1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
|
#include <sys/ptrace.h>
#include <sys/wait.h>
#include "xc_private.h"
#include "xg_private.h"
#include <time.h>
#define X86_CR0_PE 0x00000001 /* Enable Protected Mode (RW) */
#define X86_CR0_PG 0x80000000 /* Paging (RW) */
#define BSD_PAGE_MASK (PAGE_SIZE-1)
#define PDRSHIFT 22
#define PSL_T 0x00000100 /* trace enable bit */
#define VCPU 0 /* XXX */
char * ptrace_names[] = {
"PTRACE_TRACEME",
"PTRACE_PEEKTEXT",
"PTRACE_PEEKDATA",
"PTRACE_PEEKUSER",
"PTRACE_POKETEXT",
"PTRACE_POKEDATA",
"PTRACE_POKEUSER",
"PTRACE_CONT",
"PTRACE_KILL",
"PTRACE_SINGLESTEP",
"PTRACE_INVALID",
"PTRACE_INVALID",
"PTRACE_GETREGS",
"PTRACE_SETREGS",
"PTRACE_GETFPREGS",
"PTRACE_SETFPREGS",
"PTRACE_ATTACH",
"PTRACE_DETACH",
"PTRACE_GETFPXREGS",
"PTRACE_SETFPXREGS",
"PTRACE_INVALID",
"PTRACE_INVALID",
"PTRACE_INVALID",
"PTRACE_INVALID",
"PTRACE_SYSCALL",
};
struct gdb_regs {
long ebx; /* 0 */
long ecx; /* 4 */
long edx; /* 8 */
long esi; /* 12 */
long edi; /* 16 */
long ebp; /* 20 */
long eax; /* 24 */
int xds; /* 28 */
int xes; /* 32 */
int xfs; /* 36 */
int xgs; /* 40 */
long orig_eax; /* 44 */
long eip; /* 48 */
int xcs; /* 52 */
long eflags; /* 56 */
long esp; /* 60 */
int xss; /* 64 */
};
#define FETCH_REGS(cpu) \
if (!regs_valid[cpu]) \
{ \
int retval = xc_domain_get_vcpu_context( \
xc_handle, domid, cpu, &ctxt[cpu]); \
if (retval) \
goto error_out; \
cr3[cpu] = ctxt[cpu].ctrlreg[3]; /* physical address */ \
regs_valid[cpu] = 1; \
}
#define printval(x) printf("%s = %lx\n", #x, (long)x);
#define SET_PT_REGS(pt, xc) \
{ \
pt.ebx = xc.ebx; \
pt.ecx = xc.ecx; \
pt.edx = xc.edx; \
pt.esi = xc.esi; \
pt.edi = xc.edi; \
pt.ebp = xc.ebp; \
pt.eax = xc.eax; \
pt.eip = xc.eip; \
pt.xcs = xc.cs; \
pt.eflags = xc.eflags; \
pt.esp = xc.esp; \
pt.xss = xc.ss; \
pt.xes = xc.es; \
pt.xds = xc.ds; \
pt.xfs = xc.fs; \
pt.xgs = xc.gs; \
}
#define SET_XC_REGS(pt, xc) \
{ \
xc.ebx = pt->ebx; \
xc.ecx = pt->ecx; \
xc.edx = pt->edx; \
xc.esi = pt->esi; \
xc.edi = pt->edi; \
xc.ebp = pt->ebp; \
xc.eax = pt->eax; \
xc.eip = pt->eip; \
xc.cs = pt->xcs; \
xc.eflags = pt->eflags; \
xc.esp = pt->esp; \
xc.ss = pt->xss; \
xc.es = pt->xes; \
xc.ds = pt->xds; \
xc.fs = pt->xfs; \
xc.gs = pt->xgs; \
}
#define vtopdi(va) ((va) >> PDRSHIFT)
#define vtopti(va) (((va) >> PAGE_SHIFT) & 0x3ff)
/* XXX application state */
static long nr_pages = 0;
unsigned long *page_array = NULL;
static int regs_valid[MAX_VIRT_CPUS];
static unsigned long cr3[MAX_VIRT_CPUS];
static vcpu_guest_context_t ctxt[MAX_VIRT_CPUS];
static inline int paging_enabled(vcpu_guest_context_t *v)
{
unsigned long cr0 = v->ctrlreg[0];
return (cr0 & X86_CR0_PE) && (cr0 & X86_CR0_PG);
}
/* --------------------- */
static void *
map_domain_va_pae(
int xc_handle,
unsigned long domid,
int cpu,
void *guest_va,
int perm)
{
unsigned long l2p, l1p, p, va = (unsigned long)guest_va;
u64 *l3, *l2, *l1;
static void *v;
FETCH_REGS(cpu);
l3 = xc_map_foreign_range(
xc_handle, domid, PAGE_SIZE, PROT_READ, cr3[cpu] >> PAGE_SHIFT);
if ( l3 == NULL )
goto error_out;
l2p = l3[l3_table_offset_pae(va)] >> PAGE_SHIFT;
l2 = xc_map_foreign_range(xc_handle, domid, PAGE_SIZE, PROT_READ, l2p);
if ( l2 == NULL )
goto error_out;
l1p = l2[l2_table_offset_pae(va)] >> PAGE_SHIFT;
l1 = xc_map_foreign_range(xc_handle, domid, PAGE_SIZE, perm, l1p);
if ( l1 == NULL )
goto error_out;
p = l1[l1_table_offset_pae(va)] >> PAGE_SHIFT;
if ( v != NULL )
munmap(v, PAGE_SIZE);
v = xc_map_foreign_range(xc_handle, domid, PAGE_SIZE, perm, p);
if ( v == NULL )
goto error_out;
return (void *)((unsigned long)v | (va & (PAGE_SIZE - 1)));
error_out:
return NULL;
}
static void *
map_domain_va(
int xc_handle,
unsigned long domid,
int cpu,
void *guest_va,
int perm)
{
unsigned long pde, page;
unsigned long va = (unsigned long)guest_va;
long npgs = xc_get_tot_pages(xc_handle, domid);
static unsigned long cr3_phys[MAX_VIRT_CPUS];
static unsigned long *cr3_virt[MAX_VIRT_CPUS];
static unsigned long pde_phys[MAX_VIRT_CPUS];
static unsigned long *pde_virt[MAX_VIRT_CPUS];
static unsigned long page_phys[MAX_VIRT_CPUS];
static unsigned long *page_virt[MAX_VIRT_CPUS];
static int prev_perm[MAX_VIRT_CPUS];
static enum { MODE_UNKNOWN, MODE_32, MODE_PAE } mode;
if ( mode == MODE_UNKNOWN )
{
xen_capabilities_info_t caps;
(void)xc_version(xc_handle, XENVER_capabilities, caps);
mode = MODE_32;
if ( strstr(caps, "_x86_32p") )
mode = MODE_PAE;
}
if ( mode == MODE_PAE )
return map_domain_va_pae(xc_handle, domid, cpu, guest_va, perm);
if ( nr_pages != npgs )
{
if ( nr_pages > 0 )
free(page_array);
nr_pages = npgs;
if ( (page_array = malloc(nr_pages * sizeof(unsigned long))) == NULL )
{
printf("Could not allocate memory\n");
goto error_out;
}
if ( xc_get_pfn_list(xc_handle, domid,
page_array, nr_pages) != nr_pages )
{
printf("Could not get the page frame list\n");
goto error_out;
}
}
FETCH_REGS(cpu);
if ( cr3[cpu] != cr3_phys[cpu] )
{
cr3_phys[cpu] = cr3[cpu];
if ( cr3_virt[cpu] )
munmap(cr3_virt[cpu], PAGE_SIZE);
cr3_virt[cpu] = xc_map_foreign_range(
xc_handle, domid, PAGE_SIZE, PROT_READ,
cr3_phys[cpu] >> PAGE_SHIFT);
if ( cr3_virt[cpu] == NULL )
goto error_out;
}
if ( (pde = cr3_virt[cpu][vtopdi(va)]) == 0 )
goto error_out;
if ( (ctxt[cpu].flags & VGCF_VMX_GUEST) && paging_enabled(&ctxt[cpu]) )
pde = page_array[pde >> PAGE_SHIFT] << PAGE_SHIFT;
if ( pde != pde_phys[cpu] )
{
pde_phys[cpu] = pde;
if ( pde_virt[cpu] )
munmap(pde_virt[cpu], PAGE_SIZE);
pde_virt[cpu] = xc_map_foreign_range(
xc_handle, domid, PAGE_SIZE, PROT_READ,
pde_phys[cpu] >> PAGE_SHIFT);
if ( pde_virt[cpu] == NULL )
goto error_out;
}
if ( (page = pde_virt[cpu][vtopti(va)]) == 0 )
goto error_out;
if ( (ctxt[cpu].flags & VGCF_VMX_GUEST) && paging_enabled(&ctxt[cpu]) )
page = page_array[page >> PAGE_SHIFT] << PAGE_SHIFT;
if ( (page != page_phys[cpu]) || (perm != prev_perm[cpu]) )
{
page_phys[cpu] = page;
if ( page_virt[cpu] )
munmap(page_virt[cpu], PAGE_SIZE);
page_virt[cpu] = xc_map_foreign_range(
xc_handle, domid, PAGE_SIZE, perm,
page_phys[cpu] >> PAGE_SHIFT);
if ( page_virt[cpu] == NULL )
{
page_phys[cpu] = 0;
goto error_out;
}
prev_perm[cpu] = perm;
}
return (void *)(((unsigned long)page_virt[cpu]) | (va & BSD_PAGE_MASK));
error_out:
return NULL;
}
int
xc_waitdomain(
int xc_handle,
int domain,
int *status,
int options)
{
dom0_op_t op;
int retval;
struct timespec ts;
ts.tv_sec = 0;
ts.tv_nsec = 10*1000*1000;
op.cmd = DOM0_GETDOMAININFO;
op.u.getdomaininfo.domain = domain;
retry:
retval = do_dom0_op(xc_handle, &op);
if ( retval || (op.u.getdomaininfo.domain != domain) )
{
printf("getdomaininfo failed\n");
goto done;
}
*status = op.u.getdomaininfo.flags;
if ( options & WNOHANG )
goto done;
if ( !(op.u.getdomaininfo.flags & DOMFLAGS_PAUSED) )
{
nanosleep(&ts,NULL);
goto retry;
}
done:
return retval;
}
long
xc_ptrace(
int xc_handle,
enum __ptrace_request request,
u32 domid,
long eaddr,
long edata)
{
dom0_op_t op;
int status = 0;
struct gdb_regs pt;
long retval = 0;
unsigned long *guest_va;
int cpu = VCPU;
void *addr = (char *)eaddr;
void *data = (char *)edata;
op.interface_version = DOM0_INTERFACE_VERSION;
switch ( request )
{
case PTRACE_PEEKTEXT:
case PTRACE_PEEKDATA:
guest_va = (unsigned long *)map_domain_va(
xc_handle, domid, cpu, addr, PROT_READ);
if ( guest_va == NULL )
{
status = EFAULT;
goto error_out;
}
retval = *guest_va;
break;
case PTRACE_POKETEXT:
case PTRACE_POKEDATA:
guest_va = (unsigned long *)map_domain_va(
xc_handle, domid, cpu, addr, PROT_READ|PROT_WRITE);
if ( guest_va == NULL )
{
status = EFAULT;
goto error_out;
}
*guest_va = (unsigned long)data;
break;
case PTRACE_GETREGS:
case PTRACE_GETFPREGS:
case PTRACE_GETFPXREGS:
FETCH_REGS(cpu);
if ( request == PTRACE_GETREGS )
{
SET_PT_REGS(pt, ctxt[cpu].user_regs);
memcpy(data, &pt, sizeof(struct gdb_regs));
}
else if (request == PTRACE_GETFPREGS)
{
memcpy(data, &ctxt[cpu].fpu_ctxt, sizeof(ctxt[cpu].fpu_ctxt));
}
else /*if (request == PTRACE_GETFPXREGS)*/
{
memcpy(data, &ctxt[cpu].fpu_ctxt, sizeof(ctxt[cpu].fpu_ctxt));
}
break;
case PTRACE_SETREGS:
op.cmd = DOM0_SETDOMAININFO;
SET_XC_REGS(((struct gdb_regs *)data), ctxt[VCPU].user_regs);
op.u.setdomaininfo.domain = domid;
/* XXX need to understand multiple vcpus */
op.u.setdomaininfo.vcpu = cpu;
op.u.setdomaininfo.ctxt = &ctxt[cpu];
retval = do_dom0_op(xc_handle, &op);
if (retval)
goto error_out;
break;
case PTRACE_ATTACH:
op.cmd = DOM0_GETDOMAININFO;
op.u.getdomaininfo.domain = domid;
retval = do_dom0_op(xc_handle, &op);
if ( retval || (op.u.getdomaininfo.domain != domid) )
{
perror("dom0 op failed");
goto error_out;
}
if ( op.u.getdomaininfo.flags & DOMFLAGS_PAUSED )
{
printf("domain currently paused\n");
goto error_out;
}
printf("domain not currently paused\n");
op.cmd = DOM0_PAUSEDOMAIN;
op.u.pausedomain.domain = domid;
retval = do_dom0_op(xc_handle, &op);
break;
case PTRACE_SINGLESTEP:
ctxt[VCPU].user_regs.eflags |= PSL_T;
op.cmd = DOM0_SETDOMAININFO;
op.u.setdomaininfo.domain = domid;
op.u.setdomaininfo.vcpu = 0;
op.u.setdomaininfo.ctxt = &ctxt[cpu];
retval = do_dom0_op(xc_handle, &op);
if ( retval )
{
perror("dom0 op failed");
goto error_out;
}
/* FALLTHROUGH */
case PTRACE_CONT:
case PTRACE_DETACH:
if ( request != PTRACE_SINGLESTEP )
{
FETCH_REGS(cpu);
/* Clear trace flag */
if ( ctxt[cpu].user_regs.eflags & PSL_T )
{
ctxt[cpu].user_regs.eflags &= ~PSL_T;
op.cmd = DOM0_SETDOMAININFO;
op.u.setdomaininfo.domain = domid;
op.u.setdomaininfo.vcpu = cpu;
op.u.setdomaininfo.ctxt = &ctxt[cpu];
retval = do_dom0_op(xc_handle, &op);
if ( retval )
{
perror("dom0 op failed");
goto error_out;
}
}
}
regs_valid[cpu] = 0;
op.cmd = DOM0_UNPAUSEDOMAIN;
op.u.unpausedomain.domain = domid > 0 ? domid : -domid;
retval = do_dom0_op(xc_handle, &op);
break;
case PTRACE_SETFPREGS:
case PTRACE_SETFPXREGS:
case PTRACE_PEEKUSER:
case PTRACE_POKEUSER:
case PTRACE_SYSCALL:
case PTRACE_KILL:
#ifdef DEBUG
printf("unsupported xc_ptrace request %s\n", ptrace_names[request]);
#endif
/* XXX not yet supported */
status = ENOSYS;
break;
case PTRACE_TRACEME:
printf("PTRACE_TRACEME is an invalid request under Xen\n");
status = EINVAL;
}
if ( status )
{
errno = status;
retval = -1;
}
error_out:
return retval;
}
/*
* Local variables:
* mode: C
* c-set-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
|
