---
name: "ssdd"
section: "8"
platform: "linux"
package: "rt-tests"
version: "2.11-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/ssdd"
---

# ssdd(8)

have a tracer do a bunch of PTRACE\_SINGLESTEPs

\# SPDX-License-Identifier: GPL-2.0-or-later

## NAME

ssdd - have a tracer do a bunch of PTRACE\_SINGLESTEPs

## SYNOPSIS

ssdd \[-f\|--forks NUM\] \[-h\|--help\] \[-i\|--iters NUM\] \[--json FILENAME\]

## DESCRIPTION

Have a tracer do a bunch of PTRACE\_SINGLESTEPs against a tracee as fast as possible. Create several of these tracer/tracee pairs and see if they can be made to interfere with each other. The tracer waits on each PTRACE\_SINGLESTEP with a [waitpid(2)](/waitpid/2.md) and checks that waitpid's return values for correctness.

## OPTIONS

- **-f, --forks=NUM**

  number of tracer/tracee pairs to fork off.\
   Default is 10.

- **-h, --help**

  Display usage

- **-i, --iters=NUM**

  number of PTRACE\_SINGLESTEP iterations to do before declaring success, for each tracer tracee pair set up.\
   Default is 10,000.\
   NUM must be at least 1

- **--json=FILENAME**

  Write final results into FILENAME, JSON formatted.

## AUTHOR

ssdd was written by Joe Korty \<joe.korty@concurrent-rt.com\>

This manual page was written by John Kacur \<jkacur@redhat.com\>