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.
code
Clone this repository
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Pull irq fixes from Borislav Petkov:
- Drop an unused private data field in the AIC driver
- Various fixes to the realtek-rtl driver
- Make the GICv3 ITS driver compile again in !SMP configurations
- Force reset of the GICv3 ITSs at probe time to avoid issues during kexec
- Yet another kfree/bitmap_free conversion
- Various DT updates (Renesas, SiFive)
* tag 'irq_urgent_for_v5.17_rc2_p2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
dt-bindings: interrupt-controller: sifive,plic: Group interrupt tuples
dt-bindings: interrupt-controller: sifive,plic: Fix number of interrupts
dt-bindings: irqchip: renesas-irqc: Add R-Car V3U support
irqchip/gic-v3-its: Reset each ITS's BASERn register before probe
irqchip/gic-v3-its: Fix build for !SMP
irqchip/loongson-pch-ms: Use bitmap_free() to free bitmap
irqchip/realtek-rtl: Service all pending interrupts
irqchip/realtek-rtl: Fix off-by-one in routing
irqchip/realtek-rtl: Map control data to virq
irqchip/apple-aic: Drop unused ipi_hwirq field
Pull perf fixes from Borislav Petkov:
- Prevent accesses to the per-CPU cgroup context list from another CPU
except the one it belongs to, to avoid list corruption
- Make sure parent events are always woken up to avoid indefinite hangs
in the traced workload
* tag 'perf_urgent_for_v5.17_rc2_p2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix cgroup event list management
perf: Always wake the parent event
Pull irqchip fixes from Marc Zyngier:
- Drop an unused private data field in the AIC driver
- Various fixes to the realtek-rtl driver
- Make the GICv3 ITS driver compile again in !SMP configurations
- Force reset of the GICv3 ITSs at probe time to avoid issues during kexec
- Yet another kfree/bitmap_free conversion
- Various DT updates (Renesas, SiFive)
Link: https://lore.kernel.org/r/20220128174217.517041-1-maz@kernel.org
Pull scheduler fix from Borislav Petkov:
"Make sure the membarrier-rseq fence commands are part of the reported
set when querying membarrier(2) commands through MEMBARRIER_CMD_QUERY"
* tag 'sched_urgent_for_v5.17_rc2_p2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/membarrier: Fix membarrier-rseq fence command missing from query bitmask
The active cgroup events are managed in the per-cpu cgrp_cpuctx_list.
This list is only accessed from current cpu and not protected by any
locks. But from the commit ef54c1a476ae ("perf: Rework
perf_event_exit_event()"), it's possible to access (actually modify)
the list from another cpu.
In the perf_remove_from_context(), it can remove an event from the
context without an IPI when the context is not active. This is not
safe with cgroup events which can have some active events in the
context even if ctx->is_active is 0 at the moment. The target cpu
might be in the middle of list iteration at the same time.
If the event is enabled when it's about to be closed, it might call
perf_cgroup_event_disable() and list_del() with the cgrp_cpuctx_list
on a different cpu.
This resulted in a crash due to an invalid list pointer access during
the cgroup list traversal on the cpu which the event belongs to.
Let's fallback to IPI to access the cgrp_cpuctx_list from that cpu.
Similarly, perf_install_in_context() should use IPI for the cgroup
events too.
Fixes: ef54c1a476ae ("perf: Rework perf_event_exit_event()")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124195808.2252071-1-namhyung@kernel.org
When the core MSI allocation fails, then the PCI/MSI code uses an already
freed MSI descriptor to unmask the MSI mask register in order to bring it back
into reset state.
Remove MSI_FLAG_FREE_MSI_DESCS from the PCI/MSI irqdomain flags and let the
PCI/MSI code free the MSI descriptors after usage.
Fixes: 0f62d941acf9 ("genirq/msi: Provide msi_domain_alloc/free_irqs_descs_locked()")
Reported-by: Tong Zhang <ztong0001@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tong Zhang <ztong0001@gmail.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/87r1938vbn.ffs@tglx
To improve human readability and enable automatic validation, the tuples
in "interrupts-extended" properties should be grouped using angle
brackets.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/211705e74a2ce77de43d036c5dea032484119bf7.1643360419.git.geert@linux-m68k.org
Pull x86 fixes from Borislav Petkov:
- Add another Intel CPU model to the list of CPUs supporting the
processor inventory unique number
- Allow writing to MCE thresholding sysfs files again - a previous
change had accidentally disabled it and no one noticed. Goes to show
how much is this stuff used
* tag 'x86_urgent_for_v5.17_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Add Xeon Icelake-D to list of CPUs that support PPIN
x86/MCE/AMD: Allow thresholding interface updates after init
The membarrier command MEMBARRIER_CMD_QUERY allows querying the
available membarrier commands. When the membarrier-rseq fence commands
were added, a new MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ_BITMASK was
introduced with the intent to expose them with the MEMBARRIER_CMD_QUERY
command, the but it was never added to MEMBARRIER_CMD_BITMASK.
The membarrier-rseq fence commands are therefore not wired up with the
query command.
Rename MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ_BITMASK to
MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK (the bitmask is not a command
per-se), and change the erroneous
MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ_BITMASK (which does not
actually exist) to MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ.
Wire up MEMBARRIER_PRIVATE_EXPEDITED_RSEQ_BITMASK in
MEMBARRIER_CMD_BITMASK. Fixing this allows discovering availability of
the membarrier-rseq fence feature.
Fixes: 2a36ab717e8f ("rseq/membarrier: Add MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # 5.10+
Link: https://lkml.kernel.org/r/20220117203010.30129-1-mathieu.desnoyers@efficios.com
When using per-process mode and event inheritance is set to true,
forked processes will create a new perf events via inherit_event() ->
perf_event_alloc(). But these events will not have ring buffers
assigned to them. Any call to wakeup will be dropped if it's called on
an event with no ring buffer assigned because that's the object that
holds the wakeup list.
If the child event is disabled due to a call to
perf_aux_output_begin() or perf_aux_output_end(), the wakeup is
dropped leaving userspace hanging forever on the poll.
Normally the event is explicitly re-enabled by userspace after it
wakes up to read the aux data, but in this case it does not get woken
up so the event remains disabled.
This can be reproduced when using Arm SPE and 'stress' which forks once
before running the workload. By looking at the list of aux buffers read,
it's apparent that they stop after the fork:
perf record -e arm_spe// -vvv -- stress -c 1
With this patch applied they continue to be printed. This behaviour
doesn't happen when using systemwide or per-cpu mode.
Reported-by: Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211206113840.130802-2-james.clark@arm.com
Pull f2fs updates from Jaegeuk Kim:
"In this round, we've tried to address some performance issues in
f2fs_checkpoint and direct IO flows. Also, there was a work to enhance
the page cache management used for compression. Other than them, we've
done typical work including sysfs, code clean-ups, tracepoint, sanity
check, in addition to bug fixes on corner cases.
Enhancements:
- use iomap for direct IO
- try to avoid lock contention to improve f2fs_ckpt speed
- avoid unnecessary memory allocation in compression flow
- POSIX_FADV_DONTNEED drops the page cache containing compression
pages
- add some sysfs entries (gc_urgent_high_remaining, pending_discard)
Bug fixes:
- try not to expose unwritten blocks to user by DIO (this was added
to avoid merge conflict; another patch is coming to address other
missing case)
- relax minor error condition for file pinning feature used in
Android OTA
- fix potential deadlock case in compression flow
- should not truncate any block on pinned file
In addition, we've done some code clean-ups and tracepoint/sanity
check improvement"
* tag 'f2fs-for-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (29 commits)
f2fs: do not allow partial truncation on pinned file
f2fs: remove redunant invalidate compress pages
f2fs: Simplify bool conversion
f2fs: don't drop compressed page cache in .{invalidate,release}page
f2fs: fix to reserve space for IO align feature
f2fs: fix to check available space of CP area correctly in update_ckpt_flags()
f2fs: support fault injection to f2fs_trylock_op()
f2fs: clean up __find_inline_xattr() with __find_xattr()
f2fs: fix to do sanity check on last xattr entry in __f2fs_setxattr()
f2fs: do not bother checkpoint by f2fs_get_node_info
f2fs: avoid down_write on nat_tree_lock during checkpoint
f2fs: compress: fix potential deadlock of compress file
f2fs: avoid EINVAL by SBI_NEED_FSCK when pinning a file
f2fs: add gc_urgent_high_remaining sysfs node
f2fs: fix to do sanity check in is_alive()
f2fs: fix to avoid panic in is_alive() if metadata is inconsistent
f2fs: fix to do sanity check on inode type during garbage collection
f2fs: avoid duplicate call of mark_inode_dirty
f2fs: show number of pending discard commands
f2fs: support POSIX_FADV_DONTNEED drop compressed page cache
...
The number of interrupts lacks an upper bound, thus assuming one,
causing properly grouped "interrupts-extended" properties to be flagged
as an error by "make dtbs_check".
Fix this by adding the missing "maxItems", using the architectural
maximum of 15872 interrupts.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/f73a0aead89e1426b146c4c64f797aa035868bf0.1643360419.git.geert@linux-m68k.org
Merge misc fixes from Andrew Morton:
"12 patches.
Subsystems affected by this patch series: sysctl, binfmt, ia64, mm
(memory-failure, folios, kasan, and psi), selftests, and ocfs2"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
ocfs2: fix a deadlock when commit trans
jbd2: export jbd2_journal_[grab|put]_journal_head
psi: fix "defined but not used" warnings when CONFIG_PROC_FS=n
psi: fix "no previous prototype" warnings when CONFIG_CGROUPS=n
mm, kasan: use compare-exchange operation to set KASAN page tag
kasan: test: fix compatibility with FORTIFY_SOURCE
tools/testing/scatterlist: add missing defines
mm: page->mapping folio->mapping should have the same offset
memory-failure: fetch compound_head after pgmap_pfn_valid()
ia64: make IA64_MCA_RECOVERY bool instead of tristate
binfmt_misc: fix crash when load/unload module
include/linux/sysctl.h: fix register_sysctl_mount_point() return type