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PROLOG |NAME |SYNOPSIS |DESCRIPTION |RETURN VALUE |ERRORS |EXAMPLES |APPLICATION USAGE |RATIONALE |FUTURE DIRECTIONS |SEE ALSO |COPYRIGHT | |
MPROTECT(3P) POSIX Programmer's ManualMPROTECT(3P)This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
mprotect — set protection of memory mapping
#include <sys/mman.h> int mprotect(void *addr, size_tlen, intprot);
Themprotect() function shall change the access protections to be that specified byprot for those whole pages containing any part of the address space of the process starting at addressaddr and continuing forlen bytes. The parameterprot determines whether read, write, execute, or some combination of accesses are permitted to the data being mapped. Theprot argument should be either PROT_NONE or the bitwise-inclusive OR of one or more of PROT_READ, PROT_WRITE, and PROT_EXEC. If an implementation cannot support the combination of access types specified byprot, the call tomprotect() shall fail. An implementation may permit accesses other than those specified byprot; however, no implementation shall permit a write to succeed where PROT_WRITE has not been set or shall permit any access where PROT_NONE alone has been set. Implementations shall support at least the following values ofprot: PROT_NONE, PROT_READ, PROT_WRITE, and the bitwise-inclusive OR of PROT_READ and PROT_WRITE. If PROT_WRITE is specified, the application shall ensure that it has opened the mapped objects in the specified address range with write permission, unless MAP_PRIVATE was specified in the original mapping, regardless of whether the file descriptors used to map the objects have since been closed. The implementation may require thataddr be a multiple of the page size as returned bysysconf(). The behavior of this function is unspecified if the mapping was not established by a call tommap(). Whenmprotect() fails for reasons other than[EINVAL], the protections on some of the pages in the range [addr,addr+len) may have been changed.
Upon successful completion,mprotect() shall return 0; otherwise, it shall return -1 and seterrno to indicate the error.
Themprotect() function shall fail if:EACCESTheprot argument specifies a protection that violates the access permission the process has to the underlying memory object.EAGAINTheprot argument specifies PROT_WRITE over a MAP_PRIVATE mapping and there are insufficient memory resources to reserve for locking the private page.ENOMEMAddresses 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.ENOMEMTheprot argument specifies PROT_WRITE on a MAP_PRIVATE mapping, and it would require more space than the system is able to supply for locking the private pages, if required.ENOTSUP The implementation does not support the combination of accesses requested in theprot argument. Themprotect() function may fail if:EINVALTheaddr argument is not a multiple of the page size as returned bysysconf().The following sections are informative.
None.
Most implementations require thataddr is a multiple of the page size as returned bysysconf().
None.
None.
mmap(3p),sysconf(3p) The Base Definitions volume of POSIX.1‐2017,sys_mman.h(0p)
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online athttp://www.opengroup.org/unix/online.html . Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group 2017MPROTECT(3P)Pages that refer to this page:sys_mman.h(0p), mmap(3p)
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