munmap_device_memory()

Updated: April 19, 2023

Unmap previously mapped addresses

Synopsis:

#include <sys/mman.h>

int munmap_device_memory( void * addr,
                          size_t len );

Arguments:

addr
The beginning of the range of addresses that you want to unmap.
len
The length of the range of addresses, in bytes.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The munmap_device_memory() function is essentially the same as munmap(). It removes any mappings for pages in the address range starting at addr and continuing for len bytes, rounded up to the next multiple of the page size. Subsequent references to these pages cause a SIGSEGV signal to be set on the process.

If there are no mappings in the specified address range, then munmap() has no effect.

This function is the complement of mmap_device_memory().

Returns:

-1
An error occurred (errno is set).
Any other value
Success.

Errors:

EINVAL
The addresses in the specified range are outside the range allowed for the address space of a process.
ENOSYS
The munmap() function isn't supported by this implementation.

Classification:

QNX Neutrino

Safety:  
Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes