]> bbs.cooldavid.org Git - net-next-2.6.git/blame - arch/powerpc/kernel/signal_64.c
Merge branch 'fix/asoc' into for-linus
[net-next-2.6.git] / arch / powerpc / kernel / signal_64.c
CommitLineData
1da177e4 1/*
1da177e4
LT
2 * PowerPC version
3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 *
5 * Derived from "arch/i386/kernel/signal.c"
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
1da177e4
LT
15#include <linux/sched.h>
16#include <linux/mm.h>
17#include <linux/smp.h>
1da177e4
LT
18#include <linux/kernel.h>
19#include <linux/signal.h>
20#include <linux/errno.h>
21#include <linux/wait.h>
22#include <linux/unistd.h>
23#include <linux/stddef.h>
24#include <linux/elf.h>
25#include <linux/ptrace.h>
26#include <linux/module.h>
27
28#include <asm/sigcontext.h>
29#include <asm/ucontext.h>
30#include <asm/uaccess.h>
31#include <asm/pgtable.h>
1da177e4
LT
32#include <asm/unistd.h>
33#include <asm/cacheflush.h>
a7f31841 34#include <asm/syscalls.h>
1da177e4
LT
35#include <asm/vdso.h>
36
22e38f29 37#include "signal.h"
1da177e4 38
1da177e4 39#define DEBUG_SIG 0
1da177e4 40
6741f3a7 41#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
1da177e4
LT
42#define FP_REGS_SIZE sizeof(elf_fpregset_t)
43
44#define TRAMP_TRACEBACK 3
45#define TRAMP_SIZE 6
46
47/*
48 * When we have signals to deliver, we set up on the user stack,
49 * going down from the original stack pointer:
50 * 1) a rt_sigframe struct which contains the ucontext
51 * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
52 * frame for the signal handler.
53 */
54
55struct rt_sigframe {
56 /* sys_rt_sigreturn requires the ucontext be the first field */
57 struct ucontext uc;
58 unsigned long _unused[2];
59 unsigned int tramp[TRAMP_SIZE];
29e646df
AV
60 struct siginfo __user *pinfo;
61 void __user *puc;
1da177e4
LT
62 struct siginfo info;
63 /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
64 char abigap[288];
65} __attribute__ ((aligned (16)));
66
d0c3d534
OJ
67static const char fmt32[] = KERN_INFO \
68 "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
69static const char fmt64[] = KERN_INFO \
70 "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
71
1da177e4
LT
72/*
73 * Set up the sigcontext for the signal frame.
74 */
75
76static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
16c29d18
MN
77 int signr, sigset_t *set, unsigned long handler,
78 int ctx_has_vsx_region)
1da177e4
LT
79{
80 /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
81 * process never used altivec yet (MSR_VEC is zero in pt_regs of
82 * the context). This is very important because we must ensure we
83 * don't lose the VRSAVE content that may have been set prior to
84 * the process doing its first vector operation
85 * Userland shall check AT_HWCAP to know wether it can rely on the
86 * v_regs pointer or not
87 */
88#ifdef CONFIG_ALTIVEC
89 elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
90#endif
0be234a4 91 unsigned long msr = regs->msr;
1da177e4
LT
92 long err = 0;
93
94 flush_fp_to_thread(current);
95
1da177e4
LT
96#ifdef CONFIG_ALTIVEC
97 err |= __put_user(v_regs, &sc->v_regs);
98
99 /* save altivec registers */
100 if (current->thread.used_vr) {
101 flush_altivec_to_thread(current);
102 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
103 err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128));
104 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
105 * contains valid data.
106 */
0be234a4 107 msr |= MSR_VEC;
1da177e4
LT
108 }
109 /* We always copy to/from vrsave, it's 0 if we don't have or don't
110 * use altivec.
111 */
112 err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
113#else /* CONFIG_ALTIVEC */
114 err |= __put_user(0, &sc->v_regs);
115#endif /* CONFIG_ALTIVEC */
c6e6771b 116 flush_fp_to_thread(current);
6a274c08
MN
117 /* copy fpr regs and fpscr */
118 err |= copy_fpr_to_user(&sc->fp_regs, current);
c6e6771b 119#ifdef CONFIG_VSX
ce48b210
MN
120 /*
121 * Copy VSX low doubleword to local buffer for formatting,
122 * then out to userspace. Update v_regs to point after the
123 * VMX data.
124 */
16c29d18 125 if (current->thread.used_vsr && ctx_has_vsx_region) {
7c292170 126 __giveup_vsx(current);
ce48b210 127 v_regs += ELF_NVRREG;
6a274c08 128 err |= copy_vsx_to_user(v_regs, current);
ce48b210
MN
129 /* set MSR_VSX in the MSR value in the frame to
130 * indicate that sc->vs_reg) contains valid data.
131 */
132 msr |= MSR_VSX;
133 }
c6e6771b 134#endif /* CONFIG_VSX */
1da177e4 135 err |= __put_user(&sc->gp_regs, &sc->regs);
1bd79336 136 WARN_ON(!FULL_REGS(regs));
1da177e4 137 err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
0be234a4 138 err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
1da177e4
LT
139 err |= __put_user(signr, &sc->signal);
140 err |= __put_user(handler, &sc->handler);
141 if (set != NULL)
142 err |= __put_user(set->sig[0], &sc->oldmask);
143
144 return err;
145}
146
147/*
148 * Restore the sigcontext from the signal frame.
149 */
150
151static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
152 struct sigcontext __user *sc)
153{
154#ifdef CONFIG_ALTIVEC
155 elf_vrreg_t __user *v_regs;
156#endif
157 unsigned long err = 0;
158 unsigned long save_r13 = 0;
1da177e4 159 unsigned long msr;
6a274c08
MN
160#ifdef CONFIG_VSX
161 int i;
162#endif
1da177e4
LT
163
164 /* If this is not a signal return, we preserve the TLS in r13 */
165 if (!sig)
166 save_r13 = regs->gpr[13];
167
fcbc5a97
SR
168 /* copy the GPRs */
169 err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
170 err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
fab5db97
PM
171 /* get MSR separately, transfer the LE bit if doing signal return */
172 err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
173 if (sig)
174 regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
fcbc5a97
SR
175 err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
176 err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
177 err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
178 err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
179 err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
fab5db97 180 /* skip SOFTE */
9a81c16b 181 regs->trap = 0;
fcbc5a97
SR
182 err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
183 err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
184 err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
1da177e4
LT
185
186 if (!sig)
187 regs->gpr[13] = save_r13;
1da177e4
LT
188 if (set != NULL)
189 err |= __get_user(set->sig[0], &sc->oldmask);
190
5388fb10
PM
191 /*
192 * Do this before updating the thread state in
193 * current->thread.fpr/vr. That way, if we get preempted
194 * and another task grabs the FPU/Altivec, it won't be
195 * tempted to save the current CPU state into the thread_struct
196 * and corrupt what we are writing there.
197 */
198 discard_lazy_cpu_state();
199
ae62fbb5
PM
200 /*
201 * Force reload of FP/VEC.
202 * This has to be done before copying stuff into current->thread.fpr/vr
203 * for the reasons explained in the previous comment.
204 */
ce48b210 205 regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
ae62fbb5 206
1da177e4
LT
207#ifdef CONFIG_ALTIVEC
208 err |= __get_user(v_regs, &sc->v_regs);
1da177e4
LT
209 if (err)
210 return err;
7c85d1f9
PM
211 if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
212 return -EFAULT;
1da177e4
LT
213 /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
214 if (v_regs != 0 && (msr & MSR_VEC) != 0)
215 err |= __copy_from_user(current->thread.vr, v_regs,
216 33 * sizeof(vector128));
217 else if (current->thread.used_vr)
218 memset(current->thread.vr, 0, 33 * sizeof(vector128));
219 /* Always get VRSAVE back */
220 if (v_regs != 0)
221 err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
222 else
223 current->thread.vrsave = 0;
224#endif /* CONFIG_ALTIVEC */
c6e6771b 225 /* restore floating point */
6a274c08
MN
226 err |= copy_fpr_from_user(current, &sc->fp_regs);
227#ifdef CONFIG_VSX
ce48b210
MN
228 /*
229 * Get additional VSX data. Update v_regs to point after the
230 * VMX data. Copy VSX low doubleword from userspace to local
231 * buffer for formatting, then into the taskstruct.
232 */
233 v_regs += ELF_NVRREG;
234 if ((msr & MSR_VSX) != 0)
6a274c08 235 err |= copy_vsx_from_user(current, v_regs);
ce48b210 236 else
6a274c08
MN
237 for (i = 0; i < 32 ; i++)
238 current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
c6e6771b 239#endif
1da177e4
LT
240 return err;
241}
242
1da177e4
LT
243/*
244 * Setup the trampoline code on the stack
245 */
246static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
247{
248 int i;
249 long err = 0;
250
251 /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
252 err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
253 /* li r0, __NR_[rt_]sigreturn| */
254 err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
255 /* sc */
256 err |= __put_user(0x44000002UL, &tramp[2]);
257
258 /* Minimal traceback info */
259 for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
260 err |= __put_user(0, &tramp[i]);
261
262 if (!err)
263 flush_icache_range((unsigned long) &tramp[0],
264 (unsigned long) &tramp[TRAMP_SIZE]);
265
266 return err;
267}
268
c1cb299e
MN
269/*
270 * Userspace code may pass a ucontext which doesn't include VSX added
271 * at the end. We need to check for this case.
272 */
273#define UCONTEXTSIZEWITHOUTVSX \
274 (sizeof(struct ucontext) - 32*sizeof(long))
275
1da177e4
LT
276/*
277 * Handle {get,set,swap}_context operations
278 */
279int sys_swapcontext(struct ucontext __user *old_ctx,
280 struct ucontext __user *new_ctx,
281 long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
282{
283 unsigned char tmp;
284 sigset_t set;
c1cb299e 285 unsigned long new_msr = 0;
16c29d18 286 int ctx_has_vsx_region = 0;
1da177e4 287
c1cb299e 288 if (new_ctx &&
16c29d18 289 get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
c1cb299e
MN
290 return -EFAULT;
291 /*
292 * Check that the context is not smaller than the original
293 * size (with VMX but without VSX)
1da177e4 294 */
c1cb299e 295 if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
1da177e4 296 return -EINVAL;
c1cb299e
MN
297 /*
298 * If the new context state sets the MSR VSX bits but
299 * it doesn't provide VSX state.
300 */
301 if ((ctx_size < sizeof(struct ucontext)) &&
302 (new_msr & MSR_VSX))
303 return -EINVAL;
16c29d18
MN
304 /* Does the context have enough room to store VSX data? */
305 if (ctx_size >= sizeof(struct ucontext))
306 ctx_has_vsx_region = 1;
307
1da177e4 308 if (old_ctx != NULL) {
16c29d18
MN
309 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
310 || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
311 ctx_has_vsx_region)
1da177e4
LT
312 || __copy_to_user(&old_ctx->uc_sigmask,
313 &current->blocked, sizeof(sigset_t)))
314 return -EFAULT;
315 }
316 if (new_ctx == NULL)
317 return 0;
16c29d18 318 if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
1da177e4 319 || __get_user(tmp, (u8 __user *) new_ctx)
16c29d18 320 || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
1da177e4
LT
321 return -EFAULT;
322
323 /*
324 * If we get a fault copying the context into the kernel's
325 * image of the user's registers, we can't just return -EFAULT
326 * because the user's registers will be corrupted. For instance
327 * the NIP value may have been updated but not some of the
328 * other registers. Given that we have done the access_ok
329 * and successfully read the first and last bytes of the region
330 * above, this should only happen in an out-of-memory situation
331 * or if another thread unmaps the region containing the context.
332 * We kill the task with a SIGSEGV in this situation.
333 */
334
335 if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
336 do_exit(SIGSEGV);
337 restore_sigmask(&set);
338 if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
339 do_exit(SIGSEGV);
340
341 /* This returns like rt_sigreturn */
401d1f02 342 set_thread_flag(TIF_RESTOREALL);
1da177e4
LT
343 return 0;
344}
345
346
347/*
348 * Do a signal return; undo the signal stack.
349 */
350
351int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
352 unsigned long r6, unsigned long r7, unsigned long r8,
353 struct pt_regs *regs)
354{
355 struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
356 sigset_t set;
357
358 /* Always make any pending restarted system calls return -EINTR */
359 current_thread_info()->restart_block.fn = do_no_restart_syscall;
360
361 if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
362 goto badframe;
363
364 if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
365 goto badframe;
366 restore_sigmask(&set);
367 if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
368 goto badframe;
369
370 /* do_sigaltstack expects a __user pointer and won't modify
371 * what's in there anyway
372 */
373 do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
374
401d1f02
DW
375 set_thread_flag(TIF_RESTOREALL);
376 return 0;
1da177e4
LT
377
378badframe:
379#if DEBUG_SIG
380 printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
381 regs, uc, &uc->uc_mcontext);
382#endif
d0c3d534
OJ
383 if (show_unhandled_signals && printk_ratelimit())
384 printk(regs->msr & MSR_SF ? fmt64 : fmt32,
385 current->comm, current->pid, "rt_sigreturn",
386 (long)uc, regs->nip, regs->link);
387
1da177e4
LT
388 force_sig(SIGSEGV, current);
389 return 0;
390}
391
f478f543 392int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
1da177e4
LT
393 sigset_t *set, struct pt_regs *regs)
394{
395 /* Handler is *really* a pointer to the function descriptor for
396 * the signal routine. The first entry in the function
397 * descriptor is the entry address of signal and the second
398 * entry is the TOC value we need to use.
399 */
400 func_descr_t __user *funct_desc_ptr;
401 struct rt_sigframe __user *frame;
402 unsigned long newsp = 0;
403 long err = 0;
404
efbda860 405 frame = get_sigframe(ka, regs, sizeof(*frame), 0);
a3f61dc0 406 if (unlikely(frame == NULL))
1da177e4
LT
407 goto badframe;
408
409 err |= __put_user(&frame->info, &frame->pinfo);
410 err |= __put_user(&frame->uc, &frame->puc);
411 err |= copy_siginfo_to_user(&frame->info, info);
412 if (err)
413 goto badframe;
414
415 /* Create the ucontext. */
416 err |= __put_user(0, &frame->uc.uc_flags);
417 err |= __put_user(0, &frame->uc.uc_link);
418 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
419 err |= __put_user(sas_ss_flags(regs->gpr[1]),
420 &frame->uc.uc_stack.ss_flags);
421 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
422 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
16c29d18 423 (unsigned long)ka->sa.sa_handler, 1);
1da177e4
LT
424 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
425 if (err)
426 goto badframe;
427
cc657f53
PM
428 /* Make sure signal handler doesn't get spurious FP exceptions */
429 current->thread.fpscr.val = 0;
430
1da177e4 431 /* Set up to return from userspace. */
a5bba930
BH
432 if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
433 regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
1da177e4
LT
434 } else {
435 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
436 if (err)
437 goto badframe;
438 regs->link = (unsigned long) &frame->tramp[0];
439 }
440 funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler;
441
442 /* Allocate a dummy caller frame for the signal handler. */
a3f61dc0 443 newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
1da177e4
LT
444 err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
445
446 /* Set up "regs" so we "return" to the signal handler. */
447 err |= get_user(regs->nip, &funct_desc_ptr->entry);
fab5db97
PM
448 /* enter the signal handler in big-endian mode */
449 regs->msr &= ~MSR_LE;
1da177e4
LT
450 regs->gpr[1] = newsp;
451 err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
452 regs->gpr[3] = signr;
453 regs->result = 0;
454 if (ka->sa.sa_flags & SA_SIGINFO) {
455 err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
456 err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
457 regs->gpr[6] = (unsigned long) frame;
458 } else {
459 regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
460 }
461 if (err)
462 goto badframe;
463
1da177e4
LT
464 return 1;
465
466badframe:
467#if DEBUG_SIG
468 printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
469 regs, frame, newsp);
470#endif
d0c3d534
OJ
471 if (show_unhandled_signals && printk_ratelimit())
472 printk(regs->msr & MSR_SF ? fmt64 : fmt32,
473 current->comm, current->pid, "setup_rt_frame",
474 (long)frame, regs->nip, regs->link);
475
1da177e4
LT
476 force_sigsegv(signr, current);
477 return 0;
478}