useracc(9) check memory regions for accessibility

Other Alias



In sys/param.h In sys/proc.h In vm/vm.h In vm/vm_extern.h Ft int Fn kernacc void *addr int len int rw Ft int Fn useracc void *addr int len int rw


The Fn kernacc and Fn useracc functions check whether operations of the type specified in Fa rw are permitted in the range of virtual addresses given by Fa addr and Fa len . The possible values of Fa rw are any bitwise combination of VM_PROT_READ VM_PROT_WRITE and VM_PROT_EXECUTE Fn kernacc checks addresses in the kernel address space, while Fn useracc considers Fa addr to represent an user space address. The process context to use for this operation is taken from the global variable curproc


Both functions return boolean true if the type of access specified by Fa rw is permitted. Otherwise boolean false is returned.


The process pointer should be passed in as an argument to Fn useracc .