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mx_vmar_protect

NAME

vmar_protect - set protection of virtual memory pages

SYNOPSIS

#include <magenta/syscalls.h>

mx_status_t mx_vmar_protect(mx_handle_t vmar_handle,
                            uintptr_t addr, size_t len,
                            uint32_t prot);

DESCRIPTION

vmar_protect() alters the access protections for the memory mappings in the range of len bytes starting from addr. The prot argument should be a bitwise-or of one or more of the following:

  • MX_VM_FLAG_PERM_READ Map as readable. It is an error if vmar does not have MX_VM_FLAG_CAN_MAP_READ permissions or the vmar handle does not have the MX_RIGHT_READ right. It is also an error if the VMO handle used to create the mapping did not have the MX_RIGHT_READ right.
  • MX_VM_FLAG_PERM_WRITE Map as writable. It is an error if vmar does not have MX_VM_FLAG_CAN_MAP_WRITE permissions or the vmar handle does not have the MX_RIGHT_WRITE right. It is also an error if the VMO handle used to create the mapping did not have the MX_RIGHT_WRITE right.
  • MX_VM_FLAG_PERM_EXECUTE Map as executable. It is an error if vmar does not have MX_VM_FLAG_CAN_MAP_EXECUTE permissions or the vmar handle does not have the MX_RIGHT_EXECUTE right. It is also an error if the VMO handle used to create the mapping did not have the MX_RIGHT_EXECUTE right.

If len is not page-aligned, it will be rounded up the next page boundary.

RETURN VALUE

vmar_protect() returns NO_ERROR on success.

ERRORS

ERR_INVALID_ARGS prot is an unsupported combination of flags (e.g., PROT_WRITE but not PROT_READ), addr is not page-aligned, len is 0, or some subrange of the requested range is occupied by a subregion.

ERR_NOT_FOUND Some subrange of the requested range is not mapped.

ERR_ACCESS_DENIED vmar_handle does not have the proper rights for the requested change, the original VMO handle used to create the mapping did not have the rights for the requested change, or the VMAR itself does not allow the requested change.

NOTES

SEE ALSO

vmar_map. vmar_unmap.