Commit graph

5 commits

Author SHA1 Message Date
Andy Shevchenko
84d798497e ACPI / device_sysfs: Avoid OF modalias creation for removed device
commit f16eb8a4b096514ac06fb25bf599dcc792899b3d upstream.

If SSDT overlay is loaded via ConfigFS and then unloaded the device,
we would like to have OF modalias for, already gone. Thus, acpi_get_name()
returns no allocated buffer for such case and kernel crashes afterwards:

 ACPI: Host-directed Dynamic ACPI Table Unload
 ads7950 spi-PRP0001:00: Dropping the link to regulator.0
 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 #PF error: [normal kernel read fault]
 PGD 80000000070d6067 P4D 80000000070d6067 PUD 70d0067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 0 PID: 40 Comm: kworker/u4:2 Not tainted 5.0.0+ #96
 Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48
 Workqueue: kacpi_hotplug acpi_device_del_work_fn
 RIP: 0010:create_of_modalias.isra.1+0x4c/0x150
 Code: 00 00 48 89 44 24 18 31 c0 48 8d 54 24 08 48 c7 44 24 10 00 00 00 00 48 c7 44 24 08 ff ff ff ff e8 7a b0 03 00 48 8b 4c 24 10 <0f> b6 01 84 c0 74 27 48 c7 c7 00 09 f4 a5 0f b6 f0 8d 50 20 f6 04
 RSP: 0000:ffffa51040297c10 EFLAGS: 00010246
 RAX: 0000000000001001 RBX: 0000000000000785 RCX: 0000000000000000
 RDX: 0000000000001001 RSI: 0000000000000286 RDI: ffffa2163dc042e0
 RBP: ffffa216062b1196 R08: 0000000000001001 R09: ffffa21639873000
 R10: ffffffffa606761d R11: 0000000000000001 R12: ffffa21639873218
 R13: ffffa2163deb5060 R14: ffffa216063d1010 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffffa2163e000000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 0000000007114000 CR4: 00000000001006f0
 Call Trace:
  __acpi_device_uevent_modalias+0xb0/0x100
  spi_uevent+0xd/0x40

 ...

In order to fix above let create_of_modalias() check the status returned
by acpi_get_name() and bail out in case of failure.

Fixes: 8765c5ba19 ("ACPI / scan: Rework modalias creation when "compatible" is present")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201381
Reported-by: Ferry Toth <fntoth@gmail.com>
Tested-by: Ferry Toth<fntoth@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: 4.1+ <stable@vger.kernel.org> # 4.1+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23 08:44:35 +01:00
Hans de Goede
0deb9532ca ACPI / bus: Leave modalias empty for devices which are not present
[ Upstream commit 10809bb976648ac58194a629e3d7af99e7400297 ]

Most Bay and Cherry Trail devices use a generic DSDT with all possible
peripheral devices present in the DSDT, with their _STA returning 0x00 or
0x0f based on AML variables which describe what is actually present on
the board.

Since ACPI device objects with a 0x00 status (not present) still get an
entry under /sys/bus/acpi/devices, and those entry had an acpi:PNPID
modalias, userspace would end up loading modules for non present hardware.

This commit fixes this by leaving the modalias empty for non present
devices. This results in 10 modules less being loaded with a generic
distro kernel config on my Cherry Trail test-device (a GPD pocket).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-03 17:04:27 +01:00
Kees Cook
9db22d928c ACPI / property: avoid leaking format string into kobject name
The dn->name is expected to be used as a literal, so add the missing
"%s".

Fixes: 263b4c1a64 (ACPI / property: Expose data-only subnodes via sysfs)
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-08 01:01:41 +01:00
Rafael J. Wysocki
263b4c1a64 ACPI / property: Expose data-only subnodes via sysfs
Add infrastructure needed to expose data-only subnodes of ACPI
device objects introduced previously via sysfs.

Each data-only subnode is represented as a sysfs directory under
the directory corresponding to its parent object (a device or a
data-only subnode).  Each of them has a "path" attribute (containing
the full ACPI namespace path to the object the subnode data come from)
at this time.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2015-09-15 01:47:34 +02:00
Rafael J. Wysocki
c2efefb33a ACPI / scan: Move sysfs-related device code to a separate file
To reduce the size of scan.c and improve the readability of it, move
all code related to device sysfs, modalias creation etc. to a new
file called device_sysfs.c.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-07-17 22:53:43 +02:00