Linux Audio

Check our new training course

Loading...
v5.9
  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	/*FIXME: frame_size parameter is unused, remove it. */
241	frame = get_sigframe(&ksig->ka, usp, sizeof(*frame));
242
243	DBG(1,"SETUP_RT_FRAME: START\n");
244	DBG(1,"setup_rt_frame: frame %p info %p\n", frame, ksig->info);
245
246	
247#ifdef CONFIG_64BIT
248
249	compat_frame = (struct compat_rt_sigframe __user *)frame;
250	
251	if (is_compat_task()) {
252		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
253		err |= copy_siginfo_to_user32(&compat_frame->info, &ksig->info);
254		err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]);
255		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
256		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
257		err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, 
258					&compat_frame->regs, regs, in_syscall);
259		err |= put_compat_sigset(&compat_frame->uc.uc_sigmask, set,
260					 sizeof(compat_sigset_t));
261	} else
262#endif
263	{	
264		DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
265		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
266		err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]);
267		DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
268		DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
269		err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
270		/* FIXME: Should probably be converted as well for the compat case */
271		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
272	}
273	
274	if (err)
275		return -EFAULT;
276
277	/* Set up to return from userspace.  If provided, use a stub
278	   already in userspace. The first words of tramp are used to
279	   save the previous sigrestartblock trampoline that might be
280	   on the stack. We start the sigreturn trampoline at 
281	   SIGRESTARTBLOCK_TRAMP+X. */
282	err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
283			&frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
284	err |= __put_user(INSN_LDI_R20, 
285			&frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
286	err |= __put_user(INSN_BLE_SR2_R0, 
287			&frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
288	err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
289
290#if DEBUG_SIG
291	/* Assert that we're flushing in the correct space... */
292	{
293		unsigned long sid;
294		asm ("mfsp %%sr3,%0" : "=r" (sid));
295		DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
296		       sid, frame->tramp);
297	}
298#endif
299
300	start = (unsigned long) &frame->tramp[0];
301	end = (unsigned long) &frame->tramp[TRAMP_SIZE];
302	flush_user_dcache_range_asm(start, end);
303	flush_user_icache_range_asm(start, end);
304
305	/* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP
306	 * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
307	 * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
308	 */
309	rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
310
311	if (err)
312		return -EFAULT;
313
314	haddr = A(ksig->ka.sa.sa_handler);
315	/* The sa_handler may be a pointer to a function descriptor */
316#ifdef CONFIG_64BIT
317	if (is_compat_task()) {
318#endif
319		if (haddr & PA_PLABEL_FDESC) {
320			Elf32_Fdesc fdesc;
321			Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
322
323			err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
324
325			if (err)
326				return -EFAULT;
327
328			haddr = fdesc.addr;
329			regs->gr[19] = fdesc.gp;
330		}
331#ifdef CONFIG_64BIT
332	} else {
333		Elf64_Fdesc fdesc;
334		Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
335		
336		err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
337		
338		if (err)
339			return -EFAULT;
340		
341		haddr = fdesc.addr;
342		regs->gr[19] = fdesc.gp;
343		DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
344		     haddr, regs->gr[19], in_syscall);
345	}
346#endif
347
348	/* The syscall return path will create IAOQ values from r31.
349	 */
350	sigframe_size = PARISC_RT_SIGFRAME_SIZE;
351#ifdef CONFIG_64BIT
352	if (is_compat_task())
353		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
354#endif
355	if (in_syscall) {
356		regs->gr[31] = haddr;
357#ifdef CONFIG_64BIT
358		if (!test_thread_flag(TIF_32BIT))
359			sigframe_size |= 1;
360#endif
361	} else {
362		unsigned long psw = USER_PSW;
363#ifdef CONFIG_64BIT
364		if (!test_thread_flag(TIF_32BIT))
365			psw |= PSW_W;
366#endif
367
368		/* If we are singlestepping, arrange a trap to be delivered
369		   when we return to userspace. Note the semantics -- we
370		   should trap before the first insn in the handler is
371		   executed. Ref:
372			http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
373		 */
374		if (pa_psw(current)->r) {
375			pa_psw(current)->r = 0;
376			psw |= PSW_R;
377			mtctl(-1, 0);
378		}
379
380		regs->gr[0] = psw;
381		regs->iaoq[0] = haddr | 3;
382		regs->iaoq[1] = regs->iaoq[0] + 4;
383	}
384
385	regs->gr[2]  = rp;                /* userland return pointer */
386	regs->gr[26] = ksig->sig;               /* signal number */
387	
388#ifdef CONFIG_64BIT
389	if (is_compat_task()) {
390		regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
391		regs->gr[24] = A(&compat_frame->uc);   /* ucontext pointer */
392	} else
393#endif
394	{		
395		regs->gr[25] = A(&frame->info); /* siginfo pointer */
396		regs->gr[24] = A(&frame->uc);   /* ucontext pointer */
397	}
398	
399	DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
400	       regs->gr[30], sigframe_size,
401	       regs->gr[30] + sigframe_size);
402	/* Raise the user stack pointer to make a proper call frame. */
403	regs->gr[30] = (A(frame) + sigframe_size);
404
405
406	DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
407	       current->comm, current->pid, frame, regs->gr[30],
408	       regs->iaoq[0], regs->iaoq[1], rp);
409
410	return 0;
411}
412
413/*
414 * OK, we're invoking a handler.
415 */	
416
417static void
418handle_signal(struct ksignal *ksig, struct pt_regs *regs, int in_syscall)
419{
420	int ret;
421	sigset_t *oldset = sigmask_to_save();
422
423	DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
424	       ksig->sig, ksig->ka, ksig->info, oldset, regs);
425	
426	/* Set up the stack frame */
427	ret = setup_rt_frame(ksig, oldset, regs, in_syscall);
428
429	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP) ||
430			  test_thread_flag(TIF_BLOCKSTEP));
431
432	DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
433		regs->gr[28]);
434}
435
436/*
437 * Check how the syscall number gets loaded into %r20 within
438 * the delay branch in userspace and adjust as needed.
439 */
440
441static void check_syscallno_in_delay_branch(struct pt_regs *regs)
442{
443	u32 opcode, source_reg;
444	u32 __user *uaddr;
445	int err;
446
447	/* Usually we don't have to restore %r20 (the system call number)
448	 * because it gets loaded in the delay slot of the branch external
449	 * instruction via the ldi instruction.
450	 * In some cases a register-to-register copy instruction might have
451	 * been used instead, in which case we need to copy the syscall
452	 * number into the source register before returning to userspace.
453	 */
454
455	/* A syscall is just a branch, so all we have to do is fiddle the
456	 * return pointer so that the ble instruction gets executed again.
457	 */
458	regs->gr[31] -= 8; /* delayed branching */
459
460	/* Get assembler opcode of code in delay branch */
461	uaddr = (unsigned int *) ((regs->gr[31] & ~3) + 4);
462	err = get_user(opcode, uaddr);
463	if (err)
464		return;
465
466	/* Check if delay branch uses "ldi int,%r20" */
467	if ((opcode & 0xffff0000) == 0x34140000)
468		return;	/* everything ok, just return */
469
470	/* Check if delay branch uses "nop" */
471	if (opcode == INSN_NOP)
472		return;
473
474	/* Check if delay branch uses "copy %rX,%r20" */
475	if ((opcode & 0xffe0ffff) == 0x08000254) {
476		source_reg = (opcode >> 16) & 31;
477		regs->gr[source_reg] = regs->gr[20];
478		return;
479	}
480
481	pr_warn("syscall restart: %s (pid %d): unexpected opcode 0x%08x\n",
482		current->comm, task_pid_nr(current), opcode);
483}
484
485static inline void
486syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
487{
488	if (regs->orig_r28)
489		return;
490	regs->orig_r28 = 1; /* no more restarts */
491	/* Check the return code */
492	switch (regs->gr[28]) {
493	case -ERESTART_RESTARTBLOCK:
494	case -ERESTARTNOHAND:
495		DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
496		regs->gr[28] = -EINTR;
497		break;
498
499	case -ERESTARTSYS:
500		if (!(ka->sa.sa_flags & SA_RESTART)) {
501			DBG(1,"ERESTARTSYS: putting -EINTR\n");
502			regs->gr[28] = -EINTR;
503			break;
504		}
505		fallthrough;
506	case -ERESTARTNOINTR:
507		check_syscallno_in_delay_branch(regs);
508		break;
509	}
510}
511
512static inline void
513insert_restart_trampoline(struct pt_regs *regs)
514{
515	if (regs->orig_r28)
516		return;
517	regs->orig_r28 = 1; /* no more restarts */
518	switch(regs->gr[28]) {
519	case -ERESTART_RESTARTBLOCK: {
520		/* Restart the system call - no handlers present */
521		unsigned int *usp = (unsigned int *)regs->gr[30];
522		unsigned long start = (unsigned long) &usp[2];
523		unsigned long end  = (unsigned long) &usp[5];
524		long err = 0;
525
526		/* Setup a trampoline to restart the syscall
527		 * with __NR_restart_syscall
528		 *
529		 *  0: <return address (orig r31)>
530		 *  4: <2nd half for 64-bit>
531		 *  8: ldw 0(%sp), %r31
532		 * 12: be 0x100(%sr2, %r0)
533		 * 16: ldi __NR_restart_syscall, %r20
534		 */
535#ifdef CONFIG_64BIT
536		err |= put_user(regs->gr[31] >> 32, &usp[0]);
537		err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]);
538		err |= put_user(0x0fc010df, &usp[2]);
539#else
540		err |= put_user(regs->gr[31], &usp[0]);
541		err |= put_user(0x0fc0109f, &usp[2]);
542#endif
543		err |= put_user(0xe0008200, &usp[3]);
544		err |= put_user(0x34140000, &usp[4]);
545
546		WARN_ON(err);
547
548		/* flush data/instruction cache for new insns */
549		flush_user_dcache_range_asm(start, end);
550		flush_user_icache_range_asm(start, end);
551
552		regs->gr[31] = regs->gr[30] + 8;
553		return;
554	}
555	case -ERESTARTNOHAND:
556	case -ERESTARTSYS:
557	case -ERESTARTNOINTR:
558		check_syscallno_in_delay_branch(regs);
559		return;
560	default:
561		break;
562	}
563}
564
565/*
566 * Note that 'init' is a special process: it doesn't get signals it doesn't
567 * want to handle. Thus you cannot kill init even with a SIGKILL even by
568 * mistake.
569 *
570 * We need to be able to restore the syscall arguments (r21-r26) to
571 * restart syscalls.  Thus, the syscall path should save them in the
572 * pt_regs structure (it's okay to do so since they are caller-save
573 * registers).  As noted below, the syscall number gets restored for
574 * us due to the magic of delayed branching.
575 */
576asmlinkage void
577do_signal(struct pt_regs *regs, long in_syscall)
578{
579	struct ksignal ksig;
580
581	DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n",
582	       regs, regs->sr[7], in_syscall);
583
584	if (get_signal(&ksig)) {
585		DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]);
586		/* Restart a system call if necessary. */
587		if (in_syscall)
588			syscall_restart(regs, &ksig.ka);
589
590		handle_signal(&ksig, regs, in_syscall);
591		return;
592	}
593
594	/* Did we come from a system call? */
595	if (in_syscall)
596		insert_restart_trampoline(regs);
597	
598	DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n", 
599		regs->gr[28]);
600
601	restore_saved_sigmask();
602}
603
604void do_notify_resume(struct pt_regs *regs, long in_syscall)
605{
606	if (test_thread_flag(TIF_SIGPENDING))
 
607		do_signal(regs, in_syscall);
608
609	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
610		clear_thread_flag(TIF_NOTIFY_RESUME);
611		tracehook_notify_resume(regs);
612	}
613}
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}