Que signifie la valeur de ternissement du noyau?

L'exécution cat /proc/sys/kernel/taintedimprime la valeur actuelle du noyau (en base 10). Ma compréhension est que cette valeur est un champ binaire, où chaque bit indique l'absence ou la présence d'un type particulier de souillure. Vous pouvez extraire les bits en utilisant

python3 -c 'from pprint import pprint; pprint(list(zip(range(50), reversed(bin(int(open("/proc/sys/kernel/tainted").read()))[2:]))))'

J'ai cherché de la documentation, mais ce que j'ai vu n'identifie que la signification des bits 0 à 10. Par exemple, http://www.kernel.org/doc/Documentation/sysctl/kernel.txt dit:

tainted:

Non-zero if the kernel has been tainted. Numeric values, which can be
ORed together. The letters are seen in "Tainted" line of Oops reports.

     1 (P):  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 (F): A module was force loaded by insmod -f.
            Set by modutils >= 2.4.9 and module-init-tools.
     4 (S): Unsafe SMP processors: SMP with CPUs not designed for SMP.
     8 (R): A module was forcibly unloaded from the system by rmmod -f.
    16 (M): A hardware machine check error occurred on the system.
    32 (B): A bad page was discovered on the system.
    64 (U): 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 (D): The system has died.
   256 (A): The ACPI DSDT has been overridden with one supplied by the user
            instead of using the one provided by the hardware.
   512 (W): A kernel warning has occurred.
  1024 (C): A module from drivers/staging was loaded.
  2048 (I): The system is working around a severe firmware bug.
  4096 (O): An out-of-tree module has been loaded.
  8192 (E): An unsigned module has been loaded in a kernel supporting module
            signature.
 16384 (L): A soft lockup has previously occurred on the system.
 32768 (K): The kernel has been live patched.
 65536 (X): Auxiliary taint, defined and used by for distros.
131072 (T): The kernel was built with the struct randomization plugin.

J'ai également essayé d'afficher la documentation du noyau Ubuntu en installant le linux-docpackage et en l'ouvrant zless /usr/share/doc/linux-doc/sysctl/kernel.txt.gz, mais cela n'en répertorie toujours que jusqu'à 1024.

Dans mon cas, j'exécute le noyau PAE par défaut (3.2.0-36-generic-pae) sur Precise. Je vois également le bit 12 réglé.

Où est la documentation complète de ce que signifient les bits corrompus sur les noyaux Ubuntu?

En regardant panic.c:

/**
 *      print_tainted - return a string to represent the kernel taint state.
 *
 *  'P' - Proprietary module has been loaded.
 *  'F' - Module has been forcibly loaded.
 *  'S' - SMP with CPUs not designed for SMP.
 *  'R' - User forced a module unload.
 *  'M' - System experienced a machine check exception.
 *  'B' - System has hit bad_page.
 *  'U' - Userspace-defined naughtiness.
 *  'D' - Kernel has oopsed before
 *  'A' - ACPI table overridden.
 *  'W' - Taint on warning.
 *  'C' - modules from drivers/staging are loaded.
 *  'I' - Working around severe firmware bug.
 *  'O' - Out-of-tree module has been loaded.
 *  'E' - Unsigned module has been loaded.
 *  'L' - A soft lockup has previously occurred.
 *  'K' - Kernel has been live patched.
 *
 *      The string is overwritten by the next call to print_tainted().
 */