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.
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Pull genpm / pmdomain rename from Ulf Hansson:
"This renames the genpd subsystem to pmdomain.
As discussed on LKML, using 'genpd' as the name of a subsystem isn't
very self-explanatory and the acronym itself that means Generic PM
Domain, is known only by a limited group of people.
The suggestion to improve the situation is to rename the subsystem to
'pmdomain', which there seems to be a good consensus around using.
Ideally it should indicate that its purpose is to manage Power Domains
or 'PM domains' as we often also use within the Linux Kernel
terminology"
* tag 'pmdomain-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/linux-pm:
pmdomain: Rename the genpd subsystem to pmdomain
Pull tpm fix from Jarkko Sakkinen.
* tag 'tpmdd-v6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd:
tpm: Fix typo in tpmrm class definition
It has been pointed out that naming a subsystem "genpd" isn't very
self-explanatory and the acronym itself that means Generic PM Domain, is
known only by a limited group of people.
In a way to improve the situation, let's rename the subsystem to pmdomain,
which ideally should indicate that this is about so called Power Domains or
"PM domains" as we often also use within the Linux Kernel terminology.
Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230912221127.487327-1-ulf.hansson@linaro.org
Pull parisc architecture fixes from Helge Deller:
- fix reference to exported symbols for parisc64 [Masahiro Yamada]
- Block-TLB (BTLB) support on 32-bit CPUs
- sparse and build-warning fixes
* tag 'parisc-for-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
linux/export: fix reference to exported functions for parisc64
parisc: BTLB: Initialize BTLB tables at CPU startup
parisc: firmware: Simplify calling non-PA20 functions
parisc: BTLB: _edata symbol has to be page aligned for BTLB support
parisc: BTLB: Add BTLB insert and purge firmware function wrappers
parisc: BTLB: Clear possibly existing BTLB entries
parisc: Prepare for Block-TLB support on 32-bit kernel
parisc: shmparam.h: Document aliasing requirements of PA-RISC
parisc: irq: Make irq_stack_union static to avoid sparse warning
parisc: drivers: Fix sparse warning
parisc: iosapic.c: Fix sparse warnings
parisc: ccio-dma: Fix sparse warnings
parisc: sba-iommu: Fix sparse warnigs
parisc: sba: Fix compile warning wrt list of SBA devices
parisc: sba_iommu: Fix build warning if procfs if disabled
Commit d2e8071bed0be ("tpm: make all 'class' structures const")
unfortunately had a typo for the name on tpmrm.
Fixes: d2e8071bed0b ("tpm: make all 'class' structures const")
Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Pull tracing fixes from Steven Rostedt:
- Add missing LOCKDOWN checks for eventfs callers
When LOCKDOWN is active for tracing, it causes inconsistent state
when some functions succeed and others fail.
- Use dput() to free the top level eventfs descriptor
There was a race between accesses and freeing it.
- Fix a long standing bug that eventfs exposed due to changing timings
by dynamically creating files. That is, If a event file is opened for
an instance, there's nothing preventing the instance from being
removed which will make accessing the files cause use-after-free
bugs.
- Fix a ring buffer race that happens when iterating over the ring
buffer while writers are active. Check to make sure not to read the
event meta data if it's beyond the end of the ring buffer sub buffer.
- Fix the print trigger that disappeared because the test to create it
was looking for the event dir field being filled, but now it has the
"ef" field filled for the eventfs structure.
- Remove the unused "dir" field from the event structure.
- Fix the order of the trace_dynamic_info as it had it backwards for
the offset and len fields for which one was for which endianess.
- Fix NULL pointer dereference with eventfs_remove_rec()
If an allocation fails in one of the eventfs_add_*() functions, the
caller of it in event_subsystem_dir() or event_create_dir() assigns
the result to the structure. But it's assigning the ERR_PTR and not
NULL. This was passed to eventfs_remove_rec() which expects either a
good pointer or a NULL, not ERR_PTR. The fix is to not assign the
ERR_PTR to the structure, but to keep it NULL on error.
- Fix list_for_each_rcu() to use list_for_each_srcu() in
dcache_dir_open_wrapper(). One iteration of the code used RCU but
because it had to call sleepable code, it had to be changed to use
SRCU, but one of the iterations was missed.
- Fix synthetic event print function to use "as_u64" instead of passing
in a pointer to the union. To fix big/little endian issues, the u64
that represented several types was turned into a union to define the
types properly.
* tag 'trace-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
eventfs: Fix the NULL pointer dereference bug in eventfs_remove_rec()
tracefs/eventfs: Use list_for_each_srcu() in dcache_dir_open_wrapper()
tracing/synthetic: Print out u64 values properly
tracing/synthetic: Fix order of struct trace_dynamic_info
selftests/ftrace: Fix dependencies for some of the synthetic event tests
tracing: Remove unused trace_event_file dir field
tracing: Use the new eventfs descriptor for print trigger
ring-buffer: Do not attempt to read past "commit"
tracefs/eventfs: Free top level files on removal
ring-buffer: Avoid softlockup in ring_buffer_resize()
tracing: Have event inject files inc the trace array ref count
tracing: Have option files inc the trace array ref count
tracing: Have current_trace inc the trace array ref count
tracing: Have tracing_max_latency inc the trace array ref count
tracing: Increase trace array ref count on enable and filter files
tracefs/eventfs: Use dput to free the toplevel events directory
tracefs/eventfs: Add missing lockdown checks
tracefs: Add missing lockdown check to tracefs_create_dir()
John David Anglin reported parisc has been broken since commit
ddb5cdbafaaa ("kbuild: generate KSYMTAB entries by modpost").
Like ia64, parisc64 uses a function descriptor. The function
references must be prefixed with P%.
Also, symbols prefixed $$ from the library have the symbol type
STT_LOPROC instead of STT_FUNC. They should be handled as functions
too.
Fixes: ddb5cdbafaaa ("kbuild: generate KSYMTAB entries by modpost")
Reported-by: John David Anglin <dave.anglin@bell.net>
Tested-by: John David Anglin <dave.anglin@bell.net>
Tested-by: Helge Deller <deller@gmx.de>
Closes: https://lore.kernel.org/linux-parisc/1901598a-e11d-f7dd-a5d9-9a69d06e6b6e@bell.net/T/#u
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Pull btrfs fixes from David Sterba:
- several fixes for handling directory item (inserting, removing,
iteration, error handling)
- fix transaction commit stalls when auto relocation is running and
blocks other tasks that want to commit
- fix a build error when DEBUG is enabled
- fix lockdep warning in inode number lookup ioctl
- fix race when finishing block group creation
- remove link to obsolete wiki in several files
* tag 'for-6.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
MAINTAINERS: remove links to obsolete btrfs.wiki.kernel.org
btrfs: assert delayed node locked when removing delayed item
btrfs: remove BUG() after failure to insert delayed dir index item
btrfs: improve error message after failure to add delayed dir index item
btrfs: fix a compilation error if DEBUG is defined in btree_dirty_folio
btrfs: check for BTRFS_FS_ERROR in pending ordered assert
btrfs: fix lockdep splat and potential deadlock after failure running delayed items
btrfs: do not block starts waiting on previous transaction commit
btrfs: release path before inode lookup during the ino lookup ioctl
btrfs: fix race between finishing block group creation and its item update
Pull drm ci scripts from Dave Airlie:
"This is a bunch of ci integration for the freedesktop gitlab instance
where we currently do upstream userspace testing on diverse sets of
GPU hardware. From my perspective I think it's an experiment worth
going with and seeing how the benefits/noise playout keeping these
files useful.
Ideally I'd like to get this so we can do pre-merge testing on PRs
eventually.
Below is some info from danvet on why we've ended up making the
decision and how we can roll it back if we decide it was a bad plan.
Why in upstream?
- like documentation, testcases, tools CI integration is one of these
things where you can waste endless amounts of time if you
accidentally have a version that doesn't match your source code
- but also like the above, there's a balance, this is the initial cut
of what we think makes sense to keep in sync vs out-of-tree,
probably needs adjustment
- gitlab supports out-of-repo gitlab integration and that's what's
been used for the kernel in drm, but it results in per-driver
fragmentation and lots of duplicated effort. the simple act of
smashing an arbitrary winner into a topic branch already started
surfacing patches on dri-devel and sparking good cross driver team
discussions
Why gitlab?
- it's not any more shit than any of the other CI
- drm userspace uses it extensively for everything in userspace, we
have a lot of people and experience with this, including
integration of hw testing labs
- media userspace like gstreamer is also on gitlab.fd.o, and there's
discussion to extend this to the media subsystem in some fashion
Can this be shared?
- there's definitely a pile of code that could move to scripts/ if
other subsystem adopt ci integration in upstream kernel git. other
bits are more drm/gpu specific like the igt-gpu-tests/tools
integration
- docker images can be run locally or in other CI runners
Will we regret this?
- it's all in one directory, intentionally, for easy deletion
- probably 1-2 years in upstream to see whether this is worth it or a
Big Mistake. that's roughly what it took to _really_ roll out solid
CI in the bigger userspace projects we have on gitlab.fd.o like
mesa3d"
* tag 'topic/drm-ci-2023-08-31-1' of git://anongit.freedesktop.org/drm/drm:
drm: ci: docs: fix build warning - add missing escape
drm: Add initial ci/ subdirectory
Inject fault while probing btrfs.ko, if kstrdup() fails in
eventfs_prepare_ef() in eventfs_add_dir(), it will return ERR_PTR
to assign file->ef. But the eventfs_remove() check NULL in
trace_module_remove_events(), which causes the below NULL
pointer dereference.
As both Masami and Steven suggest, allocater side should handle the
error carefully and remove it, so fix the places where it failed.
Could not create tracefs 'raid56_write' directory
Btrfs loaded, zoned=no, fsverity=no
Unable to handle kernel NULL pointer dereference at virtual address 000000000000001c
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=0000000102544000
[000000000000001c] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in: btrfs(-) libcrc32c xor xor_neon raid6_pq cfg80211 rfkill 8021q garp mrp stp llc ipv6 [last unloaded: btrfs]
CPU: 15 PID: 1343 Comm: rmmod Tainted: G N 6.5.0+ #40
Hardware name: linux,dummy-virt (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : eventfs_remove_rec+0x24/0xc0
lr : eventfs_remove+0x68/0x1d8
sp : ffff800082d63b60
x29: ffff800082d63b60 x28: ffffb84b80ddd00c x27: ffffb84b3054ba40
x26: 0000000000000002 x25: ffff800082d63bf8 x24: ffffb84b8398e440
x23: ffffb84b82af3000 x22: dead000000000100 x21: dead000000000122
x20: ffff800082d63bf8 x19: fffffffffffffff4 x18: ffffb84b82508820
x17: 0000000000000000 x16: 0000000000000000 x15: 000083bc876a3166
x14: 000000000000006d x13: 000000000000006d x12: 0000000000000000
x11: 0000000000000001 x10: 00000000000017e0 x9 : 0000000000000001
x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffffb84b84289804
x5 : 0000000000000000 x4 : 9696969696969697 x3 : ffff33a5b7601f38
x2 : 0000000000000000 x1 : ffff800082d63bf8 x0 : fffffffffffffff4
Call trace:
eventfs_remove_rec+0x24/0xc0
eventfs_remove+0x68/0x1d8
remove_event_file_dir+0x88/0x100
event_remove+0x140/0x15c
trace_module_notify+0x1fc/0x230
notifier_call_chain+0x98/0x17c
blocking_notifier_call_chain+0x4c/0x74
__arm64_sys_delete_module+0x1a4/0x298
invoke_syscall+0x44/0x100
el0_svc_common.constprop.1+0x68/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x3c/0xc4
el0t_64_sync_handler+0xa0/0xc4
el0t_64_sync+0x174/0x178
Code: 5400052c a90153b3 aa0003f3 aa0103f4 (f9401400)
---[ end trace 0000000000000000 ]---
Kernel panic - not syncing: Oops: Fatal exception
SMP: stopping secondary CPUs
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: 0x384b00c00000 from 0xffff800080000000
PHYS_OFFSET: 0xffffcc5b80000000
CPU features: 0x88000203,3c020000,1000421b
Memory Limit: none
Rebooting in 1 seconds..
Link: https://lore.kernel.org/linux-trace-kernel/20230912134752.1838524-1-ruanjinjie@huawei.com
Link: https://lore.kernel.org/all/20230912025808.668187-1-ruanjinjie@huawei.com/
Link: https://lore.kernel.org/all/20230911052818.1020547-1-ruanjinjie@huawei.com/
Link: https://lore.kernel.org/all/20230909072817.182846-1-ruanjinjie@huawei.com/
Link: https://lore.kernel.org/all/20230908074816.3724716-1-ruanjinjie@huawei.com/
Cc: Ajay Kaher <akaher@vmware.com>
Fixes: 5bdcd5f5331a ("eventfs: Implement removal of meta data from eventfs")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Initialize the BTLB entries when starting up a CPU.
Note that BTLBs are not available on 64-bit CPUs.
Signed-off-by: Helge Deller <deller@gmx.de>
Pull x86 platform driver fixes from Hans de Goede:
- various platform/mellanox fixes
- one new DMI quirk for asus-wmi
* tag 'platform-drivers-x86-v6.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
platform/x86: asus-wmi: Support 2023 ROG X16 tablet mode
platform/mellanox: NVSW_SN2201 should depend on ACPI
platform/mellanox: mlxbf-bootctl: add NET dependency into Kconfig
platform/mellanox: mlxbf-pmc: Fix reading of unprogrammed events
platform/mellanox: mlxbf-pmc: Fix potential buffer overflows
platform/mellanox: mlxbf-tmfifo: Drop jumbo frames
platform/mellanox: mlxbf-tmfifo: Drop the Rx packet if no more descriptors
The wiki has been archived and is not updated anymore. Remove or replace
the links in files that contain it (MAINTAINERS, Kconfig, docs).
Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull x86 fixes from Ingo Molnar:
"Fix preemption delays in the SGX code, remove unnecessarily
UAPI-exported code, fix a ld.lld linker (in)compatibility quirk and
make the x86 SMP init code a bit more conservative to fix kexec()
lockups"
* tag 'x86-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sgx: Break up long non-preemptible delays in sgx_vepc_release()
x86: Remove the arch_calc_vm_prot_bits() macro from the UAPI
x86/build: Fix linker fill bytes quirk/incompatibility for ld.lld
x86/smp: Don't send INIT to non-present and non-booted CPUs