4f60640723
commit 2d48ea0efb8887ebba3e3720bb5b738aced4e574 upstream.
There are several places traverse RCU-list without holding any lock in
intel_iommu_init(). Fix them by acquiring dmar_global_lock.
WARNING: suspicious RCU usage
-----------------------------
drivers/iommu/intel-iommu.c:5216 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
no locks held by swapper/0/1.
Call Trace:
dump_stack+0xa0/0xea
lockdep_rcu_suspicious+0x102/0x10b
intel_iommu_init+0x947/0xb13
pci_iommu_init+0x26/0x62
do_one_initcall+0xfe/0x500
kernel_init_freeable+0x45a/0x4f8
kernel_init+0x11/0x139
ret_from_fork+0x3a/0x50
DMAR: Intel(R) Virtualization Technology for Directed I/O
Fixes: d8190dc63886 ("iommu/vt-d: Enable DMA remapping after rmrr mapped")
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.