mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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8629eea901
1467 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
8bf722c684 |
ring-buffer changes for v6.16:
- Allow the persistent ring buffer to be memory mapped
In the last merge window there was issues with the implementation of
mapping the persistent ring buffer because it was assumed that the
persistent memory was just physical memory without being part of the
kernel virtual address space. But this was incorrect and the persistent
ring buffer can be mapped the same way as the allocated ring buffer is
mapped.
The meta data for the persistent ring buffer is different than the normal
ring buffer and the organization of mapping it to user space is a little
different. Make the updates needed to the meta data to allow the
persistent ring buffer to be mapped to user space.
- Fix cpus_read_lock() with buffer->mutex and cpu_buffer->mapping_lock
Mapping the ring buffer to user space uses the cpu_buffer->mapping_lock.
The buffer->mutex can be taken when the mapping_lock is held, giving the
locking order of: cpu_buffer->mapping_lock -->> buffer->mutex. But there
also exists the ordering:
buffer->mutex -->> cpus_read_lock()
mm->mmap_lock -->> cpu_buffer->mapping_lock
cpus_read_lock() -->> mm->mmap_lock
causing a circular chain of:
cpu_buffer->mapping_lock -> buffer->mutex -->> cpus_read_lock() -->>
mm->mmap_lock -->> cpu_buffer->mapping_lock
By moving the cpus_read_lock() outside the buffer->mutex where:
cpus_read_lock() -->> buffer->mutex, breaks the deadlock chain.
- Do not trigger WARN_ON() for commit overrun
When the ring buffer is user space mapped and there's a "commit overrun"
(where an interrupt preempted an event, and then added so many events it
filled the buffer having to drop events when it hit the preempted event)
a WARN_ON() was triggered if this was read via a memory mapped buffer.
This is due to "missed events" being non zero when the reader page ended
up with the commit page. The idea was, if the writer is on the reader page,
there's only one page that has been written to and there should be no
missed events. But if a commit overrun is done where the writer is off the
commit page and looped around to the commit page causing missed events, it
is possible that the reader page is the commit page with missed events.
Instead of triggering a WARN_ON() when the reader page is the commit page
with missed events, trigger it when the reader page is the tail_page with
missed events. That's because the writer is always on the tail_page if
an event was interrupted (which holds the commit event) and continues off
the commit page.
- Reset the persistent buffer if it is fully consumed
On boot up, if the user fully consumes the last boot buffer of the
persistent buffer, if it reboots without enabling it, there will still be
events in the buffer which can cause confusion. Instead, reset the buffer
when it is fully consumed, so that the data is not read again.
- Clean up some goto out jumps
There's a few cases that the code jumps to the "out:" label that simply
returns a value. There used to be more work done at those labels but now
that they simply return a value use a return instead of jumping to a
label.
- Use guard() to simplify some of the code
Add guard() around some locking instead of jumping to a label to do the
unlocking.
- Use free() to simplify some of the code
Use free(kfree) on variables that will get freed on error and use
return_ptr() to return the variable when its not freed. There's one
instance where free(kfree) simplifies the code on a temp variable that was
allocated just for the function use.
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Merge tag 'trace-ringbuffer-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer updates from Steven Rostedt:
- Allow the persistent ring buffer to be memory mapped
In the last merge window there was issues with the implementation of
mapping the persistent ring buffer because it was assumed that the
persistent memory was just physical memory without being part of the
kernel virtual address space. But this was incorrect and the
persistent ring buffer can be mapped the same way as the allocated
ring buffer is mapped.
The metadata for the persistent ring buffer is different than the
normal ring buffer and the organization of mapping it to user space
is a little different. Make the updates needed to the meta data to
allow the persistent ring buffer to be mapped to user space.
- Fix cpus_read_lock() with buffer->mutex and cpu_buffer->mapping_lock
Mapping the ring buffer to user space uses the
cpu_buffer->mapping_lock. The buffer->mutex can be taken when the
mapping_lock is held, giving the locking order of:
cpu_buffer->mapping_lock -->> buffer->mutex. But there also exists
the ordering:
buffer->mutex -->> cpus_read_lock()
mm->mmap_lock -->> cpu_buffer->mapping_lock
cpus_read_lock() -->> mm->mmap_lock
causing a circular chain of:
cpu_buffer->mapping_lock -> buffer->mutex -->> cpus_read_lock() -->>
mm->mmap_lock -->> cpu_buffer->mapping_lock
By moving the cpus_read_lock() outside the buffer->mutex where:
cpus_read_lock() -->> buffer->mutex, breaks the deadlock chain.
- Do not trigger WARN_ON() for commit overrun
When the ring buffer is user space mapped and there's a "commit
overrun" (where an interrupt preempted an event, and then added so
many events it filled the buffer having to drop events when it hit
the preempted event) a WARN_ON() was triggered if this was read via a
memory mapped buffer.
This is due to "missed events" being non zero when the reader page
ended up with the commit page. The idea was, if the writer is on the
reader page, there's only one page that has been written to and there
should be no missed events.
But if a commit overrun is done where the writer is off the commit
page and looped around to the commit page causing missed events, it
is possible that the reader page is the commit page with missed
events.
Instead of triggering a WARN_ON() when the reader page is the commit
page with missed events, trigger it when the reader page is the
tail_page with missed events. That's because the writer is always on
the tail_page if an event was interrupted (which holds the commit
event) and continues off the commit page.
- Reset the persistent buffer if it is fully consumed
On boot up, if the user fully consumes the last boot buffer of the
persistent buffer, if it reboots without enabling it, there will
still be events in the buffer which can cause confusion. Instead,
reset the buffer when it is fully consumed, so that the data is not
read again.
- Clean up some goto out jumps
There's a few cases that the code jumps to the "out:" label that
simply returns a value. There used to be more work done at those
labels but now that they simply return a value use a return instead
of jumping to a label.
- Use guard() to simplify some of the code
Add guard() around some locking instead of jumping to a label to do
the unlocking.
- Use free() to simplify some of the code
Use free(kfree) on variables that will get freed on error and use
return_ptr() to return the variable when its not freed. There's one
instance where free(kfree) simplifies the code on a temp variable
that was allocated just for the function use.
* tag 'trace-ringbuffer-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Simplify functions with __free(kfree) to free allocations
ring-buffer: Make ring_buffer_{un}map() simpler with guard(mutex)
ring-buffer: Simplify ring_buffer_read_page() with guard()
ring-buffer: Simplify reset_disabled_cpu_buffer() with use of guard()
ring-buffer: Remove jump to out label in ring_buffer_swap_cpu()
ring-buffer: Removed unnecessary if() goto out where out is the next line
tracing: Reset last-boot buffers when reading out all cpu buffers
ring-buffer: Allow reserve_mem persistent ring buffers to be mmapped
ring-buffer: Do not trigger WARN_ON() due to a commit_overrun
ring-buffer: Move cpus_read_lock() outside of buffer->mutex
|
||
|
Linus Torvalds
|
0f70f5b08a |
automount wart removal
Calling conventions of ->d_automount() made saner (flagday change) vfs_submount() is gone - its sole remaining user (trace_automount) had been switched to saner primitives. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCaDoRWQAKCRBZ7Krx/gZQ 6wxMAQCzuMc2GiGBMXzeK4SGA7d5rsK71unf+zczOd8NvbTImQEAs1Cu3u3bF3pq EmHQWFTKBpBf+RHsLSoDHwUA+9THowM= =GXLi -----END PGP SIGNATURE----- Merge tag 'pull-automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull automount updates from Al Viro: "Automount wart removal A bunch of odd boilerplate gone from instances - the reason for those was the need to protect the yet-to-be-attched mount from mark_mounts_for_expiry() deciding to take it out. But that's easy to detect and take care of in mark_mounts_for_expiry() itself; no need to have every instance simulate mount being busy by grabbing an extra reference to it, with finish_automount() undoing that once it attaches that mount. Should've done it that way from the very beginning... This is a flagday change, thankfully there are very few instances. vfs_submount() is gone - its sole remaining user (trace_automount) had been switched to saner primitives" * tag 'pull-automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: kill vfs_submount() saner calling conventions for ->d_automount() |
||
|
Linus Torvalds
|
b78f1293f9 |
tracing updates for v6.16:
- Have module addresses get updated in the persistent ring buffer The addresses of the modules from the previous boot are saved in the persistent ring buffer. If the same modules are loaded and an address is in the old buffer points to an address that was both saved in the persistent ring buffer and is loaded in memory, shift the address to point to the address that is loaded in memory in the trace event. - Print function names for irqs off and preempt off callsites When ignoring the print fmt of a trace event and just printing the fields directly, have the fields for preempt off and irqs off events still show the function name (via kallsyms) instead of just showing the raw address. - Clean ups of the histogram code The histogram functions saved over 800 bytes on the stack to process events as they come in. Instead, create per-cpu buffers that can hold this information and have a separate location for each context level (thread, softirq, IRQ and NMI). Also add some more comments to the code. - Add "common_comm" field for histograms Add "common_comm" that uses the current->comm as a field in an event histogram and acts like any of the other fields of the event. - Show "subops" in the enabled_functions file When the function graph infrastructure is used, a subsystem has a "subops" that it attaches its callback function to. Instead of the enabled_functions just showing a function calling the function that calls the subops functions, also show the subops functions that will get called for that function too. - Add "copy_trace_marker" option to instances There are cases where an instance is created for tooling to write into, but the old tooling has the top level instance hardcoded into the application. New tools want to consume the data from an instance and not the top level buffer. By adding a copy_trace_marker option, whenever the top instance trace_marker is written into, a copy of it is also written into the instance with this option set. This allows new tools to read what old tools are writing into the top buffer. If this option is cleared by the top instance, then what is written into the trace_marker is not written into the top instance. This is a way to redirect the trace_marker writes into another instance. - Have tracepoints created by DECLARE_TRACE() use trace_<name>_tp() If a tracepoint is created by DECLARE_TRACE() instead of TRACE_EVENT(), then it will not be exposed via tracefs. Currently there's no way to differentiate in the kernel the tracepoint functions between those that are exposed via tracefs or not. A calling convention has been made manually to append a "_tp" prefix for events created by DECLARE_TRACE(). Instead of doing this manually, force it so that all DECLARE_TRACE() events have this notation. - Use __string() for task->comm in some sched events Instead of hardcoding the comm to be TASK_COMM_LEN in some of the scheduler events use __string() which makes it dynamic. Note, if these events are parsed by user space it they may break, and the event may have to be converted back to the hardcoded size. - Have function graph "depth" be unsigned to the user Internally to the kernel, the "depth" field of the function graph event is signed due to -1 being used for end of boundary. What actually gets recorded in the event itself is zero or positive. Reflect this to user space by showing "depth" as unsigned int and be consistent across all events. - Allow an arbitrary long CPU string to osnoise_cpus_write() The filtering of which CPUs to write to can exceed 256 bytes. If a machine has 256 CPUs, and the filter is to filter every other CPU, the write would take a string larger than 256 bytes. Instead of using a fixed size buffer on the stack that is 256 bytes, allocate it to handle what is passed in. - Stop having ftrace check the per-cpu data "disabled" flag The "disabled" flag in the data structure passed to most ftrace functions is checked to know if tracing has been disabled or not. This flag was added back in 2008 before the ring buffer had its own way to disable tracing. The "disable" flag is now not always set when needed, and the ring buffer flag should be used in all locations where the disabled is needed. Since the "disable" flag is redundant and incorrect, stop using it. Fix up some locations that use the "disable" flag to use the ring buffer info. - Use a new tracer_tracing_disable/enable() instead of data->disable flag There's a few cases that set the data->disable flag to stop tracing, but this flag is not consistently used. It is also an on/off switch where if a function set it and calls another function that sets it, the called function may incorrectly enable it. Use a new trace_tracing_disable() and tracer_tracing_enable() that uses a counter and can be nested. These use the ring buffer flags which are always checked making the disabling more consistent. - Save the trace clock in the persistent ring buffer Save what clock was used for tracing in the persistent ring buffer and set it back to that clock after a reboot. - Remove unused reference to a per CPU data pointer in mmiotrace functions - Remove unused buffer_page field from trace_array_cpu structure - Remove more strncpy() instances - Other minor clean ups and fixes -----BEGIN PGP SIGNATURE----- iIoEABYKADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCaDhiqRQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qkheAQDpyRHoXF1AIoEqyahDax8f3vpZQeCH B/mn+YJmU1wuVgEA7AFALov5SHKv4IzoARz68GXtR0jGhP5D8uebUhUqDAQ= =WmFG -----END PGP SIGNATURE----- Merge tag 'trace-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Have module addresses get updated in the persistent ring buffer The addresses of the modules from the previous boot are saved in the persistent ring buffer. If the same modules are loaded and an address is in the old buffer points to an address that was both saved in the persistent ring buffer and is loaded in memory, shift the address to point to the address that is loaded in memory in the trace event. - Print function names for irqs off and preempt off callsites When ignoring the print fmt of a trace event and just printing the fields directly, have the fields for preempt off and irqs off events still show the function name (via kallsyms) instead of just showing the raw address. - Clean ups of the histogram code The histogram functions saved over 800 bytes on the stack to process events as they come in. Instead, create per-cpu buffers that can hold this information and have a separate location for each context level (thread, softirq, IRQ and NMI). Also add some more comments to the code. - Add "common_comm" field for histograms Add "common_comm" that uses the current->comm as a field in an event histogram and acts like any of the other fields of the event. - Show "subops" in the enabled_functions file When the function graph infrastructure is used, a subsystem has a "subops" that it attaches its callback function to. Instead of the enabled_functions just showing a function calling the function that calls the subops functions, also show the subops functions that will get called for that function too. - Add "copy_trace_marker" option to instances There are cases where an instance is created for tooling to write into, but the old tooling has the top level instance hardcoded into the application. New tools want to consume the data from an instance and not the top level buffer. By adding a copy_trace_marker option, whenever the top instance trace_marker is written into, a copy of it is also written into the instance with this option set. This allows new tools to read what old tools are writing into the top buffer. If this option is cleared by the top instance, then what is written into the trace_marker is not written into the top instance. This is a way to redirect the trace_marker writes into another instance. - Have tracepoints created by DECLARE_TRACE() use trace_<name>_tp() If a tracepoint is created by DECLARE_TRACE() instead of TRACE_EVENT(), then it will not be exposed via tracefs. Currently there's no way to differentiate in the kernel the tracepoint functions between those that are exposed via tracefs or not. A calling convention has been made manually to append a "_tp" prefix for events created by DECLARE_TRACE(). Instead of doing this manually, force it so that all DECLARE_TRACE() events have this notation. - Use __string() for task->comm in some sched events Instead of hardcoding the comm to be TASK_COMM_LEN in some of the scheduler events use __string() which makes it dynamic. Note, if these events are parsed by user space it they may break, and the event may have to be converted back to the hardcoded size. - Have function graph "depth" be unsigned to the user Internally to the kernel, the "depth" field of the function graph event is signed due to -1 being used for end of boundary. What actually gets recorded in the event itself is zero or positive. Reflect this to user space by showing "depth" as unsigned int and be consistent across all events. - Allow an arbitrary long CPU string to osnoise_cpus_write() The filtering of which CPUs to write to can exceed 256 bytes. If a machine has 256 CPUs, and the filter is to filter every other CPU, the write would take a string larger than 256 bytes. Instead of using a fixed size buffer on the stack that is 256 bytes, allocate it to handle what is passed in. - Stop having ftrace check the per-cpu data "disabled" flag The "disabled" flag in the data structure passed to most ftrace functions is checked to know if tracing has been disabled or not. This flag was added back in 2008 before the ring buffer had its own way to disable tracing. The "disable" flag is now not always set when needed, and the ring buffer flag should be used in all locations where the disabled is needed. Since the "disable" flag is redundant and incorrect, stop using it. Fix up some locations that use the "disable" flag to use the ring buffer info. - Use a new tracer_tracing_disable/enable() instead of data->disable flag There's a few cases that set the data->disable flag to stop tracing, but this flag is not consistently used. It is also an on/off switch where if a function set it and calls another function that sets it, the called function may incorrectly enable it. Use a new trace_tracing_disable() and tracer_tracing_enable() that uses a counter and can be nested. These use the ring buffer flags which are always checked making the disabling more consistent. - Save the trace clock in the persistent ring buffer Save what clock was used for tracing in the persistent ring buffer and set it back to that clock after a reboot. - Remove unused reference to a per CPU data pointer in mmiotrace functions - Remove unused buffer_page field from trace_array_cpu structure - Remove more strncpy() instances - Other minor clean ups and fixes * tag 'trace-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (36 commits) tracing: Fix compilation warning on arm32 tracing: Record trace_clock and recover when reboot tracing/sched: Use __string() instead of fixed lengths for task->comm tracepoint: Have tracepoints created with DECLARE_TRACE() have _tp suffix tracing: Cleanup upper_empty() in pid_list tracing: Allow the top level trace_marker to write into another instances tracing: Add a helper function to handle the dereference arg in verifier tracing: Remove unnecessary "goto out" that simply returns ret is trigger code tracing: Fix error handling in event_trigger_parse() tracing: Rename event_trigger_alloc() to trigger_data_alloc() tracing: Replace deprecated strncpy() with strscpy() for stack_trace_filter_buf tracing: Remove unused buffer_page field from trace_array_cpu structure tracing: Use atomic_inc_return() for updating "disabled" counter in irqsoff tracer tracing: Convert the per CPU "disabled" counter to local from atomic tracing: branch: Use trace_tracing_is_on_cpu() instead of "disabled" field ring-buffer: Add ring_buffer_record_is_on_cpu() tracing: Do not use per CPU array_buffer.data->disabled for cpumask ftrace: Do not disabled function graph based on "disabled" field tracing: kdb: Use tracer_tracing_on/off() instead of setting per CPU disabled tracing: Use tracer_tracing_disable() instead of "disabled" field for ftrace_dump_one() ... |
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Masami Hiramatsu (Google)
|
32dc004252 |
tracing: Reset last-boot buffers when reading out all cpu buffers
Reset the last-boot ring buffers when read() reads out all cpu buffers through trace_pipe/trace_pipe_raw. This prevents ftrace to unwind ring buffer read pointer next boot. Note that this resets only when all per-cpu buffers are empty, and read via read(2) syscall. For example, if you read only one of the per-cpu trace_pipe, it does not reset it. Also, reading buffer by splice(2) syscall does not reset because some data in the reader (the last) page. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/174792929202.496143.8184644221859580999.stgit@mhiramat.tok.corp.google.com Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
|
c2a0831142 |
ring-buffer: Allow reserve_mem persistent ring buffers to be mmapped
When the persistent ring buffer is created from the memory returned by reserve_mem there is nothing prohibiting it to be memory mapped to user space. The memory is the same as the pages allocated by alloc_page(). The way the memory is managed by the ring buffer code is slightly different though and needs to be addressed. The persistent memory uses the page->id for its own purpose where as the user mmap buffer currently uses that for the subbuf array mapped to user space. If the buffer is a persistent buffer, use the page index into that buffer as the identifier instead of the page->id. That is, the page->id for a persistent buffer, represents the order of the buffer is in the link list. ->id == 0 means it is the reader page. When a reader page is swapped, the new reader page's ->id gets zero, and the old reader page gets the ->id of the page that it swapped with. The user space mapping has the ->id is the index of where it was mapped in user space and does not change while it is mapped. Since the persistent buffer is fixed in its location, the index of where a page is in the memory range can be used as the "id" to put in the meta page array, and it can be mapped in the same order to user space as it is in the persistent memory. A new rb_page_id() helper function is used to get and set the id depending on if the page is a normal memory allocated buffer or a physical memory mapped buffer. Cc: Linus Torvalds <torvalds@linux-foundation.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> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Rapoport <rppt@kernel.org> Cc: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/20250401203332.246646011@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
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Pan Taixi
|
2fbdb6d8e0 |
tracing: Fix compilation warning on arm32
On arm32, size_t is defined to be unsigned int, while PAGE_SIZE is
unsigned long. This hence triggers a compilation warning as min()
asserts the type of two operands to be equal. Casting PAGE_SIZE to size_t
solves this issue and works on other target architectures as well.
Compilation warning details:
kernel/trace/trace.c: In function 'tracing_splice_read_pipe':
./include/linux/minmax.h:20:28: warning: comparison of distinct pointer types lacks a cast
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
^
./include/linux/minmax.h:26:4: note: in expansion of macro '__typecheck'
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~
...
kernel/trace/trace.c:6771:8: note: in expansion of macro 'min'
min((size_t)trace_seq_used(&iter->seq),
^~~
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250526013731.1198030-1-pantaixi@huaweicloud.com
Fixes:
|
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Linus Torvalds
|
f1975e4765 |
Summary
* Move kern_table members out of kernel/sysctl.c Moved a subset (tracing, panic, signal, stack_tracer and sparc) out of the kern_table array. The goal is for kern_table to only have sysctl elements. All this increases modularity by placing the ctl_tables closer to where they are used while reducing the chances of merge conflicts in kernel/sysctl.c. * Fixed sysctl unit test panic by relocating it to selftests * Testing These have been in linux-next from rc2, so they have had more than a month worth of testing. -----BEGIN PGP SIGNATURE----- iQGzBAABCgAdFiEErkcJVyXmMSXOyyeQupfNUreWQU8FAmgwLsAACgkQupfNUreW QU9ghwv/VKZW+IXEvSjc8OiwntWkL7e5ddHY6O2Vf44MzhBefLTXmfx2HfkEA0Xw RaOQ28Hf/zQL83RqHHnXqI7JdGWQJUm8bCPwk4H3DCaF8qOfPVvblVYmfNL2auSY oyRRpRzZuY5EtKcrNjiHFHL2WIC8KvPVwS748oHY1eZY7kn1fcs8DDnNO4iuWop+ uJeDxu87wkRCFXF3DIM+MAHRvxSa8GHtZvb9EjAl/EHMbAyVSz3uTb7FdQDdnE09 s7P30EC03RHtgi3sd2Ku04dJsHLz7VErvpToxSH2KFlcdpJuWuCSCTT8XaD8kII8 kYYCxNpmPOf4LzEy/J2vVZB0PSHrHvuQCH7iGy+8wOPk9GHTOMkKMMXVmeGnAsef AiosPYroxXp/nBFcuNs6/1LKpsdpFr2F6u6oMgbzLaW1Xe/oc+6oynuOgeVj9LuM FrSxSwaVvpdwHYHujYPQAAWIgKRzITiEXnCgtSyohFquKb+7E8ZspwjOqYH2xWMQ WwABNRqY =45X2 -----END PGP SIGNATURE----- Merge tag 'sysctl-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl Pull sysctl updates from Joel Granados: - Move kern_table members out of kernel/sysctl.c Moved a subset (tracing, panic, signal, stack_tracer and sparc) out of the kern_table array. The goal is for kern_table to only have sysctl elements. All this increases modularity by placing the ctl_tables closer to where they are used while reducing the chances of merge conflicts in kernel/sysctl.c. - Fixed sysctl unit test panic by relocating it to selftests * tag 'sysctl-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: sysctl: Close test ctl_headers with a for loop sysctl: call sysctl tests with a for loop sysctl: Add 0012 to test the u8 range check sysctl: move u8 register test to lib/test_sysctl.c sparc: mv sparc sysctls into their own file under arch/sparc/kernel stack_tracer: move sysctl registration to kernel/trace/trace_stack.c tracing: Move trace sysctls into trace.c signal: Move signal ctl tables into signal.c panic: Move panic ctl tables into panic.c |
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|
Masami Hiramatsu (Google)
|
2632a2013f |
tracing: Record trace_clock and recover when reboot
Record trace_clock information in the trace_scratch area and recover the trace_clock when boot, so that reader can docode the timestamp correctly. Note that since most trace_clocks records the timestamp in nano- seconds, this is not a bug. But some trace_clock, like counter and tsc will record the counter value. Only for those trace_clock user needs this information. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/174720625803.1925039.1815089037443798944.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
7b382efd5e |
tracing: Allow the top level trace_marker to write into another instances
There are applications that have it hard coded to write into the top level trace_marker instance (/sys/kernel/tracing/trace_marker). This can be annoying if a profiler is using that instance for other work, or if it needs all writes to go into a new instance. A new option is created called "copy_trace_marker". By default, the top level has this set, as that is the default buffer that writing into the top level trace_marker file will go to. But now if an instance is created and sets this option, all writes into the top level trace_marker will also be written into that instance buffer just as if an application were to write into the instance's trace_marker file. If the top level instance disables this option, then writes to its own trace_marker and trace_marker_raw files will not go into its buffer. If no instance has this option set, then the write will return an error and errno will contain ENODEV. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250508095639.39f84eda@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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|
Steven Rostedt
|
969043af15 |
tracing: Do not use per CPU array_buffer.data->disabled for cpumask
The per CPU "disabled" value was the original way to disable tracing when the tracing subsystem was first created. Today, the ring buffer infrastructure has its own way to disable tracing. In fact, things have changed so much since 2008 that many things ignore the disable flag. Do not bother setting the per CPU disabled flag of the array_buffer data to use to determine what CPUs can write to the buffer and only rely on the ring buffer code itself to disabled it. 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> Link: https://lore.kernel.org/20250505212235.885452497@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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|
Steven Rostedt
|
6ba3e0533f |
tracing: Use tracer_tracing_disable() instead of "disabled" field for ftrace_dump_one()
The per CPU "disabled" value was the original way to disable tracing when the tracing subsystem was first created. Today, the ring buffer infrastructure has its own way to disable tracing. In fact, things have changed so much since 2008 that many things ignore the disable flag. The ftrace_dump_one() function iterates over all the current tracing CPUs and increments the "disabled" counter before doing the dump, and decrements it afterward. As the disabled flag can be ignored, doing this today is not reliable. Instead use the new tracer_tracing_disable() that calls into the ring buffer code to do the disabling. 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> Link: https://lore.kernel.org/20250505212235.381188238@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
dbecef68ad |
tracing: Add tracer_tracing_disable/enable() functions
Allow a tracer to disable writing to its buffer for a temporary amount of time and re-enable it. The tracer_tracing_disable() will disable writing to the trace array buffer, and requires a tracer_tracing_enable() to re-enable it. The difference between tracer_tracing_disable() and tracer_tracing_off() is that the disable version can nest, and requires as many enable() calls as disable() calls to re-enable the buffer. Where as the off() function can be called multiple times and only requires a singe tracer_tracing_on() to re-enable the buffer. Cc: Jason Wessel <jason.wessel@windriver.com> 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: Daniel Thompson <danielt@kernel.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/20250505212235.210330010@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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|
Al Viro
|
2dbf6e0df4 |
kill vfs_submount()
The last remaining user of vfs_submount() (tracefs) is easy to convert to fs_context_for_submount(); do that and bury that thing, along with SB_SUBMOUNT Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
||
|
Steven Rostedt
|
00d872dd54 |
tracing: Only return an adjusted address if it matches the kernel address
The trace_adjust_address() will take a given address and examine the persistent ring buffer to see if the address matches a module that is listed there. If it does not, it will just adjust the value to the core kernel delta. But if the address was for something that was not part of the core kernel text or data it should not be adjusted. Check the result of the adjustment and only return the adjustment if it lands in the current kernel text or data. If not, return the original address. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250506102300.0ba2f9e0@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Al Viro
|
006ff7498f |
saner calling conventions for ->d_automount()
Currently the calling conventions for ->d_automount() instances have an odd wart - returned new mount to be attached is expected to have refcount 2. That kludge is intended to make sure that mark_mounts_for_expiry() called before we get around to attaching that new mount to the tree won't decide to take it out. finish_automount() drops the extra reference after it's done with attaching mount to the tree - or drops the reference twice in case of error. ->d_automount() instances have rather counterintuitive boilerplate in them. There's a much simpler approach: have mark_mounts_for_expiry() skip the mounts that are yet to be mounted. And to hell with grabbing/dropping those extra references. Makes for simpler correctness analysis, at that... Reviewed-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Acked-by: David Howells <dhowells@redhat.com> Tested-by: David Howells <dhowells@redhat.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
||
|
Steven Rostedt
|
1be8e54a1e |
tracing: Fix trace_adjust_address() when there is no modules in scratch area
The function trace_adjust_address() is used to map addresses of modules
stored in the persistent memory and are also loaded in the current boot to
return the current address for the module.
If there's only one module entry, it will simply use that, otherwise it
performs a bsearch of the entry array to find the modules to offset with.
The issue is if there are no modules in the array. The code does not
account for that and ends up referencing the first element in the array
which does not exist and causes a crash.
If nr_entries is zero, exit out early as if this was a core kernel
address.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250501151909.65910359@gandalf.local.home
Fixes:
|
||
|
Jeongjun Park
|
f5178c41bb |
tracing: Fix oob write in trace_seq_to_buffer()
syzbot reported this bug:
==================================================================
BUG: KASAN: slab-out-of-bounds in trace_seq_to_buffer kernel/trace/trace.c:1830 [inline]
BUG: KASAN: slab-out-of-bounds in tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822
Write of size 4507 at addr ffff888032b6b000 by task syz.2.320/7260
CPU: 1 UID: 0 PID: 7260 Comm: syz.2.320 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xc3/0x670 mm/kasan/report.c:521
kasan_report+0xe0/0x110 mm/kasan/report.c:634
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
__asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106
trace_seq_to_buffer kernel/trace/trace.c:1830 [inline]
tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822
....
==================================================================
It has been reported that trace_seq_to_buffer() tries to copy more data
than PAGE_SIZE to buf. Therefore, to prevent this, we should use the
smaller of trace_seq_used(&iter->seq) and PAGE_SIZE as an argument.
Link: https://lore.kernel.org/20250422113026.13308-1-aha310510@gmail.com
Reported-by: syzbot+c8cd2d2c412b868263fb@syzkaller.appspotmail.com
Fixes:
|
||
|
Joel Granados
|
dd293df639 |
tracing: Move trace sysctls into trace.c
Move trace ctl tables into their own const array in kernel/trace/trace.c. The sysctl table register is called with subsys_initcall placing if after its original place in proc_root_init. This is part of a greater effort to move ctl tables into their respective subsystems which will reduce the merge conflicts in kernel/sysctl.c. Signed-off-by: Joel Granados <joel.granados@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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|
Steven Rostedt
|
4808595a99 |
tracing: Hide get_vm_area() from MMUless builds
The function get_vm_area() is not defined for non-MMU builds and causes a
build error if it is used. Hide the map_pages() function around a:
#ifdef CONFIG_MMU
to keep it from being compiled when CONFIG_MMU is not set.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250407120111.2ccc9319@gandalf.local.home
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/all/4f8ece8b-8862-4f7c-8ede-febd28f8a9fe@roeck-us.net/
Fixes:
|
||
|
Linus Torvalds
|
6cb0bd94c0 |
Persistent buffer cleanups and simplifications for v6.15:
It was mistaken that the physical memory returned from "reserve_mem" had to
be vmap()'d to get to it from a virtual address. But reserve_mem already
maps the memory to the virtual address of the kernel so a simple
phys_to_virt() can be used to get to the virtual address from the physical
memory returned by "reserve_mem". With this new found knowledge, the
code can be cleaned up and simplified.
- Enforce that the persistent memory is page aligned
As the buffers using the persistent memory are all going to be
mapped via pages, make sure that the memory given to the tracing
infrastructure is page aligned. If it is not, it will print a warning
and fail to map the buffer.
- Use phys_to_virt() to get the virtual address from reserve_mem
Instead of calling vmap() on the physical memory returned from
"reserve_mem", use phys_to_virt() instead.
As the memory returned by "memmap" or any other means where a physical
address is given to the tracing infrastructure, it still needs to
be vmap(). Since this memory can never be returned back to the buddy
allocator nor should it ever be memmory mapped to user space, flag
this buffer and up the ref count. The ref count will keep it from
ever being freed, and the flag will prevent it from ever being memory
mapped to user space.
- Use vmap_page_range() for memmap virtual address mapping
For the memmap buffer, instead of allocating an array of struct pages,
assigning them to the contiguous phsycial memory and then passing that to
vmap(), use vmap_page_range() instead
- Replace flush_dcache_folio() with flush_kernel_vmap_range()
Instead of calling virt_to_folio() and passing that to
flush_dcache_folio(), just call flush_kernel_vmap_range() directly.
This also fixes a bug where if a subbuffer was bigger than PAGE_SIZE
only the PAGE_SIZE portion would be flushed.
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Merge tag 'trace-ringbuffer-v6.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer updates from Steven Rostedt:
"Persistent buffer cleanups and simplifications.
It was mistaken that the physical memory returned from "reserve_mem"
had to be vmap()'d to get to it from a virtual address. But
reserve_mem already maps the memory to the virtual address of the
kernel so a simple phys_to_virt() can be used to get to the virtual
address from the physical memory returned by "reserve_mem". With this
new found knowledge, the code can be cleaned up and simplified.
- Enforce that the persistent memory is page aligned
As the buffers using the persistent memory are all going to be
mapped via pages, make sure that the memory given to the tracing
infrastructure is page aligned. If it is not, it will print a
warning and fail to map the buffer.
- Use phys_to_virt() to get the virtual address from reserve_mem
Instead of calling vmap() on the physical memory returned from
"reserve_mem", use phys_to_virt() instead.
As the memory returned by "memmap" or any other means where a
physical address is given to the tracing infrastructure, it still
needs to be vmap(). Since this memory can never be returned back to
the buddy allocator nor should it ever be memmory mapped to user
space, flag this buffer and up the ref count. The ref count will
keep it from ever being freed, and the flag will prevent it from
ever being memory mapped to user space.
- Use vmap_page_range() for memmap virtual address mapping
For the memmap buffer, instead of allocating an array of struct
pages, assigning them to the contiguous phsycial memory and then
passing that to vmap(), use vmap_page_range() instead
- Replace flush_dcache_folio() with flush_kernel_vmap_range()
Instead of calling virt_to_folio() and passing that to
flush_dcache_folio(), just call flush_kernel_vmap_range() directly.
This also fixes a bug where if a subbuffer was bigger than
PAGE_SIZE only the PAGE_SIZE portion would be flushed"
* tag 'trace-ringbuffer-v6.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Use flush_kernel_vmap_range() over flush_dcache_folio()
tracing: Use vmap_page_range() to map memmap ring buffer
tracing: Have reserve_mem use phys_to_virt() and separate from memmap buffer
tracing: Enforce the persistent ring buffer to be page aligned
|
||
|
Linus Torvalds
|
41677970ad |
tracing fixes for 6.15
- Fix build error when CONFIG_PROBE_EVENTS_BTF_ARGS is not enabled The tracing of arguments in the function tracer depends on some functions that are only defined when PROBE_EVENTS_BTF_ARGS is enabled. In fact, PROBE_EVENTS_BTF_ARGS also depends on all the same configs as the function argument tracing requires. Just have the function argument tracing depend on PROBE_EVENTS_BTF_ARGS. - Free module_delta for persistent ring buffer instance When an instance holds the persistent ring buffer, it allocates a helper array to hold the deltas between where modules are loaded on the last boot and the current boot. This array needs to be freed when the instance is freed. - Add cond_resched() to loop in ftrace_graph_set_hash() The hash functions in ftrace loop over every function that can be enabled by ftrace. This can be 50,000 functions or more. This loop is known to trigger soft lockup warnings and requires a cond_resched(). The loop in ftrace_graph_set_hash() was missing it. - Fix the event format verifier to include "%*p.." arguments To prevent events from dereferencing stale pointers that can happen if a trace event uses a dereferece pointer to something that was not copied into the ring buffer and can be freed by the time the trace is read, a verifier is called. At boot or module load, the verifier scans the print format string for pointers that can be dereferenced and it checks the arguments to make sure they do not contain something that can be freed. The "%*p" was not handled, which would add another argument and cause the verifier to not only not verify this pointer, but it will look at the wrong argument for every pointer after that. - Fix mcount sorttable building for different endian type target When modifying the ELF file to sort the mcount_loc table in the sorttable.c code, the endianess of the file and the host is used to determine if the bytes need to be swapped when calculations are done. A change was made to the sorting of the mcount_loc that read the values from the ELF file into an array and the swap happened on the filling of the array. But one of the calculations of the array still did the swap when it did not need to. This caused building on a little endian machine for a big endian target to not find the mcount function in the 'nm' table and it zeroed it out, causing there to be no functions available to trace. - Add goto out_unlock jump to rv_register_monitor() on error path One of the error paths in rv_register_monitor() just returned the error when it should have jumped to the out_unlock label to release the mutex. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZ+2tyBQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qjPYAPwJDti6nHTqheFwIa1WzJ3yC2tKRYKt 1E5PYW/2Ct5NmwEAqgg3TvJppXHymVdutLghhGFnlBnyTWMI+KIhparSBw8= =NFM5 -----END PGP SIGNATURE----- Merge tag 'trace-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix build error when CONFIG_PROBE_EVENTS_BTF_ARGS is not enabled The tracing of arguments in the function tracer depends on some functions that are only defined when PROBE_EVENTS_BTF_ARGS is enabled. In fact, PROBE_EVENTS_BTF_ARGS also depends on all the same configs as the function argument tracing requires. Just have the function argument tracing depend on PROBE_EVENTS_BTF_ARGS. - Free module_delta for persistent ring buffer instance When an instance holds the persistent ring buffer, it allocates a helper array to hold the deltas between where modules are loaded on the last boot and the current boot. This array needs to be freed when the instance is freed. - Add cond_resched() to loop in ftrace_graph_set_hash() The hash functions in ftrace loop over every function that can be enabled by ftrace. This can be 50,000 functions or more. This loop is known to trigger soft lockup warnings and requires a cond_resched(). The loop in ftrace_graph_set_hash() was missing it. - Fix the event format verifier to include "%*p.." arguments To prevent events from dereferencing stale pointers that can happen if a trace event uses a dereferece pointer to something that was not copied into the ring buffer and can be freed by the time the trace is read, a verifier is called. At boot or module load, the verifier scans the print format string for pointers that can be dereferenced and it checks the arguments to make sure they do not contain something that can be freed. The "%*p" was not handled, which would add another argument and cause the verifier to not only not verify this pointer, but it will look at the wrong argument for every pointer after that. - Fix mcount sorttable building for different endian type target When modifying the ELF file to sort the mcount_loc table in the sorttable.c code, the endianess of the file and the host is used to determine if the bytes need to be swapped when calculations are done. A change was made to the sorting of the mcount_loc that read the values from the ELF file into an array and the swap happened on the filling of the array. But one of the calculations of the array still did the swap when it did not need to. This caused building on a little endian machine for a big endian target to not find the mcount function in the 'nm' table and it zeroed it out, causing there to be no functions available to trace. - Add goto out_unlock jump to rv_register_monitor() on error path One of the error paths in rv_register_monitor() just returned the error when it should have jumped to the out_unlock label to release the mutex. * tag 'trace-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: rv: Fix missing unlock on double nested monitors return path scripts/sorttable: Fix endianness handling in build-time mcount sort tracing: Verify event formats that have "%*p.." ftrace: Add cond_resched() to ftrace_graph_set_hash() tracing: Free module_delta on freeing of persistent ring buffer ftrace: Have tracing function args depend on PROBE_EVENTS_BTF_ARGS |
||
|
Linus Torvalds
|
af54a3a151 |
more printk changes for 6.15
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||
|
Steven Rostedt
|
394f3f02de |
tracing: Use vmap_page_range() to map memmap ring buffer
The code to map the physical memory retrieved by memmap currently allocates an array of pages to cover the physical memory and then calls vmap() to map it to a virtual address. Instead of using this temporary array of struct page descriptors, simply use vmap_page_range() that can directly map the contiguous physical memory to a virtual address. Link: https://lore.kernel.org/all/CAHk-=whUOfVucfJRt7E0AH+GV41ELmS4wJqxHDnui6Giddfkzw@mail.gmail.com/ 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> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Rapoport <rppt@kernel.org> Cc: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/20250402144953.754618481@goodmis.org Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
34ea8fa084 |
tracing: Have reserve_mem use phys_to_virt() and separate from memmap buffer
The reserve_mem kernel command line option may pass back a physical address, but the memory is still part of the normal memory just like using memblock_alloc() would be. This means that the physical memory returned by the reserve_mem command line option can be converted directly to virtual memory by simply using phys_to_virt(). When freeing the buffer there's no need to call vunmap() anymore as the memory allocated by reserve_mem is freed by the call to reserve_mem_release_by_name(). Because the persistent ring buffer can also be allocated via the memmap option, which *is* different than normal memory as it cannot be added back to the buddy system, it must be treated differently. It still needs to be virtually mapped to have access to it. It also can not be freed nor can it ever be memory mapped to user space. Create a new trace_array flag called TRACE_ARRAY_FL_MEMMAP which gets set if the buffer is created by the memmap option, and this will prevent the buffer from being memory mapped by user space. Also increment the ref count for memmap'ed buffers so that they can never be freed. Link: https://lore.kernel.org/all/Z-wFszhJ_9o4dc8O@kernel.org/ Cc: Linus Torvalds <torvalds@linux-foundation.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> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/20250402144953.583750106@goodmis.org Suggested-by: Mike Rapoport <rppt@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
c44a14f216 |
tracing: Enforce the persistent ring buffer to be page aligned
Enforce that the address and the size of the memory used by the persistent ring buffer is page aligned. Also update the documentation to reflect this requirement. Link: https://lore.kernel.org/all/CAHk-=whUOfVucfJRt7E0AH+GV41ELmS4wJqxHDnui6Giddfkzw@mail.gmail.com/ 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> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Rapoport <rppt@kernel.org> Cc: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/20250402144953.412882844@goodmis.org Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
2c9ee74a6d |
tracing: Free module_delta on freeing of persistent ring buffer
If a persistent ring buffer is created, a "module_delta" array is also
allocated to hold the module deltas of loaded modules that match modules
in the scratch area. If this buffer gets freed, the module_delta array is
not freed and causes a memory leak.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250401124525.1f9ac02a@gandalf.local.home
Fixes:
|
||
|
Linus Torvalds
|
46d29f23a7 |
ring-buffer updates for v6.15
- Restructure the persistent memory to have a "scratch" area Instead of hard coding the KASLR offset in the persistent memory by the ring buffer, push that work up to the callers of the persistent memory as they are the ones that need this information. The offsets and such is not important to the ring buffer logic and it should not be part of that. A scratch pad is now created when the caller allocates a ring buffer from persistent memory by stating how much memory it needs to save. - Allow where modules are loaded to be saved in the new scratch pad Save the addresses of modules when they are loaded into the persistent memory scratch pad. - A new module_for_each_mod() helper function was created With the acknowledgement of the module maintainers a new module helper function was created to iterate over all the currently loaded modules. This has a callback to be called for each module. This is needed for when tracing is started in the persistent buffer and the currently loaded modules need to be saved in the scratch area. - Expose the last boot information where the kernel and modules were loaded The last_boot_info file is updated to print out the addresses of where the kernel "_text" location was loaded from a previous boot, as well as where the modules are loaded. If the buffer is recording the current boot, it only prints "# Current" so that it does not expose the KASLR offset of the currently running kernel. - Allow the persistent ring buffer to be released (freed) To have this in production environments, where the kernel command line can not be changed easily, the ring buffer needs to be freed when it is not going to be used. The memory for the buffer will always be allocated at boot up, but if the system isn't going to enable tracing, the memory needs to be freed. Allow it to be freed and added back to the kernel memory pool. - Allow stack traces to print the function names in the persistent buffer Now that the modules are saved in the persistent ring buffer, if the same modules are loaded, the printing of the function names will examine the saved modules. If the module is found in the scratch area and is also loaded, then it will do the offset shift and use kallsyms to display the function name. If the address is not found, it simply displays the address from the previous boot in hex. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZ+cUERQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qrAsAQCFt2nfzxoe3wtF5EqIT1VHp/8bQVjG gBe8B6ouboreogD/dS7yK8MRy24ZAmObGwYG0RbVicd50S7P8Rf7+823ng8= =OJKk -----END PGP SIGNATURE----- Merge tag 'trace-ringbuffer-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ring-buffer updates from Steven Rostedt: - Restructure the persistent memory to have a "scratch" area Instead of hard coding the KASLR offset in the persistent memory by the ring buffer, push that work up to the callers of the persistent memory as they are the ones that need this information. The offsets and such is not important to the ring buffer logic and it should not be part of that. A scratch pad is now created when the caller allocates a ring buffer from persistent memory by stating how much memory it needs to save. - Allow where modules are loaded to be saved in the new scratch pad Save the addresses of modules when they are loaded into the persistent memory scratch pad. - A new module_for_each_mod() helper function was created With the acknowledgement of the module maintainers a new module helper function was created to iterate over all the currently loaded modules. This has a callback to be called for each module. This is needed for when tracing is started in the persistent buffer and the currently loaded modules need to be saved in the scratch area. - Expose the last boot information where the kernel and modules were loaded The last_boot_info file is updated to print out the addresses of where the kernel "_text" location was loaded from a previous boot, as well as where the modules are loaded. If the buffer is recording the current boot, it only prints "# Current" so that it does not expose the KASLR offset of the currently running kernel. - Allow the persistent ring buffer to be released (freed) To have this in production environments, where the kernel command line can not be changed easily, the ring buffer needs to be freed when it is not going to be used. The memory for the buffer will always be allocated at boot up, but if the system isn't going to enable tracing, the memory needs to be freed. Allow it to be freed and added back to the kernel memory pool. - Allow stack traces to print the function names in the persistent buffer Now that the modules are saved in the persistent ring buffer, if the same modules are loaded, the printing of the function names will examine the saved modules. If the module is found in the scratch area and is also loaded, then it will do the offset shift and use kallsyms to display the function name. If the address is not found, it simply displays the address from the previous boot in hex. * tag 'trace-ringbuffer-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Use _text and the kernel offset in last_boot_info tracing: Show last module text symbols in the stacktrace ring-buffer: Remove the unused variable bmeta tracing: Skip update_last_data() if cleared and remove active check for save_mod() tracing: Initialize scratch_size to zero to prevent UB tracing: Fix a compilation error without CONFIG_MODULES tracing: Freeable reserved ring buffer mm/memblock: Add reserved memory release function tracing: Update modules to persistent instances when loaded tracing: Show module names and addresses of last boot tracing: Have persistent trace instances save module addresses module: Add module_for_each_mod() function tracing: Have persistent trace instances save KASLR offset ring-buffer: Add ring_buffer_meta_scratch() ring-buffer: Add buffer meta data for persistent ring buffer ring-buffer: Use kaslr address instead of text delta ring-buffer: Fix bytes_dropped calculation issue |
||
|
Steven Rostedt
|
028a58ec15 |
tracing: Use _text and the kernel offset in last_boot_info
Instead of using kaslr_offset() just record the location of "_text". This makes it possible for user space to use either the System.map or /proc/kallsyms as what to map all addresses to functions with. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250326220304.38dbedcd@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Masami Hiramatsu (Google)
|
35a380ddbc |
tracing: Show last module text symbols in the stacktrace
Since the previous boot trace buffer can include module text address in the stacktrace. As same as the kernel text address, convert the module text address using the module address information. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/174282689201.356346.17647540360450727687.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Masami Hiramatsu (Google)
|
486fbcb380 |
tracing: Skip update_last_data() if cleared and remove active check for save_mod()
If the last boot data is already cleared, there is no reason to update it again. Skip if the TRACE_ARRAY_FL_LAST_BOOT is cleared. Also, for calling save_mod() when module loading, we don't need to check the trace is active or not because any module address can be on the stacktrace. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/174165660328.1173316.15529357882704817499.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
5dbeb56bb9 |
tracing: Initialize scratch_size to zero to prevent UB
In allocate_trace_buffer() the following code: buf->buffer = ring_buffer_alloc_range(size, rb_flags, 0, tr->range_addr_start, tr->range_addr_size, struct_size(tscratch, entries, 128)); tscratch = ring_buffer_meta_scratch(buf->buffer, &scratch_size); setup_trace_scratch(tr, tscratch, scratch_size); Has undefined behavior if ring_buffer_alloc_range() fails because "scratch_size" is not initialize. If the allocation fails, then buf->buffer will be NULL. The ring_buffer_meta_scratch() will return NULL immediately if it is passed a NULL buffer and it will not update scratch_size. Then setup_trace_scratch() will return immediately if tscratch is NULL. Although there's no real issue here, but it is considered undefined behavior to pass an uninitialized variable to a function as input, and UBSan may complain about it. Just initialize scratch_size to zero to make the code defined behavior and a little more robust. Link: https://lore.kernel.org/all/44c5deaa-b094-4852-90f9-52f3fb10e67a@stanley.mountain/ Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Masami Hiramatsu (Google)
|
f00c9201f9 |
tracing: Fix a compilation error without CONFIG_MODULES
There are some code which depends on CONFIG_MODULES. #ifdef to enclose it. Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/174230515367.2909896.8132122175220657625.stgit@mhiramat.tok.corp.google.com Fixes: dca91c1c5468 ("tracing: Have persistent trace instances save module addresses") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Masami Hiramatsu (Google)
|
fb6d03238e |
tracing: Freeable reserved ring buffer
Make the ring buffer on reserved memory to be freeable. This allows us
to free the trace instance on the reserved memory without changing
cmdline and rebooting. Even if we can not change the kernel cmdline
for security reason, we can release the reserved memory for the ring
buffer as free (available) memory.
For example, boot kernel with reserved memory;
"reserve_mem=20M:2M:trace trace_instance=boot_mapped^traceoff@trace"
~ # free
total used free shared buff/cache available
Mem: 1995548 50544 1927568 14964 17436 1911480
Swap: 0 0 0
~ # rmdir /sys/kernel/tracing/instances/boot_mapped/
[ 23.704023] Freeing reserve_mem:trace memory: 20476K
~ # free
total used free shared buff/cache available
Mem: 2016024 41844 1956740 14968 17440 1940572
Swap: 0 0 0
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Link: https://lore.kernel.org/173989134814.230693.18199312930337815629.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
||
|
Steven Rostedt
|
5f3719f697 |
tracing: Update modules to persistent instances when loaded
When a module is loaded and a persistent buffer is actively tracing, add it to the list of modules in the persistent memory. 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> Link: https://lore.kernel.org/20250305164609.469844721@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
1bd25a6f71 |
tracing: Show module names and addresses of last boot
Add the last boot module's names and addresses to the last_boot_info file. This only shows the module information from a previous boot. If the buffer is started and is recording the current boot, this file still will only show "current". ~# cat instances/boot_mapped/last_boot_info 10c00000 [kernel] ffffffffc00ca000 usb_serial_simple ffffffffc00ae000 usbserial ffffffffc008b000 bfq ~# echo function > instances/boot_mapped/current_tracer ~# cat instances/boot_mapped/last_boot_info # Current 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> Link: https://lore.kernel.org/20250305164609.299186021@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
fd39e48fe8 |
tracing: Have persistent trace instances save module addresses
For trace instances that are mapped to persistent memory, have them use the scratch area to save the currently loaded modules. This will allow where the modules have been loaded on the next boot so that their addresses can be deciphered by using where they were loaded previously. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/20250305164609.129741650@goodmis.org Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
b65334825f |
tracing: Have persistent trace instances save KASLR offset
There's no reason to save the KASLR offset for the ring buffer itself. That is used by the tracer. Now that the tracer has a way to save data in the persistent memory of the ring buffer, have the tracing infrastructure take care of the saving of the KASLR offset. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/20250305164608.792722274@goodmis.org Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
4af0a9c518 |
ring-buffer: Add ring_buffer_meta_scratch()
Now that there's one meta data at the start of the persistent memory used by the ring buffer, allow the caller to request some memory right after that data that it can use as its own persistent memory. Also fix some white space issues with ring_buffer_alloc(). Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/20250305164608.619631731@goodmis.org Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Steven Rostedt
|
bcba8d4dbe |
ring-buffer: Use kaslr address instead of text delta
Instead of saving off the text and data pointers and using them to compare with the current boot's text and data pointers, just save off the KASLR offset. Then that can be used to figure out how to read the previous boots buffer. The last_boot_info will now show this offset, but only if it is for a previous boot: ~# cat instances/boot_mapped/last_boot_info 39000000 [kernel] ~# echo function > instances/boot_mapped/current_tracer ~# cat instances/boot_mapped/last_boot_info # Current If the KASLR offset saved is for the current boot, the last_boot_info will show the value of "current". Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/20250305164608.274956504@goodmis.org Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Andy Shevchenko
|
196a062641 |
tracing: Mark binary printing functions with __printf() attribute
Binary printing functions are using printf() type of format, and compiler is not happy about them as is: kernel/trace/trace.c:3292:9: error: function ‘trace_vbprintk’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] kernel/trace/trace_seq.c:182:9: error: function ‘trace_seq_bprintf’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format] Fix the compilation errors by adding __printf() attribute. While at it, move existing __printf() attributes from the implementations to the declarations. IT also fixes incorrect attribute parameters that are used for trace_array_printk(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Kees Cook <kees@kernel.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250321144822.324050-4-andriy.shevchenko@linux.intel.com Signed-off-by: Petr Mladek <pmladek@suse.com> |
||
|
Linus Torvalds
|
744fab2d9f |
tracing updates for v6.15:
- Add option traceoff_after_boot In order to debug kernel boot, it sometimes is helpful to enable tracing via the kernel command line. Unfortunately, by the time the login prompt appears, the trace is overwritten by the init process and other user space start up applications. Adding a "traceoff_after_boot" will disable tracing when the kernel passes control to init which will allow developers to be able to see the traces that occurred during boot. - Clean up the mmflags macros that display the GFP flags in trace events The macros to print the GFP flags for trace events had a bit of duplication. The code was restructured to remove duplication and in the process it also adds some flags that were missed before. - Removed some dead code and scripts/draw_functrace.py draw_functrace.py hasn't worked in years and as nobody complained about it, remove it. - Constify struct event_trigger_ops The event_trigger_ops is just a structure that has function pointers that are assigned when the variables are created. These variables should all be constants. - Other minor clean ups and fixes -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZ+V9IhQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qr4RAP9JhE3n69pGuOVaJTN/LGLr2Axl59n4 KqZSZS1nUM76/gD6AxYpR7nxyxgJ7VjNkLptS9tSjJVdPDxGAl0v3eO04w4= =SU30 -----END PGP SIGNATURE----- Merge tag 'trace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Add option traceoff_after_boot In order to debug kernel boot, it sometimes is helpful to enable tracing via the kernel command line. Unfortunately, by the time the login prompt appears, the trace is overwritten by the init process and other user space start up applications. Adding a "traceoff_after_boot" will disable tracing when the kernel passes control to init which will allow developers to be able to see the traces that occurred during boot. - Clean up the mmflags macros that display the GFP flags in trace events The macros to print the GFP flags for trace events had a bit of duplication. The code was restructured to remove duplication and in the process it also adds some flags that were missed before. - Removed some dead code and scripts/draw_functrace.py draw_functrace.py hasn't worked in years and as nobody complained about it, remove it. - Constify struct event_trigger_ops The event_trigger_ops is just a structure that has function pointers that are assigned when the variables are created. These variables should all be constants. - Other minor clean ups and fixes * tag 'trace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Replace strncpy with memcpy for fixed-length substring copy tracing: Fix synth event printk format for str fields tracing: Do not use PERF enums when perf is not defined tracing: Ensure module defining synth event cannot be unloaded while tracing tracing: fix return value in __ftrace_event_enable_disable for TRACE_REG_UNREGISTER tracing/osnoise: Fix possible recursive locking for cpus_read_lock() tracing: Align synth event print fmt tracing: gfp: vsprintf: Do not print "none" when using %pGg printf format tracepoint: Print the function symbol when tracepoint_debug is set tracing: Constify struct event_trigger_ops scripts/tracing: Remove scripts/tracing/draw_functrace.py tracing: Update MAINTAINERS file to include tracepoint.c tracing/user_events: Slightly simplify user_seq_show() tracing/user_events: Don't use %pK through printk tracing: gfp: Remove duplication of recording GFP flags tracing: Remove orphaned event_trace_printk ring-buffer: Fix typo in comment about header page pointer tracing: Add traceoff_after_boot option |
||
|
Linus Torvalds
|
31eb415bf6 |
ftrace changes for v6.15:
- Record function parameters for function and function graph tracers
An option has been added to function tracer (func-args) and the function
graph tracer (funcgraph-args) that when set, the tracers will record the
registers that hold the arguments into each function event. On reading of
the trace, it will use BTF to print those arguments. Most archs support up
to 6 arguments (depending on the complexity of the arguments) and those
are printed. If a function has more arguments then what was recorded, the
output will end with " ... )".
Example of function graph tracer:
6) | dummy_xmit [dummy](skb = 0x8887c100, dev = 0x872ca000) {
6) | consume_skb(skb = 0x8887c100) {
6) | skb_release_head_state(skb = 0x8887c100) {
6) 0.178 us | sock_wfree(skb = 0x8887c100)
6) 0.627 us | }
- The rest of the changes are minor clean ups and fixes
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Merge tag 'ftrace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace updates from Steven Rostedt:
- Record function parameters for function and function graph tracers
An option has been added to function tracer (func-args) and the
function graph tracer (funcgraph-args) that when set, the tracers
will record the registers that hold the arguments into each function
event. On reading of the trace, it will use BTF to print those
arguments. Most archs support up to 6 arguments (depending on the
complexity of the arguments) and those are printed.
If a function has more arguments then what was recorded, the output
will end with " ... )".
Example of function graph tracer:
6) | dummy_xmit [dummy](skb = 0x8887c100, dev = 0x872ca000) {
6) | consume_skb(skb = 0x8887c100) {
6) | skb_release_head_state(skb = 0x8887c100) {
6) 0.178 us | sock_wfree(skb = 0x8887c100)
6) 0.627 us | }
- The rest of the changes are minor clean ups and fixes
* tag 'ftrace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Use hashtable.h for event_hash
tracing: Fix use-after-free in print_graph_function_flags during tracer switching
function_graph: Remove the unused variable func
ftrace: Add arguments to function tracer
ftrace: Have funcgraph-args take affect during tracing
ftrace: Add support for function argument to graph tracer
ftrace: Add print_function_args()
ftrace: Have ftrace_free_filter() WARN and exit if ops is active
fgraph: Correct typo in ftrace_return_to_handler comment
|
||
|
Sebastian Andrzej Siewior
|
3bffa47a02 |
tracing: Use preempt_model_str()
Use preempt_model_str() instead of manually conducting the preemption model. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: "Steven Rostedt (Google)" <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20250314160810.2373416-10-bigeasy@linutronix.de |
||
|
Sven Schnelle
|
76fe0337c2 |
ftrace: Add arguments to function tracer
Wire up the code to print function arguments in the function tracer.
This functionality can be enabled/disabled during runtime with
options/func-args.
ping-689 [004] b.... 77.170220: dummy_xmit(skb = 0x82904800, dev = 0x882d0000) <-dev_hard_start_xmit
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Guo Ren <guoren@kernel.org>
Cc: Donglin Peng <dolinux.peng@gmail.com>
Cc: Zheng Yejian <zhengyejian@huaweicloud.com>
Link: https://lore.kernel.org/20250227185823.154996172@goodmis.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Co-developed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Steven Rostedt
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937fbf111a |
tracing: Add traceoff_after_boot option
Sometimes tracing is used to debug issues during the boot process. Since the trace buffer has a limited amount of storage, it may be prudent to disable tracing after the boot is finished, otherwise the critical information may be overwritten. With this option, the main tracing buffer will be turned off at the end of the boot process. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Borislav Petkov <bp@alien8.de> Link: https://lore.kernel.org/20250208103017.48a7ec83@batman.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
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Steven Rostedt
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129fe71881 |
tracing: Do not allow mmap() of persistent ring buffer
When trying to mmap a trace instance buffer that is attached to
reserve_mem, it would crash:
BUG: unable to handle page fault for address: ffffe97bd00025c8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 2862f3067 P4D 2862f3067 PUD 0
Oops: Oops: 0000 [#1] PREEMPT_RT SMP PTI
CPU: 4 UID: 0 PID: 981 Comm: mmap-rb Not tainted 6.14.0-rc2-test-00003-g7f1a5e3fbf9e-dirty #233
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:validate_page_before_insert+0x5/0xb0
Code: e2 01 89 d0 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 <48> 8b 46 08 a8 01 75 67 66 90 48 89 f0 8b 50 34 85 d2 74 76 48 89
RSP: 0018:ffffb148c2f3f968 EFLAGS: 00010246
RAX: ffff9fa5d3322000 RBX: ffff9fa5ccff9c08 RCX: 00000000b879ed29
RDX: ffffe97bd00025c0 RSI: ffffe97bd00025c0 RDI: ffff9fa5ccff9c08
RBP: ffffb148c2f3f9f0 R08: 0000000000000004 R09: 0000000000000004
R10: 0000000000000000 R11: 0000000000000200 R12: 0000000000000000
R13: 00007f16a18d5000 R14: ffff9fa5c48db6a8 R15: 0000000000000000
FS: 00007f16a1b54740(0000) GS:ffff9fa73df00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffe97bd00025c8 CR3: 00000001048c6006 CR4: 0000000000172ef0
Call Trace:
<TASK>
? __die_body.cold+0x19/0x1f
? __die+0x2e/0x40
? page_fault_oops+0x157/0x2b0
? search_module_extables+0x53/0x80
? validate_page_before_insert+0x5/0xb0
? kernelmode_fixup_or_oops.isra.0+0x5f/0x70
? __bad_area_nosemaphore+0x16e/0x1b0
? bad_area_nosemaphore+0x16/0x20
? do_kern_addr_fault+0x77/0x90
? exc_page_fault+0x22b/0x230
? asm_exc_page_fault+0x2b/0x30
? validate_page_before_insert+0x5/0xb0
? vm_insert_pages+0x151/0x400
__rb_map_vma+0x21f/0x3f0
ring_buffer_map+0x21b/0x2f0
tracing_buffers_mmap+0x70/0xd0
__mmap_region+0x6f0/0xbd0
mmap_region+0x7f/0x130
do_mmap+0x475/0x610
vm_mmap_pgoff+0xf2/0x1d0
ksys_mmap_pgoff+0x166/0x200
__x64_sys_mmap+0x37/0x50
x64_sys_call+0x1670/0x1d70
do_syscall_64+0xbb/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The reason was that the code that maps the ring buffer pages to user space
has:
page = virt_to_page((void *)cpu_buffer->subbuf_ids[s]);
And uses that in:
vm_insert_pages(vma, vma->vm_start, pages, &nr_pages);
But virt_to_page() does not work with vmap()'d memory which is what the
persistent ring buffer has. It is rather trivial to allow this, but for
now just disable mmap() of instances that have their ring buffer from the
reserve_mem option.
If an mmap() is performed on a persistent buffer it will return -ENODEV
just like it would if the .mmap field wasn't defined in the
file_operations structure.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250214115547.0d7287d3@gandalf.local.home
Fixes:
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Steven Rostedt
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60b8f71114 |
tracing: Have the error of __tracing_resize_ring_buffer() passed to user
Currently if __tracing_resize_ring_buffer() returns an error, the
tracing_resize_ringbuffer() returns -ENOMEM. But it may not be a memory
issue that caused the function to fail. If the ring buffer is memory
mapped, then the resizing of the ring buffer will be disabled. But if the
user tries to resize the buffer, it will get an -ENOMEM returned, which is
confusing because there is plenty of memory. The actual error returned was
-EBUSY, which would make much more sense to the user.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250213134132.7e4505d7@gandalf.local.home
Fixes:
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Linus Torvalds
|
e8744fbc83 |
tracing updates for v6.14:
- Cleanup with guard() and free() helpers There were several places in the code that had a lot of "goto out" in the error paths to either unlock a lock or free some memory that was allocated. But this is error prone. Convert the code over to use the guard() and free() helpers that let the compiler unlock locks or free memory when the function exits. - Update the Rust tracepoint code to use the C code too There was some duplication of the tracepoint code for Rust that did the same logic as the C code. Add a helper that makes it possible for both algorithms to use the same logic in one place. - Add poll to trace event hist files It is useful to know when an event is triggered, or even with some filtering. Since hist files of events get updated when active and the event is triggered, allow applications to poll the hist file and wake up when an event is triggered. This will let the application know that the event it is waiting for happened. - Add :mod: command to enable events for current or future modules The function tracer already has a way to enable functions to be traced in modules by writing ":mod:<module>" into set_ftrace_filter. That will enable either all the functions for the module if it is loaded, or if it is not, it will cache that command, and when the module is loaded that matches <module>, its functions will be enabled. This also allows init functions to be traced. But currently events do not have that feature. Add the command where if ':mod:<module>' is written into set_event, then either all the modules events are enabled if it is loaded, or cache it so that the module's events are enabled when it is loaded. This also works from the kernel command line, where "trace_event=:mod:<module>", when the module is loaded at boot up, its events will be enabled then. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZ5EbMxQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qkZsAP9Amgx9frSbR1pn1t0I3wVnQx7khgOu s/b8Ro+vjTx1/QD/RN2AA7f+HK4F27w3Aqfrs0nKXAPtXWsJ9Epp8raG5w8= =Pg+4 -----END PGP SIGNATURE----- Merge tag 'trace-v6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Cleanup with guard() and free() helpers There were several places in the code that had a lot of "goto out" in the error paths to either unlock a lock or free some memory that was allocated. But this is error prone. Convert the code over to use the guard() and free() helpers that let the compiler unlock locks or free memory when the function exits. - Update the Rust tracepoint code to use the C code too There was some duplication of the tracepoint code for Rust that did the same logic as the C code. Add a helper that makes it possible for both algorithms to use the same logic in one place. - Add poll to trace event hist files It is useful to know when an event is triggered, or even with some filtering. Since hist files of events get updated when active and the event is triggered, allow applications to poll the hist file and wake up when an event is triggered. This will let the application know that the event it is waiting for happened. - Add :mod: command to enable events for current or future modules The function tracer already has a way to enable functions to be traced in modules by writing ":mod:<module>" into set_ftrace_filter. That will enable either all the functions for the module if it is loaded, or if it is not, it will cache that command, and when the module is loaded that matches <module>, its functions will be enabled. This also allows init functions to be traced. But currently events do not have that feature. Add the command where if ':mod:<module>' is written into set_event, then either all the modules events are enabled if it is loaded, or cache it so that the module's events are enabled when it is loaded. This also works from the kernel command line, where "trace_event=:mod:<module>", when the module is loaded at boot up, its events will be enabled then. * tag 'trace-v6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits) tracing: Fix output of set_event for some cached module events tracing: Fix allocation of printing set_event file content tracing: Rename update_cache() to update_mod_cache() tracing: Fix #if CONFIG_MODULES to #ifdef CONFIG_MODULES selftests/ftrace: Add test that tests event :mod: commands tracing: Cache ":mod:" events for modules not loaded yet tracing: Add :mod: command to enabled module events selftests/tracing: Add hist poll() support test tracing/hist: Support POLLPRI event for poll on histogram tracing/hist: Add poll(POLLIN) support on hist file tracing: Fix using ret variable in tracing_set_tracer() tracepoint: Reduce duplication of __DO_TRACE_CALL tracing/string: Create and use __free(argv_free) in trace_dynevent.c tracing: Switch trace_stat.c code over to use guard() tracing: Switch trace_stack.c code over to use guard() tracing: Switch trace_osnoise.c code over to use guard() and __free() tracing: Switch trace_events_synth.c code over to use guard() tracing: Switch trace_events_filter.c code over to use guard() tracing: Switch trace_events_trigger.c code over to use guard() tracing: Switch trace_events_hist.c code over to use guard() ... |
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Linus Torvalds
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2e04247f7c |
ftrace updates for v6.14:
- Have fprobes built on top of function graph infrastructure The fprobe logic is an optimized kprobe that uses ftrace to attach to functions when a probe is needed at the start or end of the function. The fprobe and kretprobe logic implements a similar method as the function graph tracer to trace the end of the function. That is to hijack the return address and jump to a trampoline to do the trace when the function exits. To do this, a shadow stack needs to be created to store the original return address. Fprobes and function graph do this slightly differently. Fprobes (and kretprobes) has slots per callsite that are reserved to save the return address. This is fine when just a few points are traced. But users of fprobes, such as BPF programs, are starting to add many more locations, and this method does not scale. The function graph tracer was created to trace all functions in the kernel. In order to do this, when function graph tracing is started, every task gets its own shadow stack to hold the return address that is going to be traced. The function graph tracer has been updated to allow multiple users to use its infrastructure. Now have fprobes be one of those users. This will also allow for the fprobe and kretprobe methods to trace the return address to become obsolete. With new technologies like CFI that need to know about these methods of hijacking the return address, going toward a solution that has only one method of doing this will make the kernel less complex. - Cleanup with guard() and free() helpers There were several places in the code that had a lot of "goto out" in the error paths to either unlock a lock or free some memory that was allocated. But this is error prone. Convert the code over to use the guard() and free() helpers that let the compiler unlock locks or free memory when the function exits. - Remove disabling of interrupts in the function graph tracer When function graph tracer was first introduced, it could race with interrupts and NMIs. To prevent that race, it would disable interrupts and not trace NMIs. But the code has changed to allow NMIs and also interrupts. This change was done a long time ago, but the disabling of interrupts was never removed. Remove the disabling of interrupts in the function graph tracer is it is not needed. This greatly improves its performance. - Allow the :mod: command to enable tracing module functions on the kernel command line. The function tracer already has a way to enable functions to be traced in modules by writing ":mod:<module>" into set_ftrace_filter. That will enable either all the functions for the module if it is loaded, or if it is not, it will cache that command, and when the module is loaded that matches <module>, its functions will be enabled. This also allows init functions to be traced. But currently events do not have that feature. Because enabling function tracing can be done very early at boot up (before scheduling is enabled), the commands that can be done when function tracing is started is limited. Having the ":mod:" command to trace module functions as they are loaded is very useful. Update the kernel command line function filtering to allow it. -----BEGIN PGP SIGNATURE----- iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCZ42E2RQccm9zdGVkdEBn b29kbWlzLm9yZwAKCRAp5XQQmuv6qqXSAPwOMxuhye8tb1GYG62QD9+w7e6nOmlC 2GCPj4detnEM2QD/ciivkhespVKhHpZHRewAuSnJgHPSM45NQ3EVESzjWQ4= =snbx -----END PGP SIGNATURE----- Merge tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ftrace updates from Steven Rostedt: - Have fprobes built on top of function graph infrastructure The fprobe logic is an optimized kprobe that uses ftrace to attach to functions when a probe is needed at the start or end of the function. The fprobe and kretprobe logic implements a similar method as the function graph tracer to trace the end of the function. That is to hijack the return address and jump to a trampoline to do the trace when the function exits. To do this, a shadow stack needs to be created to store the original return address. Fprobes and function graph do this slightly differently. Fprobes (and kretprobes) has slots per callsite that are reserved to save the return address. This is fine when just a few points are traced. But users of fprobes, such as BPF programs, are starting to add many more locations, and this method does not scale. The function graph tracer was created to trace all functions in the kernel. In order to do this, when function graph tracing is started, every task gets its own shadow stack to hold the return address that is going to be traced. The function graph tracer has been updated to allow multiple users to use its infrastructure. Now have fprobes be one of those users. This will also allow for the fprobe and kretprobe methods to trace the return address to become obsolete. With new technologies like CFI that need to know about these methods of hijacking the return address, going toward a solution that has only one method of doing this will make the kernel less complex. - Cleanup with guard() and free() helpers There were several places in the code that had a lot of "goto out" in the error paths to either unlock a lock or free some memory that was allocated. But this is error prone. Convert the code over to use the guard() and free() helpers that let the compiler unlock locks or free memory when the function exits. - Remove disabling of interrupts in the function graph tracer When function graph tracer was first introduced, it could race with interrupts and NMIs. To prevent that race, it would disable interrupts and not trace NMIs. But the code has changed to allow NMIs and also interrupts. This change was done a long time ago, but the disabling of interrupts was never removed. Remove the disabling of interrupts in the function graph tracer is it is not needed. This greatly improves its performance. - Allow the :mod: command to enable tracing module functions on the kernel command line. The function tracer already has a way to enable functions to be traced in modules by writing ":mod:<module>" into set_ftrace_filter. That will enable either all the functions for the module if it is loaded, or if it is not, it will cache that command, and when the module is loaded that matches <module>, its functions will be enabled. This also allows init functions to be traced. But currently events do not have that feature. Because enabling function tracing can be done very early at boot up (before scheduling is enabled), the commands that can be done when function tracing is started is limited. Having the ":mod:" command to trace module functions as they are loaded is very useful. Update the kernel command line function filtering to allow it. * tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits) ftrace: Implement :mod: cache filtering on kernel command line tracing: Adopt __free() and guard() for trace_fprobe.c bpf: Use ftrace_get_symaddr() for kprobe_multi probes ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr Documentation: probes: Update fprobe on function-graph tracer selftests/ftrace: Add a test case for repeating register/unregister fprobe selftests: ftrace: Remove obsolate maxactive syntax check tracing/fprobe: Remove nr_maxactive from fprobe fprobe: Add fprobe_header encoding feature fprobe: Rewrite fprobe on function-graph tracer s390/tracing: Enable HAVE_FTRACE_GRAPH_FUNC ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS tracing: Add ftrace_fill_perf_regs() for perf event tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs fprobe: Use ftrace_regs in fprobe exit handler fprobe: Use ftrace_regs in fprobe entry handler fgraph: Pass ftrace_regs to retfunc fgraph: Replace fgraph_ret_regs with ftrace_regs ... |
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Steven Rostedt
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31f505dc70 |
ftrace: Implement :mod: cache filtering on kernel command line
Module functions can be set to set_ftrace_filter before the module is loaded. # echo :mod:snd_hda_intel > set_ftrace_filter This will enable all the functions for the module snd_hda_intel. If that module is not loaded, it is "cached" in the trace array for when the module is loaded, its functions will be traced. But this is not implemented in the kernel command line. That's because the kernel command line filtering is added very early in boot up as it is needed to be done before boot time function tracing can start, which is also available very early in boot up. The code used by the "set_ftrace_filter" file can not be used that early as it depends on some other initialization to occur first. But some of the functions can. Implement the ":mod:" feature of "set_ftrace_filter" in the kernel command line parsing. Now function tracing on just a single module that is loaded at boot up can be done. Adding: ftrace=function ftrace_filter=:mod:sna_hda_intel To the kernel command line will only enable the sna_hda_intel module functions when the module is loaded, and it will start tracing. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250116175832.34e39779@gandalf.local.home Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |