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1.1 root 1: #ifndef lint
2: static char sccsid[] = "@(#)access.c 4.7 8/11/83";
3: #endif
4: /*
5: * Adb: access data in file/process address space.
6: *
7: * The routines in this file access referenced data using
8: * the maps to access files, ptrace to access subprocesses,
9: * or the system page tables when debugging the kernel,
10: * to translate virtual to physical addresses.
11: */
12:
13: #include "defs.h"
14:
15:
16: MAP txtmap;
17: MAP datmap;
18: INT wtflag;
19: STRING errflg;
20: INT errno;
21:
22: INT pid;
23:
24: /*
25: * Primitives: put a value in a space, get a value from a space
26: * and get a word or byte not returning if an error occurred.
27: */
28: put(addr, space, value)
29: off_t addr; { (void) access(WT, addr, space, value); }
30:
31: u_int
32: get(addr, space)
33: off_t addr; { return (access(RD, addr, space, 0)); };
34:
35: u_int
36: chkget(addr, space)
37: off_t addr; { u_int w = get(addr, space); chkerr(); return(w); }
38:
39: u_int
40: bchkget(addr, space)
41: off_t addr; { return(chkget(addr, space) & LOBYTE); }
42:
43: /*
44: * Read/write according to mode at address addr in i/d space.
45: * Value is quantity to be written, if write.
46: *
47: * This routine decides whether to get the data from the subprocess
48: * address space with ptrace, or to get it from the files being
49: * debugged.
50: *
51: * When the kernel is being debugged with the -k flag we interpret
52: * the system page tables for data space, mapping p0 and p1 addresses
53: * relative to the ``current'' process (as specified by its p_addr in
54: * <p) and mapping system space addresses through the system page tables.
55: */
56: access(mode, addr, space, value)
57: int mode, space, value;
58: off_t addr;
59: {
60: int rd = mode == RD;
61: int file, w;
62:
63: if (space == NSP)
64: return(0);
65: if (pid) {
66: int pmode = (space&DSP?(rd?RDUSER:WDUSER):(rd?RIUSER:WIUSER));
67:
68: w = ptrace(pmode, pid, addr, value);
69: if (errno)
70: rwerr(space);
71: return (w);
72: }
73: w = 0;
74: if (mode==WT && wtflag==0)
75: error("not in write mode");
76: if (!chkmap(&addr, space))
77: return (0);
78: file = (space&DSP) ? datmap.ufd : txtmap.ufd;
79: if (kernel && space == DSP) {
80: addr = vtophys(addr);
81: if (addr < 0)
82: return (0);
83: }
84: if (physrw(file, addr, rd ? &w : &value, rd) < 0)
85: rwerr(space);
86: return (w);
87: }
88:
89: /*
90: * When looking at kernel data space through /dev/mem or
91: * with a core file, do virtual memory mapping.
92: */
93: vtophys(addr)
94: off_t addr;
95: {
96: int oldaddr = addr;
97: int v;
98: struct pte pte;
99:
100: addr &= ~0xc0000000;
101: v = btop(addr);
102: switch (oldaddr&0xc0000000) {
103:
104: case 0xc0000000:
105: case 0x80000000:
106: /*
107: * In system space get system pte. If
108: * valid or reclaimable then physical address
109: * is combination of its page number and the page
110: * offset of the original address.
111: */
112: if (v >= slr)
113: goto oor;
114: addr = ((long)(sbr+v)) &~ 0x80000000;
115: goto simple;
116:
117: case 0x40000000:
118: /*
119: * In p1 space must not be in shadow region.
120: */
121: if (v < pcb.pcb_p1lr)
122: goto oor;
123: addr = pcb.pcb_p1br+v;
124: break;
125:
126: case 0x00000000:
127: /*
128: * In p0 space must not be off end of region.
129: */
130: if (v >= pcb.pcb_p0lr)
131: goto oor;
132: addr = pcb.pcb_p0br+v;
133: break;
134: oor:
135: errflg = "address out of segment";
136: return (-1);
137: }
138: /*
139: * For p0/p1 address, user-level page table should
140: * be in kernel vm. Do second-level indirect by recursing.
141: */
142: if ((addr & 0x80000000) == 0) {
143: errflg = "bad p0br or p1br in pcb";
144: return (-1);
145: }
146: addr = vtophys(addr);
147: simple:
148: /*
149: * Addr is now address of the pte of the page we
150: * are interested in; get the pte and paste up the
151: * physical address.
152: */
153: if (physrw(fcor, addr, (int *)&pte, 1) < 0) {
154: errflg = "page table botch";
155: return (-1);
156: }
157: /* SHOULD CHECK NOT I/O ADDRESS; NEED CPU TYPE! */
158: if (pte.pg_v == 0 && (pte.pg_fod || pte.pg_pfnum == 0)) {
159: errflg = "page not valid/reclaimable";
160: return (-1);
161: }
162: return (ptob(pte.pg_pfnum) + (oldaddr & PGOFSET));
163: }
164:
165: rwerr(space)
166: int space;
167: {
168:
169: if (space & DSP)
170: errflg = "data address not found";
171: else
172: errflg = "text address not found";
173: }
174:
175: physrw(file, addr, aw, rd)
176: off_t addr;
177: int *aw, rd;
178: {
179:
180: if (longseek(file,addr)==0 ||
181: (rd ? read(file,aw,sizeof(int)) : write(file,aw,sizeof(int))) < 1)
182: return (-1);
183: return (0);
184: }
185:
186: chkmap(addr,space)
187: REG L_INT *addr;
188: REG INT space;
189: {
190: REG MAPPTR amap;
191: amap=((space&DSP?&datmap:&txtmap));
192: IF space&STAR ORF !within(*addr,amap->b1,amap->e1)
193: THEN IF within(*addr,amap->b2,amap->e2)
194: THEN *addr += (amap->f2)-(amap->b2);
195: ELSE rwerr(space); return(0);
196: FI
197: ELSE *addr += (amap->f1)-(amap->b1);
198: FI
199: return(1);
200: }
201:
202: within(addr,lbd,ubd)
203: u_int addr, lbd, ubd; { return(addr>=lbd && addr<ubd); }
204:
205: longseek(f, a)
206: off_t a; { return(lseek(f, a, 0) != -1); }
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