Harry Pan d7ce45829c powercap: intel_rapl: add NULL pointer check to rapl_mmio_cpu_online()
commit 3aa3c5882e4fb2274448908aaed605a3ed7dd15d upstream.

RAPL MMIO support depends on the RAPL common driver.  During CPU
initialization rapl_mmio_cpu_online() is called via CPU hotplug
to initialize the MMIO RAPL for the new CPU, but if that CPU is
not present in the common RAPL driver's support list, rapl_defaults
is NULL and the kernel crashes on an attempt to dereference it:

[    4.188566] BUG: kernel NULL pointer dereference, address: 0000000000000020
...snip...
[    4.189555] RIP: 0010:rapl_add_package+0x223/0x574
[    4.189555] Code: b5 a0 31 c0 49 8b 4d 78 48 01 d9 48 8b 0c c1 49 89 4c c6 10 48 ff c0 48 83 f8 05 75 e7 49 83 ff 03 75 15 48 8b 05 09 bc 18 01 <8b> 70 20 41 89 b6 0c 05 00 00 85 f6 75 1a 49 81 c6 18 9
[    4.189555] RSP: 0000:ffffb3adc00b3d90 EFLAGS: 00010246
[    4.189555] RAX: 0000000000000000 RBX: 0000000000000098 RCX: 0000000000000000
[    4.267161] usb 1-1: New USB device found, idVendor=2109, idProduct=2812, bcdDevice= b.e0
[    4.189555] RDX: 0000000000001000 RSI: 0000000000000000 RDI: ffff9340caafd000
[    4.189555] RBP: ffffb3adc00b3df8 R08: ffffffffa0246e28 R09: ffff9340caafc000
[    4.189555] R10: 000000000000024a R11: ffffffff9ff1f6f2 R12: 00000000ffffffed
[    4.189555] R13: ffff9340caa94800 R14: ffff9340caafc518 R15: 0000000000000003
[    4.189555] FS:  0000000000000000(0000) GS:ffff9340ce200000(0000) knlGS:0000000000000000
[    4.189555] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.189555] CR2: 0000000000000020 CR3: 0000000302c14001 CR4: 00000000003606f0
[    4.189555] Call Trace:
[    4.189555]  ? __switch_to_asm+0x40/0x70
[    4.189555]  rapl_mmio_cpu_online+0x47/0x64
[    4.189555]  ? rapl_mmio_write_raw+0x33/0x33
[    4.281059] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[    4.189555]  cpuhp_invoke_callback+0x29f/0x66f
[    4.189555]  ? __schedule+0x46d/0x6a0
[    4.189555]  cpuhp_thread_fun+0xb9/0x11c
[    4.189555]  smpboot_thread_fn+0x17d/0x22f
[    4.297006] usb 1-1: Product: USB2.0 Hub
[    4.189555]  ? cpu_report_death+0x43/0x43
[    4.189555]  kthread+0x137/0x13f
[    4.189555]  ? cpu_report_death+0x43/0x43
[    4.189555]  ? kthread_blkcg+0x2e/0x2e
[    4.312951] usb 1-1: Manufacturer: VIA Labs, Inc.
[    4.189555]  ret_from_fork+0x1f/0x40
[    4.189555] Modules linked in:
[    4.189555] CR2: 0000000000000020
[    4.189555] ---[ end trace 01bb812aabc791f4 ]---

To avoid that problem, check rapl_defaults NULL upfront and return an
error code if it is NULL.  [Note that it does not make sense to even
try to allocate memory in that case, because it is not going to be
used anyway.]

Fixes: 555c45fe0d04 ("int340X/processor_thermal_device: add support for MMIO RAPL")
Cc: 5.3+ <stable@vger.kernel.org> # 5.3+
Signed-off-by: Harry Pan <harry.pan@intel.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14 20:08:18 +01:00
2020-01-12 12:21:34 +01:00
2019-09-22 10:34:46 -07:00
2019-11-10 13:41:59 -08:00
2020-01-12 12:21:53 +01:00

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.

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.
Description
No description provided
Readme 5.7 GiB
Languages
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%