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The profiler uses trace->depth to find its entry on the ret_stack, but the
depth may not match the actual location of where its entry is (if an
interrupt were to preempt the processing of the profiler for another
function, the depth and the curr_ret_stack will be different).
Have it use the curr_ret_stack as the index to find its ret_stack entry
instead of using the depth variable, as that is no longer guaranteed to be
the same.
Cc: [email protected]
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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The function graph profiler uses the ret_stack to store the "subtime" and
reuse it by nested functions and also on the return. But the current logic
has the profiler callback called before the ret_stack is updated, and it is
just modifying the ret_stack that will later be allocated (it's just lucky
that the "subtime" is not touched when it is allocated).
This could also cause a crash if we are at the end of the ret_stack when
this happens.
By reversing the order of the allocating the ret_stack and then calling the
callbacks attached to a function being traced, the ret_stack entry is no
longer used before it is allocated.
Cc: [email protected]
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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In the past, curr_ret_stack had two functions. One was to denote the depth
of the call graph, the other is to keep track of where on the ret_stack the
data is used. Although they may be slightly related, there are two cases
where they need to be used differently.
The one case is that it keeps the ret_stack data from being corrupted by an
interrupt coming in and overwriting the data still in use. The other is just
to know where the depth of the stack currently is.
The function profiler uses the ret_stack to save a "subtime" variable that
is part of the data on the ret_stack. If curr_ret_stack is modified too
early, then this variable can be corrupted.
The "max_depth" option, when set to 1, will record the first functions going
into the kernel. To see all top functions (when dealing with timings), the
depth variable needs to be lowered before calling the return hook. But by
lowering the curr_ret_stack, it makes the data on the ret_stack still being
used by the return hook susceptible to being overwritten.
Now that there's two variables to handle both cases (curr_ret_depth), we can
move them to the locations where they can handle both cases.
Cc: [email protected]
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Currently, the depth of the ret_stack is determined by curr_ret_stack index.
The issue is that there's a race between setting of the curr_ret_stack and
calling of the callback attached to the return of the function.
Commit 03274a3ffb44 ("tracing/fgraph: Adjust fgraph depth before calling
trace return callback") moved the calling of the callback to after the
setting of the curr_ret_stack, even stating that it was safe to do so, when
in fact, it was the reason there was a barrier() there (yes, I should have
commented that barrier()).
Not only does the curr_ret_stack keep track of the current call graph depth,
it also keeps the ret_stack content from being overwritten by new data.
The function profiler, uses the "subtime" variable of ret_stack structure
and by moving the curr_ret_stack, it allows for interrupts to use the same
structure it was using, corrupting the data, and breaking the profiler.
To fix this, there needs to be two variables to handle the call stack depth
and the pointer to where the ret_stack is being used, as they need to change
at two different locations.
Cc: [email protected]
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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As all architectures now call function_graph_enter() to do the entry work,
no architecture should ever call ftrace_push_return_trace(). Make it static.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: [email protected]
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can
be replaced by synchronize_rcu(). Similarly, call_rcu_sched() can be
replaced by call_rcu(). This commit therefore makes these changes.
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
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Currently all the architectures do basically the same thing in preparing the
function graph tracer on entry to a function. This code can be pulled into a
generic location and then this will allow the function graph tracer to be
fixed, as well as extended.
Create a new function graph helper function_graph_enter() that will call the
hook function (ftrace_graph_entry) and the shadow stack operation
(ftrace_push_return_trace), and remove the need of the architecture code to
manage the shadow stack.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: [email protected]
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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A format string consisting of "%p" or "%s" followed by an invalid
specifier (e.g. "%p%\n" or "%s%") could pass the check which
would make format_decode (lib/vsprintf.c) to warn.
Fixes: 9c959c863f82 ("tracing: Allow BPF programs to call bpf_trace_printk()")
Reported-by: [email protected]
Signed-off-by: Martynas Pumputis <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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Fix strpbrk()'s argument order, it must pass acceptable string
in 2nd argument. Note that this can cause a kernel panic where
it recovers backup character to code->data.
Link: http://lkml.kernel.org/r/154108256792.2604.1816052586385217811.stgit@devbox
Fixes: a6682814f371 ("tracing/kprobes: Allow kprobe-events to record module symbol")
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Pull block layer fixes from Jens Axboe:
"The biggest part of this pull request is the revert of the blkcg
cleanup series. It had one fix earlier for a stacked device issue, but
another one was reported. Rather than play whack-a-mole with this,
revert the entire series and try again for the next kernel release.
Apart from that, only small fixes/changes.
Summary:
- Indentation fixup for mtip32xx (Colin Ian King)
- The blkcg cleanup series revert (Dennis Zhou)
- Two NVMe fixes. One fixing a regression in the nvme request
initialization in this merge window, causing nvme-fc to not work.
The other is a suspend/resume p2p resource issue (James, Keith)
- Fix sg discard merge, allowing us to merge in cases where we didn't
before (Jianchao Wang)
- Call rq_qos_exit() after the queue is frozen, preventing a hang
(Ming)
- Fix brd queue setup, fixing an oops if we fail setting up all
devices (Ming)"
* tag 'for-linus-20181102' of git://git.kernel.dk/linux-block:
nvme-pci: fix conflicting p2p resource adds
nvme-fc: fix request private initialization
blkcg: revert blkcg cleanups series
block: brd: associate with queue until adding disk
block: call rq_qos_exit() after queue is frozen
mtip32xx: clean an indentation issue, remove extraneous tabs
block: fix the DISCARD request merge
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This reverts a series committed earlier due to null pointer exception
bug report in [1]. It seems there are edge case interactions that I did
not consider and will need some time to understand what causes the
adverse interactions.
The original series can be found in [2] with a follow up series in [3].
[1] https://www.spinics.net/lists/cgroups/msg20719.html
[2] https://lore.kernel.org/lkml/[email protected]/
[3] https://lore.kernel.org/lkml/[email protected]/
This reverts the following commits:
d459d853c2ed, b2c3fa546705, 101246ec02b5, b3b9f24f5fcc, e2b0989954ae,
f0fcb3ec89f3, c839e7a03f92, bdc2491708c4, 74b7c02a9bc1, 5bf9a1f3b4ef,
a7b39b4e961c, 07b05bcc3213, 49f4c2dc2b50, 27e6fa996c53
Signed-off-by: Dennis Zhou <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
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git://git.infradead.org/linux-platform-drivers-x86
Pull x86 platform driver updates from Darren Hart:
- Move the Dell dcdbas and dell_rbu drivers into platform/drivers/x86
as they are closely coupled with other drivers in this location.
- Improve _init* usage for acerhdf and fix some usage issues with
messages and module parameters.
- Simplify asus-wmi by calling ACPI/WMI methods directly, eliminating
workqueue overhead, eliminate double reporting of keyboard backlight.
- Fix wake from USB failure on Bay Trail devices (intel_int0002_vgpio).
- Notify intel_telemetry users when IPC1 device is not enabled.
- Update various drivers with new laptop model IDs.
- Update several intel drivers to use SPDX identifers and order headers
alphabetically.
* tag 'platform-drivers-x86-v4.20-1' of git://git.infradead.org/linux-platform-drivers-x86: (64 commits)
HID: asus: only support backlight when it's not driven by WMI
platform/x86: asus-wmi: export function for evaluating WMI methods
platform/x86: asus-wmi: Only notify kbd LED hw_change by fn-key pressed
platform/x86: wmi: declare device_type structure as constant
platform/x86: ideapad: Add Y530-15ICH to no_hw_rfkill
platform/x86: Add Intel AtomISP2 dummy / power-management driver
platform/x86: touchscreen_dmi: Add min-x and min-y settings for various models
platform/x86: touchscreen_dmi: Add info for the Onda V80 Plus v3 tablet
platform/x86: touchscreen_dmi: Add info for the Trekstor Primetab T13B tablet
platform/x86: intel_telemetry: Get rid of custom macro
platform/x86: intel_telemetry: report debugfs failure
MAINTAINERS: intel_telemetry: Update maintainers info
platform/x86: Add LG Gram laptop special features driver
platform/x86: asus-wmi: Simplify the keyboard brightness updating process
platform/x86: touchscreen_dmi: Add info for the Trekstor Primebook C11 convertible
platform/x86: mlx-platform: Properly use mlxplat_mlxcpld_msn201x_items
MAINTAINERS: intel_pmc_core: Update MAINTAINERS
firmware: dcdbas: include linux/io.h
platform/x86: intel-wmi-thunderbolt: Add dynamic debugging
platform/x86: intel-wmi-thunderbolt: Convert to use SPDX identifier
...
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"The biggest change here is the updates to kprobes
Back in January I posted patches to create function based events.
These were the events that you suggested I make to allow developers to
easily create events in code where no trace event exists. After
posting those changes for review, it was suggested that we implement
this instead with kprobes.
The problem with kprobes is that the interface is too complex and
needs to be simplified. Masami Hiramatsu posted patches in March and
I've been playing with them a bit. There's been a bit of clean up in
the kprobe code that was inspired by the function based event patches,
and a couple of enhancements to the kprobe event interface.
- If the arch supports it (we added support for x86), you can place a
kprobe event at the start of a function and use $arg1, $arg2, etc
to reference the arguments of a function. (Before you needed to
know what register or where on the stack the argument was).
- The second is a way to see array of events. For example, if you
reference a mac address, you can add:
echo 'p:mac ip_rcv perm_addr=+574($arg2):x8[6]' > kprobe_events
And this will produce:
mac: (ip_rcv+0x0/0x140) perm_addr={0x52,0x54,0x0,0xc0,0x76,0xec}
Other changes include
- Exporting trace_dump_stack to modules
- Have the stack tracer trace the entire stack (stop trying to remove
tracing itself, as we keep removing too much).
- Added support for SDT in uprobes"
[ SDT - "Statically Defined Tracing" are userspace markers for tracing.
Let's not use random TLA's in explanations unless they are fairly
well-established as generic (at least for kernel people) - Linus ]
* tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
tracing: Have stack tracer trace full stack
tracing: Export trace_dump_stack to modules
tracing: probeevent: Fix uninitialized used of offset in parse args
tracing/kprobes: Allow kprobe-events to record module symbol
tracing/kprobes: Check the probe on unloaded module correctly
tracing/uprobes: Fix to return -EFAULT if copy_from_user failed
tracing: probeevent: Add $argN for accessing function args
x86: ptrace: Add function argument access API
tracing: probeevent: Add array type support
tracing: probeevent: Add symbol type
tracing: probeevent: Unify fetch_insn processing common part
tracing: probeevent: Append traceprobe_ for exported function
tracing: probeevent: Return consumed bytes of dynamic area
tracing: probeevent: Unify fetch type tables
tracing: probeevent: Introduce new argument fetching code
tracing: probeevent: Remove NOKPROBE_SYMBOL from print functions
tracing: probeevent: Cleanup argument field definition
tracing: probeevent: Cleanup print argument functions
trace_uprobe: support reference counter in fd-based uprobe
perf probe: Support SDT markers having reference counter (semaphore)
...
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Masami had a couple more fixes to the synthetic events. One was a
proper error return value, and the other is for the self tests"
* tag 'trace-v4.19-rc8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
selftests/ftrace: Fix synthetic event test to delete event correctly
tracing: Return -ENOENT if there is no target synthetic event
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Return -ENOENT error if there is no target synthetic event.
This notices an operation failure to user as below;
# echo 'wakeup_latency u64 lat; pid_t pid;' > synthetic_events
# echo '!wakeup' >> synthetic_events
sh: write error: No such file or directory
Link: http://lkml.kernel.org/r/154013449986.25576.9487131386597290172.stgit@devbox
Acked-by: Tom Zanussi <[email protected]>
Tested-by: Tom Zanussi <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Rajvi Jingar <[email protected]>
Cc: [email protected]
Fixes: 4b147936fa50 ('tracing: Add support for 'synthetic' events')
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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The stack tracer traces every function call checking the current stack (in
non interrupt context), looking for the deepest stack, and saving it when it
finds a new max depth. The problem is that it calls save_stack_trace(), and
with the new ORC unwinder, it can skip too much. As it looks at the ip of
the function call in the backtrace to find where it should start, it doesn't
need to skip anything.
The stack trace selftest would fail when the kernel was complied with the
ORC UNDWINDER enabled. Without skipping functions when doing the stack
trace, it now passes again.
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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There is no reason for this function to be unexprted and it's a useful
debugging aid.
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Pull block layer updates from Jens Axboe:
"This is the main pull request for block changes for 4.20. This
contains:
- Series enabling runtime PM for blk-mq (Bart).
- Two pull requests from Christoph for NVMe, with items such as;
- Better AEN tracking
- Multipath improvements
- RDMA fixes
- Rework of FC for target removal
- Fixes for issues identified by static checkers
- Fabric cleanups, as prep for TCP transport
- Various cleanups and bug fixes
- Block merging cleanups (Christoph)
- Conversion of drivers to generic DMA mapping API (Christoph)
- Series fixing ref count issues with blkcg (Dennis)
- Series improving BFQ heuristics (Paolo, et al)
- Series improving heuristics for the Kyber IO scheduler (Omar)
- Removal of dangerous bio_rewind_iter() API (Ming)
- Apply single queue IPI redirection logic to blk-mq (Ming)
- Set of fixes and improvements for bcache (Coly et al)
- Series closing a hotplug race with sysfs group attributes (Hannes)
- Set of patches for lightnvm:
- pblk trace support (Hans)
- SPDX license header update (Javier)
- Tons of refactoring patches to cleanly abstract the 1.2 and 2.0
specs behind a common core interface. (Javier, Matias)
- Enable pblk to use a common interface to retrieve chunk metadata
(Matias)
- Bug fixes (Various)
- Set of fixes and updates to the blk IO latency target (Josef)
- blk-mq queue number updates fixes (Jianchao)
- Convert a bunch of drivers from the old legacy IO interface to
blk-mq. This will conclude with the removal of the legacy IO
interface itself in 4.21, with the rest of the drivers (me, Omar)
- Removal of the DAC960 driver. The SCSI tree will introduce two
replacement drivers for this (Hannes)"
* tag 'for-4.20/block-20181021' of git://git.kernel.dk/linux-block: (204 commits)
block: setup bounce bio_sets properly
blkcg: reassociate bios when make_request() is called recursively
blkcg: fix edge case for blk_get_rl() under memory pressure
nvme-fabrics: move controller options matching to fabrics
nvme-rdma: always have a valid trsvcid
mtip32xx: fully switch to the generic DMA API
rsxx: switch to the generic DMA API
umem: switch to the generic DMA API
sx8: switch to the generic DMA API
sx8: remove dead IF_64BIT_DMA_IS_POSSIBLE code
skd: switch to the generic DMA API
ubd: remove use of blk_rq_map_sg
nvme-pci: remove duplicate check
drivers/block: Remove DAC960 driver
nvme-pci: fix hot removal during error handling
nvmet-fcloop: suppress a compiler warning
nvme-core: make implicit seed truncation explicit
nvmet-fc: fix kernel-doc headers
nvme-fc: rework the request initialization code
nvme-fc: introduce struct nvme_fcp_op_w_sgl
...
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Fix synthetic event to allow independent semicolon at end.
The synthetic_events interface accepts a semicolon after the
last word if there is no space.
# echo "myevent u64 var;" >> synthetic_events
But if there is a space, it returns an error.
# echo "myevent u64 var ;" > synthetic_events
sh: write error: Invalid argument
This behavior is difficult for users to understand. Let's
allow the last independent semicolon too.
Link: http://lkml.kernel.org/r/153986835420.18251.2191216690677025744.stgit@devbox
Cc: Shuah Khan <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: [email protected]
Fixes: commit 4b147936fa50 ("tracing: Add support for 'synthetic' events")
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Fix synthetic event to accept unsigned modifier for its field type
correctly.
Currently, synthetic_events interface returns error for "unsigned"
modifiers as below;
# echo "myevent unsigned long var" >> synthetic_events
sh: write error: Invalid argument
This is because argv_split() breaks "unsigned long" into "unsigned"
and "long", but parse_synth_field() doesn't expected it.
With this fix, synthetic_events can handle the "unsigned long"
correctly like as below;
# echo "myevent unsigned long var" >> synthetic_events
# cat synthetic_events
myevent unsigned long var
Link: http://lkml.kernel.org/r/153986832571.18251.8448135724590496531.stgit@devbox
Cc: Shuah Khan <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: [email protected]
Fixes: commit 4b147936fa50 ("tracing: Add support for 'synthetic' events")
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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The preemptirq_delay_test module is used for the ftrace selftest code that
tests the latency tracers. The problem is that it uses ktime for the delay
loop, and then checks the tracer to see if the delay loop is caught, but the
tracer uses trace_clock_local() which uses various different other clocks to
measure the latency. As ktime uses the clock cycles, and the code then
converts that to nanoseconds, it causes rounding errors, and the preemptirq
latency tests are failing due to being off by 1 (it expects to see a delay
of 500000 us, but the delay is only 499999 us). This is happening due to a
rounding error in the ktime (which is totally legit). The purpose of the
test is to see if it can catch the delay, not to test the accuracy between
trace_clock_local() and ktime_get(). Best to use apples to apples, and have
the delay loop use the same clock as the latency tracer does.
Cc: [email protected]
Fixes: f96e8577da102 ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Acked-by: Joel Fernandes (Google) <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Dan's smatch utility found an uninitialized use of offset in a path in
parse_probe_args(). Unless an offset is specifically specified for commands
that allow them, it should default to zero.
Link: http://lkml.kernel.org/r/20181012134246.5doqaobxunlqqs53@mwanda
Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code")
Reported-by: Dan Carpenter <[email protected]> (smatch)
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Allow kprobe-events to record module symbols.
Since data symbols in a non-loaded module doesn't exist, it fails to
define such symbol as an argument of kprobe-event. But if the kprobe
event is defined on that module, we can defer to resolve the symbol
address.
Note that if given symbol is not found, the event is kept unavailable.
User can enable it but the event is not recorded.
Link: http://lkml.kernel.org/r/153547312336.26502.11432902826345374463.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Current kprobe event doesn't checks correctly whether the
given event is on unloaded module or not. It just checks
the event has ":" in the name.
That is not enough because if we define a probe on non-exist
symbol on loaded module, it allows to define that (with
warning message)
To ensure it correctly, this searches the module name on
loaded module list and only if there is not, it allows to
define it. (this event will be available when the target
module is loaded)
Link: http://lkml.kernel.org/r/153547309528.26502.8300278470528281328.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Fix probe_mem_read() to return -EFAULT if copy_from_user()
failed. The copy_from_user() returns remaining bytes
when it failed, but probe_mem_read() caller expects it
returns error code like as probe_kernel_read().
Link: http://lkml.kernel.org/r/153547306719.26502.8353484532699160223.stgit@devbox
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Add $argN special fetch variable for accessing function
arguments. This allows user to trace the Nth argument easily
at the function entry.
Note that this returns most probably assignment of registers
and stacks. In some case, it may not work well. If you need
to access correct registers or stacks you should use perf-probe.
Link: http://lkml.kernel.org/r/152465888632.26224.3412465701570253696.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Add array type support for probe events.
This allows user to get arraied types from memory address.
The array type syntax is
TYPE[N]
Where TYPE is one of types (u8/16/32/64,s8/16/32/64,
x8/16/32/64, symbol, string) and N is a fixed value less
than 64.
The string array type is a bit different from other types. For
other base types, <base-type>[1] is equal to <base-type>
(e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not
equal to string. The string type itself represents "char array",
but string array type represents "char * array". So, for example,
+0(%di):string[1] is equal to +0(+0(%di)):string.
Link: http://lkml.kernel.org/r/152465891533.26224.6150658225601339931.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Add "symbol" type to probeevent, which is an alias of u32 or u64
(depends on BITS_PER_LONG). This shows the result value in
symbol+offset style. This type is only available with kprobe
events.
Link: http://lkml.kernel.org/r/152465882860.26224.14779072294412467338.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Unify the fetch_insn bottom process (from stage 2: dereference
indirect data) from kprobe and uprobe events, since those are
mostly same.
Link: http://lkml.kernel.org/r/152465879965.26224.8547240824606804815.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Append traceprobe_ for exported function set_print_fmt() as
same as other functions.
Link: http://lkml.kernel.org/r/152465877071.26224.11143125027282999726.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Cleanup string fetching routine so that returns the consumed
bytes of dynamic area and store the string information as
data_loc format instead of data_rloc.
This simplifies the fetcharg loop.
Link: http://lkml.kernel.org/r/152465874163.26224.12125143907501289031.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Unify {k,u}probe_fetch_type_table to probe_fetch_type_table
because the main difference of those type tables (fetcharg
methods) are gone. Now we can consolidate it.
Link: http://lkml.kernel.org/r/152465871274.26224.13999436317830479698.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Replace {k,u}probe event argument fetching framework with switch-case based.
Currently that is implemented with structures, macros and chain of
function-pointers, which is more complicated than necessary and may get a
performance penalty by retpoline.
This simplify that with an array of "fetch_insn" (opcode and oprands), and
make process_fetch_insn() just interprets it. No function pointers are used.
Link: http://lkml.kernel.org/r/152465868340.26224.2551120475197839464.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Remove unneeded NOKPROBE_SYMBOL from print functions since
the print functions are only used when printing out the
trace data, and not from kprobe handler.
Link: http://lkml.kernel.org/r/152465865422.26224.10111548170594014954.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Cleanup event argument definition code in one place for
maintenancability.
Link: http://lkml.kernel.org/r/152465862529.26224.9068605421476018902.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Cleanup the print-argument function to decouple it into
print-name and print-value, so that it can support more
flexible expression, like array type.
Link: http://lkml.kernel.org/r/152465859635.26224.13452846788717102315.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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This patch enables uprobes with reference counter in fd-based uprobe.
Highest 32 bits of perf_event_attr.config is used to stored offset
of the reference count (semaphore).
Format information in /sys/bus/event_source/devices/uprobe/format/ is
updated to reflect this new feature.
Link: http://lkml.kernel.org/r/[email protected]
Cc: Oleg Nesterov <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-and-tested-by: Ravi Bangoria <[email protected]>
Signed-off-by: Song Liu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Merge -rc6 in, for two reasons:
1) Resolve a trivial conflict in the blk-mq-tag.c documentation
2) A few important regression fixes went into upstream directly, so
they aren't in the 4.20 branch.
Signed-off-by: Jens Axboe <[email protected]>
* tag 'v4.19-rc6': (780 commits)
Linux 4.19-rc6
MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c
cpufreq: qcom-kryo: Fix section annotations
perf/core: Add sanity check to deal with pinned event failure
xen/blkfront: correct purging of persistent grants
Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
selftests/powerpc: Fix Makefiles for headers_install change
blk-mq: I/O and timer unplugs are inverted in blktrace
dax: Fix deadlock in dax_lock_mapping_entry()
x86/boot: Fix kexec booting failure in the SEV bit detection code
bcache: add separate workqueue for journal_write to avoid deadlock
drm/amd/display: Fix Edid emulation for linux
drm/amd/display: Fix Vega10 lightup on S3 resume
drm/amdgpu: Fix vce work queue was not cancelled when suspend
Revert "drm/panel: Add device_link from panel device to DRM device"
xen/blkfront: When purging persistent grants, keep them in the buffer
clocksource/drivers/timer-atmel-pit: Properly handle error cases
block: fix deadline elevator drain for zoned block devices
ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge
drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set
...
Signed-off-by: Jens Axboe <[email protected]>
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This is the only location on kernel that has wrong spelling
of the container_of() helper. Fix it.
Signed-off-by: Andy Shevchenko <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
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We assume to have only one reference counter for one uprobe.
Don't allow user to add multiple trace_uprobe entries having
same inode+offset but different reference counter.
Ex,
# echo "p:sdt_tick/loop2 /home/ravi/tick:0x6e4(0x10036)" > uprobe_events
# echo "p:sdt_tick/loop2_1 /home/ravi/tick:0x6e4(0xfffff)" >> uprobe_events
bash: echo: write error: Invalid argument
# dmesg
trace_kprobe: Reference counter offset mismatch.
There is one exception though:
When user is trying to replace the old entry with the new
one, we allow this if the new entry does not conflict with
any other existing entries.
Link: http://lkml.kernel.org/r/[email protected]
Acked-by: Srikar Dronamraju <[email protected]>
Reviewed-by: Song Liu <[email protected]>
Reviewed-by: Oleg Nesterov <[email protected]>
Tested-by: Song Liu <[email protected]>
Signed-off-by: Ravi Bangoria <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Userspace Statically Defined Tracepoints[1] are dtrace style markers
inside userspace applications. Applications like PostgreSQL, MySQL,
Pthread, Perl, Python, Java, Ruby, Node.js, libvirt, QEMU, glib etc
have these markers embedded in them. These markers are added by developer
at important places in the code. Each marker source expands to a single
nop instruction in the compiled code but there may be additional
overhead for computing the marker arguments which expands to couple of
instructions. In case the overhead is more, execution of it can be
omitted by runtime if() condition when no one is tracing on the marker:
if (reference_counter > 0) {
Execute marker instructions;
}
Default value of reference counter is 0. Tracer has to increment the
reference counter before tracing on a marker and decrement it when
done with the tracing.
Implement the reference counter logic in core uprobe. User will be
able to use it from trace_uprobe as well as from kernel module. New
trace_uprobe definition with reference counter will now be:
<path>:<offset>[(ref_ctr_offset)]
where ref_ctr_offset is an optional field. For kernel module, new
variant of uprobe_register() has been introduced:
uprobe_register_refctr(inode, offset, ref_ctr_offset, consumer)
No new variant for uprobe_unregister() because it's assumed to have
only one reference counter for one uprobe.
[1] https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation
Note: 'reference counter' is called as 'semaphore' in original Dtrace
(or Systemtap, bcc and even in ELF) documentation and code. But the
term 'semaphore' is misleading in this context. This is just a counter
used to hold number of tracers tracing on a marker. This is not really
used for any synchronization. So we are calling it a 'reference counter'
in kernel / perf code.
Link: http://lkml.kernel.org/r/[email protected]
Reviewed-by: Masami Hiramatsu <[email protected]>
[Only trace_uprobe.c]
Reviewed-by: Oleg Nesterov <[email protected]>
Reviewed-by: Song Liu <[email protected]>
Tested-by: Song Liu <[email protected]>
Signed-off-by: Ravi Bangoria <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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By utilizing a temporary variable, we can avoid adding another call to
strchr(). Instead, save the first call to a temp variable, and then use that
variable as the reference to set the event variable.
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Prior patches ensured that all bios are now associated with some blkg.
This now makes bio->bi_css unnecessary as blkg maintains a reference to
the blkcg already.
This patch removes the field bi_css and transfers corresponding uses to
access via bi_blkg.
Signed-off-by: Dennis Zhou <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
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When reducing ring buffer size, pages are removed by scheduling a work
item on each CPU for the corresponding CPU ring buffer. After the pages
are removed from ring buffer linked list, the pages are free()d in a
tight loop. The loop does not give up CPU until all pages are removed.
In a worst case behavior, when lot of pages are to be freed, it can
cause system stall.
After the pages are removed from the list, the free() can happen while
the work is rescheduled. Call cond_resched() in the loop to prevent the
system hangup.
Link: http://lkml.kernel.org/r/[email protected]
Cc: [email protected]
Fixes: 83f40318dab00 ("ring-buffer: Make removal of ring buffer pages atomic")
Reported-by: Jason Behmer <[email protected]>
Signed-off-by: Vaibhav Nagarnaik <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Masami found an off by one bug in the code that keeps "notrace"
functions from being traced by kprobes. During my testing, I found
that there's places that we may want to add kprobes to notrace, thus
we may end up changing this code before 4.19 is released.
The history behind this change is that we found that adding kprobes to
various notrace functions caused the kernel to crashed. We took the
safe route and decided not to allow kprobes to trace any notrace
function.
But because notrace is added to functions that just cause weird side
effects to the function tracer, but are still safe, preventing kprobes
for all notrace functios may be too much of a big hammer.
One such place is __schedule() is marked notrace, to keep function
tracer from doing strange recursive loops when it gets traced with
NEED_RESCHED set. With this change, one can not add kprobes to the
scheduler.
Masami also added code to use gcov on ftrace"
* tag 'trace-v4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/kprobes: Fix to check notrace function with correct range
tracing: Allow gcov profiling on only ftrace subsystem
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Pull more block updates from Jens Axboe:
- Set of bcache fixes and changes (Coly)
- The flush warn fix (me)
- Small series of BFQ fixes (Paolo)
- wbt hang fix (Ming)
- blktrace fix (Steven)
- blk-mq hardware queue count update fix (Jianchao)
- Various little fixes
* tag 'for-4.19/post-20180822' of git://git.kernel.dk/linux-block: (31 commits)
block/DAC960.c: make some arrays static const, shrinks object size
blk-mq: sync the update nr_hw_queues with blk_mq_queue_tag_busy_iter
blk-mq: init hctx sched after update ctx and hctx mapping
block: remove duplicate initialization
tracing/blktrace: Fix to allow setting same value
pktcdvd: fix setting of 'ret' error return for a few cases
block: change return type to bool
block, bfq: return nbytes and not zero from struct cftype .write() method
block, bfq: improve code of bfq_bfqq_charge_time
block, bfq: reduce write overcharge
block, bfq: always update the budget of an entity when needed
block, bfq: readd missing reset of parent-entity service
blk-wbt: fix IO hang in wbt_wait()
block: don't warn for flush on read-only device
bcache: add the missing comments for smp_mb()/smp_wmb()
bcache: remove unnecessary space before ioctl function pointer arguments
bcache: add missing SPDX header
bcache: move open brace at end of function definitions to next line
bcache: add static const prefix to char * array declarations
bcache: fix code comments style
...
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Fix within_notrace_func() to check notrace function correctly.
Since the ftrace_location_range(start, end) function checks
the range inclusively (start <= ftrace-loc <= end), the end
address must not include the entry address of next function.
However, within_notrace_func() uses kallsyms_lookup_size_offset()
to get the function size and calculate the end address from
adding the size to the entry address. This means the end address
is the entry address of the next function.
In the result, within_notrace_func() fails to find notrace
function if the next function of the target function is
ftraced.
Let's subtract 1 from the end address so that ftrace_location_range()
can check it correctly.
Link: http://lkml.kernel.org/r/153485669706.16611.17726752296213785504.stgit@devbox
Fixes: commit 45408c4f9250 ("tracing: kprobes: Prohibit probing on notrace function")
Reported-by: Michael Rodin <[email protected]>
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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Add GCOV_PROFILE_FTRACE to allow gcov profiling on only files in ftrace
subsystem. This config option will be used for checking kselftest/ftrace
coverage.
Link: http://lkml.kernel.org/r/153483647755.32472.4746349899604275441.stgit@devbox
Signed-off-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
- Restructure of lockdep and latency tracers
This is the biggest change. Joel Fernandes restructured the hooks
from irqs and preemption disabling and enabling. He got rid of a lot
of the preprocessor #ifdef mess that they caused.
He turned both lockdep and the latency tracers to use trace events
inserted in the preempt/irqs disabling paths. But unfortunately,
these started to cause issues in corner cases. Thus, parts of the
code was reverted back to where lockdep and the latency tracers just
get called directly (without using the trace events). But because the
original change cleaned up the code very nicely we kept that, as well
as the trace events for preempt and irqs disabling, but they are
limited to not being called in NMIs.
- Have trace events use SRCU for "rcu idle" calls. This was required
for the preempt/irqs off trace events. But it also had to not allow
them to be called in NMI context. Waiting till Paul makes an NMI safe
SRCU API.
- New notrace SRCU API to allow trace events to use SRCU.
- Addition of mcount-nop option support
- SPDX headers replacing GPL templates.
- Various other fixes and clean ups.
- Some fixes are marked for stable, but were not fully tested before
the merge window opened.
* tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
tracing: Fix SPDX format headers to use C++ style comments
tracing: Add SPDX License format tags to tracing files
tracing: Add SPDX License format to bpf_trace.c
blktrace: Add SPDX License format header
s390/ftrace: Add -mfentry and -mnop-mcount support
tracing: Add -mcount-nop option support
tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
tracing: Handle CC_FLAGS_FTRACE more accurately
Uprobe: Additional argument arch_uprobe to uprobe_write_opcode()
Uprobes: Simplify uprobe_register() body
tracepoints: Free early tracepoints after RCU is initialized
uprobes: Use synchronize_rcu() not synchronize_sched()
tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister()
ftrace: Remove unused pointer ftrace_swapper_pid
tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage"
tracing/irqsoff: Handle preempt_count for different configs
tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage"
tracing: irqsoff: Account for additional preempt_disable
trace: Use rcu_dereference_raw for hooks from trace-event subsystem
tracing/kprobes: Fix within_notrace_func() to check only notrace functions
...
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The Linux kernel adopted the SPDX License format headers to ease license
compliance management, and uses the C++ '//' style comments for the SPDX
header tags. Some files in the tracing directory used the C style /* */
comments for them. To be consistent across all files, replace the /* */
C style SPDX tags with the C++ // SPDX tags.
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
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