FUNCTION::UCALLERS(3stap) Context Functions FUNCTION::UCALLERS(3stap)

# [NAME](#NAME)

function::ucallers - Return first n elements of user stack backtrace

# [SYNOPSIS](#SYNOPSIS)

```


    ucallers:string(n:long)
```

# [ARGUMENTS](#ARGUMENTS)

*n*

number of levels to descend in the stack (not counting the top level). If n is -1, print the entire stack.

# [DESCRIPTION](#DESCRIPTION)

This function returns a string of the first n hex addresses from the backtrace of the user stack. Output may be truncated as per maximum string length (MAXSTRINGLEN).

# [NOTE](#NOTE)

To get (full) backtraces for user space applications and shared shared libraries not mentioned in the current script run stap with -d /path/to/exe-or-so and/or add --ldd to load all needed unwind data.

# [SEE ALSO0](#SEE_ALSO0)

[*tapset::ucontext*(3stap)](/man/enterprise-packages/systemtap/tapset::ucontext.3stap)

September 2026 SystemTap Tapset Reference Ver

---

Document: function::ucallers(3stap) from systemtap 5.6-r0 (Chainguard OS)
Source: https://sourceware.org/git/systemtap.git