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prof

Intro

prof - Event triggered when profiler events are enabled or disabled.

Description

The prof event is triggered when profiler events are enabled or disabled. It is used to enable and disable per-process event profiling, which is used to measure the performance and execution of a given process. The prof event allows for fine-grained control over the events that are monitored, allowing for granular tracking of process behavior.

The prof event has several drawbacks and edge-cases. Since it is specific to the process being monitored, it can be potentially slow to set up and can have unexpected side-effects on the process performance when enabled. Additionally, since the event is being monitored at the process level, it may be dependent on the type of process being monitored.

Arguments

  • FLAGS: unsigned long[K] - Flags to configure the event profiling.
  • EVENTS: unsigned int[K] - Array of events to monitor while profiling.

Available Tags

  • K - Originated from kernel-space.
  • U - Originated from user space (for example, pointer to user space memory used to get it)
  • TOCTOU - Vulnerable to TOCTOU (time of check, time of use)
  • OPT - Optional argument - might not always be available (passed with null value)

Hooks

sched_process_exec

Type

kprobe + kretprobe

Purpose

Hook the sched_process_exec function to enable and disable the profiler events when the process executes.

do_exit

Type

kprobe + kretprobe

Purpose

Hook the do_exit function to shutdown the profiler before exiting the process.

Example Use Case

The prof event can be used to measure the performance or track the execution of specific processes on the system. It's commonly used in embedded and real-time applications where precise performance measurements are necessary.

Issues

The prof event is highly process-dependent and can lead to unexpected performance issues or decreased efficiency when enabled. Additionally, because it requires a precise setup across the entire stack, it can be slow to configure and start.

The prof event is related to the perf event, which is used to observation of hardware performance counters.

This document was automatically generated by OpenAI and needs review. It might not be accurate and might contain errors. The authors of Tracee recommend that the user reads the "events.go" source file to understand the events and their arguments better.