Documentation/trace/kprobes.rst

36 There are currently two types of probes: kprobes, and kretprobes
37 (also called return probes).  A kprobe can be inserted on virtually
43 one or more probes, and the exit function unregisters them.  A
48 There are also ``register_/unregister_*probes()`` functions for batch
49 registration/unregistration of a group of ``*probes``. These functions
51 a lot of probes at once.
54 probes work and how jump optimization works.  They explain certain
138 some probes.  In the kretprobe struct, the nmissed field is set to
313 Kprobes and return probes are implemented on the following
319 - ia64 (Does not support probes on instruction slot1.)
320 - sparc64 (Return probes not yet implemented.)
351 function for each type of probe. The API also includes "register_*probes"
352 and "unregister_*probes" functions for (un)registering arrays of probes.
485 register_*probes
494 Registers each of the num probes in the specified array.  If any
495 error occurs during registration, all probes in the array, up to
496 the bad probe, are safely unregistered before the register_*probes
507 unregister_*probes
516 Removes each of the num probes in the specified array at once.
520    If the functions find some incorrect probes (ex. unregistered
521    probes) in the specified array, they clear the addr field of those
522    incorrect probes. However, other probes in the array are
552 Kprobes allows multiple probes at the same address. Also,
568 install probes there.  gcc may inline a function without being asked,
616 reason, Kprobes doesn't support return probes (or kprobes)
699 b. Kernel return probes for sparc64.
701 d. User-space probes.
702 e. Watchpoint probes (which fire on data references).
753 /sys/kernel/debug/kprobes/list: Lists all registered probes on the system::
765 such probes are marked with [GONE]. If the probe is temporarily disabled,
766 such probes are marked with [DISABLED]. If the probe is optimized, it is
774 registered probes will be disarmed, till such time a "1" is echoed to this
789 "debug.kprobes_optimization" to 0 via sysctl, all optimized probes will be
790 unoptimized, and any new probes registered after that will not be optimized.
793 probes (marked [OPTIMIZED]) will be unoptimized ([OPTIMIZED] tag will be