1 /* sys_process.c 5.9 83/05/18 */ 2 3 #include "../machine/reg.h" 4 #include "../machine/psl.h" 5 #include "../machine/pte.h" 6 7 #include "../h/param.h" 8 #include "../h/systm.h" 9 #include "../h/dir.h" 10 #include "../h/user.h" 11 #include "../h/proc.h" 12 #include "../h/inode.h" 13 #include "../h/text.h" 14 #include "../h/seg.h" 15 #include "../h/vm.h" 16 #include "../h/buf.h" 17 #include "../h/acct.h" 18 19 /* 20 * Priority for tracing 21 */ 22 #define IPCPRI PZERO 23 24 /* 25 * Tracing variables. 26 * Used to pass trace command from 27 * parent to child being traced. 28 * This data base cannot be 29 * shared and is locked 30 * per user. 31 */ 32 struct { 33 int ip_lock; 34 int ip_req; 35 int *ip_addr; 36 int ip_data; 37 } ipc; 38 39 /* 40 * sys-trace system call. 41 */ 42 ptrace() 43 { 44 register struct proc *p; 45 register struct a { 46 int req; 47 int pid; 48 int *addr; 49 int data; 50 } *uap; 51 52 uap = (struct a *)u.u_ap; 53 if (uap->req <= 0) { 54 u.u_procp->p_flag |= STRC; 55 return; 56 } 57 p = pfind(uap->pid); 58 if (p == 0 || p->p_stat != SSTOP || p->p_ppid != u.u_procp->p_pid || 59 !(p->p_flag & STRC)) { 60 u.u_error = ESRCH; 61 return; 62 } 63 while (ipc.ip_lock) 64 sleep((caddr_t)&ipc, IPCPRI); 65 ipc.ip_lock = p->p_pid; 66 ipc.ip_data = uap->data; 67 ipc.ip_addr = uap->addr; 68 ipc.ip_req = uap->req; 69 p->p_flag &= ~SWTED; 70 while (ipc.ip_req > 0) { 71 if (p->p_stat==SSTOP) 72 setrun(p); 73 sleep((caddr_t)&ipc, IPCPRI); 74 } 75 u.u_r.r_val1 = ipc.ip_data; 76 if (ipc.ip_req < 0) 77 u.u_error = EIO; 78 ipc.ip_lock = 0; 79 wakeup((caddr_t)&ipc); 80 } 81 82 #ifdef vax 83 #define NIPCREG 16 84 #endif 85 #ifdef sun 86 #define NIPCREG 17 87 #endif 88 int ipcreg[NIPCREG] = 89 #ifdef vax 90 {R0,R1,R2,R3,R4,R5,R6,R7,R8,R9,R10,R11,AP,FP,SP,PC}; 91 #endif 92 #ifdef sun 93 {R0,R1,R2,R3,R4,R5,R6,R7,AR0,AR1,AR2,AR3,AR4,AR5,AR6,AR7,PC}; 94 #endif 95 96 #define PHYSOFF(p, o) \ 97 ((physadr)(p)+((o)/sizeof(((physadr)0)->r[0]))) 98 99 /* 100 * Code that the child process 101 * executes to implement the command 102 * of the parent process in tracing. 103 */ 104 procxmt() 105 { 106 register int i; 107 register *p; 108 register struct text *xp; 109 110 if (ipc.ip_lock != u.u_procp->p_pid) 111 return (0); 112 u.u_procp->p_slptime = 0; 113 i = ipc.ip_req; 114 ipc.ip_req = 0; 115 switch (i) { 116 117 /* read user I */ 118 case 1: 119 if (!useracc((caddr_t)ipc.ip_addr, 4, B_READ)) 120 goto error; 121 ipc.ip_data = fuiword((caddr_t)ipc.ip_addr); 122 break; 123 124 /* read user D */ 125 case 2: 126 if (!useracc((caddr_t)ipc.ip_addr, 4, B_READ)) 127 goto error; 128 ipc.ip_data = fuword((caddr_t)ipc.ip_addr); 129 break; 130 131 /* read u */ 132 case 3: 133 i = (int)ipc.ip_addr; 134 if (i<0 || i >= ctob(UPAGES)) 135 goto error; 136 ipc.ip_data = *(int *)PHYSOFF(&u, i); 137 break; 138 139 /* write user I */ 140 /* Must set up to allow writing */ 141 case 4: 142 /* 143 * If text, must assure exclusive use 144 */ 145 if (xp = u.u_procp->p_textp) { 146 if (xp->x_count!=1 || xp->x_iptr->i_mode&ISVTX) 147 goto error; 148 xp->x_iptr->i_flag &= ~ITEXT; 149 } 150 i = -1; 151 if ((i = suiword((caddr_t)ipc.ip_addr, ipc.ip_data)) < 0) { 152 if (chgprot((caddr_t)ipc.ip_addr, RW) && 153 chgprot((caddr_t)ipc.ip_addr+(sizeof(int)-1), RW)) 154 i = suiword((caddr_t)ipc.ip_addr, ipc.ip_data); 155 (void) chgprot((caddr_t)ipc.ip_addr, RO); 156 (void) chgprot((caddr_t)ipc.ip_addr+(sizeof(int)-1), RO); 157 } 158 if (i < 0) 159 goto error; 160 if (xp) 161 xp->x_flag |= XWRIT; 162 break; 163 164 /* write user D */ 165 case 5: 166 if (suword((caddr_t)ipc.ip_addr, 0) < 0) 167 goto error; 168 (void) suword((caddr_t)ipc.ip_addr, ipc.ip_data); 169 break; 170 171 /* write u */ 172 case 6: 173 i = (int)ipc.ip_addr; 174 p = (int *)PHYSOFF(&u, i); 175 for (i=0; i<NIPCREG; i++) 176 if (p == &u.u_ar0[ipcreg[i]]) 177 goto ok; 178 if (p == &u.u_ar0[PS]) { 179 ipc.ip_data |= PSL_USERSET; 180 ipc.ip_data &= ~PSL_USERCLR; 181 #ifdef sun 182 if (ipc.ip_data & PSL_T) 183 traceon(); 184 else 185 traceoff(); 186 #endif 187 goto ok; 188 } 189 goto error; 190 191 ok: 192 *p = ipc.ip_data; 193 break; 194 195 /* set signal and continue */ 196 /* one version causes a trace-trap */ 197 case 9: 198 case 7: 199 if ((int)ipc.ip_addr != 1) 200 u.u_ar0[PC] = (int)ipc.ip_addr; 201 if ((unsigned)ipc.ip_data > NSIG) 202 goto error; 203 u.u_procp->p_cursig = ipc.ip_data; /* see issig */ 204 if (i == 9) 205 #ifdef sun 206 traceon(); 207 #else 208 u.u_ar0[PS] |= PSL_T; 209 #endif 210 wakeup((caddr_t)&ipc); 211 return (1); 212 213 /* force exit */ 214 case 8: 215 wakeup((caddr_t)&ipc); 216 exit(u.u_procp->p_cursig); 217 218 default: 219 error: 220 ipc.ip_req = -1; 221 } 222 wakeup((caddr_t)&ipc); 223 return (0); 224 } 225