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v4.6
 
  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.
 13 */
 14
 15#include <linux/sched.h>
 
 16#include <linux/mm.h>
 17#include <linux/smp.h>
 18#include <linux/kernel.h>
 19#include <linux/signal.h>
 20#include <linux/errno.h>
 21#include <linux/wait.h>
 22#include <linux/ptrace.h>
 23#include <linux/tracehook.h>
 24#include <linux/unistd.h>
 25#include <linux/stddef.h>
 26#include <linux/compat.h>
 27#include <linux/elf.h>
 28#include <asm/ucontext.h>
 29#include <asm/rt_sigframe.h>
 30#include <asm/uaccess.h>
 31#include <asm/pgalloc.h>
 32#include <asm/cacheflush.h>
 33#include <asm/asm-offsets.h>
 34
 35#ifdef CONFIG_COMPAT
 36#include "signal32.h"
 37#endif
 38
 39#define DEBUG_SIG 0 
 40#define DEBUG_SIG_LEVEL 2
 41
 42#if DEBUG_SIG
 43#define DBG(LEVEL, ...) \
 44        ((DEBUG_SIG_LEVEL >= LEVEL) \
 45	? printk(__VA_ARGS__) : (void) 0)
 46#else
 47#define DBG(LEVEL, ...)
 48#endif
 49	
 50/* gcc will complain if a pointer is cast to an integer of different
 51 * size.  If you really need to do this (and we do for an ELF32 user
 52 * application in an ELF64 kernel) then you have to do a cast to an
 53 * integer of the same size first.  The A() macro accomplishes
 54 * this. */
 55#define A(__x)	((unsigned long)(__x))
 56
 57/*
 58 * Do a signal return - restore sigcontext.
 59 */
 60
 61/* Trampoline for calling rt_sigreturn() */
 62#define INSN_LDI_R25_0	 0x34190000 /* ldi  0,%r25 (in_syscall=0) */
 63#define INSN_LDI_R25_1	 0x34190002 /* ldi  1,%r25 (in_syscall=1) */
 64#define INSN_LDI_R20	 0x3414015a /* ldi  __NR_rt_sigreturn,%r20 */
 65#define INSN_BLE_SR2_R0  0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */
 66#define INSN_NOP	 0x08000240 /* nop */
 67/* For debugging */
 68#define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */
 69
 70static long
 71restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
 72{
 73	long err = 0;
 74
 75	err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr));
 76	err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
 77	err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq));
 78	err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq));
 79	err |= __get_user(regs->sar, &sc->sc_sar);
 80	DBG(2,"restore_sigcontext: iaoq is %#lx / %#lx\n",
 81			regs->iaoq[0],regs->iaoq[1]);
 82	DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]);
 83	return err;
 84}
 85
 86void
 87sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
 88{
 89	struct rt_sigframe __user *frame;
 90	sigset_t set;
 91	unsigned long usp = (regs->gr[30] & ~(0x01UL));
 92	unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
 93#ifdef CONFIG_64BIT
 94	compat_sigset_t compat_set;
 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 (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set)))
116			goto give_sigsegv;
117		sigset_32to64(&set,&compat_set);
118	} else
119#endif
120	{
121		if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
122			goto give_sigsegv;
123	}
124		
125	set_current_blocked(&set);
126
127	/* Good thing we saved the old gr[30], eh? */
128#ifdef CONFIG_64BIT
129	if (is_compat_task()) {
130		DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n",
131				&compat_frame->uc.uc_mcontext);
132// FIXME: Load upper half from register file
133		if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, 
134					&compat_frame->regs, regs))
135			goto give_sigsegv;
136		DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 
137				usp, &compat_frame->uc.uc_stack);
138		if (compat_restore_altstack(&compat_frame->uc.uc_stack))
139			goto give_sigsegv;
140	} else
141#endif
142	{
143		DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n",
144				&frame->uc.uc_mcontext);
145		if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
146			goto give_sigsegv;
147		DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 
148				usp, &frame->uc.uc_stack);
149		if (restore_altstack(&frame->uc.uc_stack))
150			goto give_sigsegv;
151	}
152		
153
154
155	/* If we are on the syscall path IAOQ will not be restored, and
156	 * if we are on the interrupt path we must not corrupt gr31.
157	 */
158	if (in_syscall)
159		regs->gr[31] = regs->iaoq[0];
160#if DEBUG_SIG
161	DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]);
162	show_regs(regs);
163#endif
164	return;
165
166give_sigsegv:
167	DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n");
168	force_sig(SIGSEGV, current);
169	return;
170}
171
172/*
173 * Set up a signal frame.
174 */
175
176static inline void __user *
177get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
178{
179	/*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
180	  don't use the parameter it doesn't matter */
181
182	DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n",
183			(unsigned long)ka, sp, frame_size);
184	
185	/* Align alternate stack and reserve 64 bytes for the signal
186	   handler's frame marker.  */
187	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
188		sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */
189
190	DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp);
191	return (void __user *) sp; /* Stacks grow up.  Fun. */
192}
193
194static long
195setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
196		 
197{
198	unsigned long flags = 0;
199	long err = 0;
200
201	if (on_sig_stack((unsigned long) sc))
202		flags |= PARISC_SC_FLAG_ONSTACK;
203	if (in_syscall) {
204		flags |= PARISC_SC_FLAG_IN_SYSCALL;
205		/* regs->iaoq is undefined in the syscall return path */
206		err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
207		err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
208		err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
209		err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
210		DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n",
211			regs->gr[31], regs->gr[31]+4);
212	} else {
213		err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
214		err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
215		DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", 
216			regs->iaoq[0], regs->iaoq[1]);
217	}
218
219	err |= __put_user(flags, &sc->sc_flags);
220	err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
221	err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
222	err |= __put_user(regs->sar, &sc->sc_sar);
223	DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]);
224
225	return err;
226}
227
228static long
229setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
230	       int in_syscall)
231{
232	struct rt_sigframe __user *frame;
233	unsigned long rp, usp;
234	unsigned long haddr, sigframe_size;
 
235	int err = 0;
236#ifdef CONFIG_64BIT
237	struct compat_rt_sigframe __user * compat_frame;
238	compat_sigset_t compat_set;
239#endif
240	
241	usp = (regs->gr[30] & ~(0x01UL));
 
 
 
 
 
 
242	/*FIXME: frame_size parameter is unused, remove it. */
243	frame = get_sigframe(&ksig->ka, usp, sizeof(*frame));
244
245	DBG(1,"SETUP_RT_FRAME: START\n");
246	DBG(1,"setup_rt_frame: frame %p info %p\n", frame, ksig->info);
247
248	
249#ifdef CONFIG_64BIT
250
251	compat_frame = (struct compat_rt_sigframe __user *)frame;
252	
253	if (is_compat_task()) {
254		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
255		err |= copy_siginfo_to_user32(&compat_frame->info, &ksig->info);
256		err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]);
257		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
258		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
259		err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, 
260					&compat_frame->regs, regs, in_syscall);
261		sigset_64to32(&compat_set,set);
262		err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set));
263	} else
264#endif
265	{	
266		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
267		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
268		err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]);
269		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
270		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
271		err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
272		/* FIXME: Should probably be converted as well for the compat case */
273		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
274	}
275	
276	if (err)
277		return -EFAULT;
278
279	/* Set up to return from userspace.  If provided, use a stub
280	   already in userspace. The first words of tramp are used to
281	   save the previous sigrestartblock trampoline that might be
282	   on the stack. We start the sigreturn trampoline at 
283	   SIGRESTARTBLOCK_TRAMP+X. */
284	err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
285			&frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
286	err |= __put_user(INSN_LDI_R20, 
287			&frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
288	err |= __put_user(INSN_BLE_SR2_R0, 
289			&frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
290	err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
291
292#if DEBUG_SIG
293	/* Assert that we're flushing in the correct space... */
294	{
295		unsigned long sid;
296		asm ("mfsp %%sr3,%0" : "=r" (sid));
297		DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
298		       sid, frame->tramp);
299	}
300#endif
301
302	flush_user_dcache_range((unsigned long) &frame->tramp[0],
303			   (unsigned long) &frame->tramp[TRAMP_SIZE]);
304	flush_user_icache_range((unsigned long) &frame->tramp[0],
305			   (unsigned long) &frame->tramp[TRAMP_SIZE]);
306
307	/* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP
308	 * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
309	 * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
310	 */
311	rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
312
313	if (err)
314		return -EFAULT;
315
316	haddr = A(ksig->ka.sa.sa_handler);
317	/* The sa_handler may be a pointer to a function descriptor */
318#ifdef CONFIG_64BIT
319	if (is_compat_task()) {
320#endif
321		if (haddr & PA_PLABEL_FDESC) {
322			Elf32_Fdesc fdesc;
323			Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
324
325			err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
326
327			if (err)
328				return -EFAULT;
329
330			haddr = fdesc.addr;
331			regs->gr[19] = fdesc.gp;
332		}
333#ifdef CONFIG_64BIT
334	} else {
335		Elf64_Fdesc fdesc;
336		Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
337		
338		err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
339		
340		if (err)
341			return -EFAULT;
342		
343		haddr = fdesc.addr;
344		regs->gr[19] = fdesc.gp;
345		DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
346		     haddr, regs->gr[19], in_syscall);
347	}
348#endif
349
350	/* The syscall return path will create IAOQ values from r31.
351	 */
352	sigframe_size = PARISC_RT_SIGFRAME_SIZE;
353#ifdef CONFIG_64BIT
354	if (is_compat_task())
355		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
356#endif
357	if (in_syscall) {
358		regs->gr[31] = haddr;
359#ifdef CONFIG_64BIT
360		if (!test_thread_flag(TIF_32BIT))
361			sigframe_size |= 1;
362#endif
363	} else {
364		unsigned long psw = USER_PSW;
365#ifdef CONFIG_64BIT
366		if (!test_thread_flag(TIF_32BIT))
367			psw |= PSW_W;
368#endif
369
370		/* If we are singlestepping, arrange a trap to be delivered
371		   when we return to userspace. Note the semantics -- we
372		   should trap before the first insn in the handler is
373		   executed. Ref:
374			http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
375		 */
376		if (pa_psw(current)->r) {
377			pa_psw(current)->r = 0;
378			psw |= PSW_R;
379			mtctl(-1, 0);
380		}
381
382		regs->gr[0] = psw;
383		regs->iaoq[0] = haddr | 3;
384		regs->iaoq[1] = regs->iaoq[0] + 4;
385	}
386
387	regs->gr[2]  = rp;                /* userland return pointer */
388	regs->gr[26] = ksig->sig;               /* signal number */
389	
390#ifdef CONFIG_64BIT
391	if (is_compat_task()) {
392		regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
393		regs->gr[24] = A(&compat_frame->uc);   /* ucontext pointer */
394	} else
395#endif
396	{		
397		regs->gr[25] = A(&frame->info); /* siginfo pointer */
398		regs->gr[24] = A(&frame->uc);   /* ucontext pointer */
399	}
400	
401	DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
402	       regs->gr[30], sigframe_size,
403	       regs->gr[30] + sigframe_size);
404	/* Raise the user stack pointer to make a proper call frame. */
405	regs->gr[30] = (A(frame) + sigframe_size);
406
407
408	DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
409	       current->comm, current->pid, frame, regs->gr[30],
410	       regs->iaoq[0], regs->iaoq[1], rp);
411
412	return 0;
413}
414
415/*
416 * OK, we're invoking a handler.
417 */	
418
419static void
420handle_signal(struct ksignal *ksig, struct pt_regs *regs, int in_syscall)
421{
422	int ret;
423	sigset_t *oldset = sigmask_to_save();
424
425	DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
426	       ksig->sig, ksig->ka, ksig->info, oldset, regs);
427	
428	/* Set up the stack frame */
429	ret = setup_rt_frame(ksig, oldset, regs, in_syscall);
430
431	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP) ||
432			  test_thread_flag(TIF_BLOCKSTEP));
433
434	DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
435		regs->gr[28]);
436}
437
438/*
439 * Check how the syscall number gets loaded into %r20 within
440 * the delay branch in userspace and adjust as needed.
441 */
442
443static void check_syscallno_in_delay_branch(struct pt_regs *regs)
444{
445	u32 opcode, source_reg;
446	u32 __user *uaddr;
447	int err;
448
449	/* Usually we don't have to restore %r20 (the system call number)
450	 * because it gets loaded in the delay slot of the branch external
451	 * instruction via the ldi instruction.
452	 * In some cases a register-to-register copy instruction might have
453	 * been used instead, in which case we need to copy the syscall
454	 * number into the source register before returning to userspace.
455	 */
456
457	/* A syscall is just a branch, so all we have to do is fiddle the
458	 * return pointer so that the ble instruction gets executed again.
459	 */
460	regs->gr[31] -= 8; /* delayed branching */
461
462	/* Get assembler opcode of code in delay branch */
463	uaddr = (unsigned int *) ((regs->gr[31] & ~3) + 4);
464	err = get_user(opcode, uaddr);
465	if (err)
466		return;
467
468	/* Check if delay branch uses "ldi int,%r20" */
469	if ((opcode & 0xffff0000) == 0x34140000)
470		return;	/* everything ok, just return */
471
472	/* Check if delay branch uses "nop" */
473	if (opcode == INSN_NOP)
474		return;
475
476	/* Check if delay branch uses "copy %rX,%r20" */
477	if ((opcode & 0xffe0ffff) == 0x08000254) {
478		source_reg = (opcode >> 16) & 31;
479		regs->gr[source_reg] = regs->gr[20];
480		return;
481	}
482
483	pr_warn("syscall restart: %s (pid %d): unexpected opcode 0x%08x\n",
484		current->comm, task_pid_nr(current), opcode);
485}
486
487static inline void
488syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
489{
490	if (regs->orig_r28)
491		return;
492	regs->orig_r28 = 1; /* no more restarts */
493	/* Check the return code */
494	switch (regs->gr[28]) {
495	case -ERESTART_RESTARTBLOCK:
496	case -ERESTARTNOHAND:
497		DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
498		regs->gr[28] = -EINTR;
499		break;
500
501	case -ERESTARTSYS:
502		if (!(ka->sa.sa_flags & SA_RESTART)) {
503			DBG(1,"ERESTARTSYS: putting -EINTR\n");
504			regs->gr[28] = -EINTR;
505			break;
506		}
507		/* fallthrough */
508	case -ERESTARTNOINTR:
509		check_syscallno_in_delay_branch(regs);
510		break;
511	}
512}
513
514static inline void
515insert_restart_trampoline(struct pt_regs *regs)
516{
517	if (regs->orig_r28)
518		return;
519	regs->orig_r28 = 1; /* no more restarts */
520	switch(regs->gr[28]) {
521	case -ERESTART_RESTARTBLOCK: {
522		/* Restart the system call - no handlers present */
523		unsigned int *usp = (unsigned int *)regs->gr[30];
524		unsigned long start = (unsigned long) &usp[2];
525		unsigned long end  = (unsigned long) &usp[5];
526		long err = 0;
527
528		/* Setup a trampoline to restart the syscall
529		 * with __NR_restart_syscall
530		 *
531		 *  0: <return address (orig r31)>
532		 *  4: <2nd half for 64-bit>
533		 *  8: ldw 0(%sp), %r31
534		 * 12: be 0x100(%sr2, %r0)
535		 * 16: ldi __NR_restart_syscall, %r20
536		 */
537#ifdef CONFIG_64BIT
538		err |= put_user(regs->gr[31] >> 32, &usp[0]);
539		err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]);
540		err |= put_user(0x0fc010df, &usp[2]);
541#else
542		err |= put_user(regs->gr[31], &usp[0]);
543		err |= put_user(0x0fc0109f, &usp[2]);
544#endif
545		err |= put_user(0xe0008200, &usp[3]);
546		err |= put_user(0x34140000, &usp[4]);
547
548		WARN_ON(err);
549
550		/* flush data/instruction cache for new insns */
551		flush_user_dcache_range(start, end);
552		flush_user_icache_range(start, end);
553
554		regs->gr[31] = regs->gr[30] + 8;
555		return;
556	}
557	case -ERESTARTNOHAND:
558	case -ERESTARTSYS:
559	case -ERESTARTNOINTR:
560		check_syscallno_in_delay_branch(regs);
561		return;
562	default:
563		break;
564	}
565}
566
567/*
568 * Note that 'init' is a special process: it doesn't get signals it doesn't
569 * want to handle. Thus you cannot kill init even with a SIGKILL even by
570 * mistake.
571 *
572 * We need to be able to restore the syscall arguments (r21-r26) to
573 * restart syscalls.  Thus, the syscall path should save them in the
574 * pt_regs structure (it's okay to do so since they are caller-save
575 * registers).  As noted below, the syscall number gets restored for
576 * us due to the magic of delayed branching.
577 */
578asmlinkage void
579do_signal(struct pt_regs *regs, long in_syscall)
580{
581	struct ksignal ksig;
582
583	DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n",
584	       regs, regs->sr[7], in_syscall);
585
586	if (get_signal(&ksig)) {
587		DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]);
588		/* Restart a system call if necessary. */
589		if (in_syscall)
590			syscall_restart(regs, &ksig.ka);
591
592		handle_signal(&ksig, regs, in_syscall);
593		return;
594	}
595
596	/* Did we come from a system call? */
597	if (in_syscall)
598		insert_restart_trampoline(regs);
599	
600	DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", 
601		regs->gr[28]);
602
603	restore_saved_sigmask();
604}
605
606void do_notify_resume(struct pt_regs *regs, long in_syscall)
607{
608	if (test_thread_flag(TIF_SIGPENDING))
 
609		do_signal(regs, in_syscall);
610
611	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
612		clear_thread_flag(TIF_NOTIFY_RESUME);
613		tracehook_notify_resume(regs);
614	}
615}
v5.14.15
  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/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 * Do a signal return - restore sigcontext.
 60 */
 61
 62/* Trampoline for calling rt_sigreturn() */
 63#define INSN_LDI_R25_0	 0x34190000 /* ldi  0,%r25 (in_syscall=0) */
 64#define INSN_LDI_R25_1	 0x34190002 /* ldi  1,%r25 (in_syscall=1) */
 65#define INSN_LDI_R20	 0x3414015a /* ldi  __NR_rt_sigreturn,%r20 */
 66#define INSN_BLE_SR2_R0  0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */
 
 67/* For debugging */
 68#define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */
 69
 70static long
 71restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
 72{
 73	long err = 0;
 74
 75	err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr));
 76	err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
 77	err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq));
 78	err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq));
 79	err |= __get_user(regs->sar, &sc->sc_sar);
 80	DBG(2,"restore_sigcontext: iaoq is %#lx / %#lx\n",
 81			regs->iaoq[0],regs->iaoq[1]);
 82	DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]);
 83	return err;
 84}
 85
 86void
 87sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
 88{
 89	struct rt_sigframe __user *frame;
 90	sigset_t set;
 91	unsigned long usp = (regs->gr[30] & ~(0x01UL));
 92	unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
 93#ifdef CONFIG_64BIT
 
 94	struct compat_rt_sigframe __user * compat_frame;
 95	
 96	if (is_compat_task())
 97		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
 98#endif
 99
100	current->restart_block.fn = do_no_restart_syscall;
101
102	/* Unwind the user stack to get the rt_sigframe structure. */
103	frame = (struct rt_sigframe __user *)
104		(usp - sigframe_size);
105	DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
106
107	regs->orig_r28 = 1; /* no restarts for sigreturn */
108
109#ifdef CONFIG_64BIT
110	compat_frame = (struct compat_rt_sigframe __user *)frame;
111	
112	if (is_compat_task()) {
113		DBG(2,"sys_rt_sigreturn: ELF32 process.\n");
114		if (get_compat_sigset(&set, &compat_frame->uc.uc_sigmask))
115			goto give_sigsegv;
 
116	} else
117#endif
118	{
119		if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
120			goto give_sigsegv;
121	}
122		
123	set_current_blocked(&set);
124
125	/* Good thing we saved the old gr[30], eh? */
126#ifdef CONFIG_64BIT
127	if (is_compat_task()) {
128		DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n",
129				&compat_frame->uc.uc_mcontext);
130// FIXME: Load upper half from register file
131		if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, 
132					&compat_frame->regs, regs))
133			goto give_sigsegv;
134		DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 
135				usp, &compat_frame->uc.uc_stack);
136		if (compat_restore_altstack(&compat_frame->uc.uc_stack))
137			goto give_sigsegv;
138	} else
139#endif
140	{
141		DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n",
142				&frame->uc.uc_mcontext);
143		if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
144			goto give_sigsegv;
145		DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n", 
146				usp, &frame->uc.uc_stack);
147		if (restore_altstack(&frame->uc.uc_stack))
148			goto give_sigsegv;
149	}
150		
151
152
153	/* If we are on the syscall path IAOQ will not be restored, and
154	 * if we are on the interrupt path we must not corrupt gr31.
155	 */
156	if (in_syscall)
157		regs->gr[31] = regs->iaoq[0];
158#if DEBUG_SIG
159	DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]);
160	show_regs(regs);
161#endif
162	return;
163
164give_sigsegv:
165	DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n");
166	force_sig(SIGSEGV);
167	return;
168}
169
170/*
171 * Set up a signal frame.
172 */
173
174static inline void __user *
175get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
176{
177	/*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
178	  don't use the parameter it doesn't matter */
179
180	DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n",
181			(unsigned long)ka, sp, frame_size);
182	
183	/* Align alternate stack and reserve 64 bytes for the signal
184	   handler's frame marker.  */
185	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
186		sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */
187
188	DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp);
189	return (void __user *) sp; /* Stacks grow up.  Fun. */
190}
191
192static long
193setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
194		 
195{
196	unsigned long flags = 0;
197	long err = 0;
198
199	if (on_sig_stack((unsigned long) sc))
200		flags |= PARISC_SC_FLAG_ONSTACK;
201	if (in_syscall) {
202		flags |= PARISC_SC_FLAG_IN_SYSCALL;
203		/* regs->iaoq is undefined in the syscall return path */
204		err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
205		err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
206		err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
207		err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
208		DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n",
209			regs->gr[31], regs->gr[31]+4);
210	} else {
211		err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
212		err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
213		DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n", 
214			regs->iaoq[0], regs->iaoq[1]);
215	}
216
217	err |= __put_user(flags, &sc->sc_flags);
218	err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
219	err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
220	err |= __put_user(regs->sar, &sc->sc_sar);
221	DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]);
222
223	return err;
224}
225
226static long
227setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
228	       int in_syscall)
229{
230	struct rt_sigframe __user *frame;
231	unsigned long rp, usp;
232	unsigned long haddr, sigframe_size;
233	unsigned long start, end;
234	int err = 0;
235#ifdef CONFIG_64BIT
236	struct compat_rt_sigframe __user * compat_frame;
 
237#endif
238	
239	usp = (regs->gr[30] & ~(0x01UL));
240#ifdef CONFIG_64BIT
241	if (is_compat_task()) {
242		/* The gcc alloca implementation leaves garbage in the upper 32 bits of sp */
243		usp = (compat_uint_t)usp;
244	}
245#endif
246	/*FIXME: frame_size parameter is unused, remove it. */
247	frame = get_sigframe(&ksig->ka, usp, sizeof(*frame));
248
249	DBG(1,"SETUP_RT_FRAME: START\n");
250	DBG(1,"setup_rt_frame: frame %p info %p\n", frame, ksig->info);
251
252	
253#ifdef CONFIG_64BIT
254
255	compat_frame = (struct compat_rt_sigframe __user *)frame;
256	
257	if (is_compat_task()) {
258		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
259		err |= copy_siginfo_to_user32(&compat_frame->info, &ksig->info);
260		err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]);
261		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
262		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
263		err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, 
264					&compat_frame->regs, regs, in_syscall);
265		err |= put_compat_sigset(&compat_frame->uc.uc_sigmask, set,
266					 sizeof(compat_sigset_t));
267	} else
268#endif
269	{	
270		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
271		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
272		err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]);
273		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
274		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
275		err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
276		/* FIXME: Should probably be converted as well for the compat case */
277		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
278	}
279	
280	if (err)
281		return -EFAULT;
282
283	/* Set up to return from userspace.  If provided, use a stub
284	   already in userspace. The first words of tramp are used to
285	   save the previous sigrestartblock trampoline that might be
286	   on the stack. We start the sigreturn trampoline at 
287	   SIGRESTARTBLOCK_TRAMP+X. */
288	err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
289			&frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
290	err |= __put_user(INSN_LDI_R20, 
291			&frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
292	err |= __put_user(INSN_BLE_SR2_R0, 
293			&frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
294	err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
295
296#if DEBUG_SIG
297	/* Assert that we're flushing in the correct space... */
298	{
299		unsigned long sid;
300		asm ("mfsp %%sr3,%0" : "=r" (sid));
301		DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
302		       sid, frame->tramp);
303	}
304#endif
305
306	start = (unsigned long) &frame->tramp[0];
307	end = (unsigned long) &frame->tramp[TRAMP_SIZE];
308	flush_user_dcache_range_asm(start, end);
309	flush_user_icache_range_asm(start, end);
310
311	/* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP
312	 * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
313	 * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
314	 */
315	rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
316
317	if (err)
318		return -EFAULT;
319
320	haddr = A(ksig->ka.sa.sa_handler);
321	/* The sa_handler may be a pointer to a function descriptor */
322#ifdef CONFIG_64BIT
323	if (is_compat_task()) {
324#endif
325		if (haddr & PA_PLABEL_FDESC) {
326			Elf32_Fdesc fdesc;
327			Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
328
329			err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
330
331			if (err)
332				return -EFAULT;
333
334			haddr = fdesc.addr;
335			regs->gr[19] = fdesc.gp;
336		}
337#ifdef CONFIG_64BIT
338	} else {
339		Elf64_Fdesc fdesc;
340		Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
341		
342		err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
343		
344		if (err)
345			return -EFAULT;
346		
347		haddr = fdesc.addr;
348		regs->gr[19] = fdesc.gp;
349		DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
350		     haddr, regs->gr[19], in_syscall);
351	}
352#endif
353
354	/* The syscall return path will create IAOQ values from r31.
355	 */
356	sigframe_size = PARISC_RT_SIGFRAME_SIZE;
357#ifdef CONFIG_64BIT
358	if (is_compat_task())
359		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
360#endif
361	if (in_syscall) {
362		regs->gr[31] = haddr;
363#ifdef CONFIG_64BIT
364		if (!test_thread_flag(TIF_32BIT))
365			sigframe_size |= 1;
366#endif
367	} else {
368		unsigned long psw = USER_PSW;
369#ifdef CONFIG_64BIT
370		if (!test_thread_flag(TIF_32BIT))
371			psw |= PSW_W;
372#endif
373
374		/* If we are singlestepping, arrange a trap to be delivered
375		   when we return to userspace. Note the semantics -- we
376		   should trap before the first insn in the handler is
377		   executed. Ref:
378			http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
379		 */
380		if (pa_psw(current)->r) {
381			pa_psw(current)->r = 0;
382			psw |= PSW_R;
383			mtctl(-1, 0);
384		}
385
386		regs->gr[0] = psw;
387		regs->iaoq[0] = haddr | 3;
388		regs->iaoq[1] = regs->iaoq[0] + 4;
389	}
390
391	regs->gr[2]  = rp;                /* userland return pointer */
392	regs->gr[26] = ksig->sig;               /* signal number */
393	
394#ifdef CONFIG_64BIT
395	if (is_compat_task()) {
396		regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
397		regs->gr[24] = A(&compat_frame->uc);   /* ucontext pointer */
398	} else
399#endif
400	{		
401		regs->gr[25] = A(&frame->info); /* siginfo pointer */
402		regs->gr[24] = A(&frame->uc);   /* ucontext pointer */
403	}
404	
405	DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
406	       regs->gr[30], sigframe_size,
407	       regs->gr[30] + sigframe_size);
408	/* Raise the user stack pointer to make a proper call frame. */
409	regs->gr[30] = (A(frame) + sigframe_size);
410
411
412	DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
413	       current->comm, current->pid, frame, regs->gr[30],
414	       regs->iaoq[0], regs->iaoq[1], rp);
415
416	return 0;
417}
418
419/*
420 * OK, we're invoking a handler.
421 */	
422
423static void
424handle_signal(struct ksignal *ksig, struct pt_regs *regs, int in_syscall)
425{
426	int ret;
427	sigset_t *oldset = sigmask_to_save();
428
429	DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
430	       ksig->sig, ksig->ka, ksig->info, oldset, regs);
431	
432	/* Set up the stack frame */
433	ret = setup_rt_frame(ksig, oldset, regs, in_syscall);
434
435	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP) ||
436			  test_thread_flag(TIF_BLOCKSTEP));
437
438	DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
439		regs->gr[28]);
440}
441
442/*
443 * Check how the syscall number gets loaded into %r20 within
444 * the delay branch in userspace and adjust as needed.
445 */
446
447static void check_syscallno_in_delay_branch(struct pt_regs *regs)
448{
449	u32 opcode, source_reg;
450	u32 __user *uaddr;
451	int err;
452
453	/* Usually we don't have to restore %r20 (the system call number)
454	 * because it gets loaded in the delay slot of the branch external
455	 * instruction via the ldi instruction.
456	 * In some cases a register-to-register copy instruction might have
457	 * been used instead, in which case we need to copy the syscall
458	 * number into the source register before returning to userspace.
459	 */
460
461	/* A syscall is just a branch, so all we have to do is fiddle the
462	 * return pointer so that the ble instruction gets executed again.
463	 */
464	regs->gr[31] -= 8; /* delayed branching */
465
466	/* Get assembler opcode of code in delay branch */
467	uaddr = (unsigned int *) ((regs->gr[31] & ~3) + 4);
468	err = get_user(opcode, uaddr);
469	if (err)
470		return;
471
472	/* Check if delay branch uses "ldi int,%r20" */
473	if ((opcode & 0xffff0000) == 0x34140000)
474		return;	/* everything ok, just return */
475
476	/* Check if delay branch uses "nop" */
477	if (opcode == INSN_NOP)
478		return;
479
480	/* Check if delay branch uses "copy %rX,%r20" */
481	if ((opcode & 0xffe0ffff) == 0x08000254) {
482		source_reg = (opcode >> 16) & 31;
483		regs->gr[source_reg] = regs->gr[20];
484		return;
485	}
486
487	pr_warn("syscall restart: %s (pid %d): unexpected opcode 0x%08x\n",
488		current->comm, task_pid_nr(current), opcode);
489}
490
491static inline void
492syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
493{
494	if (regs->orig_r28)
495		return;
496	regs->orig_r28 = 1; /* no more restarts */
497	/* Check the return code */
498	switch (regs->gr[28]) {
499	case -ERESTART_RESTARTBLOCK:
500	case -ERESTARTNOHAND:
501		DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
502		regs->gr[28] = -EINTR;
503		break;
504
505	case -ERESTARTSYS:
506		if (!(ka->sa.sa_flags & SA_RESTART)) {
507			DBG(1,"ERESTARTSYS: putting -EINTR\n");
508			regs->gr[28] = -EINTR;
509			break;
510		}
511		fallthrough;
512	case -ERESTARTNOINTR:
513		check_syscallno_in_delay_branch(regs);
514		break;
515	}
516}
517
518static inline void
519insert_restart_trampoline(struct pt_regs *regs)
520{
521	if (regs->orig_r28)
522		return;
523	regs->orig_r28 = 1; /* no more restarts */
524	switch(regs->gr[28]) {
525	case -ERESTART_RESTARTBLOCK: {
526		/* Restart the system call - no handlers present */
527		unsigned int *usp = (unsigned int *)regs->gr[30];
528		unsigned long start = (unsigned long) &usp[2];
529		unsigned long end  = (unsigned long) &usp[5];
530		long err = 0;
531
532		/* Setup a trampoline to restart the syscall
533		 * with __NR_restart_syscall
534		 *
535		 *  0: <return address (orig r31)>
536		 *  4: <2nd half for 64-bit>
537		 *  8: ldw 0(%sp), %r31
538		 * 12: be 0x100(%sr2, %r0)
539		 * 16: ldi __NR_restart_syscall, %r20
540		 */
541#ifdef CONFIG_64BIT
542		err |= put_user(regs->gr[31] >> 32, &usp[0]);
543		err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]);
544		err |= put_user(0x0fc010df, &usp[2]);
545#else
546		err |= put_user(regs->gr[31], &usp[0]);
547		err |= put_user(0x0fc0109f, &usp[2]);
548#endif
549		err |= put_user(0xe0008200, &usp[3]);
550		err |= put_user(0x34140000, &usp[4]);
551
552		WARN_ON(err);
553
554		/* flush data/instruction cache for new insns */
555		flush_user_dcache_range_asm(start, end);
556		flush_user_icache_range_asm(start, end);
557
558		regs->gr[31] = regs->gr[30] + 8;
559		return;
560	}
561	case -ERESTARTNOHAND:
562	case -ERESTARTSYS:
563	case -ERESTARTNOINTR:
564		check_syscallno_in_delay_branch(regs);
565		return;
566	default:
567		break;
568	}
569}
570
571/*
572 * Note that 'init' is a special process: it doesn't get signals it doesn't
573 * want to handle. Thus you cannot kill init even with a SIGKILL even by
574 * mistake.
575 *
576 * We need to be able to restore the syscall arguments (r21-r26) to
577 * restart syscalls.  Thus, the syscall path should save them in the
578 * pt_regs structure (it's okay to do so since they are caller-save
579 * registers).  As noted below, the syscall number gets restored for
580 * us due to the magic of delayed branching.
581 */
582asmlinkage void
583do_signal(struct pt_regs *regs, long in_syscall)
584{
585	struct ksignal ksig;
586
587	DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n",
588	       regs, regs->sr[7], in_syscall);
589
590	if (get_signal(&ksig)) {
591		DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]);
592		/* Restart a system call if necessary. */
593		if (in_syscall)
594			syscall_restart(regs, &ksig.ka);
595
596		handle_signal(&ksig, regs, in_syscall);
597		return;
598	}
599
600	/* Did we come from a system call? */
601	if (in_syscall)
602		insert_restart_trampoline(regs);
603	
604	DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", 
605		regs->gr[28]);
606
607	restore_saved_sigmask();
608}
609
610void do_notify_resume(struct pt_regs *regs, long in_syscall)
611{
612	if (test_thread_flag(TIF_SIGPENDING) ||
613	    test_thread_flag(TIF_NOTIFY_SIGNAL))
614		do_signal(regs, in_syscall);
615
616	if (test_thread_flag(TIF_NOTIFY_RESUME))
 
617		tracehook_notify_resume(regs);
 
618}