Controlling Memory-Mapped Regions
A memory-mapped region often requires its attributes to be queried or changed in some fashion. This section looks at four system calls designed for this purpose:
| mprotect(2) | Change the access of the indicated memory pages. |
| madvise(2) | Advise the UNIX kernel how you intend to use your memory region. |
| mincore(2) | Determine if pages of mapped memory are currently in memory. |
| msync(2) | Where modifications exist, indicate what regions of memory should be updated to the mapped files. |
Changing the Access Protection
A memory-mapped region, entirely or in part, may have its access protections changed by the mprotect(2) system call. Its function synopsis is as follows:
#include <sys/types.h> #include <sys/mman.h> int mprotect(const ...
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