/* * Copyright (c) 1994, Sean Eric Fagan * All rights reserved. * * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Sean Eric Fagan. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * 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. * * $FreeBSD: src/sys/kern/sys_process.c,v 1.51.2.6 2003/01/08 03:06:45 kan Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* use the equivalent procfs code */ #if 0 static int pread (struct proc *procp, unsigned int addr, unsigned int *retval) { int rv; vm_map_t map, tmap; vm_object_t object; vm_map_backing_t ba; vm_offset_t kva = 0; int page_offset; /* offset into page */ vm_offset_t pageno; /* page number */ vm_map_entry_t out_entry; vm_prot_t out_prot; int wflags; vm_pindex_t pindex; vm_pindex_t pcount; /* Map page into kernel space */ map = &procp->p_vmspace->vm_map; page_offset = addr - trunc_page(addr); pageno = trunc_page(addr); tmap = map; rv = vm_map_lookup(&tmap, pageno, VM_PROT_READ, &out_entry, &ba, &pindex, &pcount, &out_prot, &wflags); if (ba) object = ba->object; else object = NULL; if (rv != KERN_SUCCESS) return EINVAL; vm_map_lookup_done (tmap, out_entry, 0); /* Find space in kernel_map for the page we're interested in */ rv = vm_map_find (kernel_map, object, NULL, IDX_TO_OFF(pindex), &kva, PAGE_SIZE, PAGE_SIZE, FALSE, VM_MAPTYPE_NORMAL, VM_SUBSYS_PROC, VM_PROT_ALL, VM_PROT_ALL, 0); if (!rv) { vm_object_reference XXX (object); /* wire the pages */ rv = vm_map_kernel_wiring(kernel_map, kva, kva + PAGE_SIZE, 0); if (!rv) { *retval = 0; bcopy ((caddr_t)kva + page_offset, retval, sizeof *retval); } vm_map_remove (kernel_map, kva, kva + PAGE_SIZE); } return rv; } static int pwrite (struct proc *procp, unsigned int addr, unsigned int datum) { int rv; vm_map_t map, tmap; vm_object_t object; vm_map_backing_t ba; vm_offset_t kva = 0; int page_offset; /* offset into page */ vm_offset_t pageno; /* page number */ vm_map_entry_t out_entry; vm_prot_t out_prot; int wflags; vm_pindex_t pindex; vm_pindex_t pcount; boolean_t fix_prot = 0; /* Map page into kernel space */ map = &procp->p_vmspace->vm_map; page_offset = addr - trunc_page(addr); pageno = trunc_page(addr); /* * Check the permissions for the area we're interested in. */ if (vm_map_check_protection (map, pageno, pageno + PAGE_SIZE, VM_PROT_WRITE, FALSE) == FALSE) { /* * If the page was not writable, we make it so. * XXX It is possible a page may *not* be read/executable, * if a process changes that! */ fix_prot = 1; /* The page isn't writable, so let's try making it so... */ if ((rv = vm_map_protect (map, pageno, pageno + PAGE_SIZE, VM_PROT_ALL, 0)) != KERN_SUCCESS) return EFAULT; /* I guess... */ } /* * Now we need to get the page. out_entry, out_prot, wflags, and * single_use aren't used. One would think the vm code would be * a *bit* nicer... We use tmap because vm_map_lookup() can * change the map argument. */ tmap = map; rv = vm_map_lookup(&tmap, pageno, VM_PROT_WRITE, &out_entry, &ba, &pindex, &pcount, &out_prot, &wflags); if (ba) object = ba->object; else object = NULL; if (rv != KERN_SUCCESS) return EINVAL; /* * Okay, we've got the page. Let's release tmap. */ vm_map_lookup_done (tmap, out_entry, 0); /* * Fault the page in... */ rv = vm_fault(map, pageno, VM_PROT_WRITE|VM_PROT_READ, FALSE); if (rv != KERN_SUCCESS) return EFAULT; /* Find space in kernel_map for the page we're interested in */ rv = vm_map_find (kernel_map, object, NULL, IDX_TO_OFF(pindex), &kva, PAGE_SIZE, PAGE_SIZE, FALSE, VM_MAPTYPE_NORMAL, VM_SUBSYS_PROC, VM_PROT_ALL, VM_PROT_ALL, 0); if (!rv) { vm_object_reference XXX (object); /* wire the pages */ rv = vm_map_kernel_wiring(kernel_map, kva, kva + PAGE_SIZE, 0); if (!rv) { bcopy (&datum, (caddr_t)kva + page_offset, sizeof datum); } vm_map_remove (kernel_map, kva, kva + PAGE_SIZE); } if (fix_prot) vm_map_protect (map, pageno, pageno + PAGE_SIZE, VM_PROT_READ|VM_PROT_EXECUTE, 0); return rv; } #endif /* * Process debugging system call. * * MPALMOSTSAFE */ int sys_ptrace(struct sysmsg *sysmsg, const struct ptrace_args *uap) { struct proc *p = curproc; /* * XXX this obfuscation is to reduce stack usage, but the register * structs may be too large to put on the stack anyway. */ union { struct ptrace_io_desc piod; struct dbreg dbreg; struct fpreg fpreg; struct reg reg; } r; void *addr; int error = 0; addr = &r; switch (uap->req) { case PT_GETREGS: case PT_GETFPREGS: #ifdef PT_GETDBREGS case PT_GETDBREGS: #endif break; case PT_SETREGS: error = copyin(uap->addr, &r.reg, sizeof r.reg); break; case PT_SETFPREGS: error = copyin(uap->addr, &r.fpreg, sizeof r.fpreg); break; #ifdef PT_SETDBREGS case PT_SETDBREGS: error = copyin(uap->addr, &r.dbreg, sizeof r.dbreg); break; #endif case PT_IO: error = copyin(uap->addr, &r.piod, sizeof r.piod); break; default: addr = uap->addr; } if (error) return (error); error = kern_ptrace(p, uap->req, uap->pid, addr, uap->data, &sysmsg->sysmsg_result); if (error) return (error); switch (uap->req) { case PT_IO: (void)copyout(&r.piod, uap->addr, sizeof r.piod); break; case PT_GETREGS: error = copyout(&r.reg, uap->addr, sizeof r.reg); break; case PT_GETFPREGS: error = copyout(&r.fpreg, uap->addr, sizeof r.fpreg); break; #ifdef PT_GETDBREGS case PT_GETDBREGS: error = copyout(&r.dbreg, uap->addr, sizeof r.dbreg); break; #endif } return (error); } int kern_ptrace(struct proc *curp, int req, pid_t pid, void *addr, int data, int *res) { struct proc *p, *pp; struct lwp *lp; struct iovec iov; struct uio uio; struct ptrace_io_desc *piod; int error = 0; int write, tmp; int t; write = 0; if (req == PT_TRACE_ME) { p = curp; PHOLD(p); } else { if ((p = pfind(pid)) == NULL) return ESRCH; } if (!PRISON_CHECK(curp->p_ucred, p->p_ucred)) { PRELE(p); return (ESRCH); } if (p->p_flags & P_SYSTEM) { PRELE(p); return EINVAL; } lwkt_gettoken(&p->p_token); /* Can't trace a process that's currently exec'ing. */ if ((p->p_flags & P_INEXEC) != 0) { lwkt_reltoken(&p->p_token); PRELE(p); return EAGAIN; } /* * Permissions check */ switch (req) { case PT_TRACE_ME: /* Always legal. */ break; case PT_ATTACH: /* Self */ if (p->p_pid == curp->p_pid) { lwkt_reltoken(&p->p_token); PRELE(p); return EINVAL; } /* Already traced */ if (p->p_flags & P_TRACED) { lwkt_reltoken(&p->p_token); PRELE(p); return EBUSY; } if (curp->p_flags & P_TRACED) for (pp = curp->p_pptr; pp != NULL; pp = pp->p_pptr) if (pp == p) { lwkt_reltoken(&p->p_token); PRELE(p); return (EINVAL); } /* not owned by you, has done setuid (unless you're root) */ if ((p->p_ucred->cr_ruid != curp->p_ucred->cr_ruid) || (p->p_flags & P_SUGID)) { error = caps_priv_check(curp->p_ucred, SYSCAP_RESTRICTEDROOT); if (error) { lwkt_reltoken(&p->p_token); PRELE(p); return error; } } /* can't trace init when securelevel > 0 */ if (securelevel > 0 && p->p_pid == 1) { lwkt_reltoken(&p->p_token); PRELE(p); return EPERM; } /* OK */ break; case PT_READ_I: case PT_READ_D: case PT_WRITE_I: case PT_WRITE_D: case PT_IO: case PT_CONTINUE: case PT_KILL: case PT_STEP: case PT_DETACH: #ifdef PT_GETREGS case PT_GETREGS: #endif #ifdef PT_SETREGS case PT_SETREGS: #endif #ifdef PT_GETFPREGS case PT_GETFPREGS: #endif #ifdef PT_SETFPREGS case PT_SETFPREGS: #endif #ifdef PT_GETDBREGS case PT_GETDBREGS: #endif #ifdef PT_SETDBREGS case PT_SETDBREGS: #endif /* not being traced... */ if ((p->p_flags & P_TRACED) == 0) { lwkt_reltoken(&p->p_token); PRELE(p); return EPERM; } /* not being traced by YOU */ if (p->p_pptr != curp) { lwkt_reltoken(&p->p_token); PRELE(p); return EBUSY; } /* not currently stopped */ if (p->p_stat != SSTOP || (p->p_flags & P_WAITED) == 0) { lwkt_reltoken(&p->p_token); PRELE(p); return EBUSY; } /* OK */ break; default: lwkt_reltoken(&p->p_token); PRELE(p); return EINVAL; } /* XXX lwp */ lp = FIRST_LWP_IN_PROC(p); if (lp == NULL) { lwkt_reltoken(&p->p_token); PRELE(p); return EINVAL; } #ifdef FIX_SSTEP /* * Single step fixup ala procfs */ FIX_SSTEP(lp); #endif /* * Actually do the requests */ *res = 0; switch (req) { case PT_TRACE_ME: /* set my trace flag and "owner" so it can read/write me */ p->p_flags |= P_TRACED; p->p_oppid = p->p_pptr->p_pid; lwkt_reltoken(&p->p_token); PRELE(p); return 0; case PT_ATTACH: /* security check done above */ p->p_flags |= P_TRACED; p->p_oppid = p->p_pptr->p_pid; proc_reparent(p, curp); data = SIGSTOP; goto sendsig; /* in PT_CONTINUE below */ case PT_STEP: case PT_CONTINUE: case PT_DETACH: /* Zero means do not send any signal */ if (data < 0 || data >= _SIG_MAXSIG) { lwkt_reltoken(&p->p_token); PRELE(p); return EINVAL; } LWPHOLD(lp); if (req == PT_STEP) { if ((error = ptrace_single_step (lp))) { LWPRELE(lp); lwkt_reltoken(&p->p_token); PRELE(p); return error; } } if (addr != (void *)1) { if ((error = ptrace_set_pc (lp, (u_long)addr))) { LWPRELE(lp); lwkt_reltoken(&p->p_token); PRELE(p); return error; } } LWPRELE(lp); if (req == PT_DETACH) { /* reset process parent */ if (p->p_oppid != p->p_pptr->p_pid) { struct proc *pp; pp = pfind(p->p_oppid); if (pp) { proc_reparent(p, pp); PRELE(pp); } } p->p_flags &= ~(P_TRACED | P_WAITED); p->p_oppid = 0; /* should we send SIGCHLD? */ } sendsig: /* * Deliver or queue signal. If the process is stopped * force it to be SACTIVE again. */ crit_enter(); if (p->p_stat == SSTOP) { p->p_xstat = data; proc_unstop(p, SSTOP); } else if (data) { ksignal(p, data); } crit_exit(); lwkt_reltoken(&p->p_token); PRELE(p); return 0; case PT_WRITE_I: case PT_WRITE_D: write = 1; /* fallthrough */ case PT_READ_I: case PT_READ_D: /* * NOTE! uio_offset represents the offset in the target * process. The iov is in the current process (the guy * making the ptrace call) so uio_td must be the current * process (though for a SYSSPACE transfer it doesn't * really matter). */ tmp = 0; /* write = 0 set above */ iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp; iov.iov_len = sizeof(int); uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = (off_t)(uintptr_t)addr; uio.uio_resid = sizeof(int); uio.uio_segflg = UIO_SYSSPACE; uio.uio_rw = write ? UIO_WRITE : UIO_READ; uio.uio_td = curthread; error = procfs_domem(curp, lp, NULL, &uio); if (uio.uio_resid != 0) { /* * XXX procfs_domem() doesn't currently return ENOSPC, * so I think write() can bogusly return 0. * XXX what happens for short writes? We don't want * to write partial data. * XXX procfs_domem() returns EPERM for other invalid * addresses. Convert this to EINVAL. Does this * clobber returns of EPERM for other reasons? */ if (error == 0 || error == ENOSPC || error == EPERM) error = EINVAL; /* EOF */ } if (!write) *res = tmp; lwkt_reltoken(&p->p_token); PRELE(p); return (error); case PT_IO: /* * NOTE! uio_offset represents the offset in the target * process. The iov is in the current process (the guy * making the ptrace call) so uio_td must be the current * process. */ piod = addr; iov.iov_base = piod->piod_addr; iov.iov_len = piod->piod_len; uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = (off_t)(uintptr_t)piod->piod_offs; uio.uio_resid = piod->piod_len; uio.uio_segflg = UIO_USERSPACE; uio.uio_td = curthread; switch (piod->piod_op) { case PIOD_READ_D: case PIOD_READ_I: uio.uio_rw = UIO_READ; break; case PIOD_WRITE_D: case PIOD_WRITE_I: uio.uio_rw = UIO_WRITE; break; default: lwkt_reltoken(&p->p_token); PRELE(p); return (EINVAL); } error = procfs_domem(curp, lp, NULL, &uio); piod->piod_len -= uio.uio_resid; lwkt_reltoken(&p->p_token); PRELE(p); return (error); case PT_KILL: data = SIGKILL; goto sendsig; /* in PT_CONTINUE above */ #ifdef PT_SETREGS case PT_SETREGS: write = 1; /* fallthrough */ #endif /* PT_SETREGS */ #ifdef PT_GETREGS case PT_GETREGS: /* write = 0 above */ #endif /* PT_SETREGS */ #if defined(PT_SETREGS) || defined(PT_GETREGS) if (!procfs_validregs(lp)) { lwkt_reltoken(&p->p_token); PRELE(p); return EINVAL; } else { iov.iov_base = addr; iov.iov_len = sizeof(struct reg); uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = 0; uio.uio_resid = sizeof(struct reg); uio.uio_segflg = UIO_SYSSPACE; uio.uio_rw = write ? UIO_WRITE : UIO_READ; uio.uio_td = curthread; t = procfs_doregs(curp, lp, NULL, &uio); lwkt_reltoken(&p->p_token); PRELE(p); return t; } #endif /* defined(PT_SETREGS) || defined(PT_GETREGS) */ #ifdef PT_SETFPREGS case PT_SETFPREGS: write = 1; /* fallthrough */ #endif /* PT_SETFPREGS */ #ifdef PT_GETFPREGS case PT_GETFPREGS: /* write = 0 above */ #endif /* PT_SETFPREGS */ #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS) if (!procfs_validfpregs(lp)) { lwkt_reltoken(&p->p_token); PRELE(p); return EINVAL; } else { iov.iov_base = addr; iov.iov_len = sizeof(struct fpreg); uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = 0; uio.uio_resid = sizeof(struct fpreg); uio.uio_segflg = UIO_SYSSPACE; uio.uio_rw = write ? UIO_WRITE : UIO_READ; uio.uio_td = curthread; t = procfs_dofpregs(curp, lp, NULL, &uio); lwkt_reltoken(&p->p_token); PRELE(p); return t; } #endif /* defined(PT_SETFPREGS) || defined(PT_GETFPREGS) */ #ifdef PT_SETDBREGS case PT_SETDBREGS: write = 1; /* fallthrough */ #endif /* PT_SETDBREGS */ #ifdef PT_GETDBREGS case PT_GETDBREGS: /* write = 0 above */ #endif /* PT_SETDBREGS */ #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS) if (!procfs_validdbregs(lp)) { lwkt_reltoken(&p->p_token); PRELE(p); return EINVAL; } else { iov.iov_base = addr; iov.iov_len = sizeof(struct dbreg); uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = 0; uio.uio_resid = sizeof(struct dbreg); uio.uio_segflg = UIO_SYSSPACE; uio.uio_rw = write ? UIO_WRITE : UIO_READ; uio.uio_td = curthread; t = procfs_dodbregs(curp, lp, NULL, &uio); lwkt_reltoken(&p->p_token); PRELE(p); return t; } #endif /* defined(PT_SETDBREGS) || defined(PT_GETDBREGS) */ default: break; } lwkt_reltoken(&p->p_token); PRELE(p); return 0; } int trace_req(struct proc *p) { return 1; } /* * stopevent() * * Stop a process because of a procfs event. Stay stopped until p->p_step * is cleared (cleared by PIOCCONT in procfs). * * MPSAFE */ void stopevent(struct proc *p, unsigned int event, unsigned int val) { /* * Set event info. Recheck p_stops in case we are * racing a close() on procfs. */ spin_lock(&p->p_spin); if ((p->p_stops & event) == 0) { spin_unlock(&p->p_spin); return; } p->p_xstat = val; p->p_stype = event; p->p_step = 1; tsleep_interlock(&p->p_step, 0); spin_unlock(&p->p_spin); /* * Wakeup any PIOCWAITing procs and wait for p_step to * be cleared. */ for (;;) { wakeup(&p->p_stype); tsleep(&p->p_step, PINTERLOCKED, "stopevent", 0); spin_lock(&p->p_spin); if (p->p_step == 0) { spin_unlock(&p->p_spin); break; } tsleep_interlock(&p->p_step, 0); spin_unlock(&p->p_spin); } }