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mprotect(2) [sunos man page]

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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mprotect(2)							System Calls Manual						       mprotect(2)

NAME
mprotect() - set or check protection of memory mapping SYNOPSIS
DESCRIPTION
The 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 to be that specified by prot. Legitimate values for prot are the same as those permitted for and are defined in Page can be read. Page can be written. Page can be executed. Page cannot be accessed. Check page effective permissions If flag is specified, checks the access protections on the mappings specified with the rest of prot value to see if the requested permis- sions are set. If the address range being modified corresponds to a mapped file that was mapped with grants write access permission only if the file descriptor used to map the file was opened for writing. If the address range corresponds to a mapped file that was mapped with the or the flag, grants all requested access permissions. When fails for reasons other than the protections on some of the pages in the range [addr, addr+len] may have been changed. For example, if an error occurs on some page at an addr2, then may have modified the protections of all whole pages in the range [addr,addr2]. RETURN VALUE
Upon successful completion, returns Otherwise, it returns and sets to indicate the error. ERRORS
The function will fail if: The prot argument specifies a protection that violates, or is different than (in the case where flag is present), the access permission the process has to the underlying memory object. prot is invalid, or addr is not a multiple of the page size as returned by The range specified by [addr, addr+len] (from, and including, addr to, but not including, addr+len) is invalid for the address space of a process, or the range specifies one or more unmapped pages. 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 prot argument specifies over a mapping and there are insufficient memory resources to reserve for locking the private page. AUTHOR
was developed by HP, AT&T, and OSF. SEE ALSO
mmap(2), sysconf(2), <sys/mman.h>. STANDARDS CONFORMANCE
mprotect(2)
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