int vmcmd_map_zero(struct lwp *l, struct exec_vmcmd *cmd) { struct proc *p = l->l_proc; int error; long diff; vm_prot_t prot, maxprot; diff = cmd->ev_addr - trunc_page(cmd->ev_addr); cmd->ev_addr -= diff; /* required by uvm_map */ cmd->ev_len += diff; prot = cmd->ev_prot; maxprot = UVM_PROT_ALL; #ifdef PAX_MPROTECT pax_mprotect(l, &prot, &maxprot); #endif /* PAX_MPROTECT */ error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, round_page(cmd->ev_len), NULL, UVM_UNKNOWN_OFFSET, 0, UVM_MAPFLAG(prot, maxprot, UVM_INH_COPY, UVM_ADV_NORMAL, UVM_FLAG_FIXED|UVM_FLAG_COPYONW)); if (cmd->ev_flags & VMCMD_STACK) curproc->p_vmspace->vm_issize += atop(round_page(cmd->ev_len)); return error; }
int vmcmd_map_pagedvn(struct lwp *l, struct exec_vmcmd *cmd) { struct uvm_object *uobj; struct vnode *vp = cmd->ev_vp; struct proc *p = l->l_proc; int error; vm_prot_t prot, maxprot; KASSERT(vp->v_iflag & VI_TEXT); /* * map the vnode in using uvm_map. */ if (cmd->ev_len == 0) return(0); if (cmd->ev_offset & PAGE_MASK) return(EINVAL); if (cmd->ev_addr & PAGE_MASK) return(EINVAL); if (cmd->ev_len & PAGE_MASK) return(EINVAL); prot = cmd->ev_prot; maxprot = UVM_PROT_ALL; #ifdef PAX_MPROTECT pax_mprotect(l, &prot, &maxprot); #endif /* PAX_MPROTECT */ /* * check the file system's opinion about mmapping the file */ error = VOP_MMAP(vp, prot, l->l_cred); if (error) return error; if ((vp->v_vflag & VV_MAPPED) == 0) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vp->v_vflag |= VV_MAPPED; VOP_UNLOCK(vp, 0); } /* * do the map, reference the object for this map entry */ uobj = &vp->v_uobj; vref(vp); error = uvm_map(&p->p_vmspace->vm_map, &cmd->ev_addr, cmd->ev_len, uobj, cmd->ev_offset, 0, UVM_MAPFLAG(prot, maxprot, UVM_INH_COPY, UVM_ADV_NORMAL, UVM_FLAG_COPYONW|UVM_FLAG_FIXED)); if (error) { uobj->pgops->pgo_detach(uobj); } return error; }
int vmcmd_readvn(struct lwp *l, struct exec_vmcmd *cmd) { struct proc *p = l->l_proc; int error; vm_prot_t prot, maxprot; error = vn_rdwr(UIO_READ, cmd->ev_vp, (void *)cmd->ev_addr, cmd->ev_len, cmd->ev_offset, UIO_USERSPACE, IO_UNIT, l->l_cred, NULL, l); if (error) return error; prot = cmd->ev_prot; maxprot = VM_PROT_ALL; #ifdef PAX_MPROTECT pax_mprotect(l, &prot, &maxprot); #endif /* PAX_MPROTECT */ #ifdef PMAP_NEED_PROCWR /* * we had to write the process, make sure the pages are synched * with the instruction cache. */ if (prot & VM_PROT_EXECUTE) pmap_procwr(p, cmd->ev_addr, cmd->ev_len); #endif /* * we had to map in the area at PROT_ALL so that vn_rdwr() * could write to it. however, the caller seems to want * it mapped read-only, so now we are going to have to call * uvm_map_protect() to fix up the protection. ICK. */ if (maxprot != VM_PROT_ALL) { error = uvm_map_protect(&p->p_vmspace->vm_map, trunc_page(cmd->ev_addr), round_page(cmd->ev_addr + cmd->ev_len), maxprot, true); if (error) return (error); } if (prot != maxprot) { error = uvm_map_protect(&p->p_vmspace->vm_map, trunc_page(cmd->ev_addr), round_page(cmd->ev_addr + cmd->ev_len), prot, false); if (error) return (error); } return 0; }
int sys_mmap(struct lwp *l, const struct sys_mmap_args *uap, register_t *retval) { /* { syscallarg(void *) addr; syscallarg(size_t) len; syscallarg(int) prot; syscallarg(int) flags; syscallarg(int) fd; syscallarg(long) pad; syscallarg(off_t) pos; } */ struct proc *p = l->l_proc; vaddr_t addr; struct vattr va; off_t pos; vsize_t size, pageoff; vm_prot_t prot, maxprot; int flags, fd; vaddr_t defaddr; struct file *fp = NULL; struct vnode *vp; void *handle; int error; #ifdef PAX_ASLR vaddr_t orig_addr; #endif /* PAX_ASLR */ /* * first, extract syscall args from the uap. */ addr = (vaddr_t)SCARG(uap, addr); size = (vsize_t)SCARG(uap, len); prot = SCARG(uap, prot) & VM_PROT_ALL; flags = SCARG(uap, flags); fd = SCARG(uap, fd); pos = SCARG(uap, pos); #ifdef PAX_ASLR orig_addr = addr; #endif /* PAX_ASLR */ /* * Fixup the old deprecated MAP_COPY into MAP_PRIVATE, and * validate the flags. */ if (flags & MAP_COPY) flags = (flags & ~MAP_COPY) | MAP_PRIVATE; if ((flags & (MAP_SHARED|MAP_PRIVATE)) == (MAP_SHARED|MAP_PRIVATE)) return (EINVAL); /* * align file position and save offset. adjust size. */ pageoff = (pos & PAGE_MASK); pos -= pageoff; size += pageoff; /* add offset */ size = (vsize_t)round_page(size); /* round up */ /* * now check (MAP_FIXED) or get (!MAP_FIXED) the "addr" */ if (flags & MAP_FIXED) { /* ensure address and file offset are aligned properly */ addr -= pageoff; if (addr & PAGE_MASK) return (EINVAL); error = range_test(addr, size, true); if (error) return error; } else if (addr == 0 || !(flags & MAP_TRYFIXED)) { /* * not fixed: make sure we skip over the largest * possible heap for non-topdown mapping arrangements. * we will refine our guess later (e.g. to account for * VAC, etc) */ defaddr = p->p_emul->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr, size); if (addr == 0 || !(p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN)) addr = MAX(addr, defaddr); else addr = MIN(addr, defaddr); } /* * check for file mappings (i.e. not anonymous) and verify file. */ if ((flags & MAP_ANON) == 0) { if ((fp = fd_getfile(fd)) == NULL) return (EBADF); if (fp->f_type != DTYPE_VNODE) { fd_putfile(fd); return (ENODEV); /* only mmap vnodes! */ } vp = fp->f_data; /* convert to vnode */ if (vp->v_type != VREG && vp->v_type != VCHR && vp->v_type != VBLK) { fd_putfile(fd); return (ENODEV); /* only REG/CHR/BLK support mmap */ } if (vp->v_type != VCHR && pos < 0) { fd_putfile(fd); return (EINVAL); } if (vp->v_type != VCHR && (pos + size) < pos) { fd_putfile(fd); return (EOVERFLOW); /* no offset wrapping */ } /* special case: catch SunOS style /dev/zero */ if (vp->v_type == VCHR && (vp->v_rdev == zerodev || COMPAT_ZERODEV(vp->v_rdev))) { flags |= MAP_ANON; fd_putfile(fd); fp = NULL; goto is_anon; } /* * Old programs may not select a specific sharing type, so * default to an appropriate one. * * XXX: how does MAP_ANON fit in the picture? */ if ((flags & (MAP_SHARED|MAP_PRIVATE)) == 0) { #if defined(DEBUG) printf("WARNING: defaulted mmap() share type to " "%s (pid %d command %s)\n", vp->v_type == VCHR ? "MAP_SHARED" : "MAP_PRIVATE", p->p_pid, p->p_comm); #endif if (vp->v_type == VCHR) flags |= MAP_SHARED; /* for a device */ else flags |= MAP_PRIVATE; /* for a file */ } /* * MAP_PRIVATE device mappings don't make sense (and aren't * supported anyway). However, some programs rely on this, * so just change it to MAP_SHARED. */ if (vp->v_type == VCHR && (flags & MAP_PRIVATE) != 0) { flags = (flags & ~MAP_PRIVATE) | MAP_SHARED; } /* * now check protection */ maxprot = VM_PROT_EXECUTE; /* check read access */ if (fp->f_flag & FREAD) maxprot |= VM_PROT_READ; else if (prot & PROT_READ) { fd_putfile(fd); return (EACCES); } /* check write access, shared case first */ if (flags & MAP_SHARED) { /* * if the file is writable, only add PROT_WRITE to * maxprot if the file is not immutable, append-only. * otherwise, if we have asked for PROT_WRITE, return * EPERM. */ if (fp->f_flag & FWRITE) { if ((error = VOP_GETATTR(vp, &va, l->l_cred))) { fd_putfile(fd); return (error); } if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) == 0) maxprot |= VM_PROT_WRITE; else if (prot & PROT_WRITE) { fd_putfile(fd); return (EPERM); } } else if (prot & PROT_WRITE) { fd_putfile(fd); return (EACCES); } } else { /* MAP_PRIVATE mappings can always write to */ maxprot |= VM_PROT_WRITE; } handle = vp; } else { /* MAP_ANON case */ /* * XXX What do we do about (MAP_SHARED|MAP_PRIVATE) == 0? */ if (fd != -1) return (EINVAL); is_anon: /* label for SunOS style /dev/zero */ handle = NULL; maxprot = VM_PROT_ALL; pos = 0; } #if NVERIEXEC > 0 if (handle != NULL) { /* * Check if the file can be executed indirectly. * * XXX: This gives false warnings about "Incorrect access type" * XXX: if the mapping is not executable. Harmless, but will be * XXX: fixed as part of other changes. */ if (veriexec_verify(l, handle, "(mmap)", VERIEXEC_INDIRECT, NULL)) { /* * Don't allow executable mappings if we can't * indirectly execute the file. */ if (prot & VM_PROT_EXECUTE) { if (fp != NULL) fd_putfile(fd); return (EPERM); } /* * Strip the executable bit from 'maxprot' to make sure * it can't be made executable later. */ maxprot &= ~VM_PROT_EXECUTE; } } #endif /* NVERIEXEC > 0 */ #ifdef PAX_MPROTECT pax_mprotect(l, &prot, &maxprot); #endif /* PAX_MPROTECT */ #ifdef PAX_ASLR pax_aslr(l, &addr, orig_addr, flags); #endif /* PAX_ASLR */ /* * now let kernel internal function uvm_mmap do the work. */ error = uvm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot, flags, handle, pos, p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur); if (error == 0) /* remember to add offset */ *retval = (register_t)(addr + pageoff); if (fp != NULL) fd_putfile(fd); return (error); }