tjh.dev
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1444015
3
928
Clone this repository
https://tangled.org/tjh.dev/kernel
https://tangled.org/did:plc:65gha4t3avpfpzmvpbwovss7/kernel
git@gordian.tjh.dev:tjh.dev/kernel
git@gordian.tjh.dev:did:plc:65gha4t3avpfpzmvpbwovss7/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
Pull init and set_fs() cleanups from Al Viro:
"Christoph's 'getting rid of ksys_...() uses under KERNEL_DS' series"
* 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (50 commits)
init: add an init_dup helper
init: add an init_utimes helper
init: add an init_stat helper
init: add an init_mknod helper
init: add an init_mkdir helper
init: add an init_symlink helper
init: add an init_link helper
init: add an init_eaccess helper
init: add an init_chmod helper
init: add an init_chown helper
init: add an init_chroot helper
init: add an init_chdir helper
init: add an init_rmdir helper
init: add an init_unlink helper
init: add an init_umount helper
init: add an init_mount helper
init: mark create_dev as __init
init: mark console_on_rootfs as __init
init: initialize ramdisk_execute_command at compile time
devtmpfs: refactor devtmpfsd()
...
Pull ptrace regset updates from Al Viro:
"Internal regset API changes:
- regularize copy_regset_{to,from}_user() callers
- switch to saner calling conventions for ->get()
- kill user_regset_copyout()
The ->put() side of things will have to wait for the next cycle,
unfortunately.
The balance is about -1KLoC and replacements for ->get() instances are
a lot saner"
* 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
regset: kill user_regset_copyout{,_zero}()
regset(): kill ->get_size()
regset: kill ->get()
csky: switch to ->regset_get()
xtensa: switch to ->regset_get()
parisc: switch to ->regset_get()
nds32: switch to ->regset_get()
nios2: switch to ->regset_get()
hexagon: switch to ->regset_get()
h8300: switch to ->regset_get()
openrisc: switch to ->regset_get()
riscv: switch to ->regset_get()
c6x: switch to ->regset_get()
ia64: switch to ->regset_get()
arc: switch to ->regset_get()
arm: switch to ->regset_get()
sh: convert to ->regset_get()
arm64: switch to ->regset_get()
mips: switch to ->regset_get()
sparc: switch to ->regset_get()
...
Add a simple helper to grab a reference to a file and install it at
the next available fd, and switch the early init code over to it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The code for preallocate_vmalloc_pages() was written under the
assumption that the p4d_offset() and pud_offset() functions will perform
present checks before dereferencing the parent entries.
This assumption is wrong an leads to a bug in the code which causes the
physical address found in the PGD be used as a page-table page, even if
the PGD is not present.
So the code flow currently is:
pgd = pgd_offset_k(addr);
p4d = p4d_offset(pgd, addr);
if (p4d_none(*p4d))
p4d = p4d_alloc(&init_mm, pgd, addr);
This lacks a check for pgd_none() at least, the correct flow would be:
pgd = pgd_offset_k(addr);
if (pgd_none(*pgd))
p4d = p4d_alloc(&init_mm, pgd, addr);
else
p4d = p4d_offset(pgd, addr);
But this is the same flow that the p4d_alloc() and the pud_alloc()
functions use internally, so there is no need to duplicate them.
Remove the p?d_none() checks from the function and just call into
p4d_alloc() and pud_alloc() to correctly pre-allocate the PGD entries.
Reported-and-tested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Fixes: 6eb82f994026 ("x86/mm: Pre-allocate P4D/PUD pages for vmalloc area")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
no callers left
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add a simple helper to set timestamps with a kernel space file name and
switch the early init code over to it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Commit 585524081ecd ("random: random.h should include archrandom.h, not
the other way around") tries to fix a problem with recursive inclusion
of linux/random.h and arch/archrandom.h for arm64. Unfortunately, this
results in the following compile error if ARCH_RANDOM is disabled.
arch/arm64/kernel/kaslr.c: In function 'kaslr_early_init':
arch/arm64/kernel/kaslr.c:128:6: error: implicit declaration of function '__early_cpu_has_rndr'; did you mean '__early_pfn_to_nid'? [-Werror=implicit-function-declaration]
if (__early_cpu_has_rndr()) {
^~~~~~~~~~~~~~~~~~~~
__early_pfn_to_nid
arch/arm64/kernel/kaslr.c:131:7: error: implicit declaration of function '__arm64_rndr' [-Werror=implicit-function-declaration]
if (__arm64_rndr(&raw))
^~~~~~~~~~~~
The problem is that arch/archrandom.h is only included from
linux/random.h if ARCH_RANDOM is enabled. If not, __arm64_rndr() and
__early_cpu_has_rndr() are undeclared, causing the problem.
Use arch_get_random_seed_long_early() instead of arm64 specific
functions to solve the problem.
Reported-by: Qian Cai <cai@lca.pw>
Fixes: 585524081ecd ("random: random.h should include archrandom.h, not the other way around")
Cc: Qian Cai <cai@lca.pw>
Cc: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
not used anymore
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add a simple helper to stat with a kernel space file name and switch
the early init code over to it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
We just don't do that. "default y" is for things that are needed for
compatibility (when an old feature is made unconditional), or for things
that are basically part of the infrastructure of a platform.
And it can possibly be used for questions that don't enable code on
their own, but are used to enable or disable a whole slew of other
questions.
A new feature that people aren't using is never 'default y', unless it
cures cancer or ends world hunger.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
no instances left
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add a simple helper to mknod with a kernel space file name and switch
the early init code over to it. Remove the now unused ksys_mknod.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull dlm updates from David Teigland:
"This set includes a some improvements to the dlm networking layer:
improving the ability to trace dlm messages for debugging, and
improved handling of bad messages or disrupted connections"
* tag 'dlm-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm:
fs: dlm: implement tcp graceful shutdown
fs: dlm: change handling of reconnects
fs: dlm: don't close socket on invalid message
fs: dlm: set skb mark per peer socket
fs: dlm: set skb mark for listen socket
net: sock: add sock_set_mark
dlm: Fix kobject memleak
README