2.5. Hello World (part 4): Licensing and Module Documentation

If you're running kernel 2.4 or later, you might have noticed something like this when you loaded proprietary modules:

# insmod xxxxxx.o Warning: loading xxxxxx.ko will taint the kernel: no license See http://www.tux.org/lkml/#export-tainted for information about tainted modules Module xxxxxx loaded, with warnings 

In kernel 2.4 and later, a mechanism was devised to identify code licensed under the GPL (and friends) so people can be warned that the code is non open-source. This is accomplished by the MODULE_LICENSE() macro which is demonstrated in the next piece of code. By setting the license to GPL, you can keep the warning from being printed. This license mechanism is defined and documented in linux/module.h:
/* a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html The following license idents are currently accepted as indicating free a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html software modules a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html "GPL" [GNU Public License v2 or later] a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html "GPL v2" [GNU Public License v2] a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html "GPL and additional rights" [GNU Public License v2 rights and more] a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html "Dual BSD/GPL" [GNU Public License v2 a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html or BSD license choice] a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html "Dual MIT/GPL" [GNU Public License v2 a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html or MIT license choice] a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html "Dual MPL/GPL" [GNU Public License v2 a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html or Mozilla license choice] a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html The following other idents are available a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html "Proprietary" [Non free products] a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html There are dual licensed components, but when running with Linux it is the a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html is a GPL combined work. a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html This exists for several reasons a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html 1. So modinfo can show license info for users wanting to vet their setup a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html is free a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html 2. So the community can ignore bug reports including proprietary modules a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html 3. So vendors can do likewise based on their own policies */

Similarly, MODULE_DESCRIPTION() is used to describe what the module does, MODULE_AUTHOR() declares the module's author, and MODULE_SUPPORTED_DEVICE() declares what types of devices the module supports.

These macros are all defined in linux/module.h and aren't used by the kernel itself. They're simply for documentation and can be viewed by a tool like objdump. As an exercise to the reader, try and search fo these macros in linux/drivers to see how module authors use these macros to document their modules.

I'd recommend to use something like grep -inr MODULE_AUTHOR a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html in /usr/src/linux-2.6.x/ . People unfamiliar with command line tools will probably like some web base solution, search for sites that offer kernel trees that got indexed with LXR. (or setup it up on your local machine).

Users of traditional Unix editors, like emacs or vi will also find tag files useful. They can be generated by make tags or make TAGS in /usr/src/linux-2.6.x/ . Once you've got such a tagfile in your kerneltree you can put the cursor on some function call and use some key combination to directly jump to the definition function.

Example 2-6. hello-4.c

/* a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html hello-4.c - Demonstrates module documentation. figures/ #include <linux/module.h> /apps /backup /bin /boot /data /dev /etc /home /lib /lost+found /media /misc /mnt /net /opt /proc /root /sbin /selinux /srv /sys /tftpboot /tmp /usr /var Needed by all modules figures/ #include <linux/kernel.h> /apps /backup /bin /boot /data /dev /etc /home /lib /lost+found /media /misc /mnt /net /opt /proc /root /sbin /selinux /srv /sys /tftpboot /tmp /usr /var Needed for KERN_INFO figures/ #include <linux/init.h> /apps /backup /bin /boot /data /dev /etc /home /lib /lost+found /media /misc /mnt /net /opt /proc /root /sbin /selinux /srv /sys /tftpboot /tmp /usr /var Needed for the macros figures/ #define DRIVER_AUTHOR "Peter Jay Salzman <p@dirac.org>" #define DRIVER_DESC "A sample driver" static int __init init_hello_4(void) { printk(KERN_INFO "Hello, world 4\n"); return 0; } static void __exit cleanup_hello_4(void) { printk(KERN_INFO "Goodbye, world 4\n"); } module_init(init_hello_4); module_exit(cleanup_hello_4); /apps /backup /bin /boot /data /dev /etc /home /lib /lost+found /media /misc /mnt /net /opt /proc /root /sbin /selinux /srv /sys /tftpboot /tmp /usr /var a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html You can use strings, like this: figures/ /apps /backup /bin /boot /data /dev /etc /home /lib /lost+found /media /misc /mnt /net /opt /proc /root /sbin /selinux /srv /sys /tftpboot /tmp /usr /var a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html Get rid of taint message by declaring code as GPL. figures/ MODULE_LICENSE("GPL"); /apps /backup /bin /boot /data /dev /etc /home /lib /lost+found /media /misc /mnt /net /opt /proc /root /sbin /selinux /srv /sys /tftpboot /tmp /usr /var a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html Or with defines, like this: figures/ MODULE_AUTHOR(DRIVER_AUTHOR); /apps /backup /bin /boot /data /dev /etc /home /lib /lost+found /media /misc /mnt /net /opt /proc /root /sbin /selinux /srv /sys /tftpboot /tmp /usr /var Who wrote this module? figures/ MODULE_DESCRIPTION(DRIVER_DESC); /apps /backup /bin /boot /data /dev /etc /home /lib /lost+found /media /misc /mnt /net /opt /proc /root /sbin /selinux /srv /sys /tftpboot /tmp /usr /var What does this module do figures/ /apps /backup /bin /boot /data /dev /etc /home /lib /lost+found /media /misc /mnt /net /opt /proc /root /sbin /selinux /srv /sys /tftpboot /tmp /usr /var a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html This module uses /dev/testdevice. The MODULE_SUPPORTED_DEVICE macro might a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html be used in the future to help automatic configuration of modules, but is a1387.htm a1387.html a1403.htm a1403.html book1.htm c1050.htm c1050.html c1159.htm c1159.html c119.htm c119.html c1209.htm c1209.html c1254.htm c1324.htm c1324.html c1350.htm c1350.html c38.htm c38.html c425.htm c425.html c567.htm c567.html c708.htm c708.html c885.htm c885.html c890.htm c890.html c976.htm c976.html doc-index.html f25.htm f25.html figures hello2.html i1413.htm index.html interrupthandlers.html ln16.html TXT_lkmpg.html x1052.html x1161.html x1194.htm x1194.html x1211.html x121.html x1256.html x1326.html x1352.html x1389.html x1405.html x181.htm x181.html x217.htm x245.htm x245.html x279.htm x279.html x27.html x30.htm x30.html x323.htm x323.html x351.htm x351.html x35.htm x35.html x380.htm x380.html x40.html x427.html x44.htm x44.html x569.html x710.html x769.htm x769.html x810.htm x810.html x861.htm x861.html x887.html x892.html x978.html currently unused other than for documentation purposes. figures/ MODULE_SUPPORTED_DEVICE("testdevice");