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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}
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
52#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
53
54/* gcc will complain if a pointer is cast to an integer of different
55 * size. If you really need to do this (and we do for an ELF32 user
56 * application in an ELF64 kernel) then you have to do a cast to an
57 * integer of the same size first. The A() macro accomplishes
58 * this. */
59#define A(__x) ((unsigned long)(__x))
60
61/*
62 * Atomically swap in the new signal mask, and wait for a signal.
63 */
64#ifdef CONFIG_64BIT
65#include "sys32.h"
66#endif
67
68/*
69 * Do a signal return - restore sigcontext.
70 */
71
72/* Trampoline for calling rt_sigreturn() */
73#define INSN_LDI_R25_0 0x34190000 /* ldi 0,%r25 (in_syscall=0) */
74#define INSN_LDI_R25_1 0x34190002 /* ldi 1,%r25 (in_syscall=1) */
75#define INSN_LDI_R20 0x3414015a /* ldi __NR_rt_sigreturn,%r20 */
76#define INSN_BLE_SR2_R0 0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */
77#define INSN_NOP 0x08000240 /* nop */
78/* For debugging */
79#define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */
80
81static long
82restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
83{
84 long err = 0;
85
86 err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr));
87 err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
88 err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq));
89 err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq));
90 err |= __get_user(regs->sar, &sc->sc_sar);
91 DBG(2,"restore_sigcontext: iaoq is 0x%#lx / 0x%#lx\n",
92 regs->iaoq[0],regs->iaoq[1]);
93 DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]);
94 return err;
95}
96
97void
98sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
99{
100 struct rt_sigframe __user *frame;
101 sigset_t set;
102 unsigned long usp = (regs->gr[30] & ~(0x01UL));
103 unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
104#ifdef CONFIG_64BIT
105 compat_sigset_t compat_set;
106 struct compat_rt_sigframe __user * compat_frame;
107
108 if (is_compat_task())
109 sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
110#endif
111
112
113 /* Unwind the user stack to get the rt_sigframe structure. */
114 frame = (struct rt_sigframe __user *)
115 (usp - sigframe_size);
116 DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
117
118#ifdef CONFIG_64BIT
119 compat_frame = (struct compat_rt_sigframe __user *)frame;
120
121 if (is_compat_task()) {
122 DBG(2,"sys_rt_sigreturn: ELF32 process.\n");
123 if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set)))
124 goto give_sigsegv;
125 sigset_32to64(&set,&compat_set);
126 } else
127#endif
128 {
129 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
130 goto give_sigsegv;
131 }
132
133 sigdelsetmask(&set, ~_BLOCKABLE);
134 spin_lock_irq(¤t->sighand->siglock);
135 current->blocked = set;
136 recalc_sigpending();
137 spin_unlock_irq(¤t->sighand->siglock);
138
139 /* Good thing we saved the old gr[30], eh? */
140#ifdef CONFIG_64BIT
141 if (is_compat_task()) {
142 DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n",
143 &compat_frame->uc.uc_mcontext);
144// FIXME: Load upper half from register file
145 if (restore_sigcontext32(&compat_frame->uc.uc_mcontext,
146 &compat_frame->regs, regs))
147 goto give_sigsegv;
148 DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
149 usp, &compat_frame->uc.uc_stack);
150 if (do_sigaltstack32(&compat_frame->uc.uc_stack, NULL, usp) == -EFAULT)
151 goto give_sigsegv;
152 } else
153#endif
154 {
155 DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n",
156 &frame->uc.uc_mcontext);
157 if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
158 goto give_sigsegv;
159 DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
160 usp, &frame->uc.uc_stack);
161 if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT)
162 goto give_sigsegv;
163 }
164
165
166
167 /* If we are on the syscall path IAOQ will not be restored, and
168 * if we are on the interrupt path we must not corrupt gr31.
169 */
170 if (in_syscall)
171 regs->gr[31] = regs->iaoq[0];
172#if DEBUG_SIG
173 DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]);
174 show_regs(regs);
175#endif
176 return;
177
178give_sigsegv:
179 DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n");
180 force_sig(SIGSEGV, current);
181 return;
182}
183
184/*
185 * Set up a signal frame.
186 */
187
188static inline void __user *
189get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
190{
191 /*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
192 don't use the parameter it doesn't matter */
193
194 DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n",
195 (unsigned long)ka, sp, frame_size);
196
197 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
198 sp = current->sas_ss_sp; /* Stacks grow up! */
199
200 DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp);
201 return (void __user *) sp; /* Stacks grow up. Fun. */
202}
203
204static long
205setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
206
207{
208 unsigned long flags = 0;
209 long err = 0;
210
211 if (on_sig_stack((unsigned long) sc))
212 flags |= PARISC_SC_FLAG_ONSTACK;
213 if (in_syscall) {
214 flags |= PARISC_SC_FLAG_IN_SYSCALL;
215 /* regs->iaoq is undefined in the syscall return path */
216 err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
217 err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
218 err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
219 err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
220 DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n",
221 regs->gr[31], regs->gr[31]+4);
222 } else {
223 err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
224 err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
225 DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n",
226 regs->iaoq[0], regs->iaoq[1]);
227 }
228
229 err |= __put_user(flags, &sc->sc_flags);
230 err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
231 err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
232 err |= __put_user(regs->sar, &sc->sc_sar);
233 DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]);
234
235 return err;
236}
237
238static long
239setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
240 sigset_t *set, struct pt_regs *regs, int in_syscall)
241{
242 struct rt_sigframe __user *frame;
243 unsigned long rp, usp;
244 unsigned long haddr, sigframe_size;
245 int err = 0;
246#ifdef CONFIG_64BIT
247 compat_int_t compat_val;
248 struct compat_rt_sigframe __user * compat_frame;
249 compat_sigset_t compat_set;
250#endif
251
252 usp = (regs->gr[30] & ~(0x01UL));
253 /*FIXME: frame_size parameter is unused, remove it. */
254 frame = get_sigframe(ka, usp, sizeof(*frame));
255
256 DBG(1,"SETUP_RT_FRAME: START\n");
257 DBG(1,"setup_rt_frame: frame %p info %p\n", frame, info);
258
259
260#ifdef CONFIG_64BIT
261
262 compat_frame = (struct compat_rt_sigframe __user *)frame;
263
264 if (is_compat_task()) {
265 DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
266 err |= copy_siginfo_to_user32(&compat_frame->info, info);
267 DBG(1,"SETUP_RT_FRAME: 1\n");
268 compat_val = (compat_int_t)current->sas_ss_sp;
269 err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_sp);
270 DBG(1,"SETUP_RT_FRAME: 2\n");
271 compat_val = (compat_int_t)current->sas_ss_size;
272 err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_size);
273 DBG(1,"SETUP_RT_FRAME: 3\n");
274 compat_val = sas_ss_flags(regs->gr[30]);
275 err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_flags);
276 DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
277 DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
278 err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext,
279 &compat_frame->regs, regs, in_syscall);
280 sigset_64to32(&compat_set,set);
281 err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set));
282 } else
283#endif
284 {
285 DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
286 err |= copy_siginfo_to_user(&frame->info, info);
287 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
288 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
289 err |= __put_user(sas_ss_flags(regs->gr[30]),
290 &frame->uc.uc_stack.ss_flags);
291 DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
292 DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
293 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
294 /* FIXME: Should probably be converted as well for the compat case */
295 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
296 }
297
298 if (err)
299 goto give_sigsegv;
300
301 /* Set up to return from userspace. If provided, use a stub
302 already in userspace. The first words of tramp are used to
303 save the previous sigrestartblock trampoline that might be
304 on the stack. We start the sigreturn trampoline at
305 SIGRESTARTBLOCK_TRAMP+X. */
306 err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
307 &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
308 err |= __put_user(INSN_LDI_R20,
309 &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
310 err |= __put_user(INSN_BLE_SR2_R0,
311 &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
312 err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
313
314#if DEBUG_SIG
315 /* Assert that we're flushing in the correct space... */
316 {
317 int sid;
318 asm ("mfsp %%sr3,%0" : "=r" (sid));
319 DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
320 sid, frame->tramp);
321 }
322#endif
323
324 flush_user_dcache_range((unsigned long) &frame->tramp[0],
325 (unsigned long) &frame->tramp[TRAMP_SIZE]);
326 flush_user_icache_range((unsigned long) &frame->tramp[0],
327 (unsigned long) &frame->tramp[TRAMP_SIZE]);
328
329 /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP
330 * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
331 * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
332 */
333 rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
334
335 if (err)
336 goto give_sigsegv;
337
338 haddr = A(ka->sa.sa_handler);
339 /* The sa_handler may be a pointer to a function descriptor */
340#ifdef CONFIG_64BIT
341 if (is_compat_task()) {
342#endif
343 if (haddr & PA_PLABEL_FDESC) {
344 Elf32_Fdesc fdesc;
345 Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
346
347 err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
348
349 if (err)
350 goto give_sigsegv;
351
352 haddr = fdesc.addr;
353 regs->gr[19] = fdesc.gp;
354 }
355#ifdef CONFIG_64BIT
356 } else {
357 Elf64_Fdesc fdesc;
358 Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
359
360 err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
361
362 if (err)
363 goto give_sigsegv;
364
365 haddr = fdesc.addr;
366 regs->gr[19] = fdesc.gp;
367 DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
368 haddr, regs->gr[19], in_syscall);
369 }
370#endif
371
372 /* The syscall return path will create IAOQ values from r31.
373 */
374 sigframe_size = PARISC_RT_SIGFRAME_SIZE;
375#ifdef CONFIG_64BIT
376 if (is_compat_task())
377 sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
378#endif
379 if (in_syscall) {
380 regs->gr[31] = haddr;
381#ifdef CONFIG_64BIT
382 if (!test_thread_flag(TIF_32BIT))
383 sigframe_size |= 1;
384#endif
385 } else {
386 unsigned long psw = USER_PSW;
387#ifdef CONFIG_64BIT
388 if (!test_thread_flag(TIF_32BIT))
389 psw |= PSW_W;
390#endif
391
392 /* If we are singlestepping, arrange a trap to be delivered
393 when we return to userspace. Note the semantics -- we
394 should trap before the first insn in the handler is
395 executed. Ref:
396 http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
397 */
398 if (pa_psw(current)->r) {
399 pa_psw(current)->r = 0;
400 psw |= PSW_R;
401 mtctl(-1, 0);
402 }
403
404 regs->gr[0] = psw;
405 regs->iaoq[0] = haddr | 3;
406 regs->iaoq[1] = regs->iaoq[0] + 4;
407 }
408
409 regs->gr[2] = rp; /* userland return pointer */
410 regs->gr[26] = sig; /* signal number */
411
412#ifdef CONFIG_64BIT
413 if (is_compat_task()) {
414 regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
415 regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */
416 } else
417#endif
418 {
419 regs->gr[25] = A(&frame->info); /* siginfo pointer */
420 regs->gr[24] = A(&frame->uc); /* ucontext pointer */
421 }
422
423 DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
424 regs->gr[30], sigframe_size,
425 regs->gr[30] + sigframe_size);
426 /* Raise the user stack pointer to make a proper call frame. */
427 regs->gr[30] = (A(frame) + sigframe_size);
428
429
430 DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
431 current->comm, current->pid, frame, regs->gr[30],
432 regs->iaoq[0], regs->iaoq[1], rp);
433
434 return 1;
435
436give_sigsegv:
437 DBG(1,"setup_rt_frame: sending SIGSEGV\n");
438 force_sigsegv(sig, current);
439 return 0;
440}
441
442/*
443 * OK, we're invoking a handler.
444 */
445
446static long
447handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
448 sigset_t *oldset, struct pt_regs *regs, int in_syscall)
449{
450 DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
451 sig, ka, info, oldset, regs);
452
453 /* Set up the stack frame */
454 if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall))
455 return 0;
456
457 spin_lock_irq(¤t->sighand->siglock);
458 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
459 if (!(ka->sa.sa_flags & SA_NODEFER))
460 sigaddset(¤t->blocked,sig);
461 recalc_sigpending();
462 spin_unlock_irq(¤t->sighand->siglock);
463
464 tracehook_signal_handler(sig, info, ka, regs,
465 test_thread_flag(TIF_SINGLESTEP) ||
466 test_thread_flag(TIF_BLOCKSTEP));
467
468 return 1;
469}
470
471static inline void
472syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
473{
474 /* Check the return code */
475 switch (regs->gr[28]) {
476 case -ERESTART_RESTARTBLOCK:
477 current_thread_info()->restart_block.fn =
478 do_no_restart_syscall;
479 case -ERESTARTNOHAND:
480 DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
481 regs->gr[28] = -EINTR;
482 break;
483
484 case -ERESTARTSYS:
485 if (!(ka->sa.sa_flags & SA_RESTART)) {
486 DBG(1,"ERESTARTSYS: putting -EINTR\n");
487 regs->gr[28] = -EINTR;
488 break;
489 }
490 /* fallthrough */
491 case -ERESTARTNOINTR:
492 /* A syscall is just a branch, so all
493 * we have to do is fiddle the return pointer.
494 */
495 regs->gr[31] -= 8; /* delayed branching */
496 /* Preserve original r28. */
497 regs->gr[28] = regs->orig_r28;
498 break;
499 }
500}
501
502static inline void
503insert_restart_trampoline(struct pt_regs *regs)
504{
505 switch(regs->gr[28]) {
506 case -ERESTART_RESTARTBLOCK: {
507 /* Restart the system call - no handlers present */
508 unsigned int *usp = (unsigned int *)regs->gr[30];
509
510 /* Setup a trampoline to restart the syscall
511 * with __NR_restart_syscall
512 *
513 * 0: <return address (orig r31)>
514 * 4: <2nd half for 64-bit>
515 * 8: ldw 0(%sp), %r31
516 * 12: be 0x100(%sr2, %r0)
517 * 16: ldi __NR_restart_syscall, %r20
518 */
519#ifdef CONFIG_64BIT
520 put_user(regs->gr[31] >> 32, &usp[0]);
521 put_user(regs->gr[31] & 0xffffffff, &usp[1]);
522 put_user(0x0fc010df, &usp[2]);
523#else
524 put_user(regs->gr[31], &usp[0]);
525 put_user(0x0fc0109f, &usp[2]);
526#endif
527 put_user(0xe0008200, &usp[3]);
528 put_user(0x34140000, &usp[4]);
529
530 /* Stack is 64-byte aligned, and we only need
531 * to flush 1 cache line.
532 * Flushing one cacheline is cheap.
533 * "sync" on bigger (> 4 way) boxes is not.
534 */
535 flush_user_dcache_range(regs->gr[30], regs->gr[30] + 4);
536 flush_user_icache_range(regs->gr[30], regs->gr[30] + 4);
537
538 regs->gr[31] = regs->gr[30] + 8;
539 /* Preserve original r28. */
540 regs->gr[28] = regs->orig_r28;
541
542 return;
543 }
544 case -ERESTARTNOHAND:
545 case -ERESTARTSYS:
546 case -ERESTARTNOINTR: {
547 /* Hooray for delayed branching. We don't
548 * have to restore %r20 (the system call
549 * number) because it gets loaded in the delay
550 * slot of the branch external instruction.
551 */
552 regs->gr[31] -= 8;
553 /* Preserve original r28. */
554 regs->gr[28] = regs->orig_r28;
555
556 return;
557 }
558 default:
559 break;
560 }
561}
562
563/*
564 * Note that 'init' is a special process: it doesn't get signals it doesn't
565 * want to handle. Thus you cannot kill init even with a SIGKILL even by
566 * mistake.
567 *
568 * We need to be able to restore the syscall arguments (r21-r26) to
569 * restart syscalls. Thus, the syscall path should save them in the
570 * pt_regs structure (it's okay to do so since they are caller-save
571 * registers). As noted below, the syscall number gets restored for
572 * us due to the magic of delayed branching.
573 */
574asmlinkage void
575do_signal(struct pt_regs *regs, long in_syscall)
576{
577 siginfo_t info;
578 struct k_sigaction ka;
579 int signr;
580 sigset_t *oldset;
581
582 DBG(1,"\ndo_signal: oldset=0x%p, regs=0x%p, sr7 %#lx, in_syscall=%d\n",
583 oldset, regs, regs->sr[7], in_syscall);
584
585 /* Everyone else checks to see if they are in kernel mode at
586 this point and exits if that's the case. I'm not sure why
587 we would be called in that case, but for some reason we
588 are. */
589
590 if (test_thread_flag(TIF_RESTORE_SIGMASK))
591 oldset = ¤t->saved_sigmask;
592 else
593 oldset = ¤t->blocked;
594
595 DBG(1,"do_signal: oldset %08lx / %08lx\n",
596 oldset->sig[0], oldset->sig[1]);
597
598
599 /* May need to force signal if handle_signal failed to deliver */
600 while (1) {
601
602 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
603 DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]);
604
605 if (signr <= 0)
606 break;
607
608 /* Restart a system call if necessary. */
609 if (in_syscall)
610 syscall_restart(regs, &ka);
611
612 /* Whee! Actually deliver the signal. If the
613 delivery failed, we need to continue to iterate in
614 this loop so we can deliver the SIGSEGV... */
615 if (handle_signal(signr, &info, &ka, oldset,
616 regs, in_syscall)) {
617 DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
618 regs->gr[28]);
619 if (test_thread_flag(TIF_RESTORE_SIGMASK))
620 clear_thread_flag(TIF_RESTORE_SIGMASK);
621 return;
622 }
623 }
624 /* end of while(1) looping forever if we can't force a signal */
625
626 /* Did we come from a system call? */
627 if (in_syscall)
628 insert_restart_trampoline(regs);
629
630 DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n",
631 regs->gr[28]);
632
633 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
634 clear_thread_flag(TIF_RESTORE_SIGMASK);
635 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
636 }
637
638 return;
639}
640
641void do_notify_resume(struct pt_regs *regs, long in_syscall)
642{
643 if (test_thread_flag(TIF_SIGPENDING) ||
644 test_thread_flag(TIF_RESTORE_SIGMASK))
645 do_signal(regs, in_syscall);
646
647 if (test_thread_flag(TIF_NOTIFY_RESUME)) {
648 clear_thread_flag(TIF_NOTIFY_RESUME);
649 tracehook_notify_resume(regs);
650 if (current->replacement_session_keyring)
651 key_replace_session_keyring();
652 }
653}