---
name: "function::ucallers"
section: "3stap"
platform: "linux"
package: "systemtap-doc"
version: "5.1-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/function::ucallers"
---

# function::ucallers(3stap)

Return first n elements of user stack backtrace

## NAME

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

## SYNOPSIS

```
    ucallers:string(n:long)
```

## ARGUMENTS

*n*

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

## 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

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

[*tapset::ucontext*(3stap)](/tapset::ucontext/3stap.md)