Linux kernel for uConsole
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Robin Murphy 2bab3df8f5 iommu/io-pgtable-arm: Fix race handling in split_blk_unmap()
[ Upstream commit 85c7a0f1ef ]

In removing the pagetable-wide lock, we gained the possibility of the
vanishingly unlikely case where we have a race between two concurrent
unmappers splitting the same block entry. The logic to handle this is
fairly straightforward - whoever loses the race frees their partial
next-level table and instead dereferences the winner's newly-installed
entry in order to fall back to a regular unmap, which intentionally
echoes the pre-existing case of recursively splitting a 1GB block down
to 4KB pages by installing a full table of 2MB blocks first.

Unfortunately, the chump who implemented that logic failed to update the
condition check for that fallback, meaning that if said race occurs at
the last level (where the loser's unmap_idx is valid) then the unmap
won't actually happen. Fix that to properly account for both the race
and recursive cases.

Fixes: 2c3d273eab ("iommu/io-pgtable-arm: Support lockless operation")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: re-jig control flow to avoid duplicate cmpxchg test]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24 08:19:30 +01:00
arch ARM: dts: sun8i: h3: bpi-m2-plus: Fix address for external RGMII Ethernet PHY 2019-11-24 08:19:23 +01:00
block blok, bfq: do not plug I/O if all queues are weight-raised 2019-11-20 18:46:44 +01:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: fix a memory leak in rsa-kcs1pad's encryption mode 2019-11-20 18:47:44 +01:00
Documentation net: phy: mdio-bcm-unimac: Allow configuring MDIO clock divider 2019-11-20 18:47:14 +01:00
drivers iommu/io-pgtable-arm: Fix race handling in split_blk_unmap() 2019-11-24 08:19:30 +01:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs f2fs: keep lazytime on remount 2019-11-24 08:19:26 +01:00
include SUNRPC: Fix priority queue fairness 2019-11-24 08:19:24 +01:00
init initramfs: don't free a non-existent initrd 2019-10-01 08:26:09 +02:00
ipc ipc/mqueue.c: only perform resource calculation if user valid 2019-08-06 19:06:52 +02:00
kernel kprobes: Don't call BUG_ON() if there is a kprobe in use on free list 2019-11-20 18:46:30 +01:00
lib idr: Fix idr_get_next race with idr_remove 2019-11-24 08:19:11 +01:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm mm/memory_hotplug: fix updating the node span 2019-11-24 08:19:13 +01:00
net SUNRPC: Fix priority queue fairness 2019-11-24 08:19:24 +01:00
samples samples/bpf: fix compilation failure 2019-11-20 18:47:13 +01:00
scripts scripts/setlocalversion: Improve -dirty check with git-status --no-optional-locks 2019-11-06 13:05:27 +01:00
security ima: fix freeing ongoing ahash_request 2019-10-11 18:21:11 +02:00
sound ASoC: rt5682: Fix the boost volume at the begining of playback 2019-11-20 18:46:55 +01:00
tools idr: Fix idr_get_next race with idr_remove 2019-11-24 08:19:11 +01:00
usr kbuild: clean compressed initramfs image 2019-10-07 18:57:16 +02:00
virt kvm: x86: mmu: Recovery of shattered NX large pages 2019-11-12 19:21:46 +01:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS USB: rio500: Remove Rio 500 kernel driver 2019-10-17 13:44:47 -07:00
Makefile Linux 4.19.85 2019-11-20 18:47:54 +01:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

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.
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.