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 reStructuredText 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
code
Clone this repository
https://tangled.org/tjh.dev/kernel
git@gordian.tjh.dev:tjh.dev/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Pull bcachefs fixes from Kent Overstreet:
- assorted syzbot fixes
- some upgrade fixes for old (pre 1.0) filesystems
- fix for moving data off a device that was switched to durability=0
after data had been written to it.
- nocow deadlock fix
- fix for new rebalance_work accounting
* tag 'bcachefs-2024-08-24' of git://evilpiepirate.org/bcachefs: (28 commits)
bcachefs: Fix rebalance_work accounting
bcachefs: Fix failure to flush moves before sleeping in copygc
bcachefs: don't use rht_bucket() in btree_key_cache_scan()
bcachefs: add missing inode_walker_exit()
bcachefs: clear path->should_be_locked in bch2_btree_key_cache_drop()
bcachefs: Fix double assignment in check_dirent_to_subvol()
bcachefs: Fix refcounting in discard path
bcachefs: Fix compat issue with old alloc_v4 keys
bcachefs: Fix warning in bch2_fs_journal_stop()
fs/super.c: improve get_tree() error message
bcachefs: Fix missing validation in bch2_sb_journal_v2_validate()
bcachefs: Fix replay_now_at() assert
bcachefs: Fix locking in bch2_ioc_setlabel()
bcachefs: fix failure to relock in btree_node_fill()
bcachefs: fix failure to relock in bch2_btree_node_mem_alloc()
bcachefs: unlock_long() before resort in journal replay
bcachefs: fix missing bch2_err_str()
bcachefs: fix time_stats_to_text()
bcachefs: Fix bch2_bucket_gens_init()
bcachefs: Fix bch2_trigger_alloc assert
...
Pull smb server fixes from Steve French:
- query directory flex array fix
- fix potential null ptr reference in open
- fix error message in some open cases
- two minor cleanups
* tag '6.11-rc5-server-fixes' of git://git.samba.org/ksmbd:
smb/server: update misguided comment of smb2_allocate_rsp_buf()
smb/server: remove useless assignment of 'file_present' in smb2_open()
smb/server: fix potential null-ptr-deref of lease_ctx_info in smb2_open()
smb/server: fix return value of smb2_open()
ksmbd: the buffer of smb2 query dir response has at least 1 byte
rebalance_work was keying off of the presence of rebelance_opts in the
extent - but that was incorrect, we keep those around after rebalance
for indirect extents since the inode's options are not directly
available
Fixes: 20ac515a9cc7 ("bcachefs: bch_acct_rebalance_work")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Pull s390 fixes from Vasily Gorbik:
- Fix KASLR base offset to account for symbol offsets in the vmlinux
ELF file, preventing tool breakages like the drgn debugger
- Fix potential memory corruption of physmem_info during kernel
physical address randomization
- Fix potential memory corruption due to overlap between the relocated
lowcore and identity mapping by correctly reserving lowcore memory
- Fix performance regression and avoid randomizing identity mapping
base by default
- Fix unnecessary delay of AP bus binding complete uevent to prevent
startup lag in KVM guests using AP
* tag 's390-6.11-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/boot: Fix KASLR base offset off by __START_KERNEL bytes
s390/boot: Avoid possible physmem_info segment corruption
s390/ap: Refine AP bus bindings complete processing
s390/mm: Pin identity mapping base to zero
s390/mm: Prevent lowcore vs identity mapping overlap
smb2_allocate_rsp_buf() will return other error code except -ENOMEM.
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This fixes an apparent deadlock - rebalance would get stuck trying to
take nocow locks because they weren't being released by copygc.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Pull SCSI fixes from James Bottomley:
"The important core fix is another tweak to our discard discovery
issues. The off by 512 in logical block count seems bad, but in fact
the inline was only ever used in debug prints, which is why no-one
noticed"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: sd: Do not attempt to configure discard unless LBPME is set
scsi: MAINTAINERS: Add header files to SCSI SUBSYSTEM
scsi: ufs: qcom: Add UFSHCD_QUIRK_BROKEN_LSDBS_CAP for SM8550 SoC
scsi: ufs: core: Add a quirk for handling broken LSDBS field in controller capabilities register
scsi: core: Fix the return value of scsi_logical_block_count()
scsi: MAINTAINERS: Update HiSilicon SAS controller driver maintainer
Symbol offsets to the KASLR base do not match symbol address in
the vmlinux image. That is the result of setting the KASLR base
to the beginning of .text section as result of an optimization.
Revert that optimization and allocate virtual memory for the
whole kernel image including __START_KERNEL bytes as per the
linker script. That allows keeping the semantics of the KASLR
base offset in sync with other architectures.
Rename __START_KERNEL to TEXT_OFFSET, since it represents the
offset of the .text section within the kernel image, rather than
a virtual address.
Still skip mapping TEXT_OFFSET bytes to save memory on pgtables
and provoke exceptions in case an attempt to access this area is
made, as no kernel symbol may reside there.
In case CONFIG_KASAN is enabled the location counter might exceed
the value of TEXT_OFFSET, while the decompressor linker script
forcefully resets it to TEXT_OFFSET, which leads to a sections
overlap link failure. Use MAX() expression to avoid that.
Reported-by: Omar Sandoval <osandov@osandov.com>
Closes: https://lore.kernel.org/linux-s390/ZnS8dycxhtXBZVky@telecaster.dhcp.thefacebook.com/
Fixes: 56b1069c40c7 ("s390/boot: Rework deployment of the kernel image")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The variable is already true here.
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
rht_bucket() does strange complicated things when a rehash is in
progress.
Instead, just skip scanning when a rehash is in progress: scanning is
going to be more expensive (many more empty slots to cover), and some
sort of infinite loop is being observed
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Pull cgroup fixes from Tejun Heo:
"Three patches addressing cpuset corner cases"
* tag 'cgroup-for-6.11-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset: Eliminate unncessary sched domains rebuilds in hotplug
cgroup/cpuset: Clear effective_xcpus on cpus_allowed clearing only if cpus.exclusive not set
cgroup/cpuset: fix panic caused by partcmd_update
Commit f874d7210d88 ("scsi: sd: Keep the discard mode stable") attempted
to address an issue where one mode of discard operation got configured
prior to the device completing full discovery. Unfortunately this
change assumed discard was always enabled on the device.
Do not attempt to configure discard unless LBPME is enabled.
Link: https://lore.kernel.org/r/20240817005325.3319384-1-martin.petersen@oracle.com
Fixes: f874d7210d88 ("scsi: sd: Keep the discard mode stable")
Reported-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
When physical memory for the kernel image is allocated it does not
consider extra memory required for offsetting the image start to
match it with the lower 20 bits of KASLR virtual base address. That
might lead to kernel access beyond its memory range.
Suggested-by: Vasily Gorbik <gor@linux.ibm.com>
Fixes: 693d41f7c938 ("s390/mm: Restore mapping of kernel image using large pages")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
null-ptr-deref will occur when (req_op_level == SMB2_OPLOCK_LEVEL_LEASE)
and parse_lease_state() return NULL.
Fix this by check if 'lease_ctx_info' is NULL.
Additionally, remove the redundant parentheses in
parse_durable_handle_context().
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
fix a small leak
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
README