+#define IPCREG
+#include "param.h"
+#include "user.h"
+#include "proc.h"
+#include "vnode.h"
+#include "text.h"
+#include "seg.h"
+#include "buf.h"
+#include "ptrace.h"
+
+#include "machine/reg.h"
+#include "machine/psl.h"
+#include "machine/pte.h"
+
+/*
+ * Priority for tracing
+ */
+#define IPCPRI PZERO
+
+/*
+ * Tracing variables.
+ * Used to pass trace command from
+ * parent to child being traced.
+ * This data base cannot be
+ * shared and is locked
+ * per user.
+ */
+struct {
+ int ip_lock;
+ int ip_req;
+ int *ip_addr;
+ int ip_data;
+} ipc;
+
+/*
+ * sys-trace system call.
+ */
+ptrace()
+{
+ register struct proc *p;
+ register struct a {
+ int req;
+ int pid;
+ int *addr;
+ int data;
+ } *uap;
+
+ uap = (struct a *)u.u_ap;
+ if (uap->req <= 0) {
+ u.u_procp->p_flag |= STRC;
+ return;
+ }
+ p = pfind(uap->pid);
+ if (p == 0 || p->p_stat != SSTOP || p->p_ppid != u.u_procp->p_pid ||
+ !(p->p_flag & STRC)) {
+ u.u_error = ESRCH;
+ return;
+ }
+ while (ipc.ip_lock)
+ sleep((caddr_t)&ipc, IPCPRI);
+ ipc.ip_lock = p->p_pid;
+ ipc.ip_data = uap->data;
+ ipc.ip_addr = uap->addr;
+ ipc.ip_req = uap->req;
+ p->p_flag &= ~SWTED;
+ while (ipc.ip_req > 0) {
+ if (p->p_stat==SSTOP)
+ setrun(p);
+ sleep((caddr_t)&ipc, IPCPRI);
+ }
+ u.u_r.r_val1 = ipc.ip_data;
+ if (ipc.ip_req < 0)
+ u.u_error = EIO;
+ ipc.ip_lock = 0;
+ wakeup((caddr_t)&ipc);
+}
+
+#define PHYSOFF(p, o) \
+ ((physadr)(p)+((o)/sizeof(((physadr)0)->r[0])))
+
+/*
+ * Code that the child process
+ * executes to implement the command
+ * of the parent process in tracing.
+ */
+procxmt()
+{
+ register int i;
+ register *p;
+ register struct text *xp;
+ struct vattr vattr;
+ struct vnode *vp;
+
+ if (ipc.ip_lock != u.u_procp->p_pid)
+ return (0);
+ u.u_procp->p_slptime = 0;
+ i = ipc.ip_req;
+ ipc.ip_req = 0;
+ switch (i) {
+
+ case PT_READ_I: /* read the child's text space */
+ if (!useracc((caddr_t)ipc.ip_addr, 4, B_READ))
+ goto error;
+ ipc.ip_data = fuiword((caddr_t)ipc.ip_addr);
+ break;
+
+ case PT_READ_D: /* read the child's data space */
+ if (!useracc((caddr_t)ipc.ip_addr, 4, B_READ))
+ goto error;
+ ipc.ip_data = fuword((caddr_t)ipc.ip_addr);
+ break;
+
+ case PT_READ_U: /* read the child's u. */
+ i = (int)ipc.ip_addr;
+ if (i<0 || i >= ctob(UPAGES))
+ goto error;
+ ipc.ip_data = *(int *)PHYSOFF(&u, i);
+ break;
+
+ case PT_WRITE_I: /* write the child's text space */
+ /*
+ * If text, must assure exclusive use
+ */
+ if (xp = u.u_procp->p_textp) {
+ vp = xp->x_vptr;
+ VOP_GETATTR(vp, &vattr, u.u_cred);
+ if (xp->x_count!=1 || (vattr.va_mode & VSVTX))
+ goto error;
+ xp->x_flag |= XTRC;
+ }
+ i = -1;
+ if ((i = suiword((caddr_t)ipc.ip_addr, ipc.ip_data)) < 0) {
+ if (chgprot((caddr_t)ipc.ip_addr, RW) &&
+ chgprot((caddr_t)ipc.ip_addr+(sizeof(int)-1), RW))
+ i = suiword((caddr_t)ipc.ip_addr, ipc.ip_data);
+ (void) chgprot((caddr_t)ipc.ip_addr, RO);
+ (void) chgprot((caddr_t)ipc.ip_addr+(sizeof(int)-1), RO);
+ }
+ if (i < 0)
+ goto error;
+#if defined(tahoe)
+ /* make sure the old value is not in cache */
+ ckeyrelease(u.u_procp->p_ckey);
+ u.u_procp->p_ckey = getcodekey();
+#endif
+ if (xp) {
+ xp->x_flag |= XWRIT;
+#if defined(tahoe)
+ xp->x_ckey = u.u_procp->p_ckey;
+#endif
+ }
+ break;
+
+ case PT_WRITE_D: /* write the child's data space */
+ if (suword((caddr_t)ipc.ip_addr, 0) < 0)
+ goto error;
+ (void) suword((caddr_t)ipc.ip_addr, ipc.ip_data);
+ break;
+
+ case PT_WRITE_U: /* write the child's u. */
+ i = (int)ipc.ip_addr;
+ p = (int *)PHYSOFF(&u, i);
+ for (i=0; i<NIPCREG; i++)
+ if (p == &u.u_ar0[ipcreg[i]])
+ goto ok;
+ if (p == &u.u_ar0[PS]) {
+ ipc.ip_data |= PSL_USERSET;
+ ipc.ip_data &= ~PSL_USERCLR;
+#ifdef PSL_CM_CLR
+ if (ipc.ip_data & PSL_CM)
+ ipc.ip_data &= ~PSL_CM_CLR;
+#endif
+ goto ok;
+ }
+ goto error;
+
+ ok:
+ *p = ipc.ip_data;
+ break;
+
+ case PT_STEP: /* single step the child */
+ case PT_CONTINUE: /* continue the child */
+ if ((int)ipc.ip_addr != 1)
+ u.u_ar0[PC] = (int)ipc.ip_addr;
+ if ((unsigned)ipc.ip_data > NSIG)
+ goto error;
+ u.u_procp->p_cursig = ipc.ip_data; /* see issig */
+ if (i == PT_STEP)
+ u.u_ar0[PS] |= PSL_T;
+ wakeup((caddr_t)&ipc);
+ return (1);
+
+ case PT_KILL: /* kill the child process */
+ wakeup((caddr_t)&ipc);
+ exit(u.u_procp->p_cursig);
+
+ default:
+ error:
+ ipc.ip_req = -1;
+ }
+ wakeup((caddr_t)&ipc);
+ return (0);
+}
projects / unix-history / blobdiff