Linux Audio

Check our new training course

Loading...
v5.4
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/arch/parisc/kernel/signal.c: Architecture-specific signal
  4 *  handling support.
  5 *
  6 *  Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
  7 *  Copyright (C) 2000 Linuxcare, Inc.
  8 *
  9 *  Based on the ia64, i386, and alpha versions.
 10 *
 11 *  Like the IA-64, we are a recent enough port (we are *starting*
 12 *  with glibc2.2) that we do not need to support the old non-realtime
 13 *  Linux signals.  Therefore we don't.
 
 14 */
 15
 16#include <linux/sched.h>
 17#include <linux/sched/debug.h>
 18#include <linux/mm.h>
 19#include <linux/smp.h>
 20#include <linux/kernel.h>
 21#include <linux/signal.h>
 22#include <linux/errno.h>
 23#include <linux/wait.h>
 24#include <linux/ptrace.h>
 25#include <linux/tracehook.h>
 26#include <linux/unistd.h>
 27#include <linux/stddef.h>
 28#include <linux/compat.h>
 29#include <linux/elf.h>
 30#include <asm/ucontext.h>
 31#include <asm/rt_sigframe.h>
 32#include <linux/uaccess.h>
 33#include <asm/pgalloc.h>
 34#include <asm/cacheflush.h>
 35#include <asm/asm-offsets.h>
 36
 37#ifdef CONFIG_COMPAT
 38#include "signal32.h"
 39#endif
 40
 41#define DEBUG_SIG 0 
 42#define DEBUG_SIG_LEVEL 2
 43
 44#if DEBUG_SIG
 45#define DBG(LEVEL, ...) \
 46        ((DEBUG_SIG_LEVEL >= LEVEL) \
 47	? printk(__VA_ARGS__) : (void) 0)
 48#else
 49#define DBG(LEVEL, ...)
 50#endif
 51	
 52/* gcc will complain if a pointer is cast to an integer of different
 53 * size.  If you really need to do this (and we do for an ELF32 user
 54 * application in an ELF64 kernel) then you have to do a cast to an
 55 * integer of the same size first.  The A() macro accomplishes
 56 * this. */
 57#define A(__x)	((unsigned long)(__x))
 58
 59/*
 
 
 
 
 
 
 
 60 * Do a signal return - restore sigcontext.
 61 */
 62
 63/* Trampoline for calling rt_sigreturn() */
 64#define INSN_LDI_R25_0	 0x34190000 /* ldi  0,%r25 (in_syscall=0) */
 65#define INSN_LDI_R25_1	 0x34190002 /* ldi  1,%r25 (in_syscall=1) */
 66#define INSN_LDI_R20	 0x3414015a /* ldi  __NR_rt_sigreturn,%r20 */
 67#define INSN_BLE_SR2_R0  0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */
 
 68/* For debugging */
 69#define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */
 70
 71static long
 72restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
 73{
 74	long err = 0;
 75
 76	err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr));
 77	err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
 78	err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq));
 79	err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq));
 80	err |= __get_user(regs->sar, &sc->sc_sar);
 81	DBG(2,"restore_sigcontext: iaoq is %#lx / %#lx\n",
 82			regs->iaoq[0],regs->iaoq[1]);
 83	DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]);
 84	return err;
 85}
 86
 87void
 88sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
 89{
 90	struct rt_sigframe __user *frame;
 91	sigset_t set;
 92	unsigned long usp = (regs->gr[30] & ~(0x01UL));
 93	unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
 94#ifdef CONFIG_64BIT
 
 95	struct compat_rt_sigframe __user * compat_frame;
 96	
 97	if (is_compat_task())
 98		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
 99#endif
100
101	current->restart_block.fn = do_no_restart_syscall;
102
103	/* Unwind the user stack to get the rt_sigframe structure. */
104	frame = (struct rt_sigframe __user *)
105		(usp - sigframe_size);
106	DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
107
108	regs->orig_r28 = 1; /* no restarts for sigreturn */
109
110#ifdef CONFIG_64BIT
111	compat_frame = (struct compat_rt_sigframe __user *)frame;
112	
113	if (is_compat_task()) {
114		DBG(2,"sys_rt_sigreturn: ELF32 process.\n");
115		if (get_compat_sigset(&set, &compat_frame->uc.uc_sigmask))
116			goto give_sigsegv;
 
117	} else
118#endif
119	{
120		if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
121			goto give_sigsegv;
122	}
123		
124	set_current_blocked(&set);
125
126	/* Good thing we saved the old gr[30], eh? */
127#ifdef CONFIG_64BIT
128	if (is_compat_task()) {
129		DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n",
130				&compat_frame->uc.uc_mcontext);
131// FIXME: Load upper half from register file
132		if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, 
133					&compat_frame->regs, regs))
134			goto give_sigsegv;
135		DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 
136				usp, &compat_frame->uc.uc_stack);
137		if (compat_restore_altstack(&compat_frame->uc.uc_stack))
138			goto give_sigsegv;
139	} else
140#endif
141	{
142		DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n",
143				&frame->uc.uc_mcontext);
144		if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
145			goto give_sigsegv;
146		DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 
147				usp, &frame->uc.uc_stack);
148		if (restore_altstack(&frame->uc.uc_stack))
149			goto give_sigsegv;
150	}
151		
152
153
154	/* If we are on the syscall path IAOQ will not be restored, and
155	 * if we are on the interrupt path we must not corrupt gr31.
156	 */
157	if (in_syscall)
158		regs->gr[31] = regs->iaoq[0];
159#if DEBUG_SIG
160	DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]);
161	show_regs(regs);
162#endif
163	return;
164
165give_sigsegv:
166	DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n");
167	force_sig(SIGSEGV);
168	return;
169}
170
171/*
172 * Set up a signal frame.
173 */
174
175static inline void __user *
176get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
177{
178	/*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
179	  don't use the parameter it doesn't matter */
180
181	DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n",
182			(unsigned long)ka, sp, frame_size);
183	
184	/* Align alternate stack and reserve 64 bytes for the signal
185	   handler's frame marker.  */
186	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
187		sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */
188
189	DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp);
190	return (void __user *) sp; /* Stacks grow up.  Fun. */
191}
192
193static long
194setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
195		 
196{
197	unsigned long flags = 0;
198	long err = 0;
199
200	if (on_sig_stack((unsigned long) sc))
201		flags |= PARISC_SC_FLAG_ONSTACK;
202	if (in_syscall) {
203		flags |= PARISC_SC_FLAG_IN_SYSCALL;
204		/* regs->iaoq is undefined in the syscall return path */
205		err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
206		err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
207		err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
208		err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
209		DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n",
210			regs->gr[31], regs->gr[31]+4);
211	} else {
212		err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
213		err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
214		DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", 
215			regs->iaoq[0], regs->iaoq[1]);
216	}
217
218	err |= __put_user(flags, &sc->sc_flags);
219	err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
220	err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
221	err |= __put_user(regs->sar, &sc->sc_sar);
222	DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]);
223
224	return err;
225}
226
227static long
228setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
229	       int in_syscall)
230{
231	struct rt_sigframe __user *frame;
232	unsigned long rp, usp;
233	unsigned long haddr, sigframe_size;
234	unsigned long start, end;
235	int err = 0;
236#ifdef CONFIG_64BIT
 
237	struct compat_rt_sigframe __user * compat_frame;
 
238#endif
239	
240	usp = (regs->gr[30] & ~(0x01UL));
241	/*FIXME: frame_size parameter is unused, remove it. */
242	frame = get_sigframe(&ksig->ka, usp, sizeof(*frame));
243
244	DBG(1,"SETUP_RT_FRAME: START\n");
245	DBG(1,"setup_rt_frame: frame %p info %p\n", frame, ksig->info);
246
247	
248#ifdef CONFIG_64BIT
249
250	compat_frame = (struct compat_rt_sigframe __user *)frame;
251	
252	if (is_compat_task()) {
253		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
254		err |= copy_siginfo_to_user32(&compat_frame->info, &ksig->info);
255		err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]);
 
 
 
 
 
 
 
 
256		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
257		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
258		err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, 
259					&compat_frame->regs, regs, in_syscall);
260		err |= put_compat_sigset(&compat_frame->uc.uc_sigmask, set,
261					 sizeof(compat_sigset_t));
262	} else
263#endif
264	{	
265		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
266		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
267		err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]);
 
 
 
268		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
269		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
270		err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
271		/* FIXME: Should probably be converted as well for the compat case */
272		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
273	}
274	
275	if (err)
276		return -EFAULT;
277
278	/* Set up to return from userspace.  If provided, use a stub
279	   already in userspace. The first words of tramp are used to
280	   save the previous sigrestartblock trampoline that might be
281	   on the stack. We start the sigreturn trampoline at 
282	   SIGRESTARTBLOCK_TRAMP+X. */
283	err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
284			&frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
285	err |= __put_user(INSN_LDI_R20, 
286			&frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
287	err |= __put_user(INSN_BLE_SR2_R0, 
288			&frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
289	err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
290
291#if DEBUG_SIG
292	/* Assert that we're flushing in the correct space... */
293	{
294		unsigned long sid;
295		asm ("mfsp %%sr3,%0" : "=r" (sid));
296		DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
297		       sid, frame->tramp);
298	}
299#endif
300
301	start = (unsigned long) &frame->tramp[0];
302	end = (unsigned long) &frame->tramp[TRAMP_SIZE];
303	flush_user_dcache_range_asm(start, end);
304	flush_user_icache_range_asm(start, end);
305
306	/* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP
307	 * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
308	 * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
309	 */
310	rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
311
312	if (err)
313		return -EFAULT;
314
315	haddr = A(ksig->ka.sa.sa_handler);
316	/* The sa_handler may be a pointer to a function descriptor */
317#ifdef CONFIG_64BIT
318	if (is_compat_task()) {
319#endif
320		if (haddr & PA_PLABEL_FDESC) {
321			Elf32_Fdesc fdesc;
322			Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
323
324			err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
325
326			if (err)
327				return -EFAULT;
328
329			haddr = fdesc.addr;
330			regs->gr[19] = fdesc.gp;
331		}
332#ifdef CONFIG_64BIT
333	} else {
334		Elf64_Fdesc fdesc;
335		Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
336		
337		err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
338		
339		if (err)
340			return -EFAULT;
341		
342		haddr = fdesc.addr;
343		regs->gr[19] = fdesc.gp;
344		DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
345		     haddr, regs->gr[19], in_syscall);
346	}
347#endif
348
349	/* The syscall return path will create IAOQ values from r31.
350	 */
351	sigframe_size = PARISC_RT_SIGFRAME_SIZE;
352#ifdef CONFIG_64BIT
353	if (is_compat_task())
354		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
355#endif
356	if (in_syscall) {
357		regs->gr[31] = haddr;
358#ifdef CONFIG_64BIT
359		if (!test_thread_flag(TIF_32BIT))
360			sigframe_size |= 1;
361#endif
362	} else {
363		unsigned long psw = USER_PSW;
364#ifdef CONFIG_64BIT
365		if (!test_thread_flag(TIF_32BIT))
366			psw |= PSW_W;
367#endif
368
369		/* If we are singlestepping, arrange a trap to be delivered
370		   when we return to userspace. Note the semantics -- we
371		   should trap before the first insn in the handler is
372		   executed. Ref:
373			http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
374		 */
375		if (pa_psw(current)->r) {
376			pa_psw(current)->r = 0;
377			psw |= PSW_R;
378			mtctl(-1, 0);
379		}
380
381		regs->gr[0] = psw;
382		regs->iaoq[0] = haddr | 3;
383		regs->iaoq[1] = regs->iaoq[0] + 4;
384	}
385
386	regs->gr[2]  = rp;                /* userland return pointer */
387	regs->gr[26] = ksig->sig;               /* signal number */
388	
389#ifdef CONFIG_64BIT
390	if (is_compat_task()) {
391		regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
392		regs->gr[24] = A(&compat_frame->uc);   /* ucontext pointer */
393	} else
394#endif
395	{		
396		regs->gr[25] = A(&frame->info); /* siginfo pointer */
397		regs->gr[24] = A(&frame->uc);   /* ucontext pointer */
398	}
399	
400	DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
401	       regs->gr[30], sigframe_size,
402	       regs->gr[30] + sigframe_size);
403	/* Raise the user stack pointer to make a proper call frame. */
404	regs->gr[30] = (A(frame) + sigframe_size);
405
406
407	DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
408	       current->comm, current->pid, frame, regs->gr[30],
409	       regs->iaoq[0], regs->iaoq[1], rp);
410
 
 
 
 
 
411	return 0;
412}
413
414/*
415 * OK, we're invoking a handler.
416 */	
417
418static void
419handle_signal(struct ksignal *ksig, struct pt_regs *regs, int in_syscall)
 
420{
421	int ret;
422	sigset_t *oldset = sigmask_to_save();
423
424	DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
425	       ksig->sig, ksig->ka, ksig->info, oldset, regs);
426	
427	/* Set up the stack frame */
428	ret = setup_rt_frame(ksig, oldset, regs, in_syscall);
 
429
430	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP) ||
431			  test_thread_flag(TIF_BLOCKSTEP));
 
432
433	DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
434		regs->gr[28]);
435}
436
437/*
438 * Check how the syscall number gets loaded into %r20 within
439 * the delay branch in userspace and adjust as needed.
440 */
441
442static void check_syscallno_in_delay_branch(struct pt_regs *regs)
443{
444	u32 opcode, source_reg;
445	u32 __user *uaddr;
446	int err;
447
448	/* Usually we don't have to restore %r20 (the system call number)
449	 * because it gets loaded in the delay slot of the branch external
450	 * instruction via the ldi instruction.
451	 * In some cases a register-to-register copy instruction might have
452	 * been used instead, in which case we need to copy the syscall
453	 * number into the source register before returning to userspace.
454	 */
455
456	/* A syscall is just a branch, so all we have to do is fiddle the
457	 * return pointer so that the ble instruction gets executed again.
458	 */
459	regs->gr[31] -= 8; /* delayed branching */
460
461	/* Get assembler opcode of code in delay branch */
462	uaddr = (unsigned int *) ((regs->gr[31] & ~3) + 4);
463	err = get_user(opcode, uaddr);
464	if (err)
465		return;
466
467	/* Check if delay branch uses "ldi int,%r20" */
468	if ((opcode & 0xffff0000) == 0x34140000)
469		return;	/* everything ok, just return */
470
471	/* Check if delay branch uses "nop" */
472	if (opcode == INSN_NOP)
473		return;
474
475	/* Check if delay branch uses "copy %rX,%r20" */
476	if ((opcode & 0xffe0ffff) == 0x08000254) {
477		source_reg = (opcode >> 16) & 31;
478		regs->gr[source_reg] = regs->gr[20];
479		return;
480	}
481
482	pr_warn("syscall restart: %s (pid %d): unexpected opcode 0x%08x\n",
483		current->comm, task_pid_nr(current), opcode);
484}
485
486static inline void
487syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
488{
489	if (regs->orig_r28)
490		return;
491	regs->orig_r28 = 1; /* no more restarts */
492	/* Check the return code */
493	switch (regs->gr[28]) {
494	case -ERESTART_RESTARTBLOCK:
495	case -ERESTARTNOHAND:
496		DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
497		regs->gr[28] = -EINTR;
498		break;
499
500	case -ERESTARTSYS:
501		if (!(ka->sa.sa_flags & SA_RESTART)) {
502			DBG(1,"ERESTARTSYS: putting -EINTR\n");
503			regs->gr[28] = -EINTR;
504			break;
505		}
506		/* fallthrough */
507	case -ERESTARTNOINTR:
508		check_syscallno_in_delay_branch(regs);
 
 
 
 
 
509		break;
510	}
511}
512
513static inline void
514insert_restart_trampoline(struct pt_regs *regs)
515{
516	if (regs->orig_r28)
517		return;
518	regs->orig_r28 = 1; /* no more restarts */
519	switch(regs->gr[28]) {
520	case -ERESTART_RESTARTBLOCK: {
521		/* Restart the system call - no handlers present */
522		unsigned int *usp = (unsigned int *)regs->gr[30];
523		unsigned long start = (unsigned long) &usp[2];
524		unsigned long end  = (unsigned long) &usp[5];
525		long err = 0;
526
527		/* Setup a trampoline to restart the syscall
528		 * with __NR_restart_syscall
529		 *
530		 *  0: <return address (orig r31)>
531		 *  4: <2nd half for 64-bit>
532		 *  8: ldw 0(%sp), %r31
533		 * 12: be 0x100(%sr2, %r0)
534		 * 16: ldi __NR_restart_syscall, %r20
535		 */
536#ifdef CONFIG_64BIT
537		err |= put_user(regs->gr[31] >> 32, &usp[0]);
538		err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]);
539		err |= put_user(0x0fc010df, &usp[2]);
540#else
541		err |= put_user(regs->gr[31], &usp[0]);
542		err |= put_user(0x0fc0109f, &usp[2]);
543#endif
544		err |= put_user(0xe0008200, &usp[3]);
545		err |= put_user(0x34140000, &usp[4]);
546
547		WARN_ON(err);
548
549		/* flush data/instruction cache for new insns */
550		flush_user_dcache_range_asm(start, end);
551		flush_user_icache_range_asm(start, end);
 
 
552
553		regs->gr[31] = regs->gr[30] + 8;
 
 
 
554		return;
555	}
556	case -ERESTARTNOHAND:
557	case -ERESTARTSYS:
558	case -ERESTARTNOINTR:
559		check_syscallno_in_delay_branch(regs);
 
 
 
 
 
 
 
 
560		return;
 
561	default:
562		break;
563	}
564}
565
566/*
567 * Note that 'init' is a special process: it doesn't get signals it doesn't
568 * want to handle. Thus you cannot kill init even with a SIGKILL even by
569 * mistake.
570 *
571 * We need to be able to restore the syscall arguments (r21-r26) to
572 * restart syscalls.  Thus, the syscall path should save them in the
573 * pt_regs structure (it's okay to do so since they are caller-save
574 * registers).  As noted below, the syscall number gets restored for
575 * us due to the magic of delayed branching.
576 */
577asmlinkage void
578do_signal(struct pt_regs *regs, long in_syscall)
579{
580	struct ksignal ksig;
 
 
581
582	DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n",
583	       regs, regs->sr[7], in_syscall);
584
585	if (get_signal(&ksig)) {
586		DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]);
 
 
 
 
 
 
 
 
 
 
 
587		/* Restart a system call if necessary. */
588		if (in_syscall)
589			syscall_restart(regs, &ksig.ka);
590
591		handle_signal(&ksig, regs, in_syscall);
592		return;
 
 
 
593	}
 
594
595	/* Did we come from a system call? */
596	if (in_syscall)
597		insert_restart_trampoline(regs);
598	
599	DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", 
600		regs->gr[28]);
601
602	restore_saved_sigmask();
603}
604
605void do_notify_resume(struct pt_regs *regs, long in_syscall)
606{
607	if (test_thread_flag(TIF_SIGPENDING))
608		do_signal(regs, in_syscall);
609
610	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
611		clear_thread_flag(TIF_NOTIFY_RESUME);
612		tracehook_notify_resume(regs);
613	}
614}
v3.5.6
 
  1/*
  2 *  linux/arch/parisc/kernel/signal.c: Architecture-specific signal
  3 *  handling support.
  4 *
  5 *  Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
  6 *  Copyright (C) 2000 Linuxcare, Inc.
  7 *
  8 *  Based on the ia64, i386, and alpha versions.
  9 *
 10 *  Like the IA-64, we are a recent enough port (we are *starting*
 11 *  with glibc2.2) that we do not need to support the old non-realtime
 12 *  Linux signals.  Therefore we don't.  HP/UX signals will go in
 13 *  arch/parisc/hpux/signal.c when we figure out how to do them.
 14 */
 15
 16#include <linux/sched.h>
 
 17#include <linux/mm.h>
 18#include <linux/smp.h>
 19#include <linux/kernel.h>
 20#include <linux/signal.h>
 21#include <linux/errno.h>
 22#include <linux/wait.h>
 23#include <linux/ptrace.h>
 24#include <linux/tracehook.h>
 25#include <linux/unistd.h>
 26#include <linux/stddef.h>
 27#include <linux/compat.h>
 28#include <linux/elf.h>
 29#include <asm/ucontext.h>
 30#include <asm/rt_sigframe.h>
 31#include <asm/uaccess.h>
 32#include <asm/pgalloc.h>
 33#include <asm/cacheflush.h>
 34#include <asm/asm-offsets.h>
 35
 36#ifdef CONFIG_COMPAT
 37#include "signal32.h"
 38#endif
 39
 40#define DEBUG_SIG 0 
 41#define DEBUG_SIG_LEVEL 2
 42
 43#if DEBUG_SIG
 44#define DBG(LEVEL, ...) \
 45        ((DEBUG_SIG_LEVEL >= LEVEL) \
 46	? printk(__VA_ARGS__) : (void) 0)
 47#else
 48#define DBG(LEVEL, ...)
 49#endif
 50	
 51/* gcc will complain if a pointer is cast to an integer of different
 52 * size.  If you really need to do this (and we do for an ELF32 user
 53 * application in an ELF64 kernel) then you have to do a cast to an
 54 * integer of the same size first.  The A() macro accomplishes
 55 * this. */
 56#define A(__x)	((unsigned long)(__x))
 57
 58/*
 59 * Atomically swap in the new signal mask, and wait for a signal.
 60 */
 61#ifdef CONFIG_64BIT
 62#include "sys32.h"
 63#endif
 64
 65/*
 66 * Do a signal return - restore sigcontext.
 67 */
 68
 69/* Trampoline for calling rt_sigreturn() */
 70#define INSN_LDI_R25_0	 0x34190000 /* ldi  0,%r25 (in_syscall=0) */
 71#define INSN_LDI_R25_1	 0x34190002 /* ldi  1,%r25 (in_syscall=1) */
 72#define INSN_LDI_R20	 0x3414015a /* ldi  __NR_rt_sigreturn,%r20 */
 73#define INSN_BLE_SR2_R0  0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */
 74#define INSN_NOP	 0x08000240 /* nop */
 75/* For debugging */
 76#define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */
 77
 78static long
 79restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
 80{
 81	long err = 0;
 82
 83	err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr));
 84	err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
 85	err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq));
 86	err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq));
 87	err |= __get_user(regs->sar, &sc->sc_sar);
 88	DBG(2,"restore_sigcontext: iaoq is 0x%#lx / 0x%#lx\n", 
 89			regs->iaoq[0],regs->iaoq[1]);
 90	DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]);
 91	return err;
 92}
 93
 94void
 95sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
 96{
 97	struct rt_sigframe __user *frame;
 98	sigset_t set;
 99	unsigned long usp = (regs->gr[30] & ~(0x01UL));
100	unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
101#ifdef CONFIG_64BIT
102	compat_sigset_t compat_set;
103	struct compat_rt_sigframe __user * compat_frame;
104	
105	if (is_compat_task())
106		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
107#endif
108
109	current_thread_info()->restart_block.fn = do_no_restart_syscall;
110
111	/* Unwind the user stack to get the rt_sigframe structure. */
112	frame = (struct rt_sigframe __user *)
113		(usp - sigframe_size);
114	DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
115
 
 
116#ifdef CONFIG_64BIT
117	compat_frame = (struct compat_rt_sigframe __user *)frame;
118	
119	if (is_compat_task()) {
120		DBG(2,"sys_rt_sigreturn: ELF32 process.\n");
121		if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set)))
122			goto give_sigsegv;
123		sigset_32to64(&set,&compat_set);
124	} else
125#endif
126	{
127		if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
128			goto give_sigsegv;
129	}
130		
131	set_current_blocked(&set);
132
133	/* Good thing we saved the old gr[30], eh? */
134#ifdef CONFIG_64BIT
135	if (is_compat_task()) {
136		DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n",
137				&compat_frame->uc.uc_mcontext);
138// FIXME: Load upper half from register file
139		if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, 
140					&compat_frame->regs, regs))
141			goto give_sigsegv;
142		DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 
143				usp, &compat_frame->uc.uc_stack);
144		if (do_sigaltstack32(&compat_frame->uc.uc_stack, NULL, usp) == -EFAULT)
145			goto give_sigsegv;
146	} else
147#endif
148	{
149		DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n",
150				&frame->uc.uc_mcontext);
151		if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
152			goto give_sigsegv;
153		DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 
154				usp, &frame->uc.uc_stack);
155		if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT)
156			goto give_sigsegv;
157	}
158		
159
160
161	/* If we are on the syscall path IAOQ will not be restored, and
162	 * if we are on the interrupt path we must not corrupt gr31.
163	 */
164	if (in_syscall)
165		regs->gr[31] = regs->iaoq[0];
166#if DEBUG_SIG
167	DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]);
168	show_regs(regs);
169#endif
170	return;
171
172give_sigsegv:
173	DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n");
174	force_sig(SIGSEGV, current);
175	return;
176}
177
178/*
179 * Set up a signal frame.
180 */
181
182static inline void __user *
183get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
184{
185	/*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
186	  don't use the parameter it doesn't matter */
187
188	DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n",
189			(unsigned long)ka, sp, frame_size);
190	
 
 
191	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
192		sp = current->sas_ss_sp; /* Stacks grow up! */
193
194	DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp);
195	return (void __user *) sp; /* Stacks grow up.  Fun. */
196}
197
198static long
199setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
200		 
201{
202	unsigned long flags = 0;
203	long err = 0;
204
205	if (on_sig_stack((unsigned long) sc))
206		flags |= PARISC_SC_FLAG_ONSTACK;
207	if (in_syscall) {
208		flags |= PARISC_SC_FLAG_IN_SYSCALL;
209		/* regs->iaoq is undefined in the syscall return path */
210		err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
211		err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
212		err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
213		err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
214		DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n",
215			regs->gr[31], regs->gr[31]+4);
216	} else {
217		err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
218		err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
219		DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", 
220			regs->iaoq[0], regs->iaoq[1]);
221	}
222
223	err |= __put_user(flags, &sc->sc_flags);
224	err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
225	err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
226	err |= __put_user(regs->sar, &sc->sc_sar);
227	DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]);
228
229	return err;
230}
231
232static long
233setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
234	       sigset_t *set, struct pt_regs *regs, int in_syscall)
235{
236	struct rt_sigframe __user *frame;
237	unsigned long rp, usp;
238	unsigned long haddr, sigframe_size;
 
239	int err = 0;
240#ifdef CONFIG_64BIT
241	compat_int_t compat_val;
242	struct compat_rt_sigframe __user * compat_frame;
243	compat_sigset_t compat_set;
244#endif
245	
246	usp = (regs->gr[30] & ~(0x01UL));
247	/*FIXME: frame_size parameter is unused, remove it. */
248	frame = get_sigframe(ka, usp, sizeof(*frame));
249
250	DBG(1,"SETUP_RT_FRAME: START\n");
251	DBG(1,"setup_rt_frame: frame %p info %p\n", frame, info);
252
253	
254#ifdef CONFIG_64BIT
255
256	compat_frame = (struct compat_rt_sigframe __user *)frame;
257	
258	if (is_compat_task()) {
259		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
260		err |= copy_siginfo_to_user32(&compat_frame->info, info);
261		DBG(1,"SETUP_RT_FRAME: 1\n");
262		compat_val = (compat_int_t)current->sas_ss_sp;
263		err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_sp);
264		DBG(1,"SETUP_RT_FRAME: 2\n");
265		compat_val = (compat_int_t)current->sas_ss_size;
266		err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_size);
267		DBG(1,"SETUP_RT_FRAME: 3\n");
268		compat_val = sas_ss_flags(regs->gr[30]);		
269		err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_flags);		
270		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
271		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
272		err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, 
273					&compat_frame->regs, regs, in_syscall);
274		sigset_64to32(&compat_set,set);
275		err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set));
276	} else
277#endif
278	{	
279		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
280		err |= copy_siginfo_to_user(&frame->info, info);
281		err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
282		err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
283		err |= __put_user(sas_ss_flags(regs->gr[30]),
284				  &frame->uc.uc_stack.ss_flags);
285		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
286		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
287		err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
288		/* FIXME: Should probably be converted as well for the compat case */
289		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
290	}
291	
292	if (err)
293		goto give_sigsegv;
294
295	/* Set up to return from userspace.  If provided, use a stub
296	   already in userspace. The first words of tramp are used to
297	   save the previous sigrestartblock trampoline that might be
298	   on the stack. We start the sigreturn trampoline at 
299	   SIGRESTARTBLOCK_TRAMP+X. */
300	err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
301			&frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
302	err |= __put_user(INSN_LDI_R20, 
303			&frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
304	err |= __put_user(INSN_BLE_SR2_R0, 
305			&frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
306	err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
307
308#if DEBUG_SIG
309	/* Assert that we're flushing in the correct space... */
310	{
311		int sid;
312		asm ("mfsp %%sr3,%0" : "=r" (sid));
313		DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
314		       sid, frame->tramp);
315	}
316#endif
317
318	flush_user_dcache_range((unsigned long) &frame->tramp[0],
319			   (unsigned long) &frame->tramp[TRAMP_SIZE]);
320	flush_user_icache_range((unsigned long) &frame->tramp[0],
321			   (unsigned long) &frame->tramp[TRAMP_SIZE]);
322
323	/* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP
324	 * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
325	 * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
326	 */
327	rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
328
329	if (err)
330		goto give_sigsegv;
331
332	haddr = A(ka->sa.sa_handler);
333	/* The sa_handler may be a pointer to a function descriptor */
334#ifdef CONFIG_64BIT
335	if (is_compat_task()) {
336#endif
337		if (haddr & PA_PLABEL_FDESC) {
338			Elf32_Fdesc fdesc;
339			Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
340
341			err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
342
343			if (err)
344				goto give_sigsegv;
345
346			haddr = fdesc.addr;
347			regs->gr[19] = fdesc.gp;
348		}
349#ifdef CONFIG_64BIT
350	} else {
351		Elf64_Fdesc fdesc;
352		Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
353		
354		err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
355		
356		if (err)
357			goto give_sigsegv;
358		
359		haddr = fdesc.addr;
360		regs->gr[19] = fdesc.gp;
361		DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
362		     haddr, regs->gr[19], in_syscall);
363	}
364#endif
365
366	/* The syscall return path will create IAOQ values from r31.
367	 */
368	sigframe_size = PARISC_RT_SIGFRAME_SIZE;
369#ifdef CONFIG_64BIT
370	if (is_compat_task())
371		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
372#endif
373	if (in_syscall) {
374		regs->gr[31] = haddr;
375#ifdef CONFIG_64BIT
376		if (!test_thread_flag(TIF_32BIT))
377			sigframe_size |= 1;
378#endif
379	} else {
380		unsigned long psw = USER_PSW;
381#ifdef CONFIG_64BIT
382		if (!test_thread_flag(TIF_32BIT))
383			psw |= PSW_W;
384#endif
385
386		/* If we are singlestepping, arrange a trap to be delivered
387		   when we return to userspace. Note the semantics -- we
388		   should trap before the first insn in the handler is
389		   executed. Ref:
390			http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
391		 */
392		if (pa_psw(current)->r) {
393			pa_psw(current)->r = 0;
394			psw |= PSW_R;
395			mtctl(-1, 0);
396		}
397
398		regs->gr[0] = psw;
399		regs->iaoq[0] = haddr | 3;
400		regs->iaoq[1] = regs->iaoq[0] + 4;
401	}
402
403	regs->gr[2]  = rp;                /* userland return pointer */
404	regs->gr[26] = sig;               /* signal number */
405	
406#ifdef CONFIG_64BIT
407	if (is_compat_task()) {
408		regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
409		regs->gr[24] = A(&compat_frame->uc);   /* ucontext pointer */
410	} else
411#endif
412	{		
413		regs->gr[25] = A(&frame->info); /* siginfo pointer */
414		regs->gr[24] = A(&frame->uc);   /* ucontext pointer */
415	}
416	
417	DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
418	       regs->gr[30], sigframe_size,
419	       regs->gr[30] + sigframe_size);
420	/* Raise the user stack pointer to make a proper call frame. */
421	regs->gr[30] = (A(frame) + sigframe_size);
422
423
424	DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
425	       current->comm, current->pid, frame, regs->gr[30],
426	       regs->iaoq[0], regs->iaoq[1], rp);
427
428	return 1;
429
430give_sigsegv:
431	DBG(1,"setup_rt_frame: sending SIGSEGV\n");
432	force_sigsegv(sig, current);
433	return 0;
434}
435
436/*
437 * OK, we're invoking a handler.
438 */	
439
440static long
441handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
442		struct pt_regs *regs, int in_syscall)
443{
 
444	sigset_t *oldset = sigmask_to_save();
 
445	DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
446	       sig, ka, info, oldset, regs);
447	
448	/* Set up the stack frame */
449	if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall))
450		return 0;
451
452	signal_delivered(sig, info, ka, regs, 
453		test_thread_flag(TIF_SINGLESTEP) ||
454		test_thread_flag(TIF_BLOCKSTEP));
455
456	DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
457		regs->gr[28]);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
458
459	return 1;
 
 
 
 
 
 
 
 
 
 
 
 
460}
461
462static inline void
463syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
464{
 
 
 
465	/* Check the return code */
466	switch (regs->gr[28]) {
467	case -ERESTART_RESTARTBLOCK:
468	case -ERESTARTNOHAND:
469		DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
470		regs->gr[28] = -EINTR;
471		break;
472
473	case -ERESTARTSYS:
474		if (!(ka->sa.sa_flags & SA_RESTART)) {
475			DBG(1,"ERESTARTSYS: putting -EINTR\n");
476			regs->gr[28] = -EINTR;
477			break;
478		}
479		/* fallthrough */
480	case -ERESTARTNOINTR:
481		/* A syscall is just a branch, so all
482		 * we have to do is fiddle the return pointer.
483		 */
484		regs->gr[31] -= 8; /* delayed branching */
485		/* Preserve original r28. */
486		regs->gr[28] = regs->orig_r28;
487		break;
488	}
489}
490
491static inline void
492insert_restart_trampoline(struct pt_regs *regs)
493{
 
 
 
494	switch(regs->gr[28]) {
495	case -ERESTART_RESTARTBLOCK: {
496		/* Restart the system call - no handlers present */
497		unsigned int *usp = (unsigned int *)regs->gr[30];
 
 
 
498
499		/* Setup a trampoline to restart the syscall
500		 * with __NR_restart_syscall
501		 *
502		 *  0: <return address (orig r31)>
503		 *  4: <2nd half for 64-bit>
504		 *  8: ldw 0(%sp), %r31
505		 * 12: be 0x100(%sr2, %r0)
506		 * 16: ldi __NR_restart_syscall, %r20
507		 */
508#ifdef CONFIG_64BIT
509		put_user(regs->gr[31] >> 32, &usp[0]);
510		put_user(regs->gr[31] & 0xffffffff, &usp[1]);
511		put_user(0x0fc010df, &usp[2]);
512#else
513		put_user(regs->gr[31], &usp[0]);
514		put_user(0x0fc0109f, &usp[2]);
515#endif
516		put_user(0xe0008200, &usp[3]);
517		put_user(0x34140000, &usp[4]);
518
519		/* Stack is 64-byte aligned, and we only need
520		 * to flush 1 cache line.
521		 * Flushing one cacheline is cheap.
522		 * "sync" on bigger (> 4 way) boxes is not.
523		 */
524		flush_user_dcache_range(regs->gr[30], regs->gr[30] + 4);
525		flush_user_icache_range(regs->gr[30], regs->gr[30] + 4);
526
527		regs->gr[31] = regs->gr[30] + 8;
528		/* Preserve original r28. */
529		regs->gr[28] = regs->orig_r28;
530
531		return;
532	}
533	case -ERESTARTNOHAND:
534	case -ERESTARTSYS:
535	case -ERESTARTNOINTR: {
536		/* Hooray for delayed branching.  We don't
537		 * have to restore %r20 (the system call
538		 * number) because it gets loaded in the delay
539		 * slot of the branch external instruction.
540		 */
541		regs->gr[31] -= 8;
542		/* Preserve original r28. */
543		regs->gr[28] = regs->orig_r28;
544
545		return;
546	}
547	default:
548		break;
549	}
550}
551
552/*
553 * Note that 'init' is a special process: it doesn't get signals it doesn't
554 * want to handle. Thus you cannot kill init even with a SIGKILL even by
555 * mistake.
556 *
557 * We need to be able to restore the syscall arguments (r21-r26) to
558 * restart syscalls.  Thus, the syscall path should save them in the
559 * pt_regs structure (it's okay to do so since they are caller-save
560 * registers).  As noted below, the syscall number gets restored for
561 * us due to the magic of delayed branching.
562 */
563asmlinkage void
564do_signal(struct pt_regs *regs, long in_syscall)
565{
566	siginfo_t info;
567	struct k_sigaction ka;
568	int signr;
569
570	DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n",
571	       regs, regs->sr[7], in_syscall);
572
573	/* Everyone else checks to see if they are in kernel mode at
574	   this point and exits if that's the case.  I'm not sure why
575	   we would be called in that case, but for some reason we
576	   are. */
577
578	/* May need to force signal if handle_signal failed to deliver */
579	while (1) {
580		signr = get_signal_to_deliver(&info, &ka, regs, NULL);
581		DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]); 
582	
583		if (signr <= 0)
584		  break;
585		
586		/* Restart a system call if necessary. */
587		if (in_syscall)
588			syscall_restart(regs, &ka);
589
590		/* Whee!  Actually deliver the signal.  If the
591		   delivery failed, we need to continue to iterate in
592		   this loop so we can deliver the SIGSEGV... */
593		if (handle_signal(signr, &info, &ka, regs, in_syscall))
594			return;
595	}
596	/* end of while(1) looping forever if we can't force a signal */
597
598	/* Did we come from a system call? */
599	if (in_syscall)
600		insert_restart_trampoline(regs);
601	
602	DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", 
603		regs->gr[28]);
604
605	restore_saved_sigmask();
606}
607
608void do_notify_resume(struct pt_regs *regs, long in_syscall)
609{
610	if (test_thread_flag(TIF_SIGPENDING))
611		do_signal(regs, in_syscall);
612
613	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
614		clear_thread_flag(TIF_NOTIFY_RESUME);
615		tracehook_notify_resume(regs);
616	}
617}