diff options
Diffstat (limited to 'Documentation/process')
| -rw-r--r-- | Documentation/process/5.Posting.rst | 2 | ||||
| -rw-r--r-- | Documentation/process/adding-syscalls.rst | 34 | ||||
| -rw-r--r-- | Documentation/process/changes.rst | 2 | ||||
| -rw-r--r-- | Documentation/process/coding-style.rst | 9 | ||||
| -rw-r--r-- | Documentation/process/howto.rst | 15 | ||||
| -rw-r--r-- | Documentation/process/kernel-driver-statement.rst | 1 | ||||
| -rw-r--r-- | Documentation/process/license-rules.rst | 20 | ||||
| -rw-r--r-- | Documentation/process/magic-number.rst | 2 | ||||
| -rw-r--r-- | Documentation/process/submitting-patches.rst | 9 |
9 files changed, 64 insertions, 30 deletions
diff --git a/Documentation/process/5.Posting.rst b/Documentation/process/5.Posting.rst index 645fa9c7388a..c209d70da66f 100644 --- a/Documentation/process/5.Posting.rst +++ b/Documentation/process/5.Posting.rst @@ -213,7 +213,7 @@ The tags in common use are: which can be found in Documentation/process/submitting-patches.rst. Code without a proper signoff cannot be merged into the mainline. - - Co-Developed-by: states that the patch was also created by another developer + - Co-developed-by: states that the patch was also created by another developer along with the original author. This is useful at times when multiple people work on a single patch. Note, this person also needs to have a Signed-off-by: line in the patch as well. diff --git a/Documentation/process/adding-syscalls.rst b/Documentation/process/adding-syscalls.rst index 8cc25a06f353..314c8bf6f2a2 100644 --- a/Documentation/process/adding-syscalls.rst +++ b/Documentation/process/adding-syscalls.rst @@ -222,7 +222,7 @@ your new syscall number may get adjusted to resolve conflicts. The file ``kernel/sys_ni.c`` provides a fallback stub implementation of each system call, returning ``-ENOSYS``. Add your new system call here too:: - cond_syscall(sys_xyzzy); + COND_SYSCALL(xyzzy); Your new kernel functionality, and the system call that controls it, should normally be optional, so add a ``CONFIG`` option (typically to @@ -487,6 +487,38 @@ patchset, for the convenience of reviewers. The man page should be cc'ed to linux-man@vger.kernel.org For more details, see https://www.kernel.org/doc/man-pages/patches.html + +Do not call System Calls in the Kernel +-------------------------------------- + +System calls are, as stated above, interaction points between userspace and +the kernel. Therefore, system call functions such as ``sys_xyzzy()`` or +``compat_sys_xyzzy()`` should only be called from userspace via the syscall +table, but not from elsewhere in the kernel. If the syscall functionality is +useful to be used within the kernel, needs to be shared between an old and a +new syscall, or needs to be shared between a syscall and its compatibility +variant, it should be implemented by means of a "helper" function (such as +``kern_xyzzy()``). This kernel function may then be called within the +syscall stub (``sys_xyzzy()``), the compatibility syscall stub +(``compat_sys_xyzzy()``), and/or other kernel code. + +At least on 64-bit x86, it will be a hard requirement from v4.17 onwards to not +call system call functions in the kernel. It uses a different calling +convention for system calls where ``struct pt_regs`` is decoded on-the-fly in a +syscall wrapper which then hands processing over to the actual syscall function. +This means that only those parameters which are actually needed for a specific +syscall are passed on during syscall entry, instead of filling in six CPU +registers with random user space content all the time (which may cause serious +trouble down the call chain). + +Moreover, rules on how data may be accessed may differ between kernel data and +user data. This is another reason why calling ``sys_xyzzy()`` is generally a +bad idea. + +Exceptions to this rule are only allowed in architecture-specific overrides, +architecture-specific compatibility wrappers, or other code in arch/. + + References and Sources ---------------------- diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index 4f19a9725f76..ddc029734b25 100644 --- a/Documentation/process/changes.rst +++ b/Documentation/process/changes.rst @@ -430,7 +430,7 @@ udev FUSE ---- -- <http://sourceforge.net/projects/fuse> +- <https://github.com/libfuse/libfuse/releases> mcelog ------ diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst index a20b44a40ec4..d98deb62c400 100644 --- a/Documentation/process/coding-style.rst +++ b/Documentation/process/coding-style.rst @@ -200,6 +200,15 @@ statement; in the latter case use braces in both branches: otherwise(); } +Also, use braces when a loop contains more than a single simple statement: + +.. code-block:: c + + while (condition) { + if (test) + do_something(); + } + 3.1) Spaces *********** diff --git a/Documentation/process/howto.rst b/Documentation/process/howto.rst index c6875b1db56f..3df55811b916 100644 --- a/Documentation/process/howto.rst +++ b/Documentation/process/howto.rst @@ -213,13 +213,6 @@ will learn the basics of getting your patch into the Linux kernel tree, and possibly be pointed in the direction of what to go work on next, if you do not already have an idea. -If you already have a chunk of code that you want to put into the kernel -tree, but need some help getting it in the proper form, the -kernel-mentors project was created to help you out with this. It is a -mailing list, and can be found at: - - https://selenic.com/mailman/listinfo/kernel-mentors - Before making any actual modifications to the Linux kernel code, it is imperative to understand how the code in question works. For this purpose, nothing is better than reading through it directly (most tricky @@ -381,14 +374,6 @@ bugs is one of the best ways to get merits among other developers, because not many people like wasting time fixing other people's bugs. To work in the already reported bug reports, go to https://bugzilla.kernel.org. -If you want to be advised of the future bug reports, you can subscribe to the -bugme-new mailing list (only new bug reports are mailed here) or to the -bugme-janitor mailing list (every change in the bugzilla is mailed here) - - https://lists.linux-foundation.org/mailman/listinfo/bugme-new - - https://lists.linux-foundation.org/mailman/listinfo/bugme-janitors - Mailing lists diff --git a/Documentation/process/kernel-driver-statement.rst b/Documentation/process/kernel-driver-statement.rst index 60d9d868f300..e78452c2164c 100644 --- a/Documentation/process/kernel-driver-statement.rst +++ b/Documentation/process/kernel-driver-statement.rst @@ -103,6 +103,7 @@ today, have in the past, or will in the future. - Auke Kok - Peter Korsgaard - Jiri Kosina + - Aaro Koskinen - Mariusz Kozlowski - Greg Kroah-Hartman - Michael Krufky diff --git a/Documentation/process/license-rules.rst b/Documentation/process/license-rules.rst index 408f77dc6157..8ea26325fe3f 100644 --- a/Documentation/process/license-rules.rst +++ b/Documentation/process/license-rules.rst @@ -4,15 +4,17 @@ Linux kernel licensing rules ============================ The Linux Kernel is provided under the terms of the GNU General Public -License version 2 only (GPL-2.0), as published by the Free Software -Foundation, and provided in the COPYING file. This documentation file is -not meant to replace the COPYING file, but provides a description of how -each source file should be annotated to make the licensing it is governed -under clear and unambiguous. - -The license in the COPYING file applies to the kernel source as a whole, -though individual source files can have a different license which is -required to be compatible with the GPL-2.0:: +License version 2 only (GPL-2.0), as provided in LICENSES/preferred/GPL-2.0, +with an explicit syscall exception described in +LICENSES/exceptions/Linux-syscall-note, as described in the COPYING file. + +This documentation file provides a description of how each source file +should be annotated to make its license clear and unambiguous. +It doesn't replace the Kernel's license. + +The license described in the COPYING file applies to the kernel source +as a whole, though individual source files can have a different license +which is required to be compatible with the GPL-2.0:: GPL-1.0+ : GNU General Public License v1.0 or later GPL-2.0+ : GNU General Public License v2.0 or later diff --git a/Documentation/process/magic-number.rst b/Documentation/process/magic-number.rst index c74199f60c6c..00cecf1fcba9 100644 --- a/Documentation/process/magic-number.rst +++ b/Documentation/process/magic-number.rst @@ -14,7 +14,7 @@ passing pointers to structures via a void * pointer. The tty code, for example, does this frequently to pass driver-specific and line discipline-specific structures back and forth. -The way to use magic numbers is to declare then at the beginning of +The way to use magic numbers is to declare them at the beginning of the structure, like so:: struct tty_ldisc { diff --git a/Documentation/process/submitting-patches.rst b/Documentation/process/submitting-patches.rst index 1ef19d3a3eee..f7152ed565e5 100644 --- a/Documentation/process/submitting-patches.rst +++ b/Documentation/process/submitting-patches.rst @@ -510,8 +510,8 @@ tracking your trees, and to people trying to troubleshoot bugs in your tree. -12) When to use Acked-by: and Cc: ---------------------------------- +12) When to use Acked-by:, Cc:, and Co-Developed-by: +------------------------------------------------------- The Signed-off-by: tag indicates that the signer was involved in the development of the patch, or that he/she was in the patch's delivery path. @@ -543,6 +543,11 @@ person it names - but it should indicate that this person was copied on the patch. This tag documents that potentially interested parties have been included in the discussion. +A Co-Developed-by: states that the patch was also created by another developer +along with the original author. This is useful at times when multiple people +work on a single patch. Note, this person also needs to have a Signed-off-by: +line in the patch as well. + 13) Using Reported-by:, Tested-by:, Reviewed-by:, Suggested-by: and Fixes: -------------------------------------------------------------------------- |