VM_MAP_RAM(9) Memory Management in Linux VM_MAP_RAM(9)NAME
vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
void * vm_map_ram(struct page ** pages, unsigned int count, int node, pgprot_t prot);
an array of pointers to the pages to be mapped
number of pages
prefer to allocate data structures on this node
memory protection to use. PAGE_KERNEL for regular RAM
a pointer to the address that has been mapped, or NULL on failure
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 VM_MAP_RAM(9)
Check Out this Related Man Page
mprotect(2) System Calls mprotect(2)NAME
mprotect - set protection of memory mapping
int mprotect(void *addr, size_t len, int prot);
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-
Upon successful completion, mprotect() returns 0. Otherwise, it returns -1 and sets errno to indicate the error.
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
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.
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 5.11 12 Jan 1998 mprotect(2)
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