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Marc Zyngier eb9c4dd9bd phy: tegra: xusb: Fix dangling pointer on probe failure
If, for some reason, the xusb PHY fails to probe, it leaves
a dangling pointer attached to the platform device structure.

This would normally be harmless, but the Tegra XHCI driver then
goes and extract that pointer from the PHY device. Things go
downhill from there:

    8.752082] [004d554e5145533c] address between user and kernel address ranges
[    8.752085] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[    8.752088] Modules linked in: max77620_regulator(E+) xhci_tegra(E+) sdhci_tegra(E+) xhci_hcd(E) sdhci_pltfm(E) cqhci(E) fixed(E) usbcore(E) scsi_mod(E) sdhci(E) host1x(E+)
[    8.752103] CPU: 4 PID: 158 Comm: systemd-udevd Tainted: G S      W   E     5.9.0-rc7-00298-gf6337624c4fe #1980
[    8.752105] Hardware name: NVIDIA Jetson TX2 Developer Kit (DT)
[    8.752108] pstate: 20000005 (nzCv daif -PAN -UAO BTYPE=--)
[    8.752115] pc : kobject_put+0x1c/0x21c
[    8.752120] lr : put_device+0x20/0x30
[    8.752121] sp : ffffffc012eb3840
[    8.752122] x29: ffffffc012eb3840 x28: ffffffc010e82638
[    8.752125] x27: ffffffc008d56440 x26: 0000000000000000
[    8.752128] x25: ffffff81eb508200 x24: 0000000000000000
[    8.752130] x23: ffffff81eb538800 x22: 0000000000000000
[    8.752132] x21: 00000000fffffdfb x20: ffffff81eb538810
[    8.752134] x19: 3d4d554e51455300 x18: 0000000000000020
[    8.752136] x17: ffffffc008d00270 x16: ffffffc008d00c94
[    8.752138] x15: 0000000000000004 x14: ffffff81ebd4ae90
[    8.752140] x13: 0000000000000000 x12: ffffff81eb86a4e8
[    8.752142] x11: ffffff81eb86a480 x10: ffffff81eb862fea
[    8.752144] x9 : ffffffc01055fb28 x8 : ffffff81eb86a4a8
[    8.752146] x7 : 0000000000000001 x6 : 0000000000000001
[    8.752148] x5 : ffffff81dff8bc38 x4 : 0000000000000000
[    8.752150] x3 : 0000000000000001 x2 : 0000000000000001
[    8.752152] x1 : 0000000000000002 x0 : 3d4d554e51455300
[    8.752155] Call trace:
[    8.752157]  kobject_put+0x1c/0x21c
[    8.752160]  put_device+0x20/0x30
[    8.752164]  tegra_xusb_padctl_put+0x24/0x3c
[    8.752170]  tegra_xusb_probe+0x8b0/0xd10 [xhci_tegra]
[    8.752174]  platform_drv_probe+0x60/0xb4
[    8.752176]  really_probe+0xf0/0x504
[    8.752179]  driver_probe_device+0x100/0x170
[    8.752181]  device_driver_attach+0xcc/0xd4
[    8.752183]  __driver_attach+0xb0/0x17c
[    8.752185]  bus_for_each_dev+0x7c/0xd4
[    8.752187]  driver_attach+0x30/0x3c
[    8.752189]  bus_add_driver+0x154/0x250
[    8.752191]  driver_register+0x84/0x140
[    8.752193]  __platform_driver_register+0x54/0x60
[    8.752197]  tegra_xusb_init+0x40/0x1000 [xhci_tegra]
[    8.752201]  do_one_initcall+0x54/0x2d0
[    8.752205]  do_init_module+0x68/0x29c
[    8.752207]  load_module+0x2178/0x26c0
[    8.752209]  __do_sys_finit_module+0xb0/0x120
[    8.752211]  __arm64_sys_finit_module+0x2c/0x40
[    8.752215]  el0_svc_common.constprop.0+0x80/0x240
[    8.752218]  do_el0_svc+0x30/0xa0
[    8.752220]  el0_svc+0x18/0x50
[    8.752223]  el0_sync_handler+0x90/0x318
[    8.752225]  el0_sync+0x158/0x180
[    8.752230] Code: a9bd7bfd 910003fd a90153f3 aa0003f3 (3940f000)
[    8.752232] ---[ end trace 90f6c89d62d85ff5 ]---

Reset the pointer on probe failure fixes the issue.

Fixes: 53d2a715c2 ("phy: Add Tegra XUSB pad controller support")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201013095820.311376-1-maz@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2020-10-28 21:42:18 +05:30
Documentation xen: branch for v5.10-rc1c 2020-10-25 10:55:35 -07:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
arch treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
block block-5.10-2020-10-24 2020-10-24 12:46:42 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto drivers-5.10-2020-10-12 2020-10-13 13:04:41 -07:00
drivers phy: tegra: xusb: Fix dangling pointer on probe failure 2020-10-28 21:42:18 +05:30
fs treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
include treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
init linux-kselftest-kunit-5.10-rc1 2020-10-18 14:45:59 -07:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
lib random32: make prandom_u32() less predictable 2020-10-25 10:40:08 -07:00
mm Refactored code for 5.10: 2020-10-23 11:33:41 -07:00
net mm: remove kzfree() compatibility definition 2020-10-25 11:39:02 -07:00
samples bpf, libbpf: Guard bpf inline asm from bpf_tail_call_static 2020-10-22 01:46:52 +02:00
scripts treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
security SafeSetID changes for v5.10 2020-10-25 10:45:26 -07:00
sound ARM: SoC platform updates 2020-10-24 10:33:08 -07:00
tools treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt kvm: x86/mmu: Support dirty logging for the TDP MMU 2020-10-23 03:42:13 -04:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.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: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap MAINTAINERS: jarkko.sakkinen@linux.intel.com -> jarkko@kernel.org 2020-10-16 11:11:19 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ARM: Devicetree updates 2020-10-24 10:44:18 -07:00
Makefile Linux 5.10-rc1 2020-10-25 15:14:11 -07:00
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.