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Tyrel Datwyler 68baf692c4 powerpc/pseries: Fix of_node_put() underflow during DLPAR remove Historically struct device_node references were tracked using a kref embedded as a struct field. Commit `75b57ecf9d` ("of: Make device nodes kobjects so they show up in sysfs") (Mar 2014) refactored device_nodes to be kobjects such that the device tree could by more simply exposed to userspace using sysfs. Commit `0829f6d1f6` ("of: device_node kobject lifecycle fixes") (Mar 2014) followed up these changes to better control the kobject lifecycle and in particular the referecne counting via of_node_get(), of_node_put(), and of_node_init(). A result of this second commit was that it introduced an of_node_put() call when a dynamic node is detached, in of_node_remove(), that removes the initial kobj reference created by of_node_init(). Traditionally as the original dynamic device node user the pseries code had assumed responsibilty for releasing this final reference in its platform specific DLPAR detach code. This patch fixes a refcount underflow introduced by commit `0829f6d1f6`, and recently exposed by the upstreaming of the recount API. Messages like the following are no longer seen in the kernel log with this patch following DLPAR remove operations of cpus and pci devices. rpadlpar_io: slot PHB 72 removed refcount_t: underflow; use-after-free. ------------[ cut here ]------------ WARNING: CPU: 5 PID: 3335 at lib/refcount.c:128 refcount_sub_and_test+0xf4/0x110 Fixes: `0829f6d1f6` ("of: device_node kobject lifecycle fixes") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> [mpe: Make change log commit references more verbose] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>		2017-04-25 00:24:59 +10:00
arch	powerpc/pseries: Fix of_node_put() underflow during DLPAR remove	2017-04-25 00:24:59 +10:00
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Documentation	Merge branch 'topic/kprobes' into next	2017-04-25 00:24:04 +10:00
drivers	cxl: Enable PCI device IDs for future IBM CXL adapters	2017-04-19 20:00:19 +10:00
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include	Merge branch 'topic/kprobes' into next	2017-04-25 00:24:04 +10:00
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kernel	powerpc/kprobes: Fix handling of function offsets on ABIv2	2017-04-20 23:18:55 +10:00
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tools	powerpc/perf: Define big-endian version of perf_mem_data_src	2017-04-19 20:00:21 +10:00
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README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.