[PATCH] acpi: fix acpi_device_{install,remove}_notify_handler() for _HID-less devices
From: Bartlomiej Zolnierkiewicz
Date: Thu Aug 06 2009 - 15:42:26 EST
From: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
Subject: [PATCH] acpi: fix acpi_device_{install,remove}_notify_handler() for _HID-less devices
The buffer pointer returned by acpi_device_hid() should be considered
as valid IFF device->flags.hardware_id flag is set (== device supports
_HID method).
This is not a problem currently (cause we use static buffers) but after
commit ed444824932d2a563858d82ec1ea29b0aa775e91 ("ACPICA: Major update
for acpi_get_object_info external interface") ->pnp.hardware_id will
be NULL for ACPI video devices which don't support _HID method (i.e.
the one in Asus Eee 901 w/ BIOSes 1202 and the latest 2103) resulting
in an OOPS and non-working Xorg (as observed with Ubuntu 9.10 UNR).
ACPI: Video Device [VGA] (multi-head: yes rom: no post: no)
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<c0302101>] strcmp+0x11/0x30
*pde = 00000000
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/LNXSYSTM:00/modalias
Modules linked in: video(+) output eeepc_laptop(+)
Pid: 249, comm: modprobe Not tainted (2.6.31-rc5-next-20090806-eee #49) 901
EIP: 0060:[<c0302101>] EFLAGS: 00010296 CPU: 0
EIP is at strcmp+0x11/0x30
EAX: 00000000 EBX: f70ea000 ECX: 00000082 EDX: c063d4a5
ESI: 00000000 EDI: c063d4a5 EBP: f6a1be14 ESP: f6a1be0c
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process modprobe (pid: 249, ti=f6a1a000 task=f6a15300 task.ti=f6a1a000)
Stack:
00000000 00000000 f6a1be30 c033073e f70ea1e4 f8051550 ffffffed f70ea1e4
<0> f8051618 f6a1be58 c0388ba9 f6a1be50 c03305bf f804fc2c 00000286 f6a1be58
<0> f70ea1e4 f8051618 f70ea218 f6a1be6c c0388d31 00000000 f6a1be78 f8051618
Call Trace:
[<c033073e>] ? acpi_device_probe+0x9c/0x11e
[<c0388ba9>] ? driver_probe_device+0x69/0x170
[<c03305bf>] ? acpi_match_device_ids+0x52/0x76
[<c0388d31>] ? __driver_attach+0x81/0x90
[<c038844b>] ? bus_for_each_dev+0x5b/0x80
[<c03305fd>] ? acpi_device_remove+0x0/0xa5
[<c0388a59>] ? driver_attach+0x19/0x20
[<c0388cb0>] ? __driver_attach+0x0/0x90
[<c0387def>] ? bus_add_driver+0x1bf/0x280
[<c03305fd>] ? acpi_device_remove+0x0/0xa5
[<c0388fb5>] ? driver_register+0x75/0x160
[<c021e5d3>] ? proc_mkdir_mode+0x33/0x50
[<c0331c1a>] ? acpi_bus_register_driver+0x3a/0x3c
[<f804f1ad>] ? acpi_video_register+0x36/0x61 [video]
[<f805407a>] ? acpi_video_init+0x69/0x6b [video]
[<f8054011>] ? acpi_video_init+0x0/0x6b [video]
[<c010112b>] ? do_one_initcall+0x2b/0x160
[<c019283f>] ? tracepoint_module_notify+0x2f/0x40
[<c05216bd>] ? notifier_call_chain+0x2d/0x70
[<c015bf4d>] ? __blocking_notifier_call_chain+0x4d/0x60
[<c016e772>] ? sys_init_module+0xb2/0x1f0
[<c010303c>] ? sysenter_do_call+0x12/0x28
Code: 8b 45 f0 8b 5d f4 8b 75 f8 8b 7d fc 89 ec 5d c3 8d 76 00 8d bc 27 00 00 00 00 55 89 e5 83 ec 08 89 34 24 89 c6 89 7c 24 04 89 d7 <ac> ae 75 08 84 c0 75 f8 31 c0 eb 04 19 c0 0c 01 8b 34 24 8b 7c
EIP: [<c0302101>] strcmp+0x11/0x30 SS:ESP 0068:f6a1be0c
CR2: 0000000000000000
---[ end trace 618b66b50ec5e42a ]---
Cc: Bob Moore <robert.moore@xxxxxxxxx>
Cc: Lin Ming <ming.m.lin@xxxxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
---
This fixes a month long -next regression.
Len, could this (or an equivalent fix) go into 2.6.31 so we will
never see the regression upstream and -next will fix itself..?
drivers/acpi/scan.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
Index: b/drivers/acpi/scan.c
===================================================================
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -375,13 +375,17 @@ static int acpi_device_install_notify_ha
acpi_status status;
char *hid;
- hid = acpi_device_hid(device);
- if (!strcmp(hid, ACPI_BUTTON_HID_POWERF))
+ if (device->flags.hardware_id)
+ hid = acpi_device_hid(device);
+ else
+ hid = NULL;
+
+ if (hid && !strcmp(hid, ACPI_BUTTON_HID_POWERF))
status =
acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
acpi_device_notify_fixed,
device);
- else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEPF))
+ else if (hid && !strcmp(hid, ACPI_BUTTON_HID_SLEEPF))
status =
acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
acpi_device_notify_fixed,
@@ -399,10 +403,17 @@ static int acpi_device_install_notify_ha
static void acpi_device_remove_notify_handler(struct acpi_device *device)
{
- if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_POWERF))
+ char *hid;
+
+ if (device->flags.hardware_id)
+ hid = acpi_device_hid(device);
+ else
+ hid = NULL;
+
+ if (hid && !strcmp(hid, ACPI_BUTTON_HID_POWERF))
acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
acpi_device_notify_fixed);
- else if (!strcmp(acpi_device_hid(device), ACPI_BUTTON_HID_SLEEPF))
+ else if (hid && !strcmp(hid, ACPI_BUTTON_HID_SLEEPF))
acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
acpi_device_notify_fixed);
else
--
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