alistair23-linux

redonkable

Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux

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Zenghui Yu beb8e02541 KVM: arm64: vgic-v3: Retire all pending LPIs on vcpu destroy [ Upstream commit `969ce8b526` ] It's likely that the vcpu fails to handle all virtual interrupts if userspace decides to destroy it, leaving the pending ones stay in the ap_list. If the un-handled one is a LPI, its vgic_irq structure will be eventually leaked because of an extra refcount increment in vgic_queue_irq_unlock(). This was detected by kmemleak on almost every guest destroy, the backtrace is as follows: unreferenced object 0xffff80725aed5500 (size 128): comm "CPU 5/KVM", pid 40711, jiffies 4298024754 (age 166366.512s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 08 01 a9 73 6d 80 ff ff ...........sm... c8 61 ee a9 00 20 ff ff 28 1e 55 81 6c 80 ff ff .a... ..(.U.l... backtrace: [<000000004bcaa122>] kmem_cache_alloc_trace+0x2dc/0x418 [<0000000069c7dabb>] vgic_add_lpi+0x88/0x418 [<00000000bfefd5c5>] vgic_its_cmd_handle_mapi+0x4dc/0x588 [<00000000cf993975>] vgic_its_process_commands.part.5+0x484/0x1198 [<000000004bd3f8e3>] vgic_its_process_commands+0x50/0x80 [<00000000b9a65b2b>] vgic_mmio_write_its_cwriter+0xac/0x108 [<0000000009641ebb>] dispatch_mmio_write+0xd0/0x188 [<000000008f79d288>] __kvm_io_bus_write+0x134/0x240 [<00000000882f39ac>] kvm_io_bus_write+0xe0/0x150 [<0000000078197602>] io_mem_abort+0x484/0x7b8 [<0000000060954e3c>] kvm_handle_guest_abort+0x4cc/0xa58 [<00000000e0d0cd65>] handle_exit+0x24c/0x770 [<00000000b44a7fad>] kvm_arch_vcpu_ioctl_run+0x460/0x1988 [<0000000025fb897c>] kvm_vcpu_ioctl+0x4f8/0xee0 [<000000003271e317>] do_vfs_ioctl+0x160/0xcd8 [<00000000e7f39607>] ksys_ioctl+0x98/0xd8 Fix it by retiring all pending LPIs in the ap_list on the destroy path. p.s. I can also reproduce it on a normal guest shutdown. It is because userspace still send LPIs to vcpu (through KVM_SIGNAL_MSI ioctl) while the guest is being shutdown and unable to handle it. A little strange though and haven't dig further... Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> [maz: moved the distributor deallocation down to avoid an UAF splat] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200414030349.625-2-yuzenghui@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>		2020-10-01 13:17:56 +02:00
Documentation	affs: fix basic permission bits to actually work	2020-09-09 19:12:34 +02:00
LICENSES	LICENSES: Rename other to deprecated	2019-05-03 06:34:32 -06:00
arch	KVM: Remove CREATE_IRQCHIP/SET_PIT2 race	2020-10-01 13:17:55 +02:00
block	block: only call sched requeue_request() for scheduled requests	2020-09-23 12:40:37 +02:00
certs	PKCS#7: Refactor verify_pkcs7_signature()	2019-08-05 18:40:18 -04:00
crypto	crypto: af_alg - Work around empty control messages without MSG_MORE	2020-09-03 11:27:05 +02:00
drivers	drivers: char: tlclk.c: Avoid data race between init and interrupt handler	2020-10-01 13:17:56 +02:00
fs	bdev: Reduce time holding bd_mutex in sync in blkdev_close()	2020-10-01 13:17:55 +02:00
include	ALSA: hda: Skip controller resume if not needed	2020-10-01 13:17:54 +02:00
init	exec: Add exec_update_mutex to replace cred_guard_mutex	2020-10-01 13:17:47 +02:00
ipc	ipc/util.c: sysvipc_find_ipc() incorrectly updates position index	2020-05-20 08:20:16 +02:00
kernel	workqueue: Remove the warning in wq_worker_sleeping()	2020-10-01 13:17:54 +02:00
lib	kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()	2020-10-01 13:17:10 +02:00
mm	mm/mmap.c: initialize align_offset explicitly for vm_unmapped_area	2020-10-01 13:17:54 +02:00
net	SUNRPC: Don't start a timer on an already queued rpc task	2020-10-01 13:17:53 +02:00
samples	bpf: Fix fds_example SIGSEGV error	2020-08-19 08:16:03 +02:00
scripts	checkpatch: fix the usage of capture group ( ... )	2020-09-09 19:12:37 +02:00
security	selinux: sel_avc_get_stat_idx should increase position index	2020-10-01 13:17:32 +02:00
sound	ALSA: hda: Skip controller resume if not needed	2020-10-01 13:17:54 +02:00
tools	perf stat: Force error in fallback on :k events	2020-10-01 13:17:55 +02:00
usr	initramfs: restore default compression behavior	2020-04-08 09:08:38 +02:00
virt	KVM: arm64: vgic-v3: Retire all pending LPIs on vcpu destroy	2020-10-01 13:17:56 +02:00
.clang-format	clang-format: Update with the latest for_each macro list	2019-08-31 10:00:51 +02:00
.cocciconfig	scripts: add Linux .cocciconfig for coccinelle	2016-07-22 12:13:39 +02:00
.get_maintainer.ignore	Opt out of scripts/get_maintainer.pl	2019-05-16 10:53:40 -07:00
.gitattributes	.gitattributes: set git diff driver for C source code files	2016-10-07 18:46:30 -07:00
.gitignore	Modules updates for v5.4	2019-09-22 10:34:46 -07:00
.mailmap	ARM: SoC fixes	2019-11-10 13:41:59 -08:00
COPYING	COPYING: use the new text with points to the license files	2018-03-23 12:41:45 -06:00
CREDITS	MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer	2019-10-10 08:12:51 -07:00
Kbuild	kbuild: do not descend to ./Kbuild when cleaning	2019-08-21 21:03:58 +09:00
Kconfig	docs: kbuild: convert docs to ReST and rename to *.rst	2019-06-14 14:21:21 -06:00
MAINTAINERS	Documentation/llvm: add documentation on building w/ Clang/LLVM	2020-08-26 10:40:46 +02:00
Makefile	Linux 5.4.68	2020-09-26 18:03:16 +02:00
README	Drop all 00-INDEX files from Documentation/	2018-09-09 15:08:58 -06:00

README

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.