From d406577526a611e6be1f6b1cfeaf094dd95fa439 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 28 Feb 2011 10:16:29 +0100 Subject: [PATCH] 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: [] 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:[] [] 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: [] fitpc2_wdt_init+0x1f/0x13c [sbc_fitpc2_wdt] [] 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 Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/sbc_fitpc2_wdt.c | 7 +++++-- 1 file 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); -- GitLab