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
|
/* $Id: winfixup.S,v 1.30 2002/02/09 19:49:30 davem Exp $
*
* winfixup.S: Handle cases where user stack pointer is found to be bogus.
*
* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
*/
#include <asm/asi.h>
#include <asm/head.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/spitfire.h>
#include <asm/thread_info.h>
.text
set_pcontext:
sethi %hi(sparc64_kern_pri_context), %l1
ldx [%l1 + %lo(sparc64_kern_pri_context)], %l1
mov PRIMARY_CONTEXT, %g1
stxa %l1, [%g1] ASI_DMMU
sethi %hi(KERNBASE), %l1
flush %l1
retl
nop
.align 32
/* Here are the rules, pay attention.
*
* The kernel is disallowed from touching user space while
* the trap level is greater than zero, except for from within
* the window spill/fill handlers. This must be followed
* so that we can easily detect the case where we tried to
* spill/fill with a bogus (or unmapped) user stack pointer.
*
* These are layed out in a special way for cache reasons,
* don't touch...
*/
.globl fill_fixup, spill_fixup
fill_fixup:
TRAP_LOAD_THREAD_REG
rdpr %tstate, %g1
andcc %g1, TSTATE_PRIV, %g0
or %g4, FAULT_CODE_WINFIXUP, %g4
be,pt %xcc, window_scheisse_from_user_common
and %g1, TSTATE_CWP, %g1
/* This is the extremely complex case, but it does happen from
* time to time if things are just right. Essentially the restore
* done in rtrap right before going back to user mode, with tl=1
* and that levels trap stack registers all setup, took a fill trap,
* the user stack was not mapped in the tlb, and tlb miss occurred,
* the pte found was not valid, and a simple ref bit watch update
* could not satisfy the miss, so we got here.
*
* We must carefully unwind the state so we get back to tl=0, preserve
* all the register values we were going to give to the user. Luckily
* most things are where they need to be, we also have the address
* which triggered the fault handy as well.
*
* Also note that we must preserve %l5 and %l6. If the user was
* returning from a system call, we must make it look this way
* after we process the fill fault on the users stack.
*
* First, get into the window where the original restore was executed.
*/
rdpr %wstate, %g2 ! Grab user mode wstate.
wrpr %g1, %cwp ! Get into the right window.
sll %g2, 3, %g2 ! NORMAL-->OTHER
wrpr %g0, 0x0, %canrestore ! Standard etrap stuff.
wrpr %g2, 0x0, %wstate ! This must be consistent.
wrpr %g0, 0x0, %otherwin ! We know this.
call set_pcontext ! Change contexts...
nop
rdpr %pstate, %l1 ! Prepare to change globals.
mov %g6, %o7 ! Get current.
andn %l1, PSTATE_MM, %l1 ! We want to be in RMO
stb %g4, [%g6 + TI_FAULT_CODE]
stx %g5, [%g6 + TI_FAULT_ADDR]
wrpr %g0, 0x0, %tl ! Out of trap levels.
wrpr %l1, (PSTATE_IE | PSTATE_AG | PSTATE_RMO), %pstate
mov %o7, %g6
ldx [%g6 + TI_TASK], %g4
LOAD_PER_CPU_BASE(%g1, %g2)
/* This is the same as below, except we handle this a bit special
* since we must preserve %l5 and %l6, see comment above.
*/
call do_sparc64_fault
add %sp, PTREGS_OFF, %o0
ba,pt %xcc, rtrap
nop ! yes, nop is correct
/* Be very careful about usage of the alternate globals here.
* You cannot touch %g4/%g5 as that has the fault information
* should this be from usermode. Also be careful for the case
* where we get here from the save instruction in etrap.S when
* coming from either user or kernel (does not matter which, it
* is the same problem in both cases). Essentially this means
* do not touch %g7 or %g2 so we handle the two cases fine.
*/
spill_fixup:
TRAP_LOAD_THREAD_REG
ldx [%g6 + TI_FLAGS], %g1
andcc %g1, _TIF_32BIT, %g0
ldub [%g6 + TI_WSAVED], %g1
sll %g1, 3, %g3
add %g6, %g3, %g3
stx %sp, [%g3 + TI_RWIN_SPTRS]
sll %g1, 7, %g3
bne,pt %xcc, 1f
add %g6, %g3, %g3
stx %l0, [%g3 + TI_REG_WINDOW + 0x00]
stx %l1, [%g3 + TI_REG_WINDOW + 0x08]
stx %l2, [%g3 + TI_REG_WINDOW + 0x10]
stx %l3, [%g3 + TI_REG_WINDOW + 0x18]
stx %l4, [%g3 + TI_REG_WINDOW + 0x20]
stx %l5, [%g3 + TI_REG_WINDOW + 0x28]
stx %l6, [%g3 + TI_REG_WINDOW + 0x30]
stx %l7, [%g3 + TI_REG_WINDOW + 0x38]
stx %i0, [%g3 + TI_REG_WINDOW + 0x40]
stx %i1, [%g3 + TI_REG_WINDOW + 0x48]
stx %i2, [%g3 + TI_REG_WINDOW + 0x50]
stx %i3, [%g3 + TI_REG_WINDOW + 0x58]
stx %i4, [%g3 + TI_REG_WINDOW + 0x60]
stx %i5, [%g3 + TI_REG_WINDOW + 0x68]
stx %i6, [%g3 + TI_REG_WINDOW + 0x70]
b,pt %xcc, 2f
stx %i7, [%g3 + TI_REG_WINDOW + 0x78]
1: stw %l0, [%g3 + TI_REG_WINDOW + 0x00]
stw %l1, [%g3 + TI_REG_WINDOW + 0x04]
stw %l2, [%g3 + TI_REG_WINDOW + 0x08]
stw %l3, [%g3 + TI_REG_WINDOW + 0x0c]
stw %l4, [%g3 + TI_REG_WINDOW + 0x10]
stw %l5, [%g3 + TI_REG_WINDOW + 0x14]
stw %l6, [%g3 + TI_REG_WINDOW + 0x18]
stw %l7, [%g3 + TI_REG_WINDOW + 0x1c]
stw %i0, [%g3 + TI_REG_WINDOW + 0x20]
stw %i1, [%g3 + TI_REG_WINDOW + 0x24]
stw %i2, [%g3 + TI_REG_WINDOW + 0x28]
stw %i3, [%g3 + TI_REG_WINDOW + 0x2c]
stw %i4, [%g3 + TI_REG_WINDOW + 0x30]
stw %i5, [%g3 + TI_REG_WINDOW + 0x34]
stw %i6, [%g3 + TI_REG_WINDOW + 0x38]
stw %i7, [%g3 + TI_REG_WINDOW + 0x3c]
2: add %g1, 1, %g1
stb %g1, [%g6 + TI_WSAVED]
rdpr %tstate, %g1
andcc %g1, TSTATE_PRIV, %g0
saved
and %g1, TSTATE_CWP, %g1
be,pn %xcc, window_scheisse_from_user_common
mov FAULT_CODE_WRITE | FAULT_CODE_DTLB | FAULT_CODE_WINFIXUP, %g4
retry
window_scheisse_from_user_common:
stb %g4, [%g6 + TI_FAULT_CODE]
stx %g5, [%g6 + TI_FAULT_ADDR]
wrpr %g1, %cwp
ba,pt %xcc, etrap
rd %pc, %g7
call do_sparc64_fault
add %sp, PTREGS_OFF, %o0
ba,a,pt %xcc, rtrap_clr_l6
.globl winfix_mna, fill_fixup_mna, spill_fixup_mna
winfix_mna:
andn %g3, 0x7f, %g3
add %g3, 0x78, %g3
wrpr %g3, %tnpc
done
fill_fixup_mna:
TRAP_LOAD_THREAD_REG
rdpr %tstate, %g1
andcc %g1, TSTATE_PRIV, %g0
be,pt %xcc, window_mna_from_user_common
and %g1, TSTATE_CWP, %g1
/* Please, see fill_fixup commentary about why we must preserve
* %l5 and %l6 to preserve absolute correct semantics.
*/
rdpr %wstate, %g2 ! Grab user mode wstate.
wrpr %g1, %cwp ! Get into the right window.
sll %g2, 3, %g2 ! NORMAL-->OTHER
wrpr %g0, 0x0, %canrestore ! Standard etrap stuff.
wrpr %g2, 0x0, %wstate ! This must be consistent.
wrpr %g0, 0x0, %otherwin ! We know this.
call set_pcontext ! Change contexts...
nop
rdpr %pstate, %l1 ! Prepare to change globals.
mov %g4, %o2 ! Setup args for
mov %g5, %o1 ! final call to mem_address_unaligned.
andn %l1, PSTATE_MM, %l1 ! We want to be in RMO
mov %g6, %o7 ! Stash away current.
wrpr %g0, 0x0, %tl ! Out of trap levels.
wrpr %l1, (PSTATE_IE | PSTATE_AG | PSTATE_RMO), %pstate
mov %o7, %g6 ! Get current back.
ldx [%g6 + TI_TASK], %g4 ! Finish it.
LOAD_PER_CPU_BASE(%g1, %g2)
call mem_address_unaligned
add %sp, PTREGS_OFF, %o0
b,pt %xcc, rtrap
nop ! yes, the nop is correct
spill_fixup_mna:
TRAP_LOAD_THREAD_REG
ldx [%g6 + TI_FLAGS], %g1
andcc %g1, _TIF_32BIT, %g0
ldub [%g6 + TI_WSAVED], %g1
sll %g1, 3, %g3
add %g6, %g3, %g3
stx %sp, [%g3 + TI_RWIN_SPTRS]
sll %g1, 7, %g3
bne,pt %xcc, 1f
add %g6, %g3, %g3
stx %l0, [%g3 + TI_REG_WINDOW + 0x00]
stx %l1, [%g3 + TI_REG_WINDOW + 0x08]
stx %l2, [%g3 + TI_REG_WINDOW + 0x10]
stx %l3, [%g3 + TI_REG_WINDOW + 0x18]
stx %l4, [%g3 + TI_REG_WINDOW + 0x20]
stx %l5, [%g3 + TI_REG_WINDOW + 0x28]
stx %l6, [%g3 + TI_REG_WINDOW + 0x30]
stx %l7, [%g3 + TI_REG_WINDOW + 0x38]
stx %i0, [%g3 + TI_REG_WINDOW + 0x40]
stx %i1, [%g3 + TI_REG_WINDOW + 0x48]
stx %i2, [%g3 + TI_REG_WINDOW + 0x50]
stx %i3, [%g3 + TI_REG_WINDOW + 0x58]
stx %i4, [%g3 + TI_REG_WINDOW + 0x60]
stx %i5, [%g3 + TI_REG_WINDOW + 0x68]
stx %i6, [%g3 + TI_REG_WINDOW + 0x70]
stx %i7, [%g3 + TI_REG_WINDOW + 0x78]
b,pt %xcc, 2f
add %g1, 1, %g1
1: std %l0, [%g3 + TI_REG_WINDOW + 0x00]
std %l2, [%g3 + TI_REG_WINDOW + 0x08]
std %l4, [%g3 + TI_REG_WINDOW + 0x10]
std %l6, [%g3 + TI_REG_WINDOW + 0x18]
std %i0, [%g3 + TI_REG_WINDOW + 0x20]
std %i2, [%g3 + TI_REG_WINDOW + 0x28]
std %i4, [%g3 + TI_REG_WINDOW + 0x30]
std %i6, [%g3 + TI_REG_WINDOW + 0x38]
add %g1, 1, %g1
2: stb %g1, [%g6 + TI_WSAVED]
rdpr %tstate, %g1
andcc %g1, TSTATE_PRIV, %g0
saved
be,pn %xcc, window_mna_from_user_common
and %g1, TSTATE_CWP, %g1
retry
window_mna_from_user_common:
wrpr %g1, %cwp
sethi %hi(109f), %g7
ba,pt %xcc, etrap
109: or %g7, %lo(109b), %g7
mov %l4, %o2
mov %l5, %o1
call mem_address_unaligned
add %sp, PTREGS_OFF, %o0
ba,pt %xcc, rtrap
clr %l6
.globl winfix_dax, fill_fixup_dax, spill_fixup_dax
winfix_dax:
andn %g3, 0x7f, %g3
add %g3, 0x74, %g3
wrpr %g3, %tnpc
done
fill_fixup_dax:
TRAP_LOAD_THREAD_REG
rdpr %tstate, %g1
andcc %g1, TSTATE_PRIV, %g0
be,pt %xcc, window_dax_from_user_common
and %g1, TSTATE_CWP, %g1
/* Please, see fill_fixup commentary about why we must preserve
* %l5 and %l6 to preserve absolute correct semantics.
*/
rdpr %wstate, %g2 ! Grab user mode wstate.
wrpr %g1, %cwp ! Get into the right window.
sll %g2, 3, %g2 ! NORMAL-->OTHER
wrpr %g0, 0x0, %canrestore ! Standard etrap stuff.
wrpr %g2, 0x0, %wstate ! This must be consistent.
wrpr %g0, 0x0, %otherwin ! We know this.
call set_pcontext ! Change contexts...
nop
rdpr %pstate, %l1 ! Prepare to change globals.
mov %g4, %o1 ! Setup args for
mov %g5, %o2 ! final call to spitfire_data_access_exception.
andn %l1, PSTATE_MM, %l1 ! We want to be in RMO
mov %g6, %o7 ! Stash away current.
wrpr %g0, 0x0, %tl ! Out of trap levels.
wrpr %l1, (PSTATE_IE | PSTATE_AG | PSTATE_RMO), %pstate
mov %o7, %g6 ! Get current back.
ldx [%g6 + TI_TASK], %g4 ! Finish it.
LOAD_PER_CPU_BASE(%g1, %g2)
call spitfire_data_access_exception
add %sp, PTREGS_OFF, %o0
b,pt %xcc, rtrap
nop ! yes, the nop is correct
spill_fixup_dax:
TRAP_LOAD_THREAD_REG
ldx [%g6 + TI_FLAGS], %g1
andcc %g1, _TIF_32BIT, %g0
ldub [%g6 + TI_WSAVED], %g1
sll %g1, 3, %g3
add %g6, %g3, %g3
stx %sp, [%g3 + TI_RWIN_SPTRS]
sll %g1, 7, %g3
bne,pt %xcc, 1f
add %g6, %g3, %g3
stx %l0, [%g3 + TI_REG_WINDOW + 0x00]
stx %l1, [%g3 + TI_REG_WINDOW + 0x08]
stx %l2, [%g3 + TI_REG_WINDOW + 0x10]
stx %l3, [%g3 + TI_REG_WINDOW + 0x18]
stx %l4, [%g3 + TI_REG_WINDOW + 0x20]
stx %l5, [%g3 + TI_REG_WINDOW + 0x28]
stx %l6, [%g3 + TI_REG_WINDOW + 0x30]
stx %l7, [%g3 + TI_REG_WINDOW + 0x38]
stx %i0, [%g3 + TI_REG_WINDOW + 0x40]
stx %i1, [%g3 + TI_REG_WINDOW + 0x48]
stx %i2, [%g3 + TI_REG_WINDOW + 0x50]
stx %i3, [%g3 + TI_REG_WINDOW + 0x58]
stx %i4, [%g3 + TI_REG_WINDOW + 0x60]
stx %i5, [%g3 + TI_REG_WINDOW + 0x68]
stx %i6, [%g3 + TI_REG_WINDOW + 0x70]
stx %i7, [%g3 + TI_REG_WINDOW + 0x78]
b,pt %xcc, 2f
add %g1, 1, %g1
1: std %l0, [%g3 + TI_REG_WINDOW + 0x00]
std %l2, [%g3 + TI_REG_WINDOW + 0x08]
std %l4, [%g3 + TI_REG_WINDOW + 0x10]
std %l6, [%g3 + TI_REG_WINDOW + 0x18]
std %i0, [%g3 + TI_REG_WINDOW + 0x20]
std %i2, [%g3 + TI_REG_WINDOW + 0x28]
std %i4, [%g3 + TI_REG_WINDOW + 0x30]
std %i6, [%g3 + TI_REG_WINDOW + 0x38]
add %g1, 1, %g1
2: stb %g1, [%g6 + TI_WSAVED]
rdpr %tstate, %g1
andcc %g1, TSTATE_PRIV, %g0
saved
be,pn %xcc, window_dax_from_user_common
and %g1, TSTATE_CWP, %g1
retry
window_dax_from_user_common:
wrpr %g1, %cwp
sethi %hi(109f), %g7
ba,pt %xcc, etrap
109: or %g7, %lo(109b), %g7
mov %l4, %o1
mov %l5, %o2
call spitfire_data_access_exception
add %sp, PTREGS_OFF, %o0
ba,pt %xcc, rtrap
clr %l6
|
