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1 | // SPDX-License-Identifier: GPL-2.0-or-later | |
2 | /* | |
3 | * PowerPC version | |
4 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
5 | * | |
6 | * Derived from "arch/i386/kernel/signal.c" | |
7 | * Copyright (C) 1991, 1992 Linus Torvalds | |
8 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson | |
9 | */ | |
10 | ||
11 | #include <linux/sched.h> | |
12 | #include <linux/mm.h> | |
13 | #include <linux/smp.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/signal.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/wait.h> | |
18 | #include <linux/unistd.h> | |
19 | #include <linux/stddef.h> | |
20 | #include <linux/elf.h> | |
21 | #include <linux/ptrace.h> | |
22 | #include <linux/ratelimit.h> | |
23 | #include <linux/syscalls.h> | |
24 | #include <linux/pagemap.h> | |
25 | ||
26 | #include <asm/sigcontext.h> | |
27 | #include <asm/ucontext.h> | |
28 | #include <linux/uaccess.h> | |
29 | #include <asm/unistd.h> | |
30 | #include <asm/cacheflush.h> | |
31 | #include <asm/syscalls.h> | |
32 | #include <asm/vdso.h> | |
33 | #include <asm/switch_to.h> | |
34 | #include <asm/tm.h> | |
35 | #include <asm/asm-prototypes.h> | |
36 | ||
37 | #include "signal.h" | |
38 | ||
39 | ||
40 | #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) | |
41 | #define FP_REGS_SIZE sizeof(elf_fpregset_t) | |
42 | ||
43 | #define TRAMP_TRACEBACK 4 | |
44 | #define TRAMP_SIZE 7 | |
45 | ||
46 | /* | |
47 | * When we have signals to deliver, we set up on the user stack, | |
48 | * going down from the original stack pointer: | |
49 | * 1) a rt_sigframe struct which contains the ucontext | |
50 | * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller | |
51 | * frame for the signal handler. | |
52 | */ | |
53 | ||
54 | struct rt_sigframe { | |
55 | /* sys_rt_sigreturn requires the ucontext be the first field */ | |
56 | struct ucontext uc; | |
57 | #ifdef CONFIG_PPC_TRANSACTIONAL_MEM | |
58 | struct ucontext uc_transact; | |
59 | #endif | |
60 | unsigned long _unused[2]; | |
61 | unsigned int tramp[TRAMP_SIZE]; | |
62 | struct siginfo __user *pinfo; | |
63 | void __user *puc; | |
64 | struct siginfo info; | |
65 | /* New 64 bit little-endian ABI allows redzone of 512 bytes below sp */ | |
66 | char abigap[USER_REDZONE_SIZE]; | |
67 | } __attribute__ ((aligned (16))); | |
68 | ||
69 | /* | |
70 | * This computes a quad word aligned pointer inside the vmx_reserve array | |
71 | * element. For historical reasons sigcontext might not be quad word aligned, | |
72 | * but the location we write the VMX regs to must be. See the comment in | |
73 | * sigcontext for more detail. | |
74 | */ | |
75 | #ifdef CONFIG_ALTIVEC | |
76 | static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc) | |
77 | { | |
78 | return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful); | |
79 | } | |
80 | #endif | |
81 | ||
82 | /* | |
83 | * Set up the sigcontext for the signal frame. | |
84 | */ | |
85 | ||
86 | static long setup_sigcontext(struct sigcontext __user *sc, | |
87 | struct task_struct *tsk, int signr, sigset_t *set, | |
88 | unsigned long handler, int ctx_has_vsx_region) | |
89 | { | |
90 | /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the | |
91 | * process never used altivec yet (MSR_VEC is zero in pt_regs of | |
92 | * the context). This is very important because we must ensure we | |
93 | * don't lose the VRSAVE content that may have been set prior to | |
94 | * the process doing its first vector operation | |
95 | * Userland shall check AT_HWCAP to know whether it can rely on the | |
96 | * v_regs pointer or not | |
97 | */ | |
98 | #ifdef CONFIG_ALTIVEC | |
99 | elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); | |
100 | unsigned long vrsave; | |
101 | #endif | |
102 | struct pt_regs *regs = tsk->thread.regs; | |
103 | unsigned long msr = regs->msr; | |
104 | long err = 0; | |
105 | /* Force usr to alway see softe as 1 (interrupts enabled) */ | |
106 | unsigned long softe = 0x1; | |
107 | ||
108 | BUG_ON(tsk != current); | |
109 | ||
110 | #ifdef CONFIG_ALTIVEC | |
111 | err |= __put_user(v_regs, &sc->v_regs); | |
112 | ||
113 | /* save altivec registers */ | |
114 | if (tsk->thread.used_vr) { | |
115 | flush_altivec_to_thread(tsk); | |
116 | /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ | |
117 | err |= __copy_to_user(v_regs, &tsk->thread.vr_state, | |
118 | 33 * sizeof(vector128)); | |
119 | /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) | |
120 | * contains valid data. | |
121 | */ | |
122 | msr |= MSR_VEC; | |
123 | } | |
124 | /* We always copy to/from vrsave, it's 0 if we don't have or don't | |
125 | * use altivec. | |
126 | */ | |
127 | vrsave = 0; | |
128 | if (cpu_has_feature(CPU_FTR_ALTIVEC)) { | |
129 | vrsave = mfspr(SPRN_VRSAVE); | |
130 | tsk->thread.vrsave = vrsave; | |
131 | } | |
132 | ||
133 | err |= __put_user(vrsave, (u32 __user *)&v_regs[33]); | |
134 | #else /* CONFIG_ALTIVEC */ | |
135 | err |= __put_user(0, &sc->v_regs); | |
136 | #endif /* CONFIG_ALTIVEC */ | |
137 | flush_fp_to_thread(tsk); | |
138 | /* copy fpr regs and fpscr */ | |
139 | err |= copy_fpr_to_user(&sc->fp_regs, tsk); | |
140 | ||
141 | /* | |
142 | * Clear the MSR VSX bit to indicate there is no valid state attached | |
143 | * to this context, except in the specific case below where we set it. | |
144 | */ | |
145 | msr &= ~MSR_VSX; | |
146 | #ifdef CONFIG_VSX | |
147 | /* | |
148 | * Copy VSX low doubleword to local buffer for formatting, | |
149 | * then out to userspace. Update v_regs to point after the | |
150 | * VMX data. | |
151 | */ | |
152 | if (tsk->thread.used_vsr && ctx_has_vsx_region) { | |
153 | flush_vsx_to_thread(tsk); | |
154 | v_regs += ELF_NVRREG; | |
155 | err |= copy_vsx_to_user(v_regs, tsk); | |
156 | /* set MSR_VSX in the MSR value in the frame to | |
157 | * indicate that sc->vs_reg) contains valid data. | |
158 | */ | |
159 | msr |= MSR_VSX; | |
160 | } | |
161 | #endif /* CONFIG_VSX */ | |
162 | err |= __put_user(&sc->gp_regs, &sc->regs); | |
163 | WARN_ON(!FULL_REGS(regs)); | |
164 | err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); | |
165 | err |= __put_user(msr, &sc->gp_regs[PT_MSR]); | |
166 | err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]); | |
167 | err |= __put_user(signr, &sc->signal); | |
168 | err |= __put_user(handler, &sc->handler); | |
169 | if (set != NULL) | |
170 | err |= __put_user(set->sig[0], &sc->oldmask); | |
171 | ||
172 | return err; | |
173 | } | |
174 | ||
175 | #ifdef CONFIG_PPC_TRANSACTIONAL_MEM | |
176 | /* | |
177 | * As above, but Transactional Memory is in use, so deliver sigcontexts | |
178 | * containing checkpointed and transactional register states. | |
179 | * | |
180 | * To do this, we treclaim (done before entering here) to gather both sets of | |
181 | * registers and set up the 'normal' sigcontext registers with rolled-back | |
182 | * register values such that a simple signal handler sees a correct | |
183 | * checkpointed register state. If interested, a TM-aware sighandler can | |
184 | * examine the transactional registers in the 2nd sigcontext to determine the | |
185 | * real origin of the signal. | |
186 | */ | |
187 | static long setup_tm_sigcontexts(struct sigcontext __user *sc, | |
188 | struct sigcontext __user *tm_sc, | |
189 | struct task_struct *tsk, | |
190 | int signr, sigset_t *set, unsigned long handler, | |
191 | unsigned long msr) | |
192 | { | |
193 | /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the | |
194 | * process never used altivec yet (MSR_VEC is zero in pt_regs of | |
195 | * the context). This is very important because we must ensure we | |
196 | * don't lose the VRSAVE content that may have been set prior to | |
197 | * the process doing its first vector operation | |
198 | * Userland shall check AT_HWCAP to know wether it can rely on the | |
199 | * v_regs pointer or not. | |
200 | */ | |
201 | #ifdef CONFIG_ALTIVEC | |
202 | elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc); | |
203 | elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc); | |
204 | #endif | |
205 | struct pt_regs *regs = tsk->thread.regs; | |
206 | long err = 0; | |
207 | ||
208 | BUG_ON(tsk != current); | |
209 | ||
210 | BUG_ON(!MSR_TM_ACTIVE(msr)); | |
211 | ||
212 | WARN_ON(tm_suspend_disabled); | |
213 | ||
214 | /* Restore checkpointed FP, VEC, and VSX bits from ckpt_regs as | |
215 | * it contains the correct FP, VEC, VSX state after we treclaimed | |
216 | * the transaction and giveup_all() was called on reclaiming. | |
217 | */ | |
218 | msr |= tsk->thread.ckpt_regs.msr & (MSR_FP | MSR_VEC | MSR_VSX); | |
219 | ||
220 | #ifdef CONFIG_ALTIVEC | |
221 | err |= __put_user(v_regs, &sc->v_regs); | |
222 | err |= __put_user(tm_v_regs, &tm_sc->v_regs); | |
223 | ||
224 | /* save altivec registers */ | |
225 | if (tsk->thread.used_vr) { | |
226 | /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ | |
227 | err |= __copy_to_user(v_regs, &tsk->thread.ckvr_state, | |
228 | 33 * sizeof(vector128)); | |
229 | /* If VEC was enabled there are transactional VRs valid too, | |
230 | * else they're a copy of the checkpointed VRs. | |
231 | */ | |
232 | if (msr & MSR_VEC) | |
233 | err |= __copy_to_user(tm_v_regs, | |
234 | &tsk->thread.vr_state, | |
235 | 33 * sizeof(vector128)); | |
236 | else | |
237 | err |= __copy_to_user(tm_v_regs, | |
238 | &tsk->thread.ckvr_state, | |
239 | 33 * sizeof(vector128)); | |
240 | ||
241 | /* set MSR_VEC in the MSR value in the frame to indicate | |
242 | * that sc->v_reg contains valid data. | |
243 | */ | |
244 | msr |= MSR_VEC; | |
245 | } | |
246 | /* We always copy to/from vrsave, it's 0 if we don't have or don't | |
247 | * use altivec. | |
248 | */ | |
249 | if (cpu_has_feature(CPU_FTR_ALTIVEC)) | |
250 | tsk->thread.ckvrsave = mfspr(SPRN_VRSAVE); | |
251 | err |= __put_user(tsk->thread.ckvrsave, (u32 __user *)&v_regs[33]); | |
252 | if (msr & MSR_VEC) | |
253 | err |= __put_user(tsk->thread.vrsave, | |
254 | (u32 __user *)&tm_v_regs[33]); | |
255 | else | |
256 | err |= __put_user(tsk->thread.ckvrsave, | |
257 | (u32 __user *)&tm_v_regs[33]); | |
258 | ||
259 | #else /* CONFIG_ALTIVEC */ | |
260 | err |= __put_user(0, &sc->v_regs); | |
261 | err |= __put_user(0, &tm_sc->v_regs); | |
262 | #endif /* CONFIG_ALTIVEC */ | |
263 | ||
264 | /* copy fpr regs and fpscr */ | |
265 | err |= copy_ckfpr_to_user(&sc->fp_regs, tsk); | |
266 | if (msr & MSR_FP) | |
267 | err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk); | |
268 | else | |
269 | err |= copy_ckfpr_to_user(&tm_sc->fp_regs, tsk); | |
270 | ||
271 | #ifdef CONFIG_VSX | |
272 | /* | |
273 | * Copy VSX low doubleword to local buffer for formatting, | |
274 | * then out to userspace. Update v_regs to point after the | |
275 | * VMX data. | |
276 | */ | |
277 | if (tsk->thread.used_vsr) { | |
278 | v_regs += ELF_NVRREG; | |
279 | tm_v_regs += ELF_NVRREG; | |
280 | ||
281 | err |= copy_ckvsx_to_user(v_regs, tsk); | |
282 | ||
283 | if (msr & MSR_VSX) | |
284 | err |= copy_vsx_to_user(tm_v_regs, tsk); | |
285 | else | |
286 | err |= copy_ckvsx_to_user(tm_v_regs, tsk); | |
287 | ||
288 | /* set MSR_VSX in the MSR value in the frame to | |
289 | * indicate that sc->vs_reg) contains valid data. | |
290 | */ | |
291 | msr |= MSR_VSX; | |
292 | } | |
293 | #endif /* CONFIG_VSX */ | |
294 | ||
295 | err |= __put_user(&sc->gp_regs, &sc->regs); | |
296 | err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs); | |
297 | WARN_ON(!FULL_REGS(regs)); | |
298 | err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE); | |
299 | err |= __copy_to_user(&sc->gp_regs, | |
300 | &tsk->thread.ckpt_regs, GP_REGS_SIZE); | |
301 | err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]); | |
302 | err |= __put_user(msr, &sc->gp_regs[PT_MSR]); | |
303 | err |= __put_user(signr, &sc->signal); | |
304 | err |= __put_user(handler, &sc->handler); | |
305 | if (set != NULL) | |
306 | err |= __put_user(set->sig[0], &sc->oldmask); | |
307 | ||
308 | return err; | |
309 | } | |
310 | #endif | |
311 | ||
312 | /* | |
313 | * Restore the sigcontext from the signal frame. | |
314 | */ | |
315 | ||
316 | static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig, | |
317 | struct sigcontext __user *sc) | |
318 | { | |
319 | #ifdef CONFIG_ALTIVEC | |
320 | elf_vrreg_t __user *v_regs; | |
321 | #endif | |
322 | unsigned long err = 0; | |
323 | unsigned long save_r13 = 0; | |
324 | unsigned long msr; | |
325 | struct pt_regs *regs = tsk->thread.regs; | |
326 | #ifdef CONFIG_VSX | |
327 | int i; | |
328 | #endif | |
329 | ||
330 | BUG_ON(tsk != current); | |
331 | ||
332 | /* If this is not a signal return, we preserve the TLS in r13 */ | |
333 | if (!sig) | |
334 | save_r13 = regs->gpr[13]; | |
335 | ||
336 | /* copy the GPRs */ | |
337 | err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr)); | |
338 | err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]); | |
339 | /* get MSR separately, transfer the LE bit if doing signal return */ | |
340 | err |= __get_user(msr, &sc->gp_regs[PT_MSR]); | |
341 | if (sig) | |
342 | regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); | |
343 | err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]); | |
344 | err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]); | |
345 | err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]); | |
346 | err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]); | |
347 | err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]); | |
348 | /* Don't allow userspace to set SOFTE */ | |
349 | set_trap_norestart(regs); | |
350 | err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); | |
351 | err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); | |
352 | err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); | |
353 | ||
354 | if (!sig) | |
355 | regs->gpr[13] = save_r13; | |
356 | if (set != NULL) | |
357 | err |= __get_user(set->sig[0], &sc->oldmask); | |
358 | ||
359 | /* | |
360 | * Force reload of FP/VEC. | |
361 | * This has to be done before copying stuff into tsk->thread.fpr/vr | |
362 | * for the reasons explained in the previous comment. | |
363 | */ | |
364 | regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); | |
365 | ||
366 | #ifdef CONFIG_ALTIVEC | |
367 | err |= __get_user(v_regs, &sc->v_regs); | |
368 | if (err) | |
369 | return err; | |
370 | if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128))) | |
371 | return -EFAULT; | |
372 | /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ | |
373 | if (v_regs != NULL && (msr & MSR_VEC) != 0) { | |
374 | err |= __copy_from_user(&tsk->thread.vr_state, v_regs, | |
375 | 33 * sizeof(vector128)); | |
376 | tsk->thread.used_vr = true; | |
377 | } else if (tsk->thread.used_vr) { | |
378 | memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); | |
379 | } | |
380 | /* Always get VRSAVE back */ | |
381 | if (v_regs != NULL) | |
382 | err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]); | |
383 | else | |
384 | tsk->thread.vrsave = 0; | |
385 | if (cpu_has_feature(CPU_FTR_ALTIVEC)) | |
386 | mtspr(SPRN_VRSAVE, tsk->thread.vrsave); | |
387 | #endif /* CONFIG_ALTIVEC */ | |
388 | /* restore floating point */ | |
389 | err |= copy_fpr_from_user(tsk, &sc->fp_regs); | |
390 | #ifdef CONFIG_VSX | |
391 | /* | |
392 | * Get additional VSX data. Update v_regs to point after the | |
393 | * VMX data. Copy VSX low doubleword from userspace to local | |
394 | * buffer for formatting, then into the taskstruct. | |
395 | */ | |
396 | v_regs += ELF_NVRREG; | |
397 | if ((msr & MSR_VSX) != 0) { | |
398 | err |= copy_vsx_from_user(tsk, v_regs); | |
399 | tsk->thread.used_vsr = true; | |
400 | } else { | |
401 | for (i = 0; i < 32 ; i++) | |
402 | tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; | |
403 | } | |
404 | #endif | |
405 | return err; | |
406 | } | |
407 | ||
408 | #ifdef CONFIG_PPC_TRANSACTIONAL_MEM | |
409 | /* | |
410 | * Restore the two sigcontexts from the frame of a transactional processes. | |
411 | */ | |
412 | ||
413 | static long restore_tm_sigcontexts(struct task_struct *tsk, | |
414 | struct sigcontext __user *sc, | |
415 | struct sigcontext __user *tm_sc) | |
416 | { | |
417 | #ifdef CONFIG_ALTIVEC | |
418 | elf_vrreg_t __user *v_regs, *tm_v_regs; | |
419 | #endif | |
420 | unsigned long err = 0; | |
421 | unsigned long msr; | |
422 | struct pt_regs *regs = tsk->thread.regs; | |
423 | #ifdef CONFIG_VSX | |
424 | int i; | |
425 | #endif | |
426 | ||
427 | BUG_ON(tsk != current); | |
428 | ||
429 | if (tm_suspend_disabled) | |
430 | return -EINVAL; | |
431 | ||
432 | /* copy the GPRs */ | |
433 | err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr)); | |
434 | err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs, | |
435 | sizeof(regs->gpr)); | |
436 | ||
437 | /* | |
438 | * TFHAR is restored from the checkpointed 'wound-back' ucontext's NIP. | |
439 | * TEXASR was set by the signal delivery reclaim, as was TFIAR. | |
440 | * Users doing anything abhorrent like thread-switching w/ signals for | |
441 | * TM-Suspended code will have to back TEXASR/TFIAR up themselves. | |
442 | * For the case of getting a signal and simply returning from it, | |
443 | * we don't need to re-copy them here. | |
444 | */ | |
445 | err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]); | |
446 | err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]); | |
447 | ||
448 | /* get MSR separately, transfer the LE bit if doing signal return */ | |
449 | err |= __get_user(msr, &sc->gp_regs[PT_MSR]); | |
450 | /* Don't allow reserved mode. */ | |
451 | if (MSR_TM_RESV(msr)) | |
452 | return -EINVAL; | |
453 | ||
454 | /* pull in MSR LE from user context */ | |
455 | regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); | |
456 | ||
457 | /* The following non-GPR non-FPR non-VR state is also checkpointed: */ | |
458 | err |= __get_user(regs->ctr, &tm_sc->gp_regs[PT_CTR]); | |
459 | err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]); | |
460 | err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]); | |
461 | err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]); | |
462 | err |= __get_user(tsk->thread.ckpt_regs.ctr, | |
463 | &sc->gp_regs[PT_CTR]); | |
464 | err |= __get_user(tsk->thread.ckpt_regs.link, | |
465 | &sc->gp_regs[PT_LNK]); | |
466 | err |= __get_user(tsk->thread.ckpt_regs.xer, | |
467 | &sc->gp_regs[PT_XER]); | |
468 | err |= __get_user(tsk->thread.ckpt_regs.ccr, | |
469 | &sc->gp_regs[PT_CCR]); | |
470 | /* Don't allow userspace to set SOFTE */ | |
471 | set_trap_norestart(regs); | |
472 | /* These regs are not checkpointed; they can go in 'regs'. */ | |
473 | err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); | |
474 | err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); | |
475 | err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); | |
476 | ||
477 | /* | |
478 | * Force reload of FP/VEC. | |
479 | * This has to be done before copying stuff into tsk->thread.fpr/vr | |
480 | * for the reasons explained in the previous comment. | |
481 | */ | |
482 | regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX); | |
483 | ||
484 | #ifdef CONFIG_ALTIVEC | |
485 | err |= __get_user(v_regs, &sc->v_regs); | |
486 | err |= __get_user(tm_v_regs, &tm_sc->v_regs); | |
487 | if (err) | |
488 | return err; | |
489 | if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128))) | |
490 | return -EFAULT; | |
491 | if (tm_v_regs && !access_ok(tm_v_regs, 34 * sizeof(vector128))) | |
492 | return -EFAULT; | |
493 | /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ | |
494 | if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) { | |
495 | err |= __copy_from_user(&tsk->thread.ckvr_state, v_regs, | |
496 | 33 * sizeof(vector128)); | |
497 | err |= __copy_from_user(&tsk->thread.vr_state, tm_v_regs, | |
498 | 33 * sizeof(vector128)); | |
499 | current->thread.used_vr = true; | |
500 | } | |
501 | else if (tsk->thread.used_vr) { | |
502 | memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128)); | |
503 | memset(&tsk->thread.ckvr_state, 0, 33 * sizeof(vector128)); | |
504 | } | |
505 | /* Always get VRSAVE back */ | |
506 | if (v_regs != NULL && tm_v_regs != NULL) { | |
507 | err |= __get_user(tsk->thread.ckvrsave, | |
508 | (u32 __user *)&v_regs[33]); | |
509 | err |= __get_user(tsk->thread.vrsave, | |
510 | (u32 __user *)&tm_v_regs[33]); | |
511 | } | |
512 | else { | |
513 | tsk->thread.vrsave = 0; | |
514 | tsk->thread.ckvrsave = 0; | |
515 | } | |
516 | if (cpu_has_feature(CPU_FTR_ALTIVEC)) | |
517 | mtspr(SPRN_VRSAVE, tsk->thread.vrsave); | |
518 | #endif /* CONFIG_ALTIVEC */ | |
519 | /* restore floating point */ | |
520 | err |= copy_fpr_from_user(tsk, &tm_sc->fp_regs); | |
521 | err |= copy_ckfpr_from_user(tsk, &sc->fp_regs); | |
522 | #ifdef CONFIG_VSX | |
523 | /* | |
524 | * Get additional VSX data. Update v_regs to point after the | |
525 | * VMX data. Copy VSX low doubleword from userspace to local | |
526 | * buffer for formatting, then into the taskstruct. | |
527 | */ | |
528 | if (v_regs && ((msr & MSR_VSX) != 0)) { | |
529 | v_regs += ELF_NVRREG; | |
530 | tm_v_regs += ELF_NVRREG; | |
531 | err |= copy_vsx_from_user(tsk, tm_v_regs); | |
532 | err |= copy_ckvsx_from_user(tsk, v_regs); | |
533 | tsk->thread.used_vsr = true; | |
534 | } else { | |
535 | for (i = 0; i < 32 ; i++) { | |
536 | tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0; | |
537 | tsk->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = 0; | |
538 | } | |
539 | } | |
540 | #endif | |
541 | tm_enable(); | |
542 | /* Make sure the transaction is marked as failed */ | |
543 | tsk->thread.tm_texasr |= TEXASR_FS; | |
544 | ||
545 | /* | |
546 | * Disabling preemption, since it is unsafe to be preempted | |
547 | * with MSR[TS] set without recheckpointing. | |
548 | */ | |
549 | preempt_disable(); | |
550 | ||
551 | /* pull in MSR TS bits from user context */ | |
552 | regs->msr |= msr & MSR_TS_MASK; | |
553 | ||
554 | /* | |
555 | * Ensure that TM is enabled in regs->msr before we leave the signal | |
556 | * handler. It could be the case that (a) user disabled the TM bit | |
557 | * through the manipulation of the MSR bits in uc_mcontext or (b) the | |
558 | * TM bit was disabled because a sufficient number of context switches | |
559 | * happened whilst in the signal handler and load_tm overflowed, | |
560 | * disabling the TM bit. In either case we can end up with an illegal | |
561 | * TM state leading to a TM Bad Thing when we return to userspace. | |
562 | * | |
563 | * CAUTION: | |
564 | * After regs->MSR[TS] being updated, make sure that get_user(), | |
565 | * put_user() or similar functions are *not* called. These | |
566 | * functions can generate page faults which will cause the process | |
567 | * to be de-scheduled with MSR[TS] set but without calling | |
568 | * tm_recheckpoint(). This can cause a bug. | |
569 | */ | |
570 | regs->msr |= MSR_TM; | |
571 | ||
572 | /* This loads the checkpointed FP/VEC state, if used */ | |
573 | tm_recheckpoint(&tsk->thread); | |
574 | ||
575 | msr_check_and_set(msr & (MSR_FP | MSR_VEC)); | |
576 | if (msr & MSR_FP) { | |
577 | load_fp_state(&tsk->thread.fp_state); | |
578 | regs->msr |= (MSR_FP | tsk->thread.fpexc_mode); | |
579 | } | |
580 | if (msr & MSR_VEC) { | |
581 | load_vr_state(&tsk->thread.vr_state); | |
582 | regs->msr |= MSR_VEC; | |
583 | } | |
584 | ||
585 | preempt_enable(); | |
586 | ||
587 | return err; | |
588 | } | |
589 | #endif | |
590 | ||
591 | /* | |
592 | * Setup the trampoline code on the stack | |
593 | */ | |
594 | static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) | |
595 | { | |
596 | int i; | |
597 | long err = 0; | |
598 | ||
599 | /* bctrl # call the handler */ | |
600 | err |= __put_user(PPC_INST_BCTRL, &tramp[0]); | |
601 | /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ | |
602 | err |= __put_user(PPC_INST_ADDI | __PPC_RT(R1) | __PPC_RA(R1) | | |
603 | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[1]); | |
604 | /* li r0, __NR_[rt_]sigreturn| */ | |
605 | err |= __put_user(PPC_INST_ADDI | (syscall & 0xffff), &tramp[2]); | |
606 | /* sc */ | |
607 | err |= __put_user(PPC_INST_SC, &tramp[3]); | |
608 | ||
609 | /* Minimal traceback info */ | |
610 | for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) | |
611 | err |= __put_user(0, &tramp[i]); | |
612 | ||
613 | if (!err) | |
614 | flush_icache_range((unsigned long) &tramp[0], | |
615 | (unsigned long) &tramp[TRAMP_SIZE]); | |
616 | ||
617 | return err; | |
618 | } | |
619 | ||
620 | /* | |
621 | * Userspace code may pass a ucontext which doesn't include VSX added | |
622 | * at the end. We need to check for this case. | |
623 | */ | |
624 | #define UCONTEXTSIZEWITHOUTVSX \ | |
625 | (sizeof(struct ucontext) - 32*sizeof(long)) | |
626 | ||
627 | /* | |
628 | * Handle {get,set,swap}_context operations | |
629 | */ | |
630 | SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, | |
631 | struct ucontext __user *, new_ctx, long, ctx_size) | |
632 | { | |
633 | sigset_t set; | |
634 | unsigned long new_msr = 0; | |
635 | int ctx_has_vsx_region = 0; | |
636 | ||
637 | if (new_ctx && | |
638 | get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR])) | |
639 | return -EFAULT; | |
640 | /* | |
641 | * Check that the context is not smaller than the original | |
642 | * size (with VMX but without VSX) | |
643 | */ | |
644 | if (ctx_size < UCONTEXTSIZEWITHOUTVSX) | |
645 | return -EINVAL; | |
646 | /* | |
647 | * If the new context state sets the MSR VSX bits but | |
648 | * it doesn't provide VSX state. | |
649 | */ | |
650 | if ((ctx_size < sizeof(struct ucontext)) && | |
651 | (new_msr & MSR_VSX)) | |
652 | return -EINVAL; | |
653 | /* Does the context have enough room to store VSX data? */ | |
654 | if (ctx_size >= sizeof(struct ucontext)) | |
655 | ctx_has_vsx_region = 1; | |
656 | ||
657 | if (old_ctx != NULL) { | |
658 | if (!access_ok(old_ctx, ctx_size) | |
659 | || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0, | |
660 | ctx_has_vsx_region) | |
661 | || __copy_to_user(&old_ctx->uc_sigmask, | |
662 | ¤t->blocked, sizeof(sigset_t))) | |
663 | return -EFAULT; | |
664 | } | |
665 | if (new_ctx == NULL) | |
666 | return 0; | |
667 | if (!access_ok(new_ctx, ctx_size) || | |
668 | fault_in_pages_readable((u8 __user *)new_ctx, ctx_size)) | |
669 | return -EFAULT; | |
670 | ||
671 | /* | |
672 | * If we get a fault copying the context into the kernel's | |
673 | * image of the user's registers, we can't just return -EFAULT | |
674 | * because the user's registers will be corrupted. For instance | |
675 | * the NIP value may have been updated but not some of the | |
676 | * other registers. Given that we have done the access_ok | |
677 | * and successfully read the first and last bytes of the region | |
678 | * above, this should only happen in an out-of-memory situation | |
679 | * or if another thread unmaps the region containing the context. | |
680 | * We kill the task with a SIGSEGV in this situation. | |
681 | */ | |
682 | ||
683 | if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) | |
684 | do_exit(SIGSEGV); | |
685 | set_current_blocked(&set); | |
686 | if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext)) | |
687 | do_exit(SIGSEGV); | |
688 | ||
689 | /* This returns like rt_sigreturn */ | |
690 | set_thread_flag(TIF_RESTOREALL); | |
691 | return 0; | |
692 | } | |
693 | ||
694 | ||
695 | /* | |
696 | * Do a signal return; undo the signal stack. | |
697 | */ | |
698 | ||
699 | SYSCALL_DEFINE0(rt_sigreturn) | |
700 | { | |
701 | struct pt_regs *regs = current_pt_regs(); | |
702 | struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; | |
703 | sigset_t set; | |
704 | #ifdef CONFIG_PPC_TRANSACTIONAL_MEM | |
705 | unsigned long msr; | |
706 | #endif | |
707 | ||
708 | /* Always make any pending restarted system calls return -EINTR */ | |
709 | current->restart_block.fn = do_no_restart_syscall; | |
710 | ||
711 | if (!access_ok(uc, sizeof(*uc))) | |
712 | goto badframe; | |
713 | ||
714 | if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) | |
715 | goto badframe; | |
716 | set_current_blocked(&set); | |
717 | ||
718 | #ifdef CONFIG_PPC_TRANSACTIONAL_MEM | |
719 | /* | |
720 | * If there is a transactional state then throw it away. | |
721 | * The purpose of a sigreturn is to destroy all traces of the | |
722 | * signal frame, this includes any transactional state created | |
723 | * within in. We only check for suspended as we can never be | |
724 | * active in the kernel, we are active, there is nothing better to | |
725 | * do than go ahead and Bad Thing later. | |
726 | * The cause is not important as there will never be a | |
727 | * recheckpoint so it's not user visible. | |
728 | */ | |
729 | if (MSR_TM_SUSPENDED(mfmsr())) | |
730 | tm_reclaim_current(0); | |
731 | ||
732 | /* | |
733 | * Disable MSR[TS] bit also, so, if there is an exception in the | |
734 | * code below (as a page fault in copy_ckvsx_to_user()), it does | |
735 | * not recheckpoint this task if there was a context switch inside | |
736 | * the exception. | |
737 | * | |
738 | * A major page fault can indirectly call schedule(). A reschedule | |
739 | * process in the middle of an exception can have a side effect | |
740 | * (Changing the CPU MSR[TS] state), since schedule() is called | |
741 | * with the CPU MSR[TS] disable and returns with MSR[TS]=Suspended | |
742 | * (switch_to() calls tm_recheckpoint() for the 'new' process). In | |
743 | * this case, the process continues to be the same in the CPU, but | |
744 | * the CPU state just changed. | |
745 | * | |
746 | * This can cause a TM Bad Thing, since the MSR in the stack will | |
747 | * have the MSR[TS]=0, and this is what will be used to RFID. | |
748 | * | |
749 | * Clearing MSR[TS] state here will avoid a recheckpoint if there | |
750 | * is any process reschedule in kernel space. The MSR[TS] state | |
751 | * does not need to be saved also, since it will be replaced with | |
752 | * the MSR[TS] that came from user context later, at | |
753 | * restore_tm_sigcontexts. | |
754 | */ | |
755 | regs->msr &= ~MSR_TS_MASK; | |
756 | ||
757 | if (__get_user(msr, &uc->uc_mcontext.gp_regs[PT_MSR])) | |
758 | goto badframe; | |
759 | if (MSR_TM_ACTIVE(msr)) { | |
760 | /* We recheckpoint on return. */ | |
761 | struct ucontext __user *uc_transact; | |
762 | ||
763 | /* Trying to start TM on non TM system */ | |
764 | if (!cpu_has_feature(CPU_FTR_TM)) | |
765 | goto badframe; | |
766 | ||
767 | if (__get_user(uc_transact, &uc->uc_link)) | |
768 | goto badframe; | |
769 | if (restore_tm_sigcontexts(current, &uc->uc_mcontext, | |
770 | &uc_transact->uc_mcontext)) | |
771 | goto badframe; | |
772 | } else | |
773 | #endif | |
774 | { | |
775 | /* | |
776 | * Fall through, for non-TM restore | |
777 | * | |
778 | * Unset MSR[TS] on the thread regs since MSR from user | |
779 | * context does not have MSR active, and recheckpoint was | |
780 | * not called since restore_tm_sigcontexts() was not called | |
781 | * also. | |
782 | * | |
783 | * If not unsetting it, the code can RFID to userspace with | |
784 | * MSR[TS] set, but without CPU in the proper state, | |
785 | * causing a TM bad thing. | |
786 | */ | |
787 | current->thread.regs->msr &= ~MSR_TS_MASK; | |
788 | if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) | |
789 | goto badframe; | |
790 | } | |
791 | ||
792 | if (restore_altstack(&uc->uc_stack)) | |
793 | goto badframe; | |
794 | ||
795 | set_thread_flag(TIF_RESTOREALL); | |
796 | return 0; | |
797 | ||
798 | badframe: | |
799 | signal_fault(current, regs, "rt_sigreturn", uc); | |
800 | ||
801 | force_sig(SIGSEGV); | |
802 | return 0; | |
803 | } | |
804 | ||
805 | int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, | |
806 | struct task_struct *tsk) | |
807 | { | |
808 | struct rt_sigframe __user *frame; | |
809 | unsigned long newsp = 0; | |
810 | long err = 0; | |
811 | struct pt_regs *regs = tsk->thread.regs; | |
812 | #ifdef CONFIG_PPC_TRANSACTIONAL_MEM | |
813 | /* Save the thread's msr before get_tm_stackpointer() changes it */ | |
814 | unsigned long msr = regs->msr; | |
815 | #endif | |
816 | ||
817 | frame = get_sigframe(ksig, tsk, sizeof(*frame), 0); | |
818 | if (!access_ok(frame, sizeof(*frame))) | |
819 | goto badframe; | |
820 | ||
821 | err |= __put_user(&frame->info, &frame->pinfo); | |
822 | err |= __put_user(&frame->uc, &frame->puc); | |
823 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); | |
824 | if (err) | |
825 | goto badframe; | |
826 | ||
827 | /* Create the ucontext. */ | |
828 | err |= __put_user(0, &frame->uc.uc_flags); | |
829 | err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]); | |
830 | #ifdef CONFIG_PPC_TRANSACTIONAL_MEM | |
831 | if (MSR_TM_ACTIVE(msr)) { | |
832 | /* The ucontext_t passed to userland points to the second | |
833 | * ucontext_t (for transactional state) with its uc_link ptr. | |
834 | */ | |
835 | err |= __put_user(&frame->uc_transact, &frame->uc.uc_link); | |
836 | err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext, | |
837 | &frame->uc_transact.uc_mcontext, | |
838 | tsk, ksig->sig, NULL, | |
839 | (unsigned long)ksig->ka.sa.sa_handler, | |
840 | msr); | |
841 | } else | |
842 | #endif | |
843 | { | |
844 | err |= __put_user(0, &frame->uc.uc_link); | |
845 | err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig, | |
846 | NULL, (unsigned long)ksig->ka.sa.sa_handler, | |
847 | 1); | |
848 | } | |
849 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
850 | if (err) | |
851 | goto badframe; | |
852 | ||
853 | /* Make sure signal handler doesn't get spurious FP exceptions */ | |
854 | tsk->thread.fp_state.fpscr = 0; | |
855 | ||
856 | /* Set up to return from userspace. */ | |
857 | if (tsk->mm->context.vdso) { | |
858 | regs->nip = VDSO64_SYMBOL(tsk->mm->context.vdso, sigtramp_rt64); | |
859 | } else { | |
860 | err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); | |
861 | if (err) | |
862 | goto badframe; | |
863 | regs->nip = (unsigned long) &frame->tramp[0]; | |
864 | } | |
865 | ||
866 | /* Allocate a dummy caller frame for the signal handler. */ | |
867 | newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE; | |
868 | err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); | |
869 | ||
870 | /* Set up "regs" so we "return" to the signal handler. */ | |
871 | if (is_elf2_task()) { | |
872 | regs->ctr = (unsigned long) ksig->ka.sa.sa_handler; | |
873 | regs->gpr[12] = regs->ctr; | |
874 | } else { | |
875 | /* Handler is *really* a pointer to the function descriptor for | |
876 | * the signal routine. The first entry in the function | |
877 | * descriptor is the entry address of signal and the second | |
878 | * entry is the TOC value we need to use. | |
879 | */ | |
880 | func_descr_t __user *funct_desc_ptr = | |
881 | (func_descr_t __user *) ksig->ka.sa.sa_handler; | |
882 | ||
883 | err |= get_user(regs->ctr, &funct_desc_ptr->entry); | |
884 | err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); | |
885 | } | |
886 | ||
887 | /* enter the signal handler in native-endian mode */ | |
888 | regs->msr &= ~MSR_LE; | |
889 | regs->msr |= (MSR_KERNEL & MSR_LE); | |
890 | regs->gpr[1] = newsp; | |
891 | regs->gpr[3] = ksig->sig; | |
892 | regs->result = 0; | |
893 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { | |
894 | err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); | |
895 | err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); | |
896 | regs->gpr[6] = (unsigned long) frame; | |
897 | } else { | |
898 | regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; | |
899 | } | |
900 | if (err) | |
901 | goto badframe; | |
902 | ||
903 | return 0; | |
904 | ||
905 | badframe: | |
906 | signal_fault(current, regs, "handle_rt_signal64", frame); | |
907 | ||
908 | return 1; | |
909 | } |