Link Training Tunable PHY Repeaters (LTTPRs) are defined in DisplayPort
1.4a specification. As the name suggests, these PHY repeaters are
capable of adjusting their output for link training purposes.
According to the DisplayPort standard, LTTPRs have two operating
modes:
- non-transparent - it replies to DPCD LTTPR field specific AUX
requests, while passes through all other AUX requests
- transparent - it passes through all AUX requests.
Switching between these two modes is done by the DPTX by issuing
an AUX write to the DPCD PHY_REPEATER_MODE register.
The msm DP driver is currently lacking any handling of LTTPRs.
This means that if at least one LTTPR is found between DPTX and DPRX,
the link training would fail if that LTTPR was not already configured
in transparent mode.
The section 3.6.6.1 from the DisplayPort v2.0 specification mandates
that before link training with the LTTPR is started, the DPTX may place
the LTTPR in non-transparent mode by first switching to transparent mode
and then to non-transparent mode. This operation seems to be needed only
on first link training and doesn't need to be done again until device is
unplugged.
It has been observed on a few X Elite-based platforms which have
such LTTPRs in their board design that the DPTX needs to follow the
procedure described above in order for the link training to be successful.
So add support for reading the LTTPR DPCD caps to figure out the number
of such LTTPRs first. Then, for platforms (or Type-C dongles) that have
at least one such an LTTPR, set its operation mode to transparent mode
first and then to non-transparent, just like the mentioned section of
the specification mandates.
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250203-drm-dp-msm-add-lttpr-transparent-mode-set-v5-4-c865d0e56d6e@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
LTTPRs operating modes are defined by the DisplayPort standard and the
generic framework now provides a helper to switch between them, which
is handling the explicit disabling of non-transparent mode and its
disable->enable sequence mentioned in the DP Standard v2.0 section
3.6.6.1.
So use the new drm generic helper instead as it makes the code a bit
cleaner. Since the driver specific implementation holds the
lttrp_common_caps, if the call to the drm generic helper fails, the
lttrp_common_caps need to be updated as the helper has already rolled
back to transparent mode.
Acked-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250203-drm-dp-msm-add-lttpr-transparent-mode-set-v5-3-c865d0e56d6e@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
According to the DisplayPort standard, LTTPRs have two operating
modes:
- non-transparent - it replies to DPCD LTTPR field specific AUX
requests, while passes through all other AUX requests
- transparent - it passes through all AUX requests.
Switching between this two modes is done by the DPTX by issuing
an AUX write to the DPCD PHY_REPEATER_MODE register.
Add a generic helper that allows switching between these modes.
Also add a generic wrapper for the helper that handles the explicit
disabling of non-transparent mode and its disable->enable sequence
mentioned in the DP Standard v2.0 section 3.6.6.1. Do this in order
to move this handling out of the vendor specific driver implementation
into the generic framework.
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250203-drm-dp-msm-add-lttpr-transparent-mode-set-v5-1-c865d0e56d6e@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
There are conditions, albeit somewhat unlikely, under which right hand
expressions, calculating the end of time period in functions like
repaper_frame_fixed_repeat(), may overflow.
For instance, if 'factor10x' in repaper_get_temperature() is high
enough (170), as is 'epd->stage_time' in repaper_probe(), then the
resulting value of 'end' will not fit in unsigned int expression.
Mitigate this by casting 'epd->factored_stage_time' to wider type before
any multiplication is done.
Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.
Fixes: 3589211e9b ("drm/tinydrm: Add RePaper e-ink driver")
Cc: stable@vger.kernel.org
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Signed-off-by: Alex Lanzano <lanzano.alex@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250116134801.22067-1-n.zhandarovich@fintech.ru
Idea is to add helpers for peeking and popping jobs from entities with
the goal of decoupling the hidden assumption in the code that queue_node
is the first element in struct drm_sched_job.
That assumption usually comes in the form of:
while ((job = to_drm_sched_job(spsc_queue_pop(&entity->job_queue))))
Which breaks if the queue_node is re-positioned due to_drm_sched_job
being implemented with a container_of.
This also allows us to remove duplicate definitions of to_drm_sched_job.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Philipp Stanner <phasta@kernel.org>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250221105038.79665-2-tvrtko.ursulin@igalia.com
Pull i2c fix from Wolfram Sang:
"Revert one cleanup which turned out to eat too much stack space"
* tag 'i2c-for-6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: core: Allocate temporary client dynamically
Pull EDAC fix from Borislav Petkov:
- Have qcom_edac use the correct interrupt enable register to configure
the RAS interrupt lines
* tag 'edac_urgent_for_v6.14_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
EDAC/qcom: Correct interrupt enable register configuration
Pull smb client fix from Steve French:
- Fix potential null pointer dereference
* tag 'v6.14-rc3-smb3-client-fix-part2' of git://git.samba.org/sfrench/cifs-2.6:
smb: client: Add check for next_buffer in receive_encrypted_standard()
Pull x86 fixes from Ingo Molnar:
- Fix AVX-VNNI CPU feature dependency bug triggered via the 'noxsave'
boot option
- Fix typos in the SVA documentation
- Add Tony Luck as RDT co-maintainer and remove Fenghua Yu
* tag 'x86-urgent-2025-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
docs: arch/x86/sva: Fix two grammar errors under Background and FAQ
x86/cpufeatures: Make AVX-VNNI depend on AVX
MAINTAINERS: Change maintainer for RDT
Pull rseq fixes from Ingo Molnar:
- Fix overly spread-out RSEQ concurrency ID allocation pattern that
regressed certain workloads
- Fix RSEQ registration syscall behavior on -EFAULT errors when
CONFIG_DEBUG_RSEQ=y (This debug option is disabled on most
distributions)
* tag 'sched-urgent-2025-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq: Fix rseq registration with CONFIG_DEBUG_RSEQ
sched: Compact RSEQ concurrency IDs with reduced threads and affinity
Pull perf event fixes from Ingo Molnar:
"Fix x86 Intel Lion Cove CPU event constraints, and fix uprobes
debug/error printk output pointer-value verbosity"
* tag 'perf-urgent-2025-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Fix event constraints for LNC
uprobes: Don't use %pK through printk
Pull s390 fixes from Vasily Gorbik:
- Fix inline asm constraint in cmma_test_essa() to avoid potential ESSA
detection miscompilation
- Fix build failure with CONFIG_GENDWARFKSYMS by disabling purgatory
symbol exports with -D__DISABLE_EXPORTS
- Update defconfigs
* tag 's390-6.14-5' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/boot: Fix ESSA detection
s390/purgatory: Use -D__DISABLE_EXPORTS
s390: Update defconfigs
Pull tracing fixes from Steven Rostedt:
"Function graph accounting fixes:
- Fix the manage ops hashes
The function graph registers a "manager ops" and "sub-ops" to
ftrace. The manager ops does not have any callback but calls the
sub-ops callbacks. The manage ops hashes (what is used to tell
ftrace what functions to attach to) is built on the sub-ops it
manages.
There was an error in the way it built the hash. An empty hash
means to attach to all functions. When the manager ops had one
sub-ops it properly copied its hash. But when the manager ops had
more than one sub-ops, it went into a loop to make a set of all
functions it needed to add to the hash. If any of the subops hashes
was empty, that would mean to attach to all functions. The error
was that the first iteration of the loop passed in an empty hash to
start with in order to add the other hashes. That starting hash was
mistaken as to attach to all functions. This made the manage ops
attach to all functions whenever it had two or more sub-ops, even
if each sub-op was attached to only a single function.
- Do not add duplicate entries to the manager ops hash
If two or more subops hashes trace the same function, an entry for
that function will be added to the manager ops for each subops.
This causes waste and extra overhead.
Fprobe accounting fixes:
- Remove last function from fprobe hash
Fprobes has a ftrace hash to manage which functions an fprobe is
attached to. It also has a counter of how many fprobes are
attached. When the last fprobe is removed, it unregisters the
fprobe from ftrace but does not remove the functions the last
fprobe was attached to from the hash. This leaves the old functions
attached. When a new fprobe is added, the fprobe infrastructure
attaches to not only the functions of the new fprobe, but also to
the functions of the last fprobe.
- Fix accounting of the fprobe counter
When a fprobe is added, it updates a counter. If the counter goes
from zero to one, it attaches its ops to ftrace. When an fprobe is
removed, the counter is decremented. If the counter goes from 1 to
zero, it removes the fprobes ops from ftrace.
There was an issue where if two fprobes trace the same function,
the addition of each fprobe would increment the counter. But when
removing the first of the fprobes, it would notice that another
fprobe is still attached to one of its functions no it does not
remove the functions from the ftrace ops.
But it also did not decrement the counter, so when the last fprobe
is removed, the counter is still one. This leaves the fprobes
callback still registered with ftrace and it being called by the
functions defined by the fprobes ops hash. Worse yet, because all
the functions from the fprobe ops hash have been removed, that
tells ftrace that it wants to trace all functions.
Thus, this puts the state of the system where every function is
calling the fprobe callback handler (which does nothing as there
are no registered fprobes), but this causes a good 13% slow down of
the entire system.
Other updates:
- Add a selftest to test the above issues to prevent regressions.
- Fix preempt count accounting in function tracing
Better recursion protection was added to function tracing which
added another layer of preempt disable. As the preempt_count gets
traced in the event, it needs to subtract the amount of preempt
disabling the tracer does to record what the preempt_count was when
the trace was triggered.
- Fix memory leak in output of set_event
A variable is passed by the seq_file functions in the location that
is set by the return of the next() function. The start() function
allocates it and the stop() function frees it. But when the last
item is found, the next() returns NULL which leaks the data that
was allocated in start(). The m->private is used for something
else, so have next() free the data when it returns NULL, as stop()
will then just receive NULL in that case"
* tag 'ftrace-v6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Fix memory leak when reading set_event file
ftrace: Correct preemption accounting for function tracing.
selftests/ftrace: Update fprobe test to check enabled_functions file
fprobe: Fix accounting of when to unregister from function graph
fprobe: Always unregister fgraph function from ops
ftrace: Do not add duplicate entries in subops manager ops
ftrace: Fix accounting of adding subops to a manager ops
drivers/i2c/i2c-core-base.c: In function ‘i2c_detect.isra’:
drivers/i2c/i2c-core-base.c:2544:1: warning: the frame size of 1312 bytes is larger than 1024 bytes [-Wframe-larger-than=]
2544 | }
| ^
Fix this by allocating the temporary client structure dynamically, as it
is a rather large structure (1216 bytes, depending on kernel config).
This is basically a revert of the to-be-fixed commit with some
checkpatch improvements.
Fixes: 735668f8e5 ("i2c: core: Allocate temp client on the stack in i2c_detect")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Su Hui <suhui@nfschina.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
[wsa: updated commit message, merged tags from similar patch]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Pull SoC fixes from Arnd Bergmann:
"Two people stepped up as platform co-maintainers: Andrew Jeffery for
ASpeed and Janne Grunau for Apple.
The rockchip platform gets 9 small fixes for devicetree files,
addressing both compile-time warnings and board specific bugs.
One bugfix for the optee firmware driver addresses a reboot-time hang.
Two drivers need improved Kconfig dependencies to allow wider compile-
testing while hiding the drivers on platforms that can't use them.
ARM SCMI and loongson-guts drivers get minor bugfixes"
* tag 'soc-fixes-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
soc: loongson: loongson2_guts: Add check for devm_kstrdup()
tee: optee: Fix supplicant wait loop
platform: cznic: CZNIC_PLATFORMS should depend on ARCH_MVEBU
firmware: imx: IMX_SCMI_MISC_DRV should depend on ARCH_MXC
MAINTAINERS: arm: apple: Add Janne as maintainer
MAINTAINERS: Mark Andrew as M: for ASPEED MACHINE SUPPORT
firmware: arm_scmi: imx: Correct tx size of scmi_imx_misc_ctrl_set
arm64: dts: rockchip: adjust SMMU interrupt type on rk3588
arm64: dts: rockchip: disable IOMMU when running rk3588 in PCIe endpoint mode
dt-bindings: rockchip: pmu: Ensure all properties are defined
arm64: defconfig: Enable TISCI Interrupt Router and Aggregator
arm64: dts: rockchip: Fix lcdpwr_en pin for Cool Pi GenBook
arm64: dts: rockchip: fix fixed-regulator renames on rk3399-gru devices
arm64: dts: rockchip: Disable DMA for uart5 on px30-ringneck
arm64: dts: rockchip: Move uart5 pin configuration to px30 ringneck SoM
arm64: dts: rockchip: change eth phy mode to rgmii-id for orangepi r1 plus lts
arm64: dts: rockchip: Fix broken tsadc pinctrl names for rk3588
Pull drm fixes from Dave Airlie:
"Weekly drm fixes pull request, lots of small things all over, msm has
a bunch of things but all very small, xe, i915, a fix for the cgroup
dmem controller.
core:
- remove MAINTAINERS entry
cgroup/dmem:
- use correct function for pool descendants
panel:
- fix signal polarity issue jd9365da-h3
nouveau:
- folio handling fix
- config fix
amdxdna:
- fix missing header
xe:
- Fix error handling in xe_irq_install
- Fix devcoredump format
i915:
- Use spin_lock_irqsave() in interruptible context on guc submission
- Fixes on DDI and TRANS programming
- Make sure all planes in use by the joiner have their crtc included
- Fix 128b/132b modeset issues
msm:
- More catalog fixes:
- to skip watchdog programming through top block if its not
present
- fix the setting of WB mask to ensure the WB input control is
programmed correctly through ping-pong
- drop lm_pair for sm6150 as that chipset does not have any
3dmerge block
- Fix the mode validation logic for DP/eDP to account for widebus
(2ppc) to allow high clock resolutions
- Fix to disable dither during encoder disable as otherwise this
was causing kms_writeback failure due to resource sharing
between WB and DSI paths as DSI uses dither but WB does not
- Fixes for virtual planes, namely to drop extraneous return and
fix uninitialized variables
- Fix to avoid spill-over of DSC encoder block bits when
programming the bits-per-component
- Fixes in the DSI PHY to protect against concurrent access of
PHY_CMN_CLK_CFG regs between clock and display drivers
- Core/GPU:
- Fix non-blocking fence wait incorrectly rounding up to 1 jiffy
timeout
- Only print GMU fw version once, instead of each time the GPU
resumes"
* tag 'drm-fixes-2025-02-22' of https://gitlab.freedesktop.org/drm/kernel: (28 commits)
drm/i915/dp: Fix disabling the transcoder function in 128b/132b mode
drm/i915/dp: Fix error handling during 128b/132b link training
accel/amdxdna: Add missing include linux/slab.h
MAINTAINERS: Remove myself
drm/nouveau/pmu: Fix gp10b firmware guard
cgroup/dmem: Don't open-code css_for_each_descendant_pre
drm/xe/guc: Fix size_t print format
drm/xe: Make GUC binaries dump consistent with other binaries in devcoredump
drm/i915: Make sure all planes in use by the joiner have their crtc included
drm/i915/ddi: Fix HDMI port width programming in DDI_BUF_CTL
drm/i915/dsi: Use TRANS_DDI_FUNC_CTL's own port width macro
drm/xe: Fix error handling in xe_irq_install()
drm/i915/gt: Use spin_lock_irqsave() in interruptible context
drm/msm/dsi/phy: Do not overwite PHY_CMN_CLK_CFG1 when choosing bitclk source
drm/msm/dsi/phy: Protect PHY_CMN_CLK_CFG1 against clock driver
drm/msm/dsi/phy: Protect PHY_CMN_CLK_CFG0 updated from driver side
drm/msm/dpu: Drop extraneous return in dpu_crtc_reassign_planes()
drm/msm/dpu: Don't leak bits_per_component into random DSC_ENC fields
drm/msm/dpu: Disable dither in phys encoder cleanup
drm/msm/dpu: Fix uninitialized variable
...
Pull block fixes from Jens Axboe:
- NVMe pull request via Keith:
- FC controller state check fixes (Daniel)
- PCI Endpoint fixes (Damien)
- TCP connection failure fixe (Caleb)
- TCP handling C2HTermReq PDU (Maurizio)
- RDMA queue state check (Ruozhu)
- Apple controller fixes (Hector)
- Target crash on disbaled namespace (Hannes)
- MD pull request via Yu:
- Fix queue limits error handling for raid0, raid1 and raid10
- Fix for a NULL pointer deref in request data mapping
- Code cleanup for request merging
* tag 'block-6.14-20250221' of git://git.kernel.dk/linux:
nvme: only allow entering LIVE from CONNECTING state
nvme-fc: rely on state transitions to handle connectivity loss
apple-nvme: Support coprocessors left idle
apple-nvme: Release power domains when probe fails
nvmet: Use enum definitions instead of hardcoded values
nvme: Cleanup the definition of the controller config register fields
nvme/ioctl: add missing space in err message
nvme-tcp: fix connect failure on receiving partial ICResp PDU
nvme: tcp: Fix compilation warning with W=1
nvmet: pci-epf: Avoid RCU stalls under heavy workload
nvmet: pci-epf: Do not uselessly write the CSTS register
nvmet: pci-epf: Correctly initialize CSTS when enabling the controller
nvmet-rdma: recheck queue state is LIVE in state lock in recv done
nvmet: Fix crash when a namespace is disabled
nvme-tcp: add basic support for the C2HTermReq PDU
nvme-pci: quirk Acer FA100 for non-uniqueue identifiers
block: fix NULL pointer dereferenced within __blk_rq_map_sg
block/merge: remove unnecessary min() with UINT_MAX
md/raid*: Fix the set_queue_limits implementations
Pull io_uring fixes from Jens Axboe:
- Series fixing an issue with multishot read on pollable files that may
return -EIOCBQUEUED from ->read_iter(). Four small patches for that,
the first one deliberately done in such a way that it'd be easy to
backport
- Remove some dead constant definitions
- Use array_index_nospec() for opcode indexing
- Work-around for worker creation retries in the presence of signals
* tag 'io_uring-6.14-20250221' of git://git.kernel.dk/linux:
io_uring/rw: clean up mshot forced sync mode
io_uring/rw: move ki_complete init into prep
io_uring/rw: don't directly use ki_complete
io_uring/rw: forbid multishot async reads
io_uring/rsrc: remove unused constants
io_uring: fix spelling error in uapi io_uring.h
io_uring: prevent opcode speculation
io-wq: backoff when retrying worker creation
Pull ACPI fix from Rafael Wysocki:
"Fix a memory leak in the ACPI platform_profile driver (Kurt Borja)"
* tag 'acpi-6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI: platform_profile: Fix memory leak in profile_class_is_visible()
Pull mtd fixes from Miquel Raynal:
"The two most important fixes in this list are probably the SST write
failure and the Qcom raw NAND controller probe failure which are due
to some refactoring, otherwise there has been a series of misc fixes
on the Cadence raw NAND controller driver and especially on the DMA
side"
* tag 'mtd/fixes-for-6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
mtd: rawnand: cadence: fix unchecked dereference
mtd: spi-nor: sst: Fix SST write failure
dt-bindings: mtd: cadence: document required clock-names
mtd: rawnand: qcom: fix broken config in qcom_param_page_type_exec
mtd: rawnand: cadence: fix incorrect device in dma_unmap_single
mtd: rawnand: cadence: use dma_map_resource for sdma address
mtd: rawnand: cadence: fix error code in cadence_nand_init()
Pull gpio fixes from Bartosz Golaszewski:
"There are two fixes for GPIO core: one adds missing retval checks to
older code, while the second adds SRCU synchronization to legs in code
that were missed during the big rework a few cycles back. There's also
one small driver fix:
- check the return value of the get_direction() callback in struct
gpio_chip
- protect the multi-line get/set legs in GPIO core with SRCU
- fix a race condition in gpio-vf610"
* tag 'gpio-fixes-for-v6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
gpiolib: don't bail out if get_direction() fails in gpiochip_add_data()
gpiolib: protect gpio_chip with SRCU in array_info paths in multi get/set
gpio: vf610: add locking to gpio direction functions
gpiolib: check the return value of gpio_chip::get_direction()
kmemleak reports the following memory leak after reading set_event file:
# cat /sys/kernel/tracing/set_event
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xff110001234449e0 (size 16):
comm "cat", pid 13645, jiffies 4294981880
hex dump (first 16 bytes):
01 00 00 00 00 00 00 00 a8 71 e7 84 ff ff ff ff .........q......
backtrace (crc c43abbc):
__kmalloc_cache_noprof+0x3ca/0x4b0
s_start+0x72/0x2d0
seq_read_iter+0x265/0x1080
seq_read+0x2c9/0x420
vfs_read+0x166/0xc30
ksys_read+0xf4/0x1d0
do_syscall_64+0x79/0x150
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The issue can be reproduced regardless of whether set_event is empty or
not. Here is an example about the valid content of set_event.
# cat /sys/kernel/tracing/set_event
sched:sched_process_fork
sched:sched_switch
sched:sched_wakeup
*:*:mod:trace_events_sample
The root cause is that s_next() returns NULL when nothing is found.
This results in s_stop() attempting to free a NULL pointer because its
parameter is NULL.
Fix the issue by freeing the memory appropriately when s_next() fails
to find anything.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250220031528.7373-1-ahuang12@lenovo.com
Fixes: b355247df1 ("tracing: Cache ":mod:" events for modules not loaded yet")
Signed-off-by: Adrian Huang <ahuang12@lenovo.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function tracer should record the preemption level at the point when
the function is invoked. If the tracing subsystem decrement the
preemption counter it needs to correct this before feeding the data into
the trace buffer. This was broken in the commit cited below while
shifting the preempt-disabled section.
Use tracing_gen_ctx_dec() which properly subtracts one from the
preemption counter on a preemptible kernel.
Cc: stable@vger.kernel.org
Cc: Wander Lairson Costa <wander@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20250220140749.pfw8qoNZ@linutronix.de
Fixes: ce5e48036c ("ftrace: disable preemption when recursion locked")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
A few bugs were found in the fprobe accounting logic along with it using
the function graph infrastructure. Update the fprobe selftest to catch
those bugs in case they or something similar shows up in the future.
The test now checks the enabled_functions file which shows all the
functions attached to ftrace or fgraph. When enabling a fprobe, make sure
that its corresponding function is also added to that file. Also add two
more fprobes to enable to make sure that the fprobe logic works properly
with multiple probes.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.733001756@goodmis.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When adding a new fprobe, it will update the function hash to the
functions the fprobe is attached to and register with function graph to
have it call the registered functions. The fprobe_graph_active variable
keeps track of the number of fprobes that are using function graph.
If two fprobes attach to the same function, it increments the
fprobe_graph_active for each of them. But when they are removed, the first
fprobe to be removed will see that the function it is attached to is also
used by another fprobe and it will not remove that function from
function_graph. The logic will skip decrementing the fprobe_graph_active
variable.
This causes the fprobe_graph_active variable to not go to zero when all
fprobes are removed, and in doing so it does not unregister from
function graph. As the fgraph ops hash will now be empty, and an empty
filter hash means all functions are enabled, this triggers function graph
to add a callback to the fprobe infrastructure for every function!
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# echo "f:myevent2 kernel_clone%return" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc0024000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# > /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
trace_initcall_start_cb (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
run_init_process (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
try_to_run_init_process (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
x86_pmu_show_pmu_cap (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
cleanup_rapl_pmus (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
uncore_free_pcibus_map (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
uncore_types_exit (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
uncore_pci_exit.part.0 (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
kvm_shutdown (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
vmx_dump_msrs (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
[..]
# cat /sys/kernel/tracing/enabled_functions | wc -l
54702
If a fprobe is being removed and all its functions are also traced by
other fprobes, still decrement the fprobe_graph_active counter.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.565129766@goodmis.org
Fixes: 4346ba1604 ("fprobe: Rewrite fprobe on function-graph tracer")
Closes: https://lore.kernel.org/all/20250217114918.10397-A-hca@linux.ibm.com/
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the last fprobe is removed, it calls unregister_ftrace_graph() to
remove the graph_ops from function graph. The issue is when it does so, it
calls return before removing the function from its graph ops via
ftrace_set_filter_ips(). This leaves the last function lingering in the
fprobe's fgraph ops and if a probe is added it also enables that last
function (even though the callback will just drop it, it does add unneeded
overhead to make that call).
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc02f3000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# echo "f:myevent2 schedule_timeout" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc02f3000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
schedule_timeout (1) tramp: 0xffffffffc02f3000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# > /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
# echo "f:myevent3 kmem_cache_free" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kmem_cache_free (1) tramp: 0xffffffffc0219000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
schedule_timeout (1) tramp: 0xffffffffc0219000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
The above enabled a fprobe on kernel_clone, and then on schedule_timeout.
The content of the enabled_functions shows the functions that have a
callback attached to them. The fprobe attached to those functions
properly. Then the fprobes were cleared, and enabled_functions was empty
after that. But after adding a fprobe on kmem_cache_free, the
enabled_functions shows that the schedule_timeout was attached again. This
is because it was still left in the fprobe ops that is used to tell
function graph what functions it wants callbacks from.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.393254452@goodmis.org
Fixes: 4346ba1604 ("fprobe: Rewrite fprobe on function-graph tracer")
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
