Merge tag 'docs-5.1' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "A fairly routine cycle for docs - lots of typo fixes, some new
  documents, and more translations. There's also some LICENSES
  adjustments from Thomas"

* tag 'docs-5.1' of git://git.lwn.net/linux: (74 commits)
  docs: Bring some order to filesystem documentation
  Documentation/locking/lockdep: Drop last two chars of sample states
  doc: rcu: Suspicious RCU usage is a warning
  docs: driver-api: iio: fix errors in documentation
  Documentation/process/howto: Update for 4.x -> 5.x versioning
  docs: Explicitly state that the 'Fixes:' tag shouldn't split lines
  doc: security: Add kern-doc for lsm_hooks.h
  doc: sctp: Merge and clean up rst files
  Docs: Correct /proc/stat path
  scripts/spdxcheck.py: fix C++ comment style detection
  doc: fix typos in license-rules.rst
  Documentation: fix admin-guide/README.rst minimum gcc version requirement
  doc: process: complete removal of info about -git patches
  doc: translations: sync translations 'remove info about -git patches'
  perf-security: wrap paragraphs on 72 columns
  perf-security: elaborate on perf_events/Perf privileged users
  perf-security: document collected perf_events/Perf data categories
  perf-security: document perf_events/Perf resource control
  sysfs.txt: add note on available attribute macros
  docs: kernel-doc: typo "if ... if" -> "if ... is"
  ...

1 files changed, 17 insertions, 1 deletions

diff --git a/include/linux/module.h b/include/linux/module.h
index f5bc4c046461..5bf5dcd91009 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -172,7 +172,7 @@ extern void cleanup_module(void);
  * The following license idents are currently accepted as indicating free
  * software modules
  *
- *      "GPL"                           [GNU Public License v2 or later]
+ *      "GPL"                           [GNU Public License v2]
  *      "GPL v2"                        [GNU Public License v2]
  *      "GPL and additional rights"     [GNU Public License v2 rights and more]
  *      "Dual BSD/GPL"                  [GNU Public License v2
@@ -186,6 +186,22 @@ extern void cleanup_module(void);
  *
  *      "Proprietary"                   [Non free products]
  *
+ * Both "GPL v2" and "GPL" (the latter also in dual licensed strings) are
+ * merely stating that the module is licensed under the GPL v2, but are not
+ * telling whether "GPL v2 only" or "GPL v2 or later". The reason why there
+ * are two variants is a historic and failed attempt to convey more
+ * information in the MODULE_LICENSE string. For module loading the
+ * "only/or later" distinction is completely irrelevant and does neither
+ * replace the proper license identifiers in the corresponding source file
+ * nor amends them in any way. The sole purpose is to make the
+ * 'Proprietary' flagging work and to refuse to bind symbols which are
+ * exported with EXPORT_SYMBOL_GPL when a non free module is loaded.
+ *
+ * In the same way "BSD" is not a clear license information. It merely
+ * states, that the module is licensed under one of the compatible BSD
+ * license variants. The detailed and correct license information is again
+ * to be found in the corresponding source files.
+ *
  * There are dual licensed components, but when running with Linux it is the
  * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
  * is a GPL combined work.