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v4.6
  1/*
  2 *  arch/sparc64/kernel/signal.c
  3 *
  4 *  Copyright (C) 1991, 1992  Linus Torvalds
  5 *  Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
  6 *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
  7 *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
  8 *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
  9 */
 10
 11#ifdef CONFIG_COMPAT
 12#include <linux/compat.h>	/* for compat_old_sigset_t */
 13#endif
 14#include <linux/sched.h>
 15#include <linux/kernel.h>
 16#include <linux/signal.h>
 17#include <linux/errno.h>
 18#include <linux/wait.h>
 19#include <linux/ptrace.h>
 20#include <linux/tracehook.h>
 21#include <linux/unistd.h>
 22#include <linux/mm.h>
 23#include <linux/tty.h>
 24#include <linux/binfmts.h>
 25#include <linux/bitops.h>
 26#include <linux/context_tracking.h>
 27
 28#include <asm/uaccess.h>
 29#include <asm/ptrace.h>
 30#include <asm/pgtable.h>
 31#include <asm/fpumacro.h>
 32#include <asm/uctx.h>
 33#include <asm/siginfo.h>
 34#include <asm/visasm.h>
 35#include <asm/switch_to.h>
 36#include <asm/cacheflush.h>
 37
 38#include "sigutil.h"
 39#include "systbls.h"
 40#include "kernel.h"
 41#include "entry.h"
 
 
 42
 43/* {set, get}context() needed for 64-bit SparcLinux userland. */
 44asmlinkage void sparc64_set_context(struct pt_regs *regs)
 45{
 46	struct ucontext __user *ucp = (struct ucontext __user *)
 47		regs->u_regs[UREG_I0];
 48	enum ctx_state prev_state = exception_enter();
 49	mc_gregset_t __user *grp;
 50	unsigned long pc, npc, tstate;
 51	unsigned long fp, i7;
 52	unsigned char fenab;
 53	int err;
 54
 55	synchronize_user_stack();
 56	if (get_thread_wsaved()					||
 57	    (((unsigned long)ucp) & (sizeof(unsigned long)-1))	||
 58	    (!__access_ok(ucp, sizeof(*ucp))))
 59		goto do_sigsegv;
 60	grp  = &ucp->uc_mcontext.mc_gregs;
 61	err  = __get_user(pc, &((*grp)[MC_PC]));
 62	err |= __get_user(npc, &((*grp)[MC_NPC]));
 63	if (err || ((pc | npc) & 3))
 64		goto do_sigsegv;
 65	if (regs->u_regs[UREG_I1]) {
 66		sigset_t set;
 67
 68		if (_NSIG_WORDS == 1) {
 69			if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
 70				goto do_sigsegv;
 71		} else {
 72			if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
 73				goto do_sigsegv;
 74		}
 75		set_current_blocked(&set);
 76	}
 77	if (test_thread_flag(TIF_32BIT)) {
 78		pc &= 0xffffffff;
 79		npc &= 0xffffffff;
 80	}
 81	regs->tpc = pc;
 82	regs->tnpc = npc;
 83	err |= __get_user(regs->y, &((*grp)[MC_Y]));
 84	err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
 85	regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 86	regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
 87	err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
 88	err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
 89	err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
 90	err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
 91	err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
 92	err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
 93
 94	/* Skip %g7 as that's the thread register in userspace.  */
 95
 96	err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
 97	err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
 98	err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
 99	err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
100	err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
101	err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
102	err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
103	err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
104
105	err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
106	err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
107	err |= __put_user(fp,
108	      (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
109	err |= __put_user(i7,
110	      (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
111
112	err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
113	if (fenab) {
114		unsigned long *fpregs = current_thread_info()->fpregs;
115		unsigned long fprs;
116		
117		fprs_write(0);
118		err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
119		if (fprs & FPRS_DL)
120			err |= copy_from_user(fpregs,
121					      &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
122					      (sizeof(unsigned int) * 32));
123		if (fprs & FPRS_DU)
124			err |= copy_from_user(fpregs+16,
125			 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
126			 (sizeof(unsigned int) * 32));
127		err |= __get_user(current_thread_info()->xfsr[0],
128				  &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
129		err |= __get_user(current_thread_info()->gsr[0],
130				  &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
131		regs->tstate &= ~TSTATE_PEF;
132	}
133	if (err)
134		goto do_sigsegv;
135out:
136	exception_exit(prev_state);
137	return;
138do_sigsegv:
139	force_sig(SIGSEGV, current);
140	goto out;
141}
142
143asmlinkage void sparc64_get_context(struct pt_regs *regs)
144{
145	struct ucontext __user *ucp = (struct ucontext __user *)
146		regs->u_regs[UREG_I0];
147	enum ctx_state prev_state = exception_enter();
148	mc_gregset_t __user *grp;
149	mcontext_t __user *mcp;
150	unsigned long fp, i7;
151	unsigned char fenab;
152	int err;
153
154	synchronize_user_stack();
155	if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
156		goto do_sigsegv;
157
158#if 1
159	fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
160#else
161	fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
162#endif
163		
164	mcp = &ucp->uc_mcontext;
165	grp = &mcp->mc_gregs;
166
167	/* Skip over the trap instruction, first. */
168	if (test_thread_flag(TIF_32BIT)) {
169		regs->tpc   = (regs->tnpc & 0xffffffff);
170		regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
171	} else {
172		regs->tpc   = regs->tnpc;
173		regs->tnpc += 4;
174	}
175	err = 0;
176	if (_NSIG_WORDS == 1)
177		err |= __put_user(current->blocked.sig[0],
178				  (unsigned long __user *)&ucp->uc_sigmask);
179	else
180		err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
181				      sizeof(sigset_t));
182
183	err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
184	err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
185	err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
186	err |= __put_user(regs->y, &((*grp)[MC_Y]));
187	err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
188	err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
189	err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
190	err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
191	err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
192	err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
193	err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
194	err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
195	err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
196	err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
197	err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
198	err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
199	err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
200	err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
201	err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
202
203	err |= __get_user(fp,
204		 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
205	err |= __get_user(i7,
206		 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
207	err |= __put_user(fp, &(mcp->mc_fp));
208	err |= __put_user(i7, &(mcp->mc_i7));
209
210	err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
211	if (fenab) {
212		unsigned long *fpregs = current_thread_info()->fpregs;
213		unsigned long fprs;
214		
215		fprs = current_thread_info()->fpsaved[0];
216		if (fprs & FPRS_DL)
217			err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
218					    (sizeof(unsigned int) * 32));
219		if (fprs & FPRS_DU)
220			err |= copy_to_user(
221                          ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
222			  (sizeof(unsigned int) * 32));
223		err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
224		err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
225		err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
226	}
227	if (err)
228		goto do_sigsegv;
229out:
230	exception_exit(prev_state);
231	return;
232do_sigsegv:
233	force_sig(SIGSEGV, current);
234	goto out;
235}
236
237struct rt_signal_frame {
238	struct sparc_stackf	ss;
239	siginfo_t		info;
240	struct pt_regs		regs;
241	__siginfo_fpu_t __user	*fpu_save;
242	stack_t			stack;
243	sigset_t		mask;
244	__siginfo_rwin_t	*rwin_save;
245};
246
247void do_rt_sigreturn(struct pt_regs *regs)
248{
249	struct rt_signal_frame __user *sf;
250	unsigned long tpc, tnpc, tstate;
251	__siginfo_fpu_t __user *fpu_save;
252	__siginfo_rwin_t __user *rwin_save;
253	sigset_t set;
254	int err;
255
256	/* Always make any pending restarted system calls return -EINTR */
257	current->restart_block.fn = do_no_restart_syscall;
258
259	synchronize_user_stack ();
260	sf = (struct rt_signal_frame __user *)
261		(regs->u_regs [UREG_FP] + STACK_BIAS);
262
263	/* 1. Make sure we are not getting garbage from the user */
264	if (((unsigned long) sf) & 3)
265		goto segv;
266
267	err = get_user(tpc, &sf->regs.tpc);
268	err |= __get_user(tnpc, &sf->regs.tnpc);
269	if (test_thread_flag(TIF_32BIT)) {
270		tpc &= 0xffffffff;
271		tnpc &= 0xffffffff;
272	}
273	err |= ((tpc | tnpc) & 3);
274
275	/* 2. Restore the state */
276	err |= __get_user(regs->y, &sf->regs.y);
277	err |= __get_user(tstate, &sf->regs.tstate);
278	err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
279
280	/* User can only change condition codes and %asi in %tstate. */
281	regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
282	regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
283
284	err |= __get_user(fpu_save, &sf->fpu_save);
285	if (!err && fpu_save)
286		err |= restore_fpu_state(regs, fpu_save);
287
288	err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
289	err |= restore_altstack(&sf->stack);
290	if (err)
291		goto segv;
292
293	err |= __get_user(rwin_save, &sf->rwin_save);
294	if (!err && rwin_save) {
295		if (restore_rwin_state(rwin_save))
296			goto segv;
297	}
298
299	regs->tpc = tpc;
300	regs->tnpc = tnpc;
301
302	/* Prevent syscall restart.  */
303	pt_regs_clear_syscall(regs);
304
305	set_current_blocked(&set);
306	return;
307segv:
308	force_sig(SIGSEGV, current);
309}
310
311/* Checks if the fp is valid */
312static int invalid_frame_pointer(void __user *fp)
313{
314	if (((unsigned long) fp) & 15)
315		return 1;
316	return 0;
317}
318
319static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
320{
321	unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
322
323	/*
324	 * If we are on the alternate signal stack and would overflow it, don't.
325	 * Return an always-bogus address instead so we will die with SIGSEGV.
326	 */
327	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
328		return (void __user *) -1L;
329
330	/* This is the X/Open sanctioned signal stack switching.  */
331	sp = sigsp(sp, ksig) - framesize;
332
333	/* Always align the stack frame.  This handles two cases.  First,
334	 * sigaltstack need not be mindful of platform specific stack
335	 * alignment.  Second, if we took this signal because the stack
336	 * is not aligned properly, we'd like to take the signal cleanly
337	 * and report that.
338	 */
339	sp &= ~15UL;
340
341	return (void __user *) sp;
342}
343
344static inline int
345setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
346{
347	struct rt_signal_frame __user *sf;
348	int wsaved, err, sf_size;
349	void __user *tail;
350
351	/* 1. Make sure everything is clean */
352	synchronize_user_stack();
353	save_and_clear_fpu();
354	
355	wsaved = get_thread_wsaved();
356
357	sf_size = sizeof(struct rt_signal_frame);
358	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
359		sf_size += sizeof(__siginfo_fpu_t);
360	if (wsaved)
361		sf_size += sizeof(__siginfo_rwin_t);
362	sf = (struct rt_signal_frame __user *)
363		get_sigframe(ksig, regs, sf_size);
364
365	if (invalid_frame_pointer (sf)) {
366		do_exit(SIGILL);	/* won't return, actually */
367		return -EINVAL;
368	}
369
370	tail = (sf + 1);
371
372	/* 2. Save the current process state */
373	err = copy_to_user(&sf->regs, regs, sizeof (*regs));
374
375	if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
376		__siginfo_fpu_t __user *fpu_save = tail;
377		tail += sizeof(__siginfo_fpu_t);
378		err |= save_fpu_state(regs, fpu_save);
379		err |= __put_user((u64)fpu_save, &sf->fpu_save);
380	} else {
381		err |= __put_user(0, &sf->fpu_save);
382	}
383	if (wsaved) {
384		__siginfo_rwin_t __user *rwin_save = tail;
385		tail += sizeof(__siginfo_rwin_t);
386		err |= save_rwin_state(wsaved, rwin_save);
387		err |= __put_user((u64)rwin_save, &sf->rwin_save);
388		set_thread_wsaved(0);
389	} else {
390		err |= __put_user(0, &sf->rwin_save);
391	}
392	
393	/* Setup sigaltstack */
394	err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
395
396	err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
397
398	if (!wsaved) {
399		err |= copy_in_user((u64 __user *)sf,
400				    (u64 __user *)(regs->u_regs[UREG_FP] +
401						   STACK_BIAS),
402				    sizeof(struct reg_window));
403	} else {
404		struct reg_window *rp;
405
406		rp = &current_thread_info()->reg_window[wsaved - 1];
407		err |= copy_to_user(sf, rp, sizeof(struct reg_window));
408	}
409	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
410		err |= copy_siginfo_to_user(&sf->info, &ksig->info);
411	else {
412		err |= __put_user(ksig->sig, &sf->info.si_signo);
413		err |= __put_user(SI_NOINFO, &sf->info.si_code);
414	}
415	if (err)
416		return err;
417	
418	/* 3. signal handler back-trampoline and parameters */
419	regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
420	regs->u_regs[UREG_I0] = ksig->sig;
421	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
422
423	/* The sigcontext is passed in this way because of how it
424	 * is defined in GLIBC's /usr/include/bits/sigcontext.h
425	 * for sparc64.  It includes the 128 bytes of siginfo_t.
426	 */
427	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
428
429	/* 5. signal handler */
430	regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
431	regs->tnpc = (regs->tpc + 4);
432	if (test_thread_flag(TIF_32BIT)) {
433		regs->tpc &= 0xffffffff;
434		regs->tnpc &= 0xffffffff;
435	}
436	/* 4. return to kernel instructions */
437	regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
438	return 0;
439}
440
441static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
442				   struct sigaction *sa)
443{
444	switch (regs->u_regs[UREG_I0]) {
445	case ERESTART_RESTARTBLOCK:
446	case ERESTARTNOHAND:
447	no_system_call_restart:
448		regs->u_regs[UREG_I0] = EINTR;
449		regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
450		break;
451	case ERESTARTSYS:
452		if (!(sa->sa_flags & SA_RESTART))
453			goto no_system_call_restart;
454		/* fallthrough */
455	case ERESTARTNOINTR:
456		regs->u_regs[UREG_I0] = orig_i0;
457		regs->tpc -= 4;
458		regs->tnpc -= 4;
459	}
460}
461
462/* Note that 'init' is a special process: it doesn't get signals it doesn't
463 * want to handle. Thus you cannot kill init even with a SIGKILL even by
464 * mistake.
465 */
466static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
467{
468	struct ksignal ksig;
469	int restart_syscall;
470	bool has_handler;
471	
472	/* It's a lot of work and synchronization to add a new ptrace
473	 * register for GDB to save and restore in order to get
474	 * orig_i0 correct for syscall restarts when debugging.
475	 *
476	 * Although it should be the case that most of the global
477	 * registers are volatile across a system call, glibc already
478	 * depends upon that fact that we preserve them.  So we can't
479	 * just use any global register to save away the orig_i0 value.
480	 *
481	 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
482	 * preserved across a system call trap by various pieces of
483	 * code in glibc.
484	 *
485	 * %g7 is used as the "thread register".   %g6 is not used in
486	 * any fixed manner.  %g6 is used as a scratch register and
487	 * a compiler temporary, but it's value is never used across
488	 * a system call.  Therefore %g6 is usable for orig_i0 storage.
489	 */
490	if (pt_regs_is_syscall(regs) &&
491	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
492		regs->u_regs[UREG_G6] = orig_i0;
493
494#ifdef CONFIG_COMPAT
495	if (test_thread_flag(TIF_32BIT)) {
 
496		do_signal32(regs);
497		return;
498	}
499#endif	
500
501	has_handler = get_signal(&ksig);
502
503	restart_syscall = 0;
504	if (pt_regs_is_syscall(regs) &&
505	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
506		restart_syscall = 1;
507		orig_i0 = regs->u_regs[UREG_G6];
508	}
509
510	if (has_handler) {
511		if (restart_syscall)
512			syscall_restart(orig_i0, regs, &ksig.ka.sa);
513		signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
514	} else {
515		if (restart_syscall) {
516			switch (regs->u_regs[UREG_I0]) {
517			case ERESTARTNOHAND:
518	     		case ERESTARTSYS:
519			case ERESTARTNOINTR:
520				/* replay the system call when we are done */
521				regs->u_regs[UREG_I0] = orig_i0;
522				regs->tpc -= 4;
523				regs->tnpc -= 4;
524				pt_regs_clear_syscall(regs);
525			case ERESTART_RESTARTBLOCK:
526				regs->u_regs[UREG_G1] = __NR_restart_syscall;
527				regs->tpc -= 4;
528				regs->tnpc -= 4;
529				pt_regs_clear_syscall(regs);
530			}
531		}
532		restore_saved_sigmask();
533	}
534}
535
536void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
537{
538	user_exit();
539	if (thread_info_flags & _TIF_SIGPENDING)
540		do_signal(regs, orig_i0);
541	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
542		clear_thread_flag(TIF_NOTIFY_RESUME);
543		tracehook_notify_resume(regs);
544	}
545	user_enter();
546}
547
v3.15
  1/*
  2 *  arch/sparc64/kernel/signal.c
  3 *
  4 *  Copyright (C) 1991, 1992  Linus Torvalds
  5 *  Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
  6 *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
  7 *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
  8 *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
  9 */
 10
 11#ifdef CONFIG_COMPAT
 12#include <linux/compat.h>	/* for compat_old_sigset_t */
 13#endif
 14#include <linux/sched.h>
 15#include <linux/kernel.h>
 16#include <linux/signal.h>
 17#include <linux/errno.h>
 18#include <linux/wait.h>
 19#include <linux/ptrace.h>
 20#include <linux/tracehook.h>
 21#include <linux/unistd.h>
 22#include <linux/mm.h>
 23#include <linux/tty.h>
 24#include <linux/binfmts.h>
 25#include <linux/bitops.h>
 26#include <linux/context_tracking.h>
 27
 28#include <asm/uaccess.h>
 29#include <asm/ptrace.h>
 30#include <asm/pgtable.h>
 31#include <asm/fpumacro.h>
 32#include <asm/uctx.h>
 33#include <asm/siginfo.h>
 34#include <asm/visasm.h>
 35#include <asm/switch_to.h>
 36#include <asm/cacheflush.h>
 37
 
 
 
 38#include "entry.h"
 39#include "systbls.h"
 40#include "sigutil.h"
 41
 42/* {set, get}context() needed for 64-bit SparcLinux userland. */
 43asmlinkage void sparc64_set_context(struct pt_regs *regs)
 44{
 45	struct ucontext __user *ucp = (struct ucontext __user *)
 46		regs->u_regs[UREG_I0];
 47	enum ctx_state prev_state = exception_enter();
 48	mc_gregset_t __user *grp;
 49	unsigned long pc, npc, tstate;
 50	unsigned long fp, i7;
 51	unsigned char fenab;
 52	int err;
 53
 54	flush_user_windows();
 55	if (get_thread_wsaved()					||
 56	    (((unsigned long)ucp) & (sizeof(unsigned long)-1))	||
 57	    (!__access_ok(ucp, sizeof(*ucp))))
 58		goto do_sigsegv;
 59	grp  = &ucp->uc_mcontext.mc_gregs;
 60	err  = __get_user(pc, &((*grp)[MC_PC]));
 61	err |= __get_user(npc, &((*grp)[MC_NPC]));
 62	if (err || ((pc | npc) & 3))
 63		goto do_sigsegv;
 64	if (regs->u_regs[UREG_I1]) {
 65		sigset_t set;
 66
 67		if (_NSIG_WORDS == 1) {
 68			if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
 69				goto do_sigsegv;
 70		} else {
 71			if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
 72				goto do_sigsegv;
 73		}
 74		set_current_blocked(&set);
 75	}
 76	if (test_thread_flag(TIF_32BIT)) {
 77		pc &= 0xffffffff;
 78		npc &= 0xffffffff;
 79	}
 80	regs->tpc = pc;
 81	regs->tnpc = npc;
 82	err |= __get_user(regs->y, &((*grp)[MC_Y]));
 83	err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
 84	regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
 85	regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
 86	err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
 87	err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
 88	err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
 89	err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
 90	err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
 91	err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
 92
 93	/* Skip %g7 as that's the thread register in userspace.  */
 94
 95	err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
 96	err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
 97	err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
 98	err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
 99	err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
100	err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
101	err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
102	err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
103
104	err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
105	err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
106	err |= __put_user(fp,
107	      (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
108	err |= __put_user(i7,
109	      (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
110
111	err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
112	if (fenab) {
113		unsigned long *fpregs = current_thread_info()->fpregs;
114		unsigned long fprs;
115		
116		fprs_write(0);
117		err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
118		if (fprs & FPRS_DL)
119			err |= copy_from_user(fpregs,
120					      &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
121					      (sizeof(unsigned int) * 32));
122		if (fprs & FPRS_DU)
123			err |= copy_from_user(fpregs+16,
124			 ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
125			 (sizeof(unsigned int) * 32));
126		err |= __get_user(current_thread_info()->xfsr[0],
127				  &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
128		err |= __get_user(current_thread_info()->gsr[0],
129				  &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
130		regs->tstate &= ~TSTATE_PEF;
131	}
132	if (err)
133		goto do_sigsegv;
134out:
135	exception_exit(prev_state);
136	return;
137do_sigsegv:
138	force_sig(SIGSEGV, current);
139	goto out;
140}
141
142asmlinkage void sparc64_get_context(struct pt_regs *regs)
143{
144	struct ucontext __user *ucp = (struct ucontext __user *)
145		regs->u_regs[UREG_I0];
146	enum ctx_state prev_state = exception_enter();
147	mc_gregset_t __user *grp;
148	mcontext_t __user *mcp;
149	unsigned long fp, i7;
150	unsigned char fenab;
151	int err;
152
153	synchronize_user_stack();
154	if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
155		goto do_sigsegv;
156
157#if 1
158	fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
159#else
160	fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
161#endif
162		
163	mcp = &ucp->uc_mcontext;
164	grp = &mcp->mc_gregs;
165
166	/* Skip over the trap instruction, first. */
167	if (test_thread_flag(TIF_32BIT)) {
168		regs->tpc   = (regs->tnpc & 0xffffffff);
169		regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
170	} else {
171		regs->tpc   = regs->tnpc;
172		regs->tnpc += 4;
173	}
174	err = 0;
175	if (_NSIG_WORDS == 1)
176		err |= __put_user(current->blocked.sig[0],
177				  (unsigned long __user *)&ucp->uc_sigmask);
178	else
179		err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
180				      sizeof(sigset_t));
181
182	err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
183	err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
184	err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
185	err |= __put_user(regs->y, &((*grp)[MC_Y]));
186	err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
187	err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
188	err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
189	err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
190	err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
191	err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
192	err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
193	err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
194	err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
195	err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
196	err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
197	err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
198	err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
199	err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
200	err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
201
202	err |= __get_user(fp,
203		 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
204	err |= __get_user(i7,
205		 (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
206	err |= __put_user(fp, &(mcp->mc_fp));
207	err |= __put_user(i7, &(mcp->mc_i7));
208
209	err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
210	if (fenab) {
211		unsigned long *fpregs = current_thread_info()->fpregs;
212		unsigned long fprs;
213		
214		fprs = current_thread_info()->fpsaved[0];
215		if (fprs & FPRS_DL)
216			err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
217					    (sizeof(unsigned int) * 32));
218		if (fprs & FPRS_DU)
219			err |= copy_to_user(
220                          ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
221			  (sizeof(unsigned int) * 32));
222		err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
223		err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
224		err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
225	}
226	if (err)
227		goto do_sigsegv;
228out:
229	exception_exit(prev_state);
230	return;
231do_sigsegv:
232	force_sig(SIGSEGV, current);
233	goto out;
234}
235
236struct rt_signal_frame {
237	struct sparc_stackf	ss;
238	siginfo_t		info;
239	struct pt_regs		regs;
240	__siginfo_fpu_t __user	*fpu_save;
241	stack_t			stack;
242	sigset_t		mask;
243	__siginfo_rwin_t	*rwin_save;
244};
245
246void do_rt_sigreturn(struct pt_regs *regs)
247{
248	struct rt_signal_frame __user *sf;
249	unsigned long tpc, tnpc, tstate;
250	__siginfo_fpu_t __user *fpu_save;
251	__siginfo_rwin_t __user *rwin_save;
252	sigset_t set;
253	int err;
254
255	/* Always make any pending restarted system calls return -EINTR */
256	current_thread_info()->restart_block.fn = do_no_restart_syscall;
257
258	synchronize_user_stack ();
259	sf = (struct rt_signal_frame __user *)
260		(regs->u_regs [UREG_FP] + STACK_BIAS);
261
262	/* 1. Make sure we are not getting garbage from the user */
263	if (((unsigned long) sf) & 3)
264		goto segv;
265
266	err = get_user(tpc, &sf->regs.tpc);
267	err |= __get_user(tnpc, &sf->regs.tnpc);
268	if (test_thread_flag(TIF_32BIT)) {
269		tpc &= 0xffffffff;
270		tnpc &= 0xffffffff;
271	}
272	err |= ((tpc | tnpc) & 3);
273
274	/* 2. Restore the state */
275	err |= __get_user(regs->y, &sf->regs.y);
276	err |= __get_user(tstate, &sf->regs.tstate);
277	err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
278
279	/* User can only change condition codes and %asi in %tstate. */
280	regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
281	regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
282
283	err |= __get_user(fpu_save, &sf->fpu_save);
284	if (!err && fpu_save)
285		err |= restore_fpu_state(regs, fpu_save);
286
287	err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
288	err |= restore_altstack(&sf->stack);
289	if (err)
290		goto segv;
291
292	err |= __get_user(rwin_save, &sf->rwin_save);
293	if (!err && rwin_save) {
294		if (restore_rwin_state(rwin_save))
295			goto segv;
296	}
297
298	regs->tpc = tpc;
299	regs->tnpc = tnpc;
300
301	/* Prevent syscall restart.  */
302	pt_regs_clear_syscall(regs);
303
304	set_current_blocked(&set);
305	return;
306segv:
307	force_sig(SIGSEGV, current);
308}
309
310/* Checks if the fp is valid */
311static int invalid_frame_pointer(void __user *fp)
312{
313	if (((unsigned long) fp) & 15)
314		return 1;
315	return 0;
316}
317
318static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
319{
320	unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
321
322	/*
323	 * If we are on the alternate signal stack and would overflow it, don't.
324	 * Return an always-bogus address instead so we will die with SIGSEGV.
325	 */
326	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
327		return (void __user *) -1L;
328
329	/* This is the X/Open sanctioned signal stack switching.  */
330	sp = sigsp(sp, ksig) - framesize;
331
332	/* Always align the stack frame.  This handles two cases.  First,
333	 * sigaltstack need not be mindful of platform specific stack
334	 * alignment.  Second, if we took this signal because the stack
335	 * is not aligned properly, we'd like to take the signal cleanly
336	 * and report that.
337	 */
338	sp &= ~15UL;
339
340	return (void __user *) sp;
341}
342
343static inline int
344setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
345{
346	struct rt_signal_frame __user *sf;
347	int wsaved, err, sf_size;
348	void __user *tail;
349
350	/* 1. Make sure everything is clean */
351	synchronize_user_stack();
352	save_and_clear_fpu();
353	
354	wsaved = get_thread_wsaved();
355
356	sf_size = sizeof(struct rt_signal_frame);
357	if (current_thread_info()->fpsaved[0] & FPRS_FEF)
358		sf_size += sizeof(__siginfo_fpu_t);
359	if (wsaved)
360		sf_size += sizeof(__siginfo_rwin_t);
361	sf = (struct rt_signal_frame __user *)
362		get_sigframe(ksig, regs, sf_size);
363
364	if (invalid_frame_pointer (sf)) {
365		do_exit(SIGILL);	/* won't return, actually */
366		return -EINVAL;
367	}
368
369	tail = (sf + 1);
370
371	/* 2. Save the current process state */
372	err = copy_to_user(&sf->regs, regs, sizeof (*regs));
373
374	if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
375		__siginfo_fpu_t __user *fpu_save = tail;
376		tail += sizeof(__siginfo_fpu_t);
377		err |= save_fpu_state(regs, fpu_save);
378		err |= __put_user((u64)fpu_save, &sf->fpu_save);
379	} else {
380		err |= __put_user(0, &sf->fpu_save);
381	}
382	if (wsaved) {
383		__siginfo_rwin_t __user *rwin_save = tail;
384		tail += sizeof(__siginfo_rwin_t);
385		err |= save_rwin_state(wsaved, rwin_save);
386		err |= __put_user((u64)rwin_save, &sf->rwin_save);
387		set_thread_wsaved(0);
388	} else {
389		err |= __put_user(0, &sf->rwin_save);
390	}
391	
392	/* Setup sigaltstack */
393	err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
394
395	err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));
396
397	if (!wsaved) {
398		err |= copy_in_user((u64 __user *)sf,
399				    (u64 __user *)(regs->u_regs[UREG_FP] +
400						   STACK_BIAS),
401				    sizeof(struct reg_window));
402	} else {
403		struct reg_window *rp;
404
405		rp = &current_thread_info()->reg_window[wsaved - 1];
406		err |= copy_to_user(sf, rp, sizeof(struct reg_window));
407	}
408	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
409		err |= copy_siginfo_to_user(&sf->info, &ksig->info);
410	else {
411		err |= __put_user(ksig->sig, &sf->info.si_signo);
412		err |= __put_user(SI_NOINFO, &sf->info.si_code);
413	}
414	if (err)
415		return err;
416	
417	/* 3. signal handler back-trampoline and parameters */
418	regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
419	regs->u_regs[UREG_I0] = ksig->sig;
420	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
421
422	/* The sigcontext is passed in this way because of how it
423	 * is defined in GLIBC's /usr/include/bits/sigcontext.h
424	 * for sparc64.  It includes the 128 bytes of siginfo_t.
425	 */
426	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
427
428	/* 5. signal handler */
429	regs->tpc = (unsigned long) ksig->ka.sa.sa_handler;
430	regs->tnpc = (regs->tpc + 4);
431	if (test_thread_flag(TIF_32BIT)) {
432		regs->tpc &= 0xffffffff;
433		regs->tnpc &= 0xffffffff;
434	}
435	/* 4. return to kernel instructions */
436	regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
437	return 0;
438}
439
440static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
441				   struct sigaction *sa)
442{
443	switch (regs->u_regs[UREG_I0]) {
444	case ERESTART_RESTARTBLOCK:
445	case ERESTARTNOHAND:
446	no_system_call_restart:
447		regs->u_regs[UREG_I0] = EINTR;
448		regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
449		break;
450	case ERESTARTSYS:
451		if (!(sa->sa_flags & SA_RESTART))
452			goto no_system_call_restart;
453		/* fallthrough */
454	case ERESTARTNOINTR:
455		regs->u_regs[UREG_I0] = orig_i0;
456		regs->tpc -= 4;
457		regs->tnpc -= 4;
458	}
459}
460
461/* Note that 'init' is a special process: it doesn't get signals it doesn't
462 * want to handle. Thus you cannot kill init even with a SIGKILL even by
463 * mistake.
464 */
465static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
466{
467	struct ksignal ksig;
468	int restart_syscall;
469	bool has_handler;
470	
471	/* It's a lot of work and synchronization to add a new ptrace
472	 * register for GDB to save and restore in order to get
473	 * orig_i0 correct for syscall restarts when debugging.
474	 *
475	 * Although it should be the case that most of the global
476	 * registers are volatile across a system call, glibc already
477	 * depends upon that fact that we preserve them.  So we can't
478	 * just use any global register to save away the orig_i0 value.
479	 *
480	 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
481	 * preserved across a system call trap by various pieces of
482	 * code in glibc.
483	 *
484	 * %g7 is used as the "thread register".   %g6 is not used in
485	 * any fixed manner.  %g6 is used as a scratch register and
486	 * a compiler temporary, but it's value is never used across
487	 * a system call.  Therefore %g6 is usable for orig_i0 storage.
488	 */
489	if (pt_regs_is_syscall(regs) &&
490	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)))
491		regs->u_regs[UREG_G6] = orig_i0;
492
493#ifdef CONFIG_COMPAT
494	if (test_thread_flag(TIF_32BIT)) {
495		extern void do_signal32(struct pt_regs *);
496		do_signal32(regs);
497		return;
498	}
499#endif	
500
501	has_handler = get_signal(&ksig);
502
503	restart_syscall = 0;
504	if (pt_regs_is_syscall(regs) &&
505	    (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
506		restart_syscall = 1;
507		orig_i0 = regs->u_regs[UREG_G6];
508	}
509
510	if (has_handler) {
511		if (restart_syscall)
512			syscall_restart(orig_i0, regs, &ksig.ka.sa);
513		signal_setup_done(setup_rt_frame(&ksig, regs), &ksig, 0);
514	} else {
515		if (restart_syscall) {
516			switch (regs->u_regs[UREG_I0]) {
517			case ERESTARTNOHAND:
518	     		case ERESTARTSYS:
519			case ERESTARTNOINTR:
520				/* replay the system call when we are done */
521				regs->u_regs[UREG_I0] = orig_i0;
522				regs->tpc -= 4;
523				regs->tnpc -= 4;
524				pt_regs_clear_syscall(regs);
525			case ERESTART_RESTARTBLOCK:
526				regs->u_regs[UREG_G1] = __NR_restart_syscall;
527				regs->tpc -= 4;
528				regs->tnpc -= 4;
529				pt_regs_clear_syscall(regs);
530			}
531		}
532		restore_saved_sigmask();
533	}
534}
535
536void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
537{
538	user_exit();
539	if (thread_info_flags & _TIF_SIGPENDING)
540		do_signal(regs, orig_i0);
541	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
542		clear_thread_flag(TIF_NOTIFY_RESUME);
543		tracehook_notify_resume(regs);
544	}
545	user_enter();
546}
547