Merge tag 'docs-6.3' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "It has been a moderately calm cycle for documentation; the significant
  changes include:

   - Some significant additions to the memory-management documentation

   - Some improvements to navigation in the HTML-rendered docs

   - More Spanish and Chinese translations

  ... and the usual set of typo fixes and such"

* tag 'docs-6.3' of git://git.lwn.net/linux: (68 commits)
  Documentation/watchdog/hpwdt: Fix Format
  Documentation/watchdog/hpwdt: Fix Reference
  Documentation: core-api: padata: correct spelling
  docs/mm: Physical Memory: correct spelling in reference to CONFIG_PAGE_EXTENSION
  docs: Use HTML comments for the kernel-toc SPDX line
  docs: Add more information to the HTML sidebar
  Documentation: KVM: Update AMD memory encryption link
  printk: Document that CONFIG_BOOT_PRINTK_DELAY required for boot_delay=
  Documentation: userspace-api: correct spelling
  Documentation: sparc: correct spelling
  Documentation: driver-api: correct spelling
  Documentation: admin-guide: correct spelling
  docs: add workload-tracing document to admin-guide
  docs/admin-guide/mm: remove useless markup
  docs/mm: remove useless markup
  docs/mm: Physical Memory: remove useless markup
  docs/sp_SP: Add process magic-number translation
  docs: ftrace: always use canonical ftrace path
  Doc/damon: fix the data path error
  dma-buf: Add "dma-buf" to title of documentation
  ...

4 files changed, 77 insertions, 73 deletions

diff --git a/Documentation/process/botching-up-ioctls.rst b/Documentation/process/botching-up-ioctls.rst
index ba4667ab396b6..9739b88463a5f 100644
--- a/Documentation/process/botching-up-ioctls.rst
+++ b/Documentation/process/botching-up-ioctls.rst
@@ -41,7 +41,7 @@ will need to add a 32-bit compat layer:
    structures to the kernel, or if the kernel checks the structure size, which
    e.g. the drm core does.
 
- * Pointers are __u64, cast from/to a uintprt_t on the userspace side and
+ * Pointers are __u64, cast from/to a uintptr_t on the userspace side and
    from/to a void __user * in the kernel. Try really hard not to delay this
    conversion or worse, fiddle the raw __u64 through your code since that
    diminishes the checking tools like sparse can provide. The macro
diff --git a/Documentation/process/deprecated.rst b/Documentation/process/deprecated.rst
index c8fd53a11a207..f91b8441f2ef7 100644
--- a/Documentation/process/deprecated.rst
+++ b/Documentation/process/deprecated.rst
@@ -346,3 +346,29 @@ struct_size() and flex_array_size() helpers::
         instance->count = count;
 
         memcpy(instance->items, source, flex_array_size(instance, items, instance->count));
+
+There are two special cases of replacement where the DECLARE_FLEX_ARRAY()
+helper needs to be used. (Note that it is named __DECLARE_FLEX_ARRAY() for
+use in UAPI headers.) Those cases are when the flexible array is either
+alone in a struct or is part of a union. These are disallowed by the C99
+specification, but for no technical reason (as can be seen by both the
+existing use of such arrays in those places and the work-around that
+DECLARE_FLEX_ARRAY() uses). For example, to convert this::
+
+	struct something {
+		...
+		union {
+			struct type1 one[0];
+			struct type2 two[0];
+		};
+	};
+
+The helper must be used::
+
+	struct something {
+		...
+		union {
+			DECLARE_FLEX_ARRAY(struct type1, one);
+			DECLARE_FLEX_ARRAY(struct type2, two);
+		};
+	};
diff --git a/Documentation/process/email-clients.rst b/Documentation/process/email-clients.rst
index fc2c46f3f82dd..471e1f93fa09c 100644
--- a/Documentation/process/email-clients.rst
+++ b/Documentation/process/email-clients.rst
@@ -350,3 +350,23 @@ although tab2space problem can be solved with external editor.
 
 Another problem is that Gmail will base64-encode any message that has a
 non-ASCII character. That includes things like European names.
+
+Proton Mail
+***********
+
+Proton Mail has a "feature" where it looks up keys using Web Key Directory
+(WKD) and encrypts mail to any recipients for which it finds a key.
+Kernel.org publishes the WKD for all developers who have kernel.org accounts.
+As a result, emails sent using Proton Mail to kernel.org addresses will be
+encrypted.
+Unfortunately, Proton Mail does not provide a mechanism to disable the
+automatic encryption, viewing it as a privacy feature.
+The automatic encryption feature is also enabled for mail sent via the Proton
+Mail Bridge, so this affects all outgoing messages, including patches sent with
+``git send-email``.
+Encrypted mail adds unnecessary friction, as other developers may not have mail
+clients, or tooling, configured for use with encrypted mail and some mail
+clients may encrypt responses to encrypted mail for all recipients, including
+the mailing lists.
+Unless a way to disable this "feature" is introduced, Proton Mail is unsuited
+to kernel development.
diff --git a/Documentation/process/maintainer-pgp-guide.rst b/Documentation/process/maintainer-pgp-guide.rst
index 40bfbd3b7648f..f5277993b1959 100644
--- a/Documentation/process/maintainer-pgp-guide.rst
+++ b/Documentation/process/maintainer-pgp-guide.rst
@@ -60,36 +60,18 @@ establish the integrity of the Linux kernel itself.
 PGP tools
 =========
 
-Use GnuPG v2
-------------
+Use GnuPG 2.2 or later
+----------------------
 
 Your distro should already have GnuPG installed by default, you just
-need to verify that you are using version 2.x and not the legacy 1.4
-release -- many distributions still package both, with the default
-``gpg`` command invoking GnuPG v.1. To check, run::
+need to verify that you are using a reasonably recent version of it.
+To check, run::
 
     $ gpg --version | head -n1
 
-If you see ``gpg (GnuPG) 1.4.x``, then you are using GnuPG v.1. Try the
-``gpg2`` command (if you don't have it, you may need to install the
-gnupg2 package)::
-
-    $ gpg2 --version | head -n1
-
-If you see ``gpg (GnuPG) 2.x.x``, then you are good to go. This guide
-will assume you have the version 2.2 of GnuPG (or later). If you are
-using version 2.0 of GnuPG, then some of the commands in this guide will
-not work, and you should consider installing the latest 2.2 version of
-GnuPG. Versions of gnupg-2.1.11 and later should be compatible for the
-purposes of this guide as well.
-
-If you have both ``gpg`` and ``gpg2`` commands, you should make sure you
-are always using GnuPG v2, not the legacy version. You can enforce this
-by setting the appropriate alias::
-
-    $ alias gpg=gpg2
-
-You can put that in your ``.bashrc`` to make sure it's always the case.
+If you have version 2.2 or above, then you are good to go. If you have a
+version that is prior than 2.2, then some commands from this guide may
+not work.
 
 Configure gpg-agent options
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -150,9 +132,9 @@ PGP defines four capabilities that a key can have:
 The key with the **[C]** capability is often called the "master" key,
 but this terminology is misleading because it implies that the Certify
 key can be used in place of any of other subkey on the same chain (like
-a physical "master key" can be used to open the locks made for other
-keys). Since this is not the case, this guide will refer to it as "the
-Certify key" to avoid any ambiguity.
+a physical "master key" can be used to open locks made for other keys).
+Since this is not the case, this guide will refer to it as "the Certify
+key" to avoid any ambiguity.
 
 It is critical to fully understand the following:
 
@@ -186,10 +168,10 @@ If you used the default parameters when generating your key, then that
 is what you will have. You can verify by running ``gpg --list-secret-keys``,
 for example::
 
-    sec   rsa2048 2018-01-23 [SC] [expires: 2020-01-23]
+    sec   ed25519 2022-12-20 [SC] [expires: 2024-12-19]
           000000000000000000000000AAAABBBBCCCCDDDD
     uid           [ultimate] Alice Dev <adev@kernel.org>
-    ssb   rsa2048 2018-01-23 [E] [expires: 2020-01-23]
+    ssb   cv25519 2022-12-20 [E] [expires: 2024-12-19]
 
 The long line under the ``sec`` entry is your key fingerprint --
 whenever you see ``[fpr]`` in the examples below, that 40-character
@@ -219,18 +201,9 @@ separate signing subkey::
 
 .. note:: ECC support in GnuPG
 
-    GnuPG 2.1 and later has full support for Elliptic Curve
-    Cryptography, with ability to combine ECC subkeys with traditional
-    RSA keys. The main upside of ECC cryptography is that it is much
-    faster computationally and creates much smaller signatures when
-    compared byte for byte with 2048+ bit RSA keys. Unless you plan on
-    using a smartcard device that does not support ECC operations, we
-    recommend that you create an ECC signing subkey for your kernel
-    work.
-
-    Note, that if you plan to use a hardware device that does not
+    Note, that if you intend to use a hardware token that does not
     support ED25519 ECC keys, you should choose "nistp256" instead or
-    "ed25519."
+    "ed25519." See the section below on recommended hardware devices.
 
 
 Back up your Certify key for disaster recovery
@@ -336,13 +309,13 @@ First, identify the keygrip of your Certify key::
 
 The output will be something like this::
 
-    pub   rsa2048 2018-01-24 [SC] [expires: 2020-01-24]
+    pub   ed25519 2022-12-20 [SC] [expires: 2022-12-19]
           000000000000000000000000AAAABBBBCCCCDDDD
           Keygrip = 1111000000000000000000000000000000000000
     uid           [ultimate] Alice Dev <adev@kernel.org>
-    sub   rsa2048 2018-01-24 [E] [expires: 2020-01-24]
+    sub   cv25519 2022-12-20 [E] [expires: 2022-12-19]
           Keygrip = 2222000000000000000000000000000000000000
-    sub   ed25519 2018-01-24 [S]
+    sub   ed25519 2022-12-20 [S]
           Keygrip = 3333000000000000000000000000000000000000
 
 Find the keygrip entry that is beneath the ``pub`` line (right under the
@@ -365,14 +338,14 @@ Now, if you issue the ``--list-secret-keys`` command, it will show that
 the Certify key is missing (the ``#`` indicates it is not available)::
 
     $ gpg --list-secret-keys
-    sec#  rsa2048 2018-01-24 [SC] [expires: 2020-01-24]
+    sec#  ed25519 2022-12-20 [SC] [expires: 2024-12-19]
           000000000000000000000000AAAABBBBCCCCDDDD
     uid           [ultimate] Alice Dev <adev@kernel.org>
-    ssb   rsa2048 2018-01-24 [E] [expires: 2020-01-24]
-    ssb   ed25519 2018-01-24 [S]
+    ssb   cv25519 2022-12-20 [E] [expires: 2024-12-19]
+    ssb   ed25519 2022-12-20 [S]
 
 You should also remove any ``secring.gpg`` files in the ``~/.gnupg``
-directory, which are left over from earlier versions of GnuPG.
+directory, which may be left over from previous versions of GnuPG.
 
 If you don't have the "private-keys-v1.d" directory
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -437,8 +410,7 @@ functionality. There are several options available:
   U2F, among others, and now finally supports NISTP and ED25519 ECC
   keys.
 
-`LWN has a good review`_ of some of the above models, as well as several
-others. Your choice will depend on cost, shipping availability in your
+Your choice will depend on cost, shipping availability in your
 geographical region, and open/proprietary hardware considerations.
 
 .. note::
@@ -451,7 +423,6 @@ geographical region, and open/proprietary hardware considerations.
 .. _`Nitrokey Pro 2`: https://shop.nitrokey.com/shop/product/nkpr2-nitrokey-pro-2-3
 .. _`Yubikey 5`: https://www.yubico.com/products/yubikey-5-overview/
 .. _Gnuk: https://www.fsij.org/doc-gnuk/
-.. _`LWN has a good review`: https://lwn.net/Articles/736231/
 .. _`qualify for a free Nitrokey Start`: https://www.kernel.org/nitrokey-digital-tokens-for-kernel-developers.html
 
 Configure your smartcard device
@@ -509,11 +480,11 @@ passphrase and the admin PIN of the card for most operations::
 
     Secret subkeys are available.
 
-    pub  rsa2048/AAAABBBBCCCCDDDD
-         created: 2018-01-23  expires: 2020-01-23  usage: SC
+    pub  ed25519/AAAABBBBCCCCDDDD
+         created: 2022-12-20  expires: 2024-12-19  usage: SC
          trust: ultimate      validity: ultimate
-    ssb  rsa2048/1111222233334444
-         created: 2018-01-23  expires: never       usage: E
+    ssb  cv25519/1111222233334444
+         created: 2022-12-20  expires: never       usage: E
     ssb  ed25519/5555666677778888
          created: 2017-12-07  expires: never       usage: S
     [ultimate] (1). Alice Dev <adev@kernel.org>
@@ -577,11 +548,11 @@ If you perform ``--list-secret-keys`` now, you will see a subtle
 difference in the output::
 
     $ gpg --list-secret-keys
-    sec#  rsa2048 2018-01-24 [SC] [expires: 2020-01-24]
+    sec#  ed25519 2022-12-20 [SC] [expires: 2024-12-19]
           000000000000000000000000AAAABBBBCCCCDDDD
     uid           [ultimate] Alice Dev <adev@kernel.org>
-    ssb>  rsa2048 2018-01-24 [E] [expires: 2020-01-24]
-    ssb>  ed25519 2018-01-24 [S]
+    ssb>  cv25519 2022-12-20 [E] [expires: 2024-12-19]
+    ssb>  ed25519 2022-12-20 [S]
 
 The ``>`` in the ``ssb>`` output indicates that the subkey is only
 available on the smartcard. If you go back into your secret keys
@@ -644,7 +615,7 @@ run::
 You can also use a specific date if that is easier to remember (e.g.
 your birthday, January 1st, or Canada Day)::
 
-    $ gpg --quick-set-expire [fpr] 2020-07-01
+    $ gpg --quick-set-expire [fpr] 2025-07-01
 
 Remember to send the updated key back to keyservers::
 
@@ -707,12 +678,6 @@ should be used (``[fpr]`` is the fingerprint of your key)::
 
     $ git config --global user.signingKey [fpr]
 
-**IMPORTANT**: If you have a distinct ``gpg2`` command, then you should
-tell git to always use it instead of the legacy ``gpg`` from version 1::
-
-    $ git config --global gpg.program gpg2
-    $ git config --global gpgv.program gpgv2
-
 How to work with signed tags
 ----------------------------
 
@@ -751,13 +716,6 @@ If you are verifying someone else's git tag, then you will need to
 import their PGP key. Please refer to the
 ":ref:`verify_identities`" section below.
 
-.. note::
-
-    If you get "``gpg: Can't check signature: unknown pubkey
-    algorithm``" error, you need to tell git to use gpgv2 for
-    verification, so it properly processes signatures made by ECC keys.
-    See instructions at the start of this section.
-
 Configure git to always sign annotated tags
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~