diff options
Diffstat (limited to 'sys/compat/cloudabi/cloudabi_vdso.c')
-rw-r--r-- | sys/compat/cloudabi/cloudabi_vdso.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/sys/compat/cloudabi/cloudabi_vdso.c b/sys/compat/cloudabi/cloudabi_vdso.c new file mode 100644 index 0000000..27c3d36 --- /dev/null +++ b/sys/compat/cloudabi/cloudabi_vdso.c @@ -0,0 +1,88 @@ +/*- + * Copyright (c) 2016 Nuxi, https://nuxi.nl/ + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/lock.h> +#include <sys/sysent.h> +#include <sys/rwlock.h> + +#include <vm/vm.h> +#include <vm/pmap.h> +#include <vm/vm_extern.h> +#include <vm/vm_object.h> +#include <vm/vm_page.h> +#include <vm/vm_pager.h> + +#include <compat/cloudabi/cloudabi_util.h> + +void +cloudabi_vdso_init(struct sysentvec *sv, char *begin, char *end) +{ + vm_page_t m; + vm_object_t obj; + vm_offset_t addr; + size_t i, pages, pages_length, vdso_length; + + /* Determine the number of pages needed to store the vDSO. */ + vdso_length = end - begin; + pages = howmany(vdso_length, PAGE_SIZE); + pages_length = pages * PAGE_SIZE; + + /* Allocate a VM object and fill it with the vDSO. */ + obj = vm_pager_allocate(OBJT_PHYS, 0, pages_length, + VM_PROT_DEFAULT, 0, NULL); + addr = kva_alloc(PAGE_SIZE); + for (i = 0; i < pages; ++i) { + VM_OBJECT_WLOCK(obj); + m = vm_page_grab(obj, i, VM_ALLOC_NOBUSY | VM_ALLOC_ZERO); + m->valid = VM_PAGE_BITS_ALL; + VM_OBJECT_WUNLOCK(obj); + + pmap_qenter(addr, &m, 1); + memcpy((void *)addr, begin + i * PAGE_SIZE, + MIN(vdso_length - i * PAGE_SIZE, PAGE_SIZE)); + pmap_qremove(addr, 1); + } + kva_free(addr, PAGE_SIZE); + + /* + * Place the vDSO at the top of the address space. The user + * stack can start right below it. + */ + sv->sv_shared_page_base = sv->sv_maxuser - pages_length; + sv->sv_shared_page_len = pages_length; + sv->sv_shared_page_obj = obj; + sv->sv_usrstack = sv->sv_shared_page_base; +} + +void +cloudabi_vdso_destroy(struct sysentvec *sv) +{ + + vm_object_deallocate(sv->sv_shared_page_obj); +} |