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path: root/arch/powerpc/platforms/powernv/opal-dump.c
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2022-03-08powerpc: declare unmodified attribute_group usages constRohan McLure
Inspired by (bd75b4ef4977: Constify static attribute_group structs), accepted by linux-next, reported: https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20220210202805.7750-4-rikard.falkeborn@gmail.com/ Nearly all singletons of type struct attribute_group are never modified, and so are candidates for being const. Declare them as const. Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220307231414.86560-1-rmclure@linux.ibm.com
2022-01-05powerpc/opal: use default_groups in kobj_typeGreg Kroah-Hartman
There are currently 2 ways to create a set of sysfs files for a kobj_type, through the default_attrs field, and the default_groups field. Move the powerpc opal dump and elog sysfs code to use default_groups field which has been the preferred way since aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") so that we can soon get rid of the obsolete default_attrs field. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220104161318.1306023-1-gregkh@linuxfoundation.org
2021-10-09powerpc/powernv/dump: Fix typo in commentVasant Hegde
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210914143802.54325-1-hegdevasant@linux.vnet.ibm.com
2020-10-19powerpc/powernv/dump: Handle multiple writes to ack attributeVasant Hegde
Even though we use self removing sysfs helper, we still need to make sure we do the final kobject delete conditionally. sysfs_remove_file_self() will handle parallel calls to remove the sysfs attribute file and returns true only in the caller that removed the attribute file. The other parallel callers are returned false. Do the final kobject delete checking the return value of sysfs_remove_file_self(). Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201017164236.264713-1-hegdevasant@linux.vnet.ibm.com
2020-10-19powerpc/powernv/dump: Fix race while processing OPAL dumpVasant Hegde
Every dump reported by OPAL is exported to userspace through a sysfs interface and notified using kobject_uevent(). The userspace daemon (opal_errd) then reads the dump and acknowledges that the dump is saved safely to disk. Once acknowledged the kernel removes the respective sysfs file entry causing respective resources to be released including kobject. However it's possible the userspace daemon may already be scanning dump entries when a new sysfs dump entry is created by the kernel. User daemon may read this new entry and ack it even before kernel can notify userspace about it through kobject_uevent() call. If that happens then we have a potential race between dump_ack_store->kobject_put() and kobject_uevent which can lead to use-after-free of a kernfs object resulting in a kernel crash. This patch fixes this race by protecting the sysfs file creation/notification by holding a reference count on kobject until we safely send kobject_uevent(). The function create_dump_obj() returns the dump object which if used by caller function will end up in use-after-free problem again. However, the return value of create_dump_obj() function isn't being used today and there is no need as well. Hence change it to return void to make this fix complete. Fixes: c7e64b9ce04a ("powerpc/powernv Platform dump interface") Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201017164210.264619-1-hegdevasant@linux.vnet.ibm.com
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-24powerpc/powernv/opal-dump : Use IRQ_HANDLED instead of numbers in interrupt ↵Mukesh Ojha
handler Fixes: 8034f715f ("powernv/opal-dump: Convert to irq domain") Converts all the return explicit number to a more proper IRQ_HANDLED, which looks proper incase of interrupt handler returning case. Here, It also removes error message like "nobody cared" which was getting unveiled while returning -1 or 0 from handler. Signed-off-by: Mukesh Ojha <mukesh02@linux.vnet.ibm.com> Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-24powerpc/powernv/opal-dump : Handles opal_dump_info properlyMukesh Ojha
Moves the return value check of 'opal_dump_info' to a proper place which was previously unnecessarily filling all the dump info even on failure. Signed-off-by: Mukesh Ojha <mukesh02@linux.vnet.ibm.com> Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com> Acked-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-22powerpc: Use octal numbers for file permissionsRussell Currey
Symbolic macros are unintuitive and hard to read, whereas octal constants are much easier to interpret. Replace macros for the basic permission flags (user/group/other read/write/execute) with numeric constants instead, across the whole powerpc tree. Introducing a significant number of changes across the tree for no runtime benefit isn't exactly desirable, but so long as these macros are still used in the tree people will keep sending patches that add them. Not only are they hard to parse at a glance, there are multiple ways of coming to the same value (as you can see with 0444 and 0644 in this patch) which hurts readability. Signed-off-by: Russell Currey <ruscur@russell.cc> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-29powerpc/powernv : Drop reference added by kset_find_obj()Mukesh Ojha
In a situation, where Linux kernel gets notified about duplicate error log from OPAL, it is been observed that kernel fails to remove sysfs entries (/sys/firmware/opal/elog/0xXXXXXXXX) of such error logs. This is because, we currently search the error log/dump kobject in the kset list via 'kset_find_obj()' routine. Which eventually increment the reference count by one, once it founds the kobject. So, unless we decrement the reference count by one after it found the kobject, we would not be able to release the kobject properly later. This patch adds the 'kobject_put()' which was missing earlier. Signed-off-by: Mukesh Ojha <mukesh02@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Reviewed-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2015-05-22powernv/opal-dump: Convert to irq domainAlistair Popple
Convert the opal dump driver to the new opal irq domain. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-03-16powerpc/powernv: only call OPAL_RESEND_DUMP if firmware supports itStewart Smith
Not all OPAL platforms support resending system dumps, so check that current firmware supports it first. Otherwise we get firmware complaining: "OPAL: Called with bad token 91 !" Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Acked-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-09-25powerpc/powernv: Check OPAL dump calls exist before usingMichael Neuling
Check that the OPAL_DUMP_READ token exists before initalising the elog infrastructure. This avoids littering the OPAL console with: "OPAL: Called with bad token 91" Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-09-25powerpc/powernv: Improve error messages in dump codeVasant Hegde
Presently we only support initiating Service Processor dump from host. Hence update sysfs message. Also update couple of other error/info messages. Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-08-07arch/powerpc/platforms/powernv/opal-dump.c: fix world-writable sysfs filesRusty Russell
If you don't have a store function, you're not writable anyway! Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-04-28powerpc/powernv: Fix little endian issues in OPAL dump codeAnton Blanchard
Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-28powerpc/powernv: Create OPAL sglist helper functions and fix endian issuesAnton Blanchard
We have two copies of code that creates an OPAL sg list. Consolidate these into a common set of helpers and fix the endian issues. The flash interface embedded a version number in the num_entries field, whereas the dump interface did did not. Since versioning wasn't added to the flash interface and it is impossible to add this in a backwards compatible way, just remove it. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-04-09powerpc/powernv Adapt opal-elog and opal-dump to new sysfs_remove_file_selfStewart Smith
We are currently using sysfs_schedule_callback() which is deprecated and about to be removed. Switch to the new interface instead. Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-03-07powerpc/powernv Platform dump interfaceStewart Smith
This enables support for userspace to fetch and initiate FSP and Platform dumps from the service processor (via firmware) through sysfs. Based on original patch from Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Flow: - We register for OPAL notification events. - OPAL sends new dump available notification. - We make information on dump available via sysfs - Userspace requests dump contents - We retrieve the dump via OPAL interface - User copies the dump data - userspace sends ack for dump - We send ACK to OPAL. sysfs files: - We add the /sys/firmware/opal/dump directory - echoing 1 (well, anything, but in future we may support different dump types) to /sys/firmware/opal/dump/initiate_dump will initiate a dump. - Each dump that we've been notified of gets a directory in /sys/firmware/opal/dump/ with a name of the dump type and ID (in hex, as this is what's used elsewhere to identify the dump). - Each dump has files: id, type, dump and acknowledge dump is binary and is the dump itself. echoing 'ack' to acknowledge (currently any string will do) will acknowledge the dump and it will soon after disappear from sysfs. OPAL APIs: - opal_dump_init() - opal_dump_info() - opal_dump_read() - opal_dump_ack() - opal_dump_resend_notification() Currently we are only ever notified for one dump at a time (until the user explicitly acks the current dump, then we get a notification of the next dump), but this kernel code should "just work" when OPAL starts notifying us of all the dumps present. Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>