replace with a completely rewritten version, based around the 4.4BSD
procfs. Now the author of the old version will stop complaining that we're using his code.
This commit is contained in:
cgd
parent
b48d84b629
commit
97bdeab31e
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@ -1,4 +1,7 @@
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/* $NetBSD: sys_process.c,v 1.36 1994/08/15 16:32:41 cgd Exp $ */
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/*-
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* Copyright (c) 1994 Christopher G. Demetriou. All rights reserved.
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* Copyright (c) 1982, 1986, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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@ -38,9 +41,30 @@
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* from: @(#)sys_process.c 8.1 (Berkeley) 6/10/93
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*/
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/*
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* References:
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* (1) Bach's "The Design of the UNIX Operating System",
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* (2) sys/miscfs/procfs from UCB's 4.4BSD-Lite distribution,
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* (3) the "4.4BSD Programmer's Reference Manual" published
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* by USENIX and O'Reilly & Associates.
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* The 4.4BSD PRM does a reasonably good job of documenting what the various
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* ptrace() requests should actually do, and its text is quoted several times
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* in this file.
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*/
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#include <sys/param.h>
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#include <sys/proc.h>
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#include <sys/errno.h>
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#include <sys/ptrace.h>
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#include <sys/uio.h>
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#include <sys/user.h>
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#include <machine/reg.h>
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/* Macros to clear/set/test flags. */
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#define SET(t, f) (t) |= (f)
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#define CLR(t, f) (t) &= ~(f)
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#define ISSET(t, f) ((t) & (f))
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/*
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* Process debugging system call.
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@ -51,24 +75,335 @@ struct ptrace_args {
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caddr_t addr;
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int data;
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};
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ptrace(a1, a2, a3)
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struct proc *a1;
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struct ptrace_args *a2;
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int *a3;
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ptrace(p, uap, retval)
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struct proc *p;
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struct ptrace_args *uap;
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int *retval;
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{
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struct proc *t; /* target process */
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struct uio uio;
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struct iovec iov;
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int error, step, write;
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/*
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* Body deleted.
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*/
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return (ENOSYS);
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/* "A foolish consistency..." XXX */
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if (uap->req == PT_TRACE_ME)
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t = p;
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else {
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/* Find the process we're supposed to be operating on. */
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if ((t = pfind(uap->pid)) == NULL)
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return (ESRCH);
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}
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/* Make sure we can operate on it. */
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switch (uap->req) {
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case PT_TRACE_ME:
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/* Saying that you're being traced is always legal. */
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break;
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case PT_ATTACH:
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/*
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* You can't attach to a process if:
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* (1) it's the process that's doing the attaching,
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*/
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if (t->p_pid == p->p_pid)
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return (EINVAL);
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/*
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* (2) it's already being traced, or
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*/
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if (!ISSET(t->p_flag, P_TRACED))
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return (EBUSY);
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/*
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* (3) it's not owned by you, or is set-id on exec
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* (unless you're root).
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*/
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if ((t->p_cred->p_ruid != p->p_cred->p_ruid ||
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ISSET(t->p_flag, P_SUGID)) &&
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(error = suser(p->p_ucred, &p->p_acflag)) != 0)
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return (error);
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break;
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case PT_READ_I:
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case PT_READ_D:
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case PT_READ_U:
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case PT_WRITE_I:
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case PT_WRITE_D:
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case PT_WRITE_U:
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case PT_CONTINUE:
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case PT_KILL:
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case PT_DETACH:
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#ifdef PT_STEP
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case PT_STEP:
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#endif
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#ifdef PT_GETREGS
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case PT_GETREGS:
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#endif
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#ifdef PT_SETREGS
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case PT_SETREGS:
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#endif
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#ifdef PT_GETFPREGS
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case PT_GETFPREGS:
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#endif
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#ifdef PT_SETFPREGS
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case PT_SETFPREGS:
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#endif
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/*
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* You can't do what you want to the process if:
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* (1) It's not being traced at all,
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*/
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if (!ISSET(t->p_flag, P_TRACED))
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return (EPERM);
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/*
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* (2) it's not being traced by _you_, or
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*/
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if (t->p_pptr != p)
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return (EBUSY);
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/*
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* (3) it's not currently stopped.
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*/
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if (t->p_stat != SSTOP || !ISSET(t->p_flag, P_WAITED))
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return (EBUSY);
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break;
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default: /* It was not a legal request. */
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return (EINVAL);
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}
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/* Do single-step fixup if needed. */
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FIX_SSTEP(t);
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/* Now do the operation. */
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step = write = 0;
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*retval = 0;
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switch (uap->req) {
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case PT_TRACE_ME:
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/* Just set the trace flag. */
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SET(t->p_flag, P_TRACED);
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return (0);
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case PT_WRITE_I: /* XXX no seperate I and D spaces */
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case PT_WRITE_D:
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write = 1;
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case PT_READ_I: /* XXX no seperate I and D spaces */
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case PT_READ_D:
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/* write = 0 done above. */
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iov.iov_base = write ? (caddr_t)&uap->data : (caddr_t)retval;
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iov.iov_len = sizeof(int);
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uio.uio_iov = &iov;
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uio.uio_iovcnt = 1;
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uio.uio_offset = (off_t)uap->addr;
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uio.uio_resid = sizeof(int);
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uio.uio_segflg = UIO_SYSSPACE;
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uio.uio_rw = write ? UIO_WRITE : UIO_READ;
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uio.uio_procp = p;
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return (procfs_domem(p, t, NULL, &uio));
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case PT_READ_U:
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/*
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* The 4.4BSD PRM says that only the first 512 bytes
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* of the user area are accessible for reading. This
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* disagrees with common practice, and would render PT_READ_U
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* almost worthless. Additionally, we _always_ require
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* that the address be int-aligned.
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*/
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if ((u_long)uap->addr > (ctob(UPAGES) - sizeof(int)) ||
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((u_long)uap->addr & (sizeof(int) - 1)) != 0)
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return (EINVAL);
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/*
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* Fill in eproc in user area, because user.h says that
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* it's valid for ptrace(). Do it the same way as coredump().
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*/
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bcopy(t, &t->p_addr->u_kproc.kp_proc, sizeof(struct proc));
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fill_eproc(t, &t->p_addr->u_kproc.kp_eproc);
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/* Finally, pull the appropriate int out of the user area. */
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*retval = *(int *)((caddr_t)t->p_addr + (u_long)uap->addr);
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return (0);
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case PT_WRITE_U:
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/*
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* Mostly the same as PT_READ_U, but write data instead of
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* reading it. Don't bother filling in the eproc, because
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* it won't be used for anything anyway.
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* XXX THERE IS A SERIOUS SECURITY HOLE HERE.
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*/
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/* Check that the address is legal (XXX) */
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if ((u_long)uap->addr > (ctob(UPAGES) - sizeof(int)) ||
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((u_long)uap->addr & (sizeof(int) - 1)) != 0)
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return (EINVAL);
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/* And write the data. */
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*(int *)((caddr_t)t->p_addr + (u_long)uap->addr) = uap->data;
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return (0);
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#ifdef PT_STEP
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case PT_STEP:
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/*
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* From the 4.4BSD PRM:
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* "Execution continues as in request PT_CONTINUE; however
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* as soon as possible after execution of at least one
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* instruction, execution stops again. [ ... ]"
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*/
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step = 1;
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#endif
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case PT_CONTINUE:
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/*
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* From the 4.4BSD PRM:
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* "The data argument is taken as a signal number and the
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* child's execution continues at location addr as if it
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* incurred that signal. Nromally the signal number will
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* be either 0 to indicate that the signal that caused the
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* stop should be ignored, or that value fetched out of
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* the process's image indicating which signal caused
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* the stop. If addr is (int *)1 then execution continues
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* from where it stopped."
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*/
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/* step = 0 done above. */
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/* Check that uap->data is a valid signal number or zero. */
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if (uap->data < 0 || uap->data >= NSIG)
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return (EINVAL);
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/*
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* Arrange for a single-step, if that's requested and possible.
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*/
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if (error = process_sstep(t, step))
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return (error);
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/* If the address paramter is not (int *)1, set the pc. */
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if ((int *)uap->addr != (int *)1)
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if (error = process_set_pc(t, uap->addr))
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return (error);
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/* Finally, deliver the requested signal (or none). */
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sendsig:
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t->p_xstat = uap->data;
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setrunnable(t);
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return (0);
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case PT_KILL:
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/* just send the process a KILL signal. */
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uap->data = SIGKILL;
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goto sendsig; /* in PT_CONTINUE, above. */
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case PT_ATTACH:
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/*
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* As done in procfs:
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* Go ahead and set the trace flag.
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* Save the old parent (it's reset in
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* _DETACH, and also in kern_exit.c:wait4()
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* Reparent the process so that the tracing
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* proc gets to see all the action.
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* Stop the target.
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*/
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SET(t->p_flag, P_TRACED);
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t->p_xstat = 0; /* XXX ? */
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if (t->p_pptr != p) {
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t->p_oppid = t->p_pptr->p_pid;
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proc_reparent(t, p);
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}
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psignal(t, SIGSTOP);
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return (0);
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case PT_DETACH:
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/* Again, as done in procfs: */
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#ifdef notdef /* not allowed, by checks above. */
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/* if not being traced, then this is a painless no-op */
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if (!ISSET(t->p_flag, P_TRACED))
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return (0);
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#endif
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/* not being traced any more */
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CLR(t->p_flag, P_TRACED);
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/* give process back to original parent */
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if (t->p_oppid != t->p_pptr->p_pid) {
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struct proc *pp;
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pp = pfind(t->p_oppid);
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if (pp)
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proc_reparent(t, pp);
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}
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t->p_oppid = 0;
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CLR(t->p_flag, P_WAITED); /* XXX? */
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/* and deliver any signal requested by tracer. */
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if (t->p_stat == SSTOP) {
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t->p_xstat = uap->data;
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setrunnable(t);
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} else if (uap->data)
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psignal(t, uap->data);
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return (0);
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#ifdef PT_SETREGS
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case PT_SETREGS:
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write = 1;
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#endif
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#ifdef PT_GETREGS
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case PT_GETREGS:
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/* write = 0 done above. */
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#endif
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#if defined(PT_SETREGS) || defined(PT_GETREGS)
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if (!procfs_validregs(t))
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return (EINVAL);
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else {
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iov.iov_base = uap->addr;
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iov.iov_len = sizeof(struct reg);
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uio.uio_iov = &iov;
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uio.uio_iovcnt = 1;
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uio.uio_offset = 0;
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uio.uio_resid = sizeof(struct reg);
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uio.uio_segflg = UIO_USERSPACE;
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uio.uio_rw = write ? UIO_WRITE : UIO_READ;
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uio.uio_procp = p;
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return (procfs_doregs(p, t, NULL, &uio));
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}
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#endif
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#ifdef PT_SETFPREGS
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case PT_SETFPREGS:
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write = 1;
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#endif
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#ifdef PT_GETFPREGS
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case PT_GETFPREGS:
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/* write = 0 done above. */
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#endif
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#if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
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if (!procfs_validfpregs(t))
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return (EINVAL);
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else {
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iov.iov_base = uap->addr;
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iov.iov_len = sizeof(struct fpreg);
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uio.uio_iov = &iov;
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uio.uio_iovcnt = 1;
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uio.uio_offset = 0;
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uio.uio_resid = sizeof(struct fpreg);
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uio.uio_segflg = UIO_USERSPACE;
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uio.uio_rw = write ? UIO_WRITE : UIO_READ;
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uio.uio_procp = p;
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return (procfs_dofpregs(p, t, NULL, &uio));
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}
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#endif
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}
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#ifdef DIAGNOSTIC
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panic("ptrace: impossible");
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#endif
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}
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trace_req(a1)
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struct proc *a1;
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{
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/*
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* Body deleted.
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*/
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return (0);
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/* just return 1 to keep other parts of the system happy */
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return (1);
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}
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Reference in New Issue