probe matching, unlike ->match matching, depends on > CONFIG_OF. This can break i2c device probing on !CONFIG_OF systems > if the device does not provide .id_table. > > i2c_device_probe() > ... > if (!driver->id_table && > !i2c_acpi_match_device(dev->driver->acpi_match_table, client) && > !i2c_of_match_device(dev->driver->of_match_table, client)) { > status = -ENODEV; > goto put_sync_adapter; > } > > i2c_of_match_device() on !CONFIG_OF systems is always false, so we never > perform of_match_table matching. i2c_acpi_match_device() does ACPI match > only, no of_compatible() matching takes place, even though the device > provides .of_match_table and ACPI is capable of matching such device. > > It is not entirely clear why the device is matched again in bus > ->probe after successful and proper matching in bus ->match. Let's > remove ->probe matching. Hi, Gentle ping. -ss
Powered by blists - more mailing lists