- 29 Mar, 2023 15 commits
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Beau Belgrave authored
Operators want to be able to ensure enough tracepoints exist on the system for kernel components as well as for user components. Since there are only up to 64K events, by default allow up to half to be used by user events. Add a kernel sysctl parameter (kernel.user_events_max) to set a global limit that is honored among all groups on the system. This ensures hard limits can be setup to prevent user processes from consuming all event IDs on the system. Link: https://lkml.kernel.org/r/20230328235219.203-12-beaub@linux.microsoft.comSigned-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
Operators need a way to limit how much memory cgroups use. User events need to be included into that accounting. Fix this by using GFP_KERNEL_ACCOUNT for allocations generated by user programs for user_event tracing. Link: https://lkml.kernel.org/r/20230328235219.203-11-beaub@linux.microsoft.comSigned-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
The ABI for user_events has changed from mmap() based to remote writes. Update the documentation to reflect these changes, add new section for unregistering events since lifetime is now tied to tasks instead of files. Link: https://lkml.kernel.org/r/20230328235219.203-10-beaub@linux.microsoft.comSigned-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
The ABI has changed to use a remote write approach. Update the example to show the expected use of this new ABI. Also remove debugfs path and use tracefs to ensure example works in more environments. Link: https://lkml.kernel.org/r/20230328235219.203-9-beaub@linux.microsoft.comSigned-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
Add ABI specific self-test to ensure enablements work in various scenarios such as fork, VM_CLONE, and basic event enable/disable. Ensure ABI contracts/limits are also being upheld, such as bit limits and data size limits. Link: https://lkml.kernel.org/r/20230328235219.203-8-beaub@linux.microsoft.comSigned-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
ABI has been changed to remote writes, update existing test cases to use this new ABI to ensure existing functionality continues to work. Link: https://lkml.kernel.org/r/20230328235219.203-7-beaub@linux.microsoft.comSigned-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
Enablements are now tracked by the lifetime of the task/mm. User processes need to be able to disable their addresses if tracing is requested to be turned off. Before unmapping the page would suffice. However, we now need a stronger contract. Add an ioctl to enable this. A new flag bit is added, freeing, to user_event_enabler to ensure that if the event is attempted to be removed while a fault is being handled that the remove is delayed until after the fault is reattempted. Link: https://lkml.kernel.org/r/20230328235219.203-6-beaub@linux.microsoft.comSigned-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
When events are enabled within the various tracing facilities, such as ftrace/perf, the event_mutex is held. As events are enabled pages are accessed. We do not want page faults to occur under this lock. Instead queue the fault to a workqueue to be handled in a process context safe way without the lock. The enable address is marked faulting while the async fault-in occurs. This ensures that we don't attempt to fault-in more than is necessary. Once the page has been faulted in, an address write is re-attempted. If the page couldn't fault-in, then we wait until the next time the event is enabled to prevent any potential infinite loops. Link: https://lkml.kernel.org/r/20230328235219.203-5-beaub@linux.microsoft.comSigned-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
As part of the discussions for user_events aligned with user space tracers, it was determined that user programs should register a aligned value to set or clear a bit when an event becomes enabled. Currently a shared page is being used that requires mmap(). Remove the shared page implementation and move to a user registered address implementation. In this new model during the event registration from user programs 3 new values are specified. The first is the address to update when the event is either enabled or disabled. The second is the bit to set/clear to reflect the event being enabled. The third is the size of the value at the specified address. This allows for a local 32/64-bit value in user programs to support both kernel and user tracers. As an example, setting bit 31 for kernel tracers when the event becomes enabled allows for user tracers to use the other bits for ref counts or other flags. The kernel side updates the bit atomically, user programs need to also update these values atomically. User provided addresses must be aligned on a natural boundary, this allows for single page checking and prevents odd behaviors such as a enable value straddling 2 pages instead of a single page. Currently page faults are only logged, future patches will handle these. Link: https://lkml.kernel.org/r/20230328235219.203-4-beaub@linux.microsoft.comSuggested-by:
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
During tracefs discussions it was decided instead of requiring a mapping within a user-process to track the lifetime of memory descriptors we should hook the appropriate calls. Do this by adding the minimal stubs required for task fork, exec, and exit. Currently this is just a NOP. Future patches will implement these calls fully. Link: https://lkml.kernel.org/r/20230328235219.203-3-beaub@linux.microsoft.comSuggested-by:
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Beau Belgrave authored
The UAPI parts need to be split out from the kernel parts of user_events now that other parts of the kernel will reference it. Do so by moving the existing include/linux/user_events.h into include/uapi/linux/user_events.h. Link: https://lkml.kernel.org/r/20230328235219.203-2-beaub@linux.microsoft.comSigned-off-by:
Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Steven Rostedt (Google) authored
The hex, raw and bin formats come from the old PREEMPT_RT patch set latency tracer. That actually gave real alternatives to reading the ascii buffer. But they have started to bit rot and they do not give a good representation of the tracing data. Add "fields" option that will read the trace event fields and parse the data from how the fields are defined: With "fields" = 0 (default) echo 1 > events/sched/sched_switch/enable cat trace <idle>-0 [003] d..2. 540.078653: sched_switch: prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=kworker/3:1 next_pid=83 next_prio=120 kworker/3:1-83 [003] d..2. 540.078860: sched_switch: prev_comm=kworker/3:1 prev_pid=83 prev_prio=120 prev_state=I ==> next_comm=swapper/3 next_pid=0 next_prio=120 <idle>-0 [003] d..2. 540.206423: sched_switch: prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=sshd next_pid=807 next_prio=120 sshd-807 [003] d..2. 540.206531: sched_switch: prev_comm=sshd prev_pid=807 prev_prio=120 prev_state=S ==> next_comm=swapper/3 next_pid=0 next_prio=120 <idle>-0 [001] d..2. 540.206597: sched_switch: prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=kworker/u16:4 next_pid=58 next_prio=120 kworker/u16:4-58 [001] d..2. 540.206617: sched_switch: prev_comm=kworker/u16:4 prev_pid=58 prev_prio=120 prev_state=I ==> next_comm=bash next_pid=830 next_prio=120 bash-830 [001] d..2. 540.206678: sched_switch: prev_comm=bash prev_pid=830 prev_prio=120 prev_state=R ==> next_comm=kworker/u16:4 next_pid=58 next_prio=120 kworker/u16:4-58 [001] d..2. 540.206696: sched_switch: prev_comm=kworker/u16:4 prev_pid=58 prev_prio=120 prev_state=I ==> next_comm=bash next_pid=830 next_prio=120 bash-830 [001] d..2. 540.206713: sched_switch: prev_comm=bash prev_pid=830 prev_prio=120 prev_state=R ==> next_comm=kworker/u16:4 next_pid=58 next_prio=120 echo 1 > options/fields <...>-998 [002] d..2. 538.643732: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/2 prev_state=0x20 (32) prev_prio=0x78 (120) prev_pid=0x3e6 (998) prev_comm=trace-cmd <idle>-0 [001] d..2. 538.643806: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x0 (0) prev_comm=swapper/1 bash-830 [001] d..2. 538.644106: sched_switch: next_prio=0x78 (120) next_pid=0x3a (58) next_comm=kworker/u16:4 prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash kworker/u16:4-58 [001] d..2. 538.644130: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x80 (128) prev_prio=0x78 (120) prev_pid=0x3a (58) prev_comm=kworker/u16:4 bash-830 [001] d..2. 538.644180: sched_switch: next_prio=0x78 (120) next_pid=0x3a (58) next_comm=kworker/u16:4 prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash kworker/u16:4-58 [001] d..2. 538.644185: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x80 (128) prev_prio=0x78 (120) prev_pid=0x3a (58) prev_comm=kworker/u16:4 bash-830 [001] d..2. 538.644204: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/1 prev_state=0x1 (1) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash <idle>-0 [003] d..2. 538.644211: sched_switch: next_prio=0x78 (120) next_pid=0x327 (807) next_comm=sshd prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x0 (0) prev_comm=swapper/3 sshd-807 [003] d..2. 538.644340: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/3 prev_state=0x1 (1) prev_prio=0x78 (120) prev_pid=0x327 (807) prev_comm=sshd It traces the data safely without using the trace print formatting. Link: https://lore.kernel.org/linux-trace-kernel/20230328145156.497651be@gandalf.local.home Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Ross Zwisler authored
The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing A comment in kvm_stat still refers to this older debugfs path, so let's update it to avoid confusion. Link: https://lkml.kernel.org/r/20230313211746.1541525-3-zwisler@kernel.org Cc: "Tobin C. Harding" <me@tobin.cc> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Tycho Andersen <tycho@tycho.pizza> Acked-by:
Paolo Bonzini <pbonzini@redhat.com> Reviewed-by:
Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by:
Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by:
Ross Zwisler <zwisler@google.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Ross Zwisler authored
The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing scripts/leaking_addresses.pl only skipped this older debugfs path, so let's add the canonical path as well. Link: https://lkml.kernel.org/r/20230313211746.1541525-2-zwisler@kernel.org Cc: "Tobin C. Harding" <me@tobin.cc> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Acked-by:
Tycho Andersen <tycho@tycho.pizza> Reviewed-by:
Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by:
Ross Zwisler <zwisler@google.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Ross Zwisler authored
The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing A few spots in tools/testing/selftests still refer to this older debugfs path, so let's update them to avoid confusion. Link: https://lkml.kernel.org/r/20230313211746.1541525-1-zwisler@kernel.org Cc: "Tobin C. Harding" <me@tobin.cc> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tycho Andersen <tycho@tycho.pizza> Reviewed-by:
Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by:
Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by:
Ross Zwisler <zwisler@google.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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- 28 Mar, 2023 7 commits
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Masami Hiramatsu (Google) authored
Update fprobe.rst for - the private entry_data argument - the return value of the entry handler - the nr_rethook_node field. Link: https://lkml.kernel.org/r/167526701579.433354.3057889264263546659.stgit@mhiramat.roam.corp.google.com Cc: Florent Revest <revest@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Masami Hiramatsu (Google) authored
Add a testcase for skipping exit_handler if entry_handler returns !0. Link: https://lkml.kernel.org/r/167526700658.433354.12922388040490848613.stgit@mhiramat.roam.corp.google.com Cc: Florent Revest <revest@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Masami Hiramatsu (Google) authored
Skip hooking function return and calling exit_handler if the entry_handler() returns !0. Link: https://lkml.kernel.org/r/167526699798.433354.10998365726830117303.stgit@mhiramat.roam.corp.google.com Cc: Florent Revest <revest@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Masami Hiramatsu (Google) authored
Add a test case for nr_maxactive. If the number of active functions is more than nr_maxactive, it must be skipped. Link: https://lkml.kernel.org/r/167526698856.433354.4430007340787176666.stgit@mhiramat.roam.corp.google.com Cc: Florent Revest <revest@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Masami Hiramatsu (Google) authored
Add nr_maxactive to specify rethook_node pool size. This means the maximum number of actively running target functions concurrently for probing by exit_handler. Note that if the running function is preempted or sleep, it is still counted as 'active'. Link: https://lkml.kernel.org/r/167526697917.433354.17779774988245113106.stgit@mhiramat.roam.corp.google.com Cc: Florent Revest <revest@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Masami Hiramatsu (Google) authored
Add test cases for checking whether private entry_data is correctly passed or not. Link: https://lkml.kernel.org/r/167526697074.433354.17790288501657876219.stgit@mhiramat.roam.corp.google.com Cc: Florent Revest <revest@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Masami Hiramatsu (Google) authored
Pass the private entry_data to the entry and exit handlers so that they can share the context data, something like saved function arguments etc. User must specify the private entry_data size by @entry_data_size field before registering the fprobe. Link: https://lkml.kernel.org/r/167526696173.433354.17408372048319432574.stgit@mhiramat.roam.corp.google.com Cc: Florent Revest <revest@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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- 21 Mar, 2023 11 commits
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Steven Rostedt (Google) authored
When debugging a crash that appears to be related to ftrace, but not for sure, it is useful to know if a function was ever enabled by ftrace or not. It could be that a BPF program was attached to it, or possibly a live patch. We are having crashes in the field where this information is not always known. But having ftrace set a flag if a function has ever been attached since boot up helps tremendously in trying to know if a crash had to do with something using ftrace. For analyzing crashes, the use of a kdump image can have access to the flags. When looking at issues where the kernel did not panic, the touched_functions file can simply be used. Link: https://lore.kernel.org/linux-trace-kernel/20230124095653.6fd1640e@gandalf.local.home Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Tested-by:
Mark Rutland <mark.rutland@arm.com> Tested-by:
Chris Li <chriscli@google.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Uros Bizjak authored
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg fails. There is no need to re-read the value in the loop. No functional change intended. Link: https://lkml.kernel.org/r/20230305155532.5549-4-ubizjak@gmail.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Uros Bizjak <ubizjak@gmail.com> Acked-by:
Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Uros Bizjak authored
The return values of some functions are of boolean type. Change the type of these function to bool and adjust their return values. Also change type of some internal varibles to bool. No functional change intended. Link: https://lkml.kernel.org/r/20230305155532.5549-3-ubizjak@gmail.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by:
Uros Bizjak <ubizjak@gmail.com> Reviewed-by:
Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Uros Bizjak authored
The results of some static functions are not used. Change the type of these function to void and remove unnecessary returns. No functional change intended. Link: https://lkml.kernel.org/r/20230305155532.5549-2-ubizjak@gmail.comSigned-off-by:
Uros Bizjak <ubizjak@gmail.com> Reviewed-by:
Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by:
Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Mark Rutland authored
The ftrace selftest code has a trace_direct_tramp() function which it uses as a direct call trampoline. This happens to work on x86, since the direct call's return address is in the usual place, and can be returned to via a RET, but in general the calling convention for direct calls is different from regular function calls, and requires a trampoline written in assembly. On s390, regular function calls place the return address in %r14, and an ftrace patch-site in an instrumented function places the trampoline's return address (which is within the instrumented function) in %r0, preserving the original %r14 value in-place. As a regular C function will return to the address in %r14, using a C function as the trampoline results in the trampoline returning to the caller of the instrumented function, skipping the body of the instrumented function. Note that the s390 issue is not detcted by the ftrace selftest code, as the instrumented function is trivial, and returning back into the caller happens to be equivalent. On arm64, regular function calls place the return address in x30, and an ftrace patch-site in an instrumented function saves this into r9 and places the trampoline's return address (within the instrumented function) in x30. A regular C function will return to the address in x30, but will not restore x9 into x30. Consequently, using a C function as the trampoline results in returning to the trampoline's return address having corrupted x30, such that when the instrumented function returns, it will return back into itself. To avoid future issues in this area, remove the trace_direct_tramp() function, and require that each architecture with direct calls provides a stub trampoline, named ftrace_stub_direct_tramp. This can be written to handle the architecture's trampoline calling convention, and in future could be used elsewhere (e.g. in the ftrace ops sample, to measure the overhead of direct calls), so we may as well always build it in. Link: https://lkml.kernel.org/r/20230321140424.345218-8-revest@chromium.orgSigned-off-by:
Mark Rutland <mark.rutland@arm.com> Cc: Li Huafei <lihuafei1@huawei.com> Cc: Xu Kuohai <xukuohai@huawei.com> Signed-off-by:
Florent Revest <revest@chromium.org> Acked-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Florent Revest authored
Direct called trampolines can be called in two ways: - either from the ftrace callsite. In this case, they do not access any struct ftrace_regs nor pt_regs - Or, if a ftrace ops is also attached, from the end of a ftrace trampoline. In this case, the call_direct_funcs ops is in charge of setting the direct call trampoline's address in a struct ftrace_regs Since: commit 9705bc70 ("ftrace: pass fregs to arch_ftrace_set_direct_caller()") The later case no longer requires a full pt_regs. It only needs a struct ftrace_regs so DIRECT_CALLS can work with both WITH_ARGS or WITH_REGS. With architectures like arm64 already abandoning WITH_REGS in favor of WITH_ARGS, it's important to have DIRECT_CALLS work WITH_ARGS only. Link: https://lkml.kernel.org/r/20230321140424.345218-7-revest@chromium.orgSigned-off-by:
Florent Revest <revest@chromium.org> Co-developed-by:
Mark Rutland <mark.rutland@arm.com> Signed-off-by:
Mark Rutland <mark.rutland@arm.com> Acked-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Florent Revest authored
All direct calls are now registered using the register_ftrace_direct API so each ops can jump to only one direct-called trampoline. By storing the direct called trampoline address directly in the ops we can save one hashmap lookup in the direct call ops and implement arm64 direct calls on top of call ops. Link: https://lkml.kernel.org/r/20230321140424.345218-6-revest@chromium.orgSigned-off-by:
Florent Revest <revest@chromium.org> Acked-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Florent Revest authored
Now that the original _ftrace_direct APIs are gone, the "_multi" suffixes only add confusion. Link: https://lkml.kernel.org/r/20230321140424.345218-5-revest@chromium.orgSigned-off-by:
Florent Revest <revest@chromium.org> Acked-by:
Mark Rutland <mark.rutland@arm.com> Tested-by:
Mark Rutland <mark.rutland@arm.com> Acked-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Florent Revest authored
This API relies on a single global ops, used for all direct calls registered with it. However, to implement arm64 direct calls, we need each ops to point to a single direct call trampoline. Link: https://lkml.kernel.org/r/20230321140424.345218-4-revest@chromium.orgSigned-off-by:
Florent Revest <revest@chromium.org> Acked-by:
Mark Rutland <mark.rutland@arm.com> Tested-by:
Mark Rutland <mark.rutland@arm.com> Acked-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Florent Revest authored
The _multi API requires that users keep their own ops but can enforce that an op is only associated to one direct call. Link: https://lkml.kernel.org/r/20230321140424.345218-3-revest@chromium.orgSigned-off-by:
Florent Revest <revest@chromium.org> Acked-by:
Mark Rutland <mark.rutland@arm.com> Tested-by:
Mark Rutland <mark.rutland@arm.com> Acked-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Florent Revest authored
A common pattern when using the ftrace_direct_multi API is to unregister the ops and also immediately free its filter. We've noticed it's very easy for users to miss calling ftrace_free_filter(). This adds a "free_filters" argument to unregister_ftrace_direct_multi() to both remind the user they should free filters and also to make their life easier. Link: https://lkml.kernel.org/r/20230321140424.345218-2-revest@chromium.orgSuggested-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
Florent Revest <revest@chromium.org> Acked-by:
Mark Rutland <mark.rutland@arm.com> Acked-by:
Jiri Olsa <jolsa@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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- 19 Mar, 2023 7 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds authored
Pull tracing fixes from Steven Rostedt: - Fix setting affinity of hwlat threads in containers Using sched_set_affinity() has unwanted side effects when being called within a container. Use set_cpus_allowed_ptr() instead - Fix per cpu thread management of the hwlat tracer: - Do not start per_cpu threads if one is already running for the CPU - When starting per_cpu threads, do not clear the kthread variable as it may already be set to running per cpu threads - Fix return value for test_gen_kprobe_cmd() On error the return value was overwritten by being set to the result of the call from kprobe_event_delete(), which would likely succeed, and thus have the function return success - Fix splice() reads from the trace file that was broken by commit 36e2c742 ("fs: don't allow splice read/write without explicit ops") - Remove obsolete and confusing comment in ring_buffer.c The original design of the ring buffer used struct page flags for tricks to optimize, which was shortly removed due to them being tricks. But a comment for those tricks remained - Set local functions and variables to static * tag 'trace-v6.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/hwlat: Replace sched_setaffinity with set_cpus_allowed_ptr ring-buffer: remove obsolete comment for free_buffer_page() tracing: Make splice_read available again ftrace: Set direct_ops storage-class-specifier to static trace/hwlat: Do not start per-cpu thread if it is already running trace/hwlat: Do not wipe the contents of per-cpu thread data tracing/osnoise: set several trace_osnoise.c variables storage-class-specifier to static tracing: Fix wrong return in kprobe_event_gen_test.c
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Costa Shulyupin authored
There is a problem with the behavior of hwlat in a container, resulting in incorrect output. A warning message is generated: "cpumask changed while in round-robin mode, switching to mode none", and the tracing_cpumask is ignored. This issue arises because the kernel thread, hwlatd, is not a part of the container, and the function sched_setaffinity is unable to locate it using its PID. Additionally, the task_struct of hwlatd is already known. Ultimately, the function set_cpus_allowed_ptr achieves the same outcome as sched_setaffinity, but employs task_struct instead of PID. Test case: # cd /sys/kernel/tracing # echo 0 > tracing_on # echo round-robin > hwlat_detector/mode # echo hwlat > current_tracer # unshare --fork --pid bash -c 'echo 1 > tracing_on' # dmesg -c Actual behavior: [573502.809060] hwlat_detector: cpumask changed while in round-robin mode, switching to mode none Link: https://lore.kernel.org/linux-trace-kernel/20230316144535.1004952-1-costa.shul@redhat.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Fixes: 0330f7aa ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by:
Costa Shulyupin <costa.shul@redhat.com> Acked-by:
Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Vlastimil Babka authored
The comment refers to mm/slob.c which is being removed. It comes from commit ed56829c ("ring_buffer: reset buffer page when freeing") and according to Steven the borrowed code was a page mapcount and mapping reset, which was later removed by commit e4c2ce82 ("ring_buffer: allocate buffer page pointer"). Thus the comment is not accurate anyway, remove it. Link: https://lore.kernel.org/linux-trace-kernel/20230315142446.27040-1-vbabka@suse.cz Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Reported-by:
Mike Rapoport <mike.rapoport@gmail.com> Suggested-by:
Steven Rostedt (Google) <rostedt@goodmis.org> Fixes: e4c2ce82 ("ring_buffer: allocate buffer page pointer") Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Sung-hun Kim authored
Since the commit 36e2c742 ("fs: don't allow splice read/write without explicit ops") is applied to the kernel, splice() and sendfile() calls on the trace file (/sys/kernel/debug/tracing /trace) return EINVAL. This patch restores these system calls by initializing splice_read in file_operations of the trace file. This patch only enables such functionalities for the read case. Link: https://lore.kernel.org/linux-trace-kernel/20230314013707.28814-1-sfoon.kim@samsung.com Cc: stable@vger.kernel.org Fixes: 36e2c742 ("fs: don't allow splice read/write without explicit ops") Signed-off-by:
Sung-hun Kim <sfoon.kim@samsung.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/ttyLinus Torvalds authored
Pull tty/serial driver fixes from Greg KH: "Here are some small tty and serial driver fixes for 6.3-rc3 to resolve some reported issues. They include: - 8250 driver Kconfig issue pointed out by you that showed up in -rc1 - qcom-geni serial driver fixes - various 8250 driver fixes for reported problems - fsl_lpuart driver fixes - serdev fix for regression in -rc1 - vt.c bugfix All have been in linux-next for over a week with no reported problems" * tag 'tty-6.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: tty: vt: protect KD_FONT_OP_GET_TALL from unbound access serial: qcom-geni: drop bogus uart_write_wakeup() serial: qcom-geni: fix mapping of empty DMA buffer serial: qcom-geni: fix DMA mapping leak on shutdown serial: qcom-geni: fix console shutdown hang serdev: Set fwnode for serdev devices tty: serial: fsl_lpuart: fix race on RX DMA shutdown serial: 8250_pci1xxxx: Disable SERIAL_8250_PCI1XXXX config by default serial: 8250_fsl: fix handle_irq locking serial: 8250_em: Fix UART port type serial: 8250: ASPEED_VUART: select REGMAP instead of depending on it tty: serial: fsl_lpuart: skip waiting for transmission complete when UARTCTRL_SBK is asserted Revert "tty: serial: fsl_lpuart: adjust SERIAL_FSL_LPUART_CONSOLE config dependency"
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-miscLinus Torvalds authored
Pull char/misc driver fixes from Greg KH: "Here are a few small char/misc/other driver subsystem patches to resolve reported problems for 6.3-rc3. Included in here are: - Interconnect driver fixes for reported problems - Memory driver fixes for reported problems - nvmem core fix - firmware driver fix for reported problem All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-6.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (23 commits) memory: tegra30-emc: fix interconnect registration race memory: tegra20-emc: fix interconnect registration race memory: tegra124-emc: fix interconnect registration race memory: tegra: fix interconnect registration race interconnect: exynos: drop redundant link destroy interconnect: exynos: fix registration race interconnect: exynos: fix node leak in probe PM QoS error path interconnect: qcom: msm8974: fix registration race interconnect: qcom: rpmh: fix registration race interconnect: qcom: rpmh: fix probe child-node error handling interconnect: qcom: rpm: fix registration race nvmem: core: return -ENOENT if nvmem cell is not found firmware: xilinx: don't make a sleepable memory allocation from an atomic context interconnect: qcom: rpm: fix probe child-node error handling interconnect: qcom: osm-l3: fix registration race interconnect: imx: fix registration race interconnect: fix provider registration API interconnect: fix icc_provider_del() error handling interconnect: fix mem leak when freeing nodes interconnect: qcom: qcm2290: Fix MASTER_SNOC_BIMC_NRT ...
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