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| author | Jiri Slaby <jslaby@suse.cz> | 2011-02-28 10:16:29 +0100 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2011-03-09 21:33:37 +0000 |
| commit | d406577526a611e6be1f6b1cfeaf094dd95fa439 (patch) | |
| tree | 9b4e97d33a9e18ce003eda0e3446dac9c6ec1828 /drivers/watchdog/sbc_fitpc2_wdt.c | |
| parent | a5abba989deceb731047425812d268daf7536575 (diff) | |
| download | lwn-d406577526a611e6be1f6b1cfeaf094dd95fa439.tar.gz lwn-d406577526a611e6be1f6b1cfeaf094dd95fa439.zip | |
watchdog: sbc_fitpc2_wdt, fix crash on systems without DMI_BOARD_NAME
Some systems don't provide DMI_BOARD_NAME in their DMI tables. Avoid
crash in such situations in fitpc2_wdt_init.
The fix is to check if the dmi_get_system_info return value is NULL.
The oops:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff81253ae6>] strstr+0x26/0xa0
PGD 3966e067 PUD 39605067 PMD 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/system/cpu/cpu1/cache/index2/shared_cpu_map
CPU 1
Modules linked in: ...
Pid: 1748, comm: modprobe Not tainted 2.6.37-22-default #1 /Bochs
RIP: 0010:[<ffffffff81253ae6>] [<ffffffff81253ae6>] strstr+0x26/0xa0
RSP: 0018:ffff88003ad73f18 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 00000000ffffffed RCX: 00000000ffffffff
RDX: ffffffffa003f4cc RSI: ffffffffa003f4c2 RDI: 0000000000000000
...
CR2: 0000000000000000 CR3: 000000003b7ac000 CR4: 00000000000006e0
...
Process modprobe (pid: 1748, threadinfo ffff88003ad72000, task ffff88002e6365c0)
Stack: ...
Call Trace:
[<ffffffffa004201f>] fitpc2_wdt_init+0x1f/0x13c [sbc_fitpc2_wdt]
[<ffffffff810002da>] do_one_initcall+0x3a/0x170
...
Code: f3 c3 0f 1f 00 80 3e 00 53 48 89 f8 74 1b 48 89 f2 0f 1f 40 00 48 83 c2 01 80 3a 00 75 f7 49 89 d0 48 89 f8 49 29 f0 75 02 5b c3 <80> 3f 00 74 0e 0f 1f 44 00 00 48 83 c0 01 80 38 00 75 f7 49 89
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/sbc_fitpc2_wdt.c')
| -rw-r--r-- | drivers/watchdog/sbc_fitpc2_wdt.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/watchdog/sbc_fitpc2_wdt.c b/drivers/watchdog/sbc_fitpc2_wdt.c index c7d67e9a7465..79906255eeb6 100644 --- a/drivers/watchdog/sbc_fitpc2_wdt.c +++ b/drivers/watchdog/sbc_fitpc2_wdt.c @@ -201,11 +201,14 @@ static struct miscdevice fitpc2_wdt_miscdev = { static int __init fitpc2_wdt_init(void) { int err; + const char *brd_name; - if (!strstr(dmi_get_system_info(DMI_BOARD_NAME), "SBC-FITPC2")) + brd_name = dmi_get_system_info(DMI_BOARD_NAME); + + if (!brd_name || !strstr(brd_name, "SBC-FITPC2")) return -ENODEV; - pr_info("%s found\n", dmi_get_system_info(DMI_BOARD_NAME)); + pr_info("%s found\n", brd_name); if (!request_region(COMMAND_PORT, 1, WATCHDOG_NAME)) { pr_err("I/O address 0x%04x already in use\n", COMMAND_PORT); |