日志中会有一些信息：
dmesg | grep -i tainted
具体代码可以通过proc看到：
cat /proc/sys/kernel/tainted
数字的意义：
tainted:
Non-zero if the kernel has been tainted. Numeric values, which
can be ORed together:
1 - A module with a non-GPL license has been loaded, this includes modules with no license.Set by modutils >= 2.4.9 and module-init-tools.
2 - A module was force loaded by insmod -f.Set by modutils >= 2.4.9 and module-init-tools.
4 - Unsafe SMP processors: SMP with CPUs not designed for SMP.
8 - A module was forcibly unloaded from the system by rmmod -f.
16 - A hardware machine check error occurred on the system.
32 - A bad page was discovered on the system.
64 - The user has asked that the system be marked "tainted". This could be because they are running software that directly modifies the hardware, or for other reasons.
128 - The system has died.
256 - The ACPI DSDT has been overridden with one supplied by the user instead of using the one provided by the hardware.
512 - A kernel warning has occurred.
1024 - A module from drivers/staging was loaded.
2048 - The system is working around a severe firmware bug.
4096 - An out-of-tree module has been loaded.
8192 - An unsigned module has been loaded in a kernel supporting module signature.
16384 - A soft lockup has previously occurred on the system.
32768 - The kernel has been live patched.
原文：http://www.cnblogs.com/skynext/p/4793627.html