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mprotect(2) [mojave man page]

MPROTECT(2)						      BSD System Calls Manual						       MPROTECT(2)

NAME
mprotect -- control the protection of pages SYNOPSIS
#include <sys/mman.h> int mprotect(void *addr, size_t len, int prot); DESCRIPTION
The mprotect() system call changes the specified pages to have protection prot. Not all implementations will guarantee protection on a page basis but Mac OS X's current implementation does. When a program violates the protections of a page, it gets a SIGBUS or SIGSEGV signal. Currently prot can be one or more of the following: PROT_NONE No permissions at all. PROT_READ The pages can be read. PROT_WRITE The pages can be written. PROT_EXEC The pages can be executed. RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error. ERRORS
mprotect() will fail if: [EACCES] The requested protection conflicts with the access permissions of the process on the specified address range. [EINVAL] addr is not a multiple of the page size (i.e. addr is not page-aligned). [ENOTSUP] The combination of accesses requested in prot is not supported. LEGACY SYNOPSIS
#include <sys/types.h> #include <sys/mman.h> The include file <sys/types.h> is necessary. int mprotect(caddr_t addr, size_t len, int prot); The type of addr has changed. SEE ALSO
madvise(2), mincore(2), msync(2), munmap(2), compat(5) HISTORY
The mprotect() function first appeared in 4.4BSD. BSD
October 16, 2008 BSD

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mprotect(2)							   System Calls 						       mprotect(2)

NAME
mprotect - set protection of memory mapping SYNOPSIS
#include <sys/mman.h> int mprotect(void *addr, size_t len, int prot); DESCRIPTION
The mprotect() function changes the access protections on the mappings specified by the range [addr, addr + len), rounding len up to the next multiple of the page size as returned by sysconf(3C), to be that specified by prot. Legitimate values for prot are the same as those permitted for mmap(2) and are defined in <sys/mman.h> as: PROT_READ /* page can be read */ PROT_WRITE /* page can be written */ PROT_EXEC /* page can be executed */ PROT_NONE /* page can not be accessed */ When mprotect() fails for reasons other than EINVAL, the protections on some of the pages in the range [addr, addr + len) may have been changed. If the error occurs on some page at addr2, then the protections of all whole pages in the range [addr, addr2] will have been modi- fied. RETURN VALUES
Upon successful completion, mprotect() returns 0. Otherwise, it returns -1 and sets errno to indicate the error. ERRORS
The mprotect() function will fail if: EACCES The prot argument specifies a protection that violates the access permission the process has to the underlying memory object. EINVAL The len argument has a value equal to 0, or addr is not a multiple of the page size as returned by sysconf(3C). ENOMEM Addresses in the range [addr, addr + len) are invalid for the address space of a process, or specify one or more pages which are not mapped. The mprotect() function may fail if: EAGAIN The address range [addr, addr + len) includes one or more pages that have been locked in memory and that were mapped MAP_PRIVATE; prot includes PROT_WRITE; and the system has insufficient resources to reserve memory for the private pages that may be created. These private pages may be created by store operations in the now-writable address range. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
mmap(2), plock(3C), mlock(3C), mlockall(3C), sysconf(3C), attributes(5), standards(5) SunOS 5.10 12 Jan 1998 mprotect(2)
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