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rt_sigqueueinfo - send a signal with associated data to a thread


The rt_sigqueueinfo() system call sends a signal, sig, and associated data, info, to the thread identified by tgid. This call is like kill(), but allows to pass the extra data.

Compared to sigqueue(), the info is passed as a pointer rather than an argument.

The siginfo_tdata type typically includes signal information such as signal number and sender information.

In kernels prior to 2.6.9, the info argument is limited to a si_value value, which indicate the signal value.

Using rt_sigqueueinfo has some advantages: * It can pass the additional data, such as si_value, for signal information. * Its use is thread-safe.


  • tgid:pid_t[K] - thread group identifier for which signal is to be sent.
  • sig:int[U] - signal to be sent.
  • info:siginfo_t*[U] - signal info.

Available Tags

  • K - Originated from kernel-space.
  • U - Originated from user space (for example, pointer to user space memory used to get it)
  • TOCTOU - Vulnerable to TOCTOU (time of check, time of use)
  • OPT - Optional argument - might not always be available (passed with null value)






To get the signal information before being sent.

Example Use Case

An example use case of rt_sigqueueinfo is when an application needs to send a signal with data from kernel-space to a thread in user-space. It can be used to report information about a critical event or abort a process.


  • The signal info (siginfo_t) is limited to a si_value value for kernels prior to 2.6.9.
  • The third argument, info, is a pointer to user space. Therefore, information from user space might not be reliable, as it might be subject to TOCTOU attacks.
  • kill() - send a signal to a process.
  • sigqueue() - send a signal with data to a process or thread.

This document was automatically generated by OpenAI and needs review. It might not be accurate and might contain errors. The authors of Tracee recommend that the user reads the "events.go" source file to understand the events and their arguments better.