---
name: "PR_SET_TSC"
section: "2const"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/PR_SET_TSC"
---

# PR\_SET\_TSC(2const)

change whether the timestamp counter can be read by the process

## NAME

PR\_SET\_TSC - change whether the timestamp counter can be read by the process

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

```
#include <linux/prctl.h>  /* Definition of PR_* constants */
#include <sys/prctl.h>
```

**int prctl(PR\_SET\_TSC, long** *flag***);**

## DESCRIPTION

Set the state of the flag determining whether the timestamp counter can be read by the process. Pass **PR\_TSC\_ENABLE** to *flag* to allow it to be read, or **PR\_TSC\_SIGSEGV** to generate a **SIGSEGV** when the process tries to read the timestamp counter.

## RETURN VALUE

On success, 0 is returned. On error, -1 is returned, and *errno* is set to indicate the error.

## ERRORS

- **EINVAL**

  *flag* is not a valid value.

## STANDARDS

Linux. x86 only.

## HISTORY

Linux 2.6.26 (x86).

## SEE ALSO

[**prctl**(2)](/prctl/2.md), [**PR\_GET\_TSC**(2const)](/PR_GET_TSC/2const.md)