/*
* Helper routines to allow the backing object of a shared memory file
* descriptor to be mapped in the kernel.
*/
int
shm_map(struct file *fp, size_t size, off_t offset, void **memp)
{
struct shmfd *shmfd;
vm_offset_t kva, ofs;
vm_object_t obj;
int rv;
if (fp->f_type != DTYPE_SHM)
return (EINVAL);
shmfd = fp->f_data;
obj = shmfd->shm_object;
VM_OBJECT_LOCK(obj);
/*
* XXXRW: This validation is probably insufficient, and subject to
* sign errors. It should be fixed.
*/
if (offset >= shmfd->shm_size ||
offset + size > round_page(shmfd->shm_size)) {
VM_OBJECT_UNLOCK(obj);
return (EINVAL);
}
shmfd->shm_kmappings++;
vm_object_reference_locked(obj);
VM_OBJECT_UNLOCK(obj);
/* Map the object into the kernel_map and wire it. */
kva = vm_map_min(kernel_map);
ofs = offset & PAGE_MASK;
offset = trunc_page(offset);
size = round_page(size + ofs);
rv = vm_map_find(kernel_map, obj, offset, &kva, size,
VMFS_ALIGNED_SPACE, VM_PROT_READ | VM_PROT_WRITE,
VM_PROT_READ | VM_PROT_WRITE, 0);
if (rv == KERN_SUCCESS) {
rv = vm_map_wire(kernel_map, kva, kva + size,
VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
if (rv == KERN_SUCCESS) {
*memp = (void *)(kva + ofs);
return (0);
}
vm_map_remove(kernel_map, kva, kva + size);
} else
vm_object_deallocate(obj);
/* On failure, drop our mapping reference. */
VM_OBJECT_LOCK(obj);
shmfd->shm_kmappings--;
VM_OBJECT_UNLOCK(obj);
return (vm_mmap_to_errno(rv));
}
static int
load_coff_section(struct vmspace *vmspace, struct vnode *vp, vm_offset_t offset,
caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot)
{
size_t map_len;
vm_offset_t map_offset;
vm_offset_t map_addr;
int error;
unsigned char *data_buf = 0;
size_t copy_len;
map_offset = trunc_page(offset);
map_addr = trunc_page((vm_offset_t)vmaddr);
if (memsz > filsz) {
/*
* We have the stupid situation that
* the section is longer than it is on file,
* which means it has zero-filled areas, and
* we have to work for it. Stupid iBCS!
*/
map_len = trunc_page(offset + filsz) - trunc_page(map_offset);
} else {
/*
* The only stuff we care about is on disk, and we
* don't care if we map in more than is really there.
*/
map_len = round_page(offset + filsz) - trunc_page(map_offset);
}
DPRINTF(("%s(%d): vm_mmap(&vmspace->vm_map, &0x%08jx, 0x%x, 0x%x, "
"VM_PROT_ALL, MAP_PRIVATE | MAP_FIXED, OBJT_VNODE, vp, 0x%x)\n",
__FILE__, __LINE__, (uintmax_t)map_addr, map_len, prot,
map_offset));
if ((error = vm_mmap(&vmspace->vm_map,
&map_addr,
map_len,
prot,
VM_PROT_ALL,
MAP_PRIVATE | MAP_FIXED,
OBJT_VNODE,
vp,
map_offset)) != 0)
return error;
if (memsz == filsz) {
/* We're done! */
return 0;
}
/*
* Now we have screwball stuff, to accomodate stupid COFF.
* We have to map the remaining bit of the file into the kernel's
* memory map, allocate some anonymous memory, copy that last
* bit into it, and then we're done. *sigh*
* For clean-up reasons, we actally map in the file last.
*/
copy_len = (offset + filsz) - trunc_page(offset + filsz);
map_addr = trunc_page((vm_offset_t)vmaddr + filsz);
map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr;
DPRINTF(("%s(%d): vm_map_find(&vmspace->vm_map, NULL, 0, &0x%08jx,0x%x, VMFS_NO_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0)\n", __FILE__, __LINE__, (uintmax_t)map_addr, map_len));
if (map_len != 0) {
error = vm_map_find(&vmspace->vm_map, NULL, 0, &map_addr,
map_len, 0, VMFS_NO_SPACE, VM_PROT_ALL, VM_PROT_ALL, 0);
if (error)
return (vm_mmap_to_errno(error));
}
if ((error = vm_mmap(exec_map,
(vm_offset_t *) &data_buf,
PAGE_SIZE,
VM_PROT_READ,
VM_PROT_READ,
0,
OBJT_VNODE,
vp,
trunc_page(offset + filsz))) != 0)
return error;
error = copyout(data_buf, (caddr_t) map_addr, copy_len);
kmap_free_wakeup(exec_map, (vm_offset_t)data_buf, PAGE_SIZE);
return error;
}
/*
* Destroy old address space, and allocate a new stack.
* The new stack is only sgrowsiz large because it is grown
* automatically on a page fault.
*/
int
exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv)
{
int error;
struct proc *p = imgp->proc;
struct vmspace *vmspace = p->p_vmspace;
vm_object_t obj;
struct rlimit rlim_stack;
vm_offset_t sv_minuser, stack_addr;
vm_map_t map;
u_long ssiz;
imgp->vmspace_destroyed = 1;
imgp->sysent = sv;
/* May be called with Giant held */
EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp);
/*
* Blow away entire process VM, if address space not shared,
* otherwise, create a new VM space so that other threads are
* not disrupted
*/
map = &vmspace->vm_map;
if (map_at_zero)
sv_minuser = sv->sv_minuser;
else
sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE);
if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv_minuser &&
vm_map_max(map) == sv->sv_maxuser &&
cpu_exec_vmspace_reuse(p, map)) {
shmexit(vmspace);
pmap_remove_pages(vmspace_pmap(vmspace));
vm_map_remove(map, vm_map_min(map), vm_map_max(map));
/*
* An exec terminates mlockall(MCL_FUTURE), ASLR state
* must be re-evaluated.
*/
vm_map_lock(map);
vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR |
MAP_ASLR_IGNSTART);
vm_map_unlock(map);
} else {
error = vmspace_exec(p, sv_minuser, sv->sv_maxuser);
if (error)
return (error);
vmspace = p->p_vmspace;
map = &vmspace->vm_map;
}
map->flags |= imgp->map_flags;
/* Map a shared page */
obj = sv->sv_shared_page_obj;
if (obj != NULL) {
vm_object_reference(obj);
error = vm_map_fixed(map, obj, 0,
sv->sv_shared_page_base, sv->sv_shared_page_len,
VM_PROT_READ | VM_PROT_EXECUTE,
VM_PROT_READ | VM_PROT_EXECUTE,
MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE);
if (error != KERN_SUCCESS) {
vm_object_deallocate(obj);
return (vm_mmap_to_errno(error));
}
}
/* Allocate a new stack */
if (imgp->stack_sz != 0) {
ssiz = trunc_page(imgp->stack_sz);
PROC_LOCK(p);
lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack);
PROC_UNLOCK(p);
if (ssiz > rlim_stack.rlim_max)
ssiz = rlim_stack.rlim_max;
if (ssiz > rlim_stack.rlim_cur) {
rlim_stack.rlim_cur = ssiz;
kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack);
}
} else if (sv->sv_maxssiz != NULL) {
ssiz = *sv->sv_maxssiz;
} else {
ssiz = maxssiz;
}
stack_addr = sv->sv_usrstack - ssiz;
error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz,
obj != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
if (error != KERN_SUCCESS)
return (vm_mmap_to_errno(error));
/*
* vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they
* are still used to enforce the stack rlimit on the process stack.
*/
vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
vmspace->vm_maxsaddr = (char *)stack_addr;
return (0);
}