| UVM_MAP(9) | Kernel Developer's Manual | UVM_MAP(9) |
uvm_map —
#include <sys/param.h>
#include <uvm/uvm.h>
int
uvm_map(struct
vm_map *map, vaddr_t
*startp, vsize_t
size, struct uvm_object
*uobj, voff_t
uoffset, vsize_t
align, uvm_flag_t
flags);
void
uvm_unmap(struct
vm_map *map, vaddr_t
start, vaddr_t
end);
int
uvm_map_pageable(struct
vm_map *map, vaddr_t
start, vaddr_t end,
bool new_pageable,
int lockflags);
bool
uvm_map_checkprot(struct
vm_map *map, vaddr_t
start, vaddr_t end,
vm_prot_t
protection);
int
uvm_map_protect(struct
vm_map *map, vaddr_t
start, vaddr_t end,
vm_prot_t new_prot,
bool set_max);
int
uvm_map_protect_user(struct
lwp *l, vaddr_t
start, vaddr_t end,
vm_prot_t new_prot);
int
uvm_deallocate(struct
vm_map *map, vaddr_t
start, vsize_t
size);
struct vmspace *
uvmspace_alloc(vaddr_t
min, vaddr_t
max);
void
uvmspace_exec(struct
lwp *l, vaddr_t
start, vaddr_t
end);
struct vmspace *
uvmspace_fork(struct
vmspace *vm);
void
uvmspace_free(struct
vmspace *vm);
void
uvmspace_share(struct
proc *p1, struct proc
*p2);
vaddr_t
uvm_uarea_alloc(void);
void
uvm_uarea_free(vaddr_t
uaddr);
vaddr_t
uvm_uarea_system_alloc(void);
void
uvm_uarea_system_free(vaddr_t
uaddr);
uvm_map() establishes a valid mapping in map
map, which must be unlocked. The new mapping has size
size, which must be a multiple of
PAGE_SIZE.
The uobj and uoffset arguments can have four meanings:
NULL and
uoffset is
UVM_UNKNOWN_OFFSET,
uvm_map() does not use the machine-dependent
PMAP_PREFER function.NULL and
uoffset is any other value, it is used as the hint
to PMAP_PREFER.NULL and
uoffset is
UVM_UNKNOWN_OFFSET,
uvm_map() finds the offset based upon the virtual
address, passed as startp.NULL and
uoffset is any other value, then a regular mapping
is performed at this offset. The start address of the map will be returned
in startp.uvm_map() consumes the caller's
reference to uobj on success;
uvm_unmap() will release it when removing this
mapping. On failure, uvm_map() leaves the reference
count of uobj unmodified.
align specifies alignment of mapping unless
UVM_FLAG_FIXED is specified in
flags. align must be a power of
2.
flags passed to
uvm_map() are typically created using the
UVM_MAPFLAG(vm_prot_t prot,
vm_prot_t maxprot, vm_inherit_t
inh, int advice, int
flags) macro, which uses the following values.
The values that prot and maxprot can take are:
UVM_PROT_RW, UVM_PROT_RX,
UVM_PROT_WX and UVM_PROT_RWX.
The values that inh can take are:
The values that advice can take are:
The values that flags can take are:
uvm_unmap().UVM_FLAG_FIXED is a bug.The UVM_MAPFLAG macro arguments can be
combined with an or operator. There are several special purpose macros for
checking protection combinations, e.g., the
UVM_PROT_WX. There are also some additional macros
to extract bits from the flags. The UVM_PROTECTION,
UVM_INHERIT,
UVM_MAXPROTECTION and
UVM_ADVICE macros return the protection,
inheritance, maximum protection, and advice, respectively.
uvm_map() returns zero on success or error number
otherwise.
uvm_unmap() removes a valid mapping, from
start to end, in map
map, which must be unlocked.
uvm_map_pageable() changes the pageability
of the pages in the range from start to
end in map map to
new_pageable.
uvm_map_pageable() returns zero on success or error
number otherwise.
uvm_map_checkprot() checks the protection
of the range from start to end
in map map against protection.
This returns either true or
false.
uvm_map_protect() changes the protection
start to end in map
map to new_prot, also setting
the maximum protection to the region to new_prot if
set_max is true. This function returns a standard UVM
return value.
uvm_map_protect_user() verifies that the
new permissions honor PAX restrictions if applicable and forwards to
uvm_map_protect() on passing.
uvm_deallocate() deallocates kernel memory
in map map from address start to
start + size.
uvmspace_alloc() allocates and returns a
new address space, with ranges from min to
max.
uvmspace_exec() either reuses the address
space of thread l (its process) if there are no other
references to it, or creates a new one with
uvmspace_alloc(). The range of valid addresses in
the address space is reset to start through
end.
uvmspace_fork() creates and returns a new
address space based upon the vm address space,
typically used when allocating an address space for a child process.
uvmspace_free() lowers the reference count
on the address space vm, freeing the data structures
if there are no other references.
uvmspace_share() causes process
p2 to share the address space of
p1.
uvm_uarea_alloc() allocates memory for a
u-area (i.e. kernel stack, PCB, etc) and returns the address.
uvm_uarea_free() frees a u-area allocated
with uvm_uarea_alloc().
uvm_uarea_system_alloc() and
uvm_uarea_system_free() are optimized routines,
which are used for kernel threads.
uvm_map first appeared in
NetBSD 1.4.
| May 20, 2017 | NetBSD 10.1 |