You can fully specify a probe by listing each component of the 4–tuple that uniquely identifies that probe. The format for the probe specification is provider:module:function:name. An empty component in a probe specification matches anything. For example, the specification fbt::alloc:entry specifies a probe with the following attributes:
The probe must be from the fbt provider
The probe may be in any module
The probe must be in the alloc function
The probe must be named entry
Elements on the left hand side of the 4–tuple are optional. The probe specification ::open:entry is equivalent to the specification open:entry. Either specification will match probes from all providers and kernel modules that have a function name of open and are named entry.
# dtrace -l -n open:entry ID PROVIDER MODULE FUNCTION NAME 14 syscall open entry 7386 fbt genunix open entry
You can also describe probes with a pattern matching syntax that is similar to the syntax that is described in the File Name Generation section of the sh(1) man page. The syntax supports the special characters *, ?, [, and ]. The probe description syscall::open*:entry matches both the open and open64 system calls. The ? character represents any single character in the name. The [ and ] characters are used to specify a set of specific characters in the name.