Pull dma-mapping fixes from Christoph Hellwig:
"This has a set of swiotlb alignment fixes for sometimes very long
standing bugs from Will. We've been discussion them for a while and
they should be solid now"
* tag 'dma-mapping-6.9-2024-03-24' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: Reinstate page-alignment for mappings >= PAGE_SIZE
iommu/dma: Force swiotlb_max_mapping_size on an untrusted device
swiotlb: Fix alignment checks when both allocation and DMA masks are present
swiotlb: Honour dma_alloc_coherent() alignment in swiotlb_alloc()
swiotlb: Enforce page alignment in swiotlb_alloc()
swiotlb: Fix double-allocation of slots due to broken alignment handling
Pull timer fixes from Thomas Gleixner:
"Two regression fixes for the timer and timer migration code:
- Prevent endless timer requeuing which is caused by two CPUs racing
out of idle. This happens when the last CPU goes idle and therefore
has to ensure to expire the pending global timers and some other
CPU come out of idle at the same time and the other CPU wins the
race and expires the global queue. This causes the last CPU to
chase ghost timers forever and reprogramming it's clockevent device
endlessly.
Cure this by re-evaluating the wakeup time unconditionally.
- The split into local (pinned) and global timers in the timer wheel
caused a regression for NOHZ full as it broke the idle tracking of
global timers. On NOHZ full this prevents an self IPI being sent
which in turn causes the timer to be not programmed and not being
expired on time.
Restore the idle tracking for the global timer base so that the
self IPI condition for NOHZ full is working correctly again"
* tag 'timers-urgent-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers: Fix removed self-IPI on global timer's enqueue in nohz_full
timers/migration: Fix endless timer requeue after idle interrupts
Pull core entry fix from Thomas Gleixner:
"A single fix for the generic entry code:
The trace_sys_enter() tracepoint can modify the syscall number via
kprobes or BPF in pt_regs, but that requires that the syscall number
is re-evaluted from pt_regs after the tracepoint.
A seccomp fix in that area removed the re-evaluation so the change
does not take effect as the code just uses the locally cached number.
Restore the original behaviour by re-evaluating the syscall number
after the tracepoint"
* tag 'core-entry-2024-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
entry: Respect changes to system call number by trace_sys_enter()
Pull RISC-V updates from Palmer Dabbelt:
- Support for various vector-accelerated crypto routines
- Hibernation is now enabled for portable kernel builds
- mmap_rnd_bits_max is larger on systems with larger VAs
- Support for fast GUP
- Support for membarrier-based instruction cache synchronization
- Support for the Andes hart-level interrupt controller and PMU
- Some cleanups around unaligned access speed probing and Kconfig
settings
- Support for ACPI LPI and CPPC
- Various cleanus related to barriers
- A handful of fixes
* tag 'riscv-for-linus-6.9-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (66 commits)
riscv: Fix syscall wrapper for >word-size arguments
crypto: riscv - add vector crypto accelerated AES-CBC-CTS
crypto: riscv - parallelize AES-CBC decryption
riscv: Only flush the mm icache when setting an exec pte
riscv: Use kcalloc() instead of kzalloc()
riscv/barrier: Add missing space after ','
riscv/barrier: Consolidate fence definitions
riscv/barrier: Define RISCV_FULL_BARRIER
riscv/barrier: Define __{mb,rmb,wmb}
RISC-V: defconfig: Enable CONFIG_ACPI_CPPC_CPUFREQ
cpufreq: Move CPPC configs to common Kconfig and add RISC-V
ACPI: RISC-V: Add CPPC driver
ACPI: Enable ACPI_PROCESSOR for RISC-V
ACPI: RISC-V: Add LPI driver
cpuidle: RISC-V: Move few functions to arch/riscv
riscv: Introduce set_compat_task() in asm/compat.h
riscv: Introduce is_compat_thread() into compat.h
riscv: add compile-time test into is_compat_task()
riscv: Replace direct thread flag check with is_compat_task()
riscv: Improve arch_get_mmap_end() macro
...
Pull RTC updates from Alexandre Belloni:
"Subsytem:
- rtc_class is now const
Drivers:
- ds1511: cleanup, set date and time range and alarm offset limit
- max31335: fix interrupt handler
- pcf8523: improve suspend support"
* tag 'rtc-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (28 commits)
MAINTAINER: Include linux-arm-msm for Qualcomm RTC patches
dt-bindings: rtc: zynqmp: Add support for Versal/Versal NET SoCs
rtc: class: make rtc_class constant
dt-bindings: rtc: abx80x: Improve checks on trickle charger constraints
MAINTAINERS: adjust file entry in ARM/Mediatek RTC DRIVER
rtc: nct3018y: fix possible NULL dereference
rtc: max31335: fix interrupt status reg
rtc: mt6397: select IRQ_DOMAIN instead of depending on it
dt-bindings: rtc: abx80x: convert to yaml
rtc: m41t80: Use the unified property API get the wakeup-source property
dt-bindings: at91rm9260-rtt: add sam9x7 compatible
dt-bindings: rtc: convert MT7622 RTC to the json-schema
dt-bindings: rtc: convert MT2717 RTC to the json-schema
rtc: pcf8523: add suspend handlers for alarm IRQ
rtc: ds1511: set alarm offset limit
rtc: ds1511: set range
rtc: ds1511: drop inline/noinline hints
rtc: ds1511: rename pdata
rtc: ds1511: implement ds1511_rtc_read_alarm properly
rtc: ds1511: remove partial alarm support
...
Pull networking fixes from Jakub Kicinski:
"Including fixes from CAN, netfilter, wireguard and IPsec.
I'd like to highlight [ lowlight? - Linus ] Florian W stepping down as
a netfilter maintainer due to constant stream of bug reports. Not sure
what we can do but IIUC this is not the first such case.
Current release - regressions:
- rxrpc: fix use of page_frag_alloc_align(), it changed semantics and
we added a new caller in a different subtree
- xfrm: allow UDP encapsulation only in offload modes
Current release - new code bugs:
- tcp: fix refcnt handling in __inet_hash_connect()
- Revert "net: Re-use and set mono_delivery_time bit for userspace
tstamp packets", conflicted with some expectations in BPF uAPI
Previous releases - regressions:
- ipv4: raw: fix sending packets from raw sockets via IPsec tunnels
- devlink: fix devlink's parallel command processing
- veth: do not manipulate GRO when using XDP
- esp: fix bad handling of pages from page_pool
Previous releases - always broken:
- report RCU QS for busy network kthreads (with Paul McK's blessing)
- tcp/rds: fix use-after-free on netns with kernel TCP reqsk
- virt: vmxnet3: fix missing reserved tailroom with XDP
Misc:
- couple of build fixes for Documentation"
* tag 'net-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (59 commits)
selftests: forwarding: Fix ping failure due to short timeout
MAINTAINERS: step down as netfilter maintainer
netfilter: nf_tables: Fix a memory leak in nf_tables_updchain
net: dsa: mt7530: fix handling of all link-local frames
net: dsa: mt7530: fix link-local frames that ingress vlan filtering ports
bpf: report RCU QS in cpumap kthread
net: report RCU QS on threaded NAPI repolling
rcu: add a helper to report consolidated flavor QS
ionic: update documentation for XDP support
lib/bitmap: Fix bitmap_scatter() and bitmap_gather() kernel doc
netfilter: nf_tables: do not compare internal table flags on updates
netfilter: nft_set_pipapo: release elements in clone only from destroy path
octeontx2-af: Use separate handlers for interrupts
octeontx2-pf: Send UP messages to VF only when VF is up.
octeontx2-pf: Use default max_active works instead of one
octeontx2-pf: Wait till detach_resources msg is complete
octeontx2: Detect the mbox up or down message via register
devlink: fix port new reply cmd type
tcp: Clear req->syncookie in reqsk_alloc().
net/bnx2x: Prevent access to a freed page in page_pool
...
Pull Kbuild updates from Masahiro Yamada:
- Generate a list of built DTB files (arch/*/boot/dts/dtbs-list)
- Use more threads when building Debian packages in parallel
- Fix warnings shown during the RPM kernel package uninstallation
- Change OBJECT_FILES_NON_STANDARD_*.o etc. to take a relative path to
Makefile
- Support GCC's -fmin-function-alignment flag
- Fix a null pointer dereference bug in modpost
- Add the DTB support to the RPM package
- Various fixes and cleanups in Kconfig
* tag 'kbuild-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (67 commits)
kconfig: tests: test dependency after shuffling choices
kconfig: tests: add a test for randconfig with dependent choices
kconfig: tests: support KCONFIG_SEED for the randconfig runner
kbuild: rpm-pkg: add dtb files in kernel rpm
kconfig: remove unneeded menu_is_visible() call in conf_write_defconfig()
kconfig: check prompt for choice while parsing
kconfig: lxdialog: remove unused dialog colors
kconfig: lxdialog: fix button color for blackbg theme
modpost: fix null pointer dereference
kbuild: remove GCC's default -Wpacked-bitfield-compat flag
kbuild: unexport abs_srctree and abs_objtree
kbuild: Move -Wenum-{compare-conditional,enum-conversion} into W=1
kconfig: remove named choice support
kconfig: use linked list in get_symbol_str() to iterate over menus
kconfig: link menus to a symbol
kbuild: fix inconsistent indentation in top Makefile
kbuild: Use -fmin-function-alignment when available
alpha: merge two entries for CONFIG_ALPHA_GAMMA
alpha: merge two entries for CONFIG_ALPHA_EV4
kbuild: change DTC_FLAGS_<basetarget>.o to take the path relative to $(obj)
...
Pull driver core updates from Greg KH:
"Here is the "big" set of driver core and kernfs changes for 6.9-rc1.
Nothing all that crazy here, just some good updates that include:
- automatic attribute group hiding from Dan Williams (he fixed up my
horrible attempt at doing this.)
- kobject lock contention fixes from Eric Dumazet
- driver core cleanups from Andy
- kernfs rcu work from Tejun
- fw_devlink changes to resolve some reported issues
- other minor changes, all details in the shortlog
All of these have been in linux-next for a long time with no reported
issues"
* tag 'driver-core-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (28 commits)
device: core: Log warning for devices pending deferred probe on timeout
driver: core: Use dev_* instead of pr_* so device metadata is added
driver: core: Log probe failure as error and with device metadata
of: property: fw_devlink: Add support for "post-init-providers" property
driver core: Add FWLINK_FLAG_IGNORE to completely ignore a fwnode link
driver core: Adds flags param to fwnode_link_add()
debugfs: fix wait/cancellation handling during remove
device property: Don't use "proxy" headers
device property: Move enum dev_dma_attr to fwnode.h
driver core: Move fw_devlink stuff to where it belongs
driver core: Drop unneeded 'extern' keyword in fwnode.h
firmware_loader: Suppress warning on FW_OPT_NO_WARN flag
sysfs:Addresses documentation in sysfs_merge_group and sysfs_unmerge_group.
firmware_loader: introduce __free() cleanup hanler
platform-msi: Remove usage of the deprecated ida_simple_xx() API
sysfs: Introduce DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE()
sysfs: Document new "group visible" helpers
sysfs: Fix crash on empty group attributes array
sysfs: Introduce a mechanism to hide static attribute_groups
sysfs: Introduce a mechanism to hide static attribute_groups
...
Pull tty / serial driver updates from Greg KH:
"Here is the big set of TTY/Serial driver updates and cleanups for
6.9-rc1. Included in here are:
- more tty cleanups from Jiri
- loads of 8250 driver cleanups from Andy
- max310x driver updates
- samsung serial driver updates
- uart_prepare_sysrq_char() updates for many drivers
- platform driver remove callback void cleanups
- stm32 driver updates
- other small tty/serial driver updates
All of these have been in linux-next for a long time with no reported
issues"
* tag 'tty-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
dt-bindings: serial: stm32: add power-domains property
serial: 8250_dw: Replace ACPI device check by a quirk
serial: Lock console when calling into driver before registration
serial: 8250_uniphier: Switch to use uart_read_port_properties()
serial: 8250_tegra: Switch to use uart_read_port_properties()
serial: 8250_pxa: Switch to use uart_read_port_properties()
serial: 8250_omap: Switch to use uart_read_port_properties()
serial: 8250_of: Switch to use uart_read_port_properties()
serial: 8250_lpc18xx: Switch to use uart_read_port_properties()
serial: 8250_ingenic: Switch to use uart_read_port_properties()
serial: 8250_dw: Switch to use uart_read_port_properties()
serial: 8250_bcm7271: Switch to use uart_read_port_properties()
serial: 8250_bcm2835aux: Switch to use uart_read_port_properties()
serial: 8250_aspeed_vuart: Switch to use uart_read_port_properties()
serial: port: Introduce a common helper to read properties
serial: core: Add UPIO_UNKNOWN constant for unknown port type
serial: core: Move struct uart_port::quirks closer to possible values
serial: sh-sci: Call sci_serial_{in,out}() directly
serial: core: only stop transmit when HW fifo is empty
serial: pch: Use uart_prepare_sysrq_char().
...
Pull more power management updates from Rafael Wysocki:
"These update the Energy Model to make it prevent errors due to power
unit mismatches, fix a typo in power management documentation, convert
one driver to using a platform remove callback returning void, address
two cpufreq issues (one in the core and one in the DT driver), and
enable boost support in the SCMI cpufreq driver.
Specifics:
- Modify the Energy Model code to bail out and complain if the unit
of power is not uW to prevent errors due to unit mismatches (Lukasz
Luba)
- Make the intel_rapl platform driver use a remove callback returning
void (Uwe Kleine-König)
- Fix typo in the suspend and interrupts document (Saravana Kannan)
- Make per-policy boost flags actually take effect on platforms using
cpufreq_boost_set_sw() (Sibi Sankar)
- Enable boost support in the SCMI cpufreq driver (Sibi Sankar)
- Make the DT cpufreq driver use zalloc_cpumask_var() for allocating
cpumasks to avoid using unitinialized memory (Marek Szyprowski)"
* tag 'pm-6.9-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: scmi: Enable boost support
firmware: arm_scmi: Add support for marking certain frequencies as turbo
cpufreq: dt: always allocate zeroed cpumask
cpufreq: Fix per-policy boost behavior on SoCs using cpufreq_boost_set_sw()
Documentation: power: Fix typo in suspend and interrupts doc
PM: EM: Force device drivers to provide power in uW
powercap: intel_rapl: Convert to platform remove callback returning void
While running in nohz_full mode, a task may enqueue a timer while the
tick is stopped. However the only places where the timer wheel,
alongside the timer migration machinery's decision, may reprogram the
next event accordingly with that new timer's expiry are the idle loop or
any IRQ tail.
However neither the idle task nor an interrupt may run on the CPU if it
resumes busy work in userspace for a long while in full dynticks mode.
To solve this, the timer enqueue path raises a self-IPI that will
re-evaluate the timer wheel on its IRQ tail. This asynchronous solution
avoids potential locking inversion.
This is supposed to happen both for local and global timers but commit:
b2cf7507e1 ("timers: Always queue timers on the local CPU")
broke the global timers case with removing the ->is_idle field handling
for the global base. As a result, global timers enqueue may go unnoticed
in nohz_full.
Fix this with restoring the idle tracking of the global timer's base,
allowing self-IPIs again on enqueue time.
Fixes: b2cf7507e1 ("timers: Always queue timers on the local CPU")
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240318230729.15497-3-frederic@kernel.org
When a CPU is an idle migrator, but another CPU wakes up before it,
becomes an active migrator and handles the queue, the initial idle
migrator may end up endlessly reprogramming its clockevent, chasing ghost
timers forever such as in the following scenario:
[GRP0:0]
migrator = 0
active = 0
nextevt = T1
/ \
0 1
active idle (T1)
0) CPU 1 is idle and has a timer queued (T1), CPU 0 is active and is
the active migrator.
[GRP0:0]
migrator = NONE
active = NONE
nextevt = T1
/ \
0 1
idle idle (T1)
wakeup = T1
1) CPU 0 is now idle and is therefore the idle migrator. It has
programmed its next timer interrupt to handle T1.
[GRP0:0]
migrator = 1
active = 1
nextevt = KTIME_MAX
/ \
0 1
idle active
wakeup = T1
2) CPU 1 has woken up, it is now active and it has just handled its own
timer T1.
3) CPU 0 gets a timer interrupt to handle T1 but tmigr_handle_remote()
realize it is not the migrator anymore. So it early returns without
observing that T1 has been expired already and therefore without
updating its ->wakeup value.
4) CPU 0 goes into tmigr_cpu_new_timer() which also early returns
because it doesn't queue a timer of its own. So ->wakeup is left
unchanged and the next timer is programmed to fire now.
5) goto 3) forever
This results in timer interrupt storms in idle and also in nohz_full (as
observed in rcutorture's TREE07 scenario).
Fix this with forcing a re-evaluation of tmc->wakeup while trying
remote timer handling when the CPU isn't the migrator anymmore. The
check is inherently racy but in the worst case the CPU just races setting
the KTIME_MAX value that a remote expiry also tries to set.
Fixes: 7ee9887703 ("timers: Implement the hierarchical pull model")
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240318230729.15497-2-frederic@kernel.org
Pull tracing updates from Steven Rostedt:
"Main user visible change:
- User events can now have "multi formats"
The current user events have a single format. If another event is
created with a different format, it will fail to be created. That
is, once an event name is used, it cannot be used again with a
different format. This can cause issues if a library is using an
event and updates its format. An application using the older format
will prevent an application using the new library from registering
its event.
A task could also DOS another application if it knows the event
names, and it creates events with different formats.
The multi-format event is in a different name space from the single
format. Both the event name and its format are the unique
identifier. This will allow two different applications to use the
same user event name but with different payloads.
- Added support to have ftrace_dump_on_oops dump out instances and
not just the main top level tracing buffer.
Other changes:
- Add eventfs_root_inode
Only the root inode has a dentry that is static (never goes away)
and stores it upon creation. There's no reason that the thousands
of other eventfs inodes should have a pointer that never gets set
in its descriptor. Create a eventfs_root_inode desciptor that has a
eventfs_inode descriptor and a dentry pointer, and only the root
inode will use this.
- Added WARN_ON()s in eventfs
There's some conditionals remaining in eventfs that should never be
hit, but instead of removing them, add WARN_ON() around them to
make sure that they are never hit.
- Have saved_cmdlines allocation also include the map_cmdline_to_pid
array
The saved_cmdlines structure allocates a large amount of data to
hold its mappings. Within it, it has three arrays. Two are already
apart of it: map_pid_to_cmdline[] and saved_cmdlines[]. More memory
can be saved by also including the map_cmdline_to_pid[] array as
well.
- Restructure __string() and __assign_str() macros used in
TRACE_EVENT()
Dynamic strings in TRACE_EVENT() are declared with:
__string(name, source)
And assigned with:
__assign_str(name, source)
In the tracepoint callback of the event, the __string() is used to
get the size needed to allocate on the ring buffer and
__assign_str() is used to copy the string into the ring buffer.
There's a helper structure that is created in the TRACE_EVENT()
macro logic that will hold the string length and its position in
the ring buffer which is created by __string().
There are several trace events that have a function to create the
string to save. This function is executed twice. Once for
__string() and again for __assign_str(). There's no reason for
this. The helper structure could also save the string it used in
__string() and simply copy that into __assign_str() (it also
already has its length).
By using the structure to store the source string for the
assignment, it means that the second argument to __assign_str() is
no longer needed.
It will be removed in the next merge window, but for now add a
warning if the source string given to __string() is different than
the source string given to __assign_str(), as the source to
__assign_str() isn't even used and will be going away.
- Added checks to make sure that the source of __string() is also the
source of __assign_str() so that it can be safely removed in the
next merge window.
Included fixes that the above check found.
- Other minor clean ups and fixes"
* tag 'trace-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (34 commits)
tracing: Add __string_src() helper to help compilers not to get confused
tracing: Use strcmp() in __assign_str() WARN_ON() check
tracepoints: Use WARN() and not WARN_ON() for warnings
tracing: Use div64_u64() instead of do_div()
tracing: Support to dump instance traces by ftrace_dump_on_oops
tracing: Remove second parameter to __assign_rel_str()
tracing: Add warning if string in __assign_str() does not match __string()
tracing: Add __string_len() example
tracing: Remove __assign_str_len()
ftrace: Fix most kernel-doc warnings
tracing: Decrement the snapshot if the snapshot trigger fails to register
tracing: Fix snapshot counter going between two tracers that use it
tracing: Use EVENT_NULL_STR macro instead of open coding "(null)"
tracing: Use ? : shortcut in trace macros
tracing: Do not calculate strlen() twice for __string() fields
tracing: Rework __assign_str() and __string() to not duplicate getting the string
cxl/trace: Properly initialize cxl_poison region name
net: hns3: tracing: fix hclgevf trace event strings
drm/i915: Add missing ; to __assign_str() macros in tracepoint code
NFSD: Fix nfsd_clid_class use of __string_len() macro
...
Currently ftrace only dumps the global trace buffer on an OOPs. For
debugging a production usecase, instance trace will be helpful to
check specific problems since global trace buffer may be used for
other purposes.
This patch extend the ftrace_dump_on_oops parameter to dump a specific
or multiple trace instances:
- ftrace_dump_on_oops=0: as before -- don't dump
- ftrace_dump_on_oops[=1]: as before -- dump the global trace buffer
on all CPUs
- ftrace_dump_on_oops=2 or =orig_cpu: as before -- dump the global
trace buffer on CPU that triggered the oops
- ftrace_dump_on_oops=<instance_name>: new behavior -- dump the
tracing instance matching <instance_name>
- ftrace_dump_on_oops[=2/orig_cpu],<instance1_name>[=2/orig_cpu],
<instrance2_name>[=2/orig_cpu]: new behavior -- dump the global trace
buffer and multiple instance buffer on all CPUs, or only dump on CPU
that triggered the oops if =2 or =orig_cpu is given
Also, the sysctl node can handle the input accordingly.
Link: https://lore.kernel.org/linux-trace-kernel/20240223083126.1817731-1-quic_hyiwei@quicinc.com
Cc: Ross Zwisler <zwisler@google.com>
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: <mcgrof@kernel.org>
Cc: <keescook@chromium.org>
Cc: <j.granados@samsung.com>
Cc: <mathieu.desnoyers@efficios.com>
Cc: <corbet@lwn.net>
Signed-off-by: Huang Yiwei <quic_hyiwei@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Running the ftrace selftests caused the ring buffer mapping test to fail.
Investigating, I found that the snapshot counter would be incremented
every time a snapshot trigger was added, even if that snapshot trigger
failed.
# cd /sys/kernel/tracing
# echo "snapshot" > events/sched/sched_process_fork/trigger
# echo "snapshot" > events/sched/sched_process_fork/trigger
-bash: echo: write error: File exists
That second one that fails increments the snapshot counter but doesn't
decrement it. It needs to be decremented when the snapshot fails.
Link: https://lore.kernel.org/linux-trace-kernel/20240223013344.729055907@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Fixes: 16f7e48ffc53a ("tracing: Add snapshot refcount")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Running the ftrace selftests caused the ring buffer mapping test to fail.
Investigating, I found that the snapshot counter would be incremented
every time a tracer that uses the snapshot is enabled even if the snapshot
was used by the previous tracer.
That is:
# cd /sys/kernel/tracing
# echo wakeup_rt > current_tracer
# echo wakeup_dl > current_tracer
# echo nop > current_tracer
would leave the snapshot counter at 1 and not zero. That's because the
enabling of wakeup_dl would increment the counter again but the setting
the tracer to nop would only decrement it once.
Do not arm the snapshot for a tracer if the previous tracer already had it
armed.
Link: https://lore.kernel.org/linux-trace-kernel/20240223013344.570525723@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Fixes: 16f7e48ffc53a ("tracing: Add snapshot refcount")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Currently user_events supports 1 event with the same name and must have
the exact same format when referenced by multiple programs. This opens
an opportunity for malicious or poorly thought through programs to
create events that others use with different formats. Another scenario
is user programs wishing to use the same event name but add more fields
later when the software updates. Various versions of a program may be
running side-by-side, which is prevented by the current single format
requirement.
Add a new register flag (USER_EVENT_REG_MULTI_FORMAT) which indicates
the user program wishes to use the same user_event name, but may have
several different formats of the event. When this flag is used, create
the underlying tracepoint backing the user_event with a unique name
per-version of the format. It's important that existing ABI users do
not get this logic automatically, even if one of the multi format
events matches the format. This ensures existing programs that create
events and assume the tracepoint name will match exactly continue to
work as expected. Add logic to only check multi-format events with
other multi-format events and single-format events to only check
single-format events during find.
Change system name of the multi-format event tracepoint to ensure that
multi-format events are isolated completely from single-format events.
This prevents single-format names from conflicting with multi-format
events if they end with the same suffix as the multi-format events.
Add a register_name (reg_name) to the user_event struct which allows for
split naming of events. We now have the name that was used to register
within user_events as well as the unique name for the tracepoint. Upon
registering events ensure matches based on first the reg_name, followed
by the fields and format of the event. This allows for multiple events
with the same registered name to have different formats. The underlying
tracepoint will have a unique name in the format of {reg_name}.{unique_id}.
For example, if both "test u32 value" and "test u64 value" are used with
the USER_EVENT_REG_MULTI_FORMAT the system would have 2 unique
tracepoints. The dynamic_events file would then show the following:
u:test u64 count
u:test u32 count
The actual tracepoint names look like this:
test.0
test.1
Both would be under the new user_events_multi system name to prevent the
older ABI from being used to squat on multi-formatted events and block
their use.
Deleting events via "!u:test u64 count" would only delete the first
tracepoint that matched that format. When the delete ABI is used all
events with the same name will be attempted to be deleted. If
per-version deletion is required, user programs should either not use
persistent events or delete them via dynamic_events.
Link: https://lore.kernel.org/linux-trace-kernel/20240222001807.1463-3-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The current code for finding and deleting events assumes that there will
never be cases when user_events are registered with the same name, but
different formats. Scenarios exist where programs want to use the same
name but have different formats. An example is multiple versions of a
program running side-by-side using the same event name, but with updated
formats in each version.
This change does not yet allow for multi-format events. If user_events
are registered with the same name but different arguments the programs
see the same return values as before. This change simply makes it
possible to easily accommodate for this.
Update find_user_event() to take in argument parameters and register
flags to accommodate future multi-format event scenarios. Have find
validate argument matching and return error pointers to cover when
an existing event has the same name but different format. Update
callers to handle error pointer logic.
Move delete_user_event() to use hash walking directly now that
find_user_event() has changed. Delete all events found that match the
register name, stop if an error occurs and report back to the user.
Update user_fields_match() to cover list_empty() scenarios now that
find_user_event() uses it directly. This makes the logic consistent
across several callsites.
Link: https://lore.kernel.org/linux-trace-kernel/20240222001807.1463-2-beaub@linux.microsoft.com
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When a ring-buffer is memory mapped by user-space, no trace or
ring-buffer swap is possible. This means the snapshot feature is
mutually exclusive with the memory mapping. Having a refcount on
snapshot users will help to know if a mapping is possible or not.
Instead of relying on the global trace_types_lock, a new spinlock is
introduced to serialize accesses to trace_array->snapshot. This intends
to allow access to that variable in a context where the mmap lock is
already held.
Link: https://lore.kernel.org/linux-trace-kernel/20240220202310.2489614-4-vdonnefort@google.com
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The default behavior of ring_buffer_wait() when passed a NULL "cond"
parameter is to exit the function the first time it is woken up. The
current implementation uses a counter that starts at zero and when it is
greater than one it exits the wait_event_interruptible().
But this relies on the internal working of wait_event_interruptible() as
that code basically has:
if (cond)
return;
prepare_to_wait();
if (!cond)
schedule();
finish_wait();
That is, cond is called twice before it sleeps. The default cond of
ring_buffer_wait() needs to account for that and wait for its counter to
increment twice before exiting.
Instead, use the seq/atomic_inc logic that is used by the tracing code
that calls this function. Add an atomic_t seq to rb_irq_work and when cond
is NULL, have the default callback take a descriptor as its data that
holds the rbwork and the value of the seq when it started.
The wakeups will now increment the rbwork->seq and the cond callback will
simply check if that number is different, and no longer have to rely on
the implementation of wait_event_interruptible().
Link: https://lore.kernel.org/linux-trace-kernel/20240315063115.6cb5d205@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 7af9ded0c2 ("ring-buffer: Use wait_event_interruptible() in ring_buffer_wait()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pull timer fix from Ingo Molnar:
"Fix timer migration bug that can result in long bootup delays and
other oddities"
* tag 'timers-urgent-2024-03-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timer/migration: Remove buggy early return on deactivation
