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MPROTECT(2) | System Calls Manual | MPROTECT(2) |
NAME¶
mprotect
—
control the protection of pages
LIBRARY¶
Standard C Library (libc, -lc)SYNOPSIS¶
#include
<sys/mman.h>
int
mprotect
(const
void *addr,
size_t len,
int prot);
DESCRIPTION¶
Themprotect
() system call changes the
specified pages to have protection prot. Not
all implementations will guarantee protection on a page basis; the granularity
of protection changes may be as large as an entire region. A region is the
virtual address space defined by the start and end addresses of a
struct vm_map_entry.
Currently these protection bits are known, which can be combined, OR'd together:
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¶
Themprotect
() function returns the
value 0 if successful; otherwise the value -1 is returned and
the global variable errno is set to indicate
the error.
ERRORS¶
Themprotect
() system call will fail if:
- [
EINVAL
] - The virtual address range specified by the addr and len arguments is not valid.
- [
EACCES
] - The calling process was not allowed to change the protection to the value specified by the prot argument.
SEE ALSO¶
madvise(2), mincore(2), msync(2), munmap(2)HISTORY¶
Themprotect
() system call first appeared in
4.4BSD.June 9, 1993 | Debian |