blob: 441b25992846d3413088e19794d4a418f6cf5b48 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/kernel.h>
20#include <linux/signal.h>
21#include <linux/errno.h>
22#include <linux/wait.h>
23#include <linux/ptrace.h>
Kyle McMartinecf02de2009-04-27 00:29:53 -040024#include <linux/tracehook.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/unistd.h>
26#include <linux/stddef.h>
27#include <linux/compat.h>
28#include <linux/elf.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#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>
Sam Ravnborg0013a852005-09-09 20:57:26 +020034#include <asm/asm-offsets.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36#ifdef CONFIG_COMPAT
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#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
Linus Torvalds1da177e2005-04-16 15:20:36 -070061/*
62 * Atomically swap in the new signal mask, and wait for a signal.
63 */
Helge Dellera8f44e32007-01-28 14:58:52 +010064#ifdef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -070065#include "sys32.h"
66#endif
67
Linus Torvalds1da177e2005-04-16 15:20:36 -070068/*
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 sigset_t set;
102 unsigned long usp = (regs->gr[30] & ~(0x01UL));
103 unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
Helge Dellera8f44e32007-01-28 14:58:52 +0100104#ifdef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 compat_sigset_t compat_set;
106 struct compat_rt_sigframe __user * compat_frame;
107
Kyle McMartina3ea84f2006-06-16 19:10:02 +0000108 if (is_compat_task())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
110#endif
111
Al Viro85a847f2012-04-22 03:15:40 -0400112 current_thread_info()->restart_block.fn = do_no_restart_syscall;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113
114 /* Unwind the user stack to get the rt_sigframe structure. */
115 frame = (struct rt_sigframe __user *)
116 (usp - sigframe_size);
117 DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
118
Helge Dellera8f44e32007-01-28 14:58:52 +0100119#ifdef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 compat_frame = (struct compat_rt_sigframe __user *)frame;
121
Kyle McMartina3ea84f2006-06-16 19:10:02 +0000122 if (is_compat_task()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 DBG(2,"sys_rt_sigreturn: ELF32 process.\n");
124 if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set)))
125 goto give_sigsegv;
126 sigset_32to64(&set,&compat_set);
127 } else
128#endif
129 {
130 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
131 goto give_sigsegv;
132 }
133
134 sigdelsetmask(&set, ~_BLOCKABLE);
Matt Flemingade77282012-05-11 10:58:58 +1000135 set_current_blocked(&set);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137 /* Good thing we saved the old gr[30], eh? */
Helge Dellera8f44e32007-01-28 14:58:52 +0100138#ifdef CONFIG_64BIT
Kyle McMartina3ea84f2006-06-16 19:10:02 +0000139 if (is_compat_task()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n",
141 &compat_frame->uc.uc_mcontext);
142// FIXME: Load upper half from register file
143 if (restore_sigcontext32(&compat_frame->uc.uc_mcontext,
144 &compat_frame->regs, regs))
145 goto give_sigsegv;
146 DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
147 usp, &compat_frame->uc.uc_stack);
148 if (do_sigaltstack32(&compat_frame->uc.uc_stack, NULL, usp) == -EFAULT)
149 goto give_sigsegv;
150 } else
151#endif
152 {
153 DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n",
154 &frame->uc.uc_mcontext);
155 if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
156 goto give_sigsegv;
157 DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
158 usp, &frame->uc.uc_stack);
159 if (do_sigaltstack(&frame->uc.uc_stack, NULL, usp) == -EFAULT)
160 goto give_sigsegv;
161 }
162
163
164
165 /* If we are on the syscall path IAOQ will not be restored, and
166 * if we are on the interrupt path we must not corrupt gr31.
167 */
168 if (in_syscall)
169 regs->gr[31] = regs->iaoq[0];
170#if DEBUG_SIG
171 DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]);
172 show_regs(regs);
173#endif
174 return;
175
176give_sigsegv:
177 DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n");
Kyle McMartin67bace72010-11-29 20:34:38 -0500178 force_sig(SIGSEGV, current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 return;
180}
181
182/*
183 * Set up a signal frame.
184 */
185
186static inline void __user *
187get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
188{
189 /*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
190 don't use the parameter it doesn't matter */
191
192 DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n",
193 (unsigned long)ka, sp, frame_size);
194
Laurent MEYERd09042d2006-06-23 02:05:36 -0700195 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 sp = current->sas_ss_sp; /* Stacks grow up! */
197
198 DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp);
199 return (void __user *) sp; /* Stacks grow up. Fun. */
200}
201
202static long
203setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
204
205{
206 unsigned long flags = 0;
207 long err = 0;
208
209 if (on_sig_stack((unsigned long) sc))
210 flags |= PARISC_SC_FLAG_ONSTACK;
211 if (in_syscall) {
212 flags |= PARISC_SC_FLAG_IN_SYSCALL;
213 /* regs->iaoq is undefined in the syscall return path */
214 err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
215 err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
216 err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
217 err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
218 DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n",
219 regs->gr[31], regs->gr[31]+4);
220 } else {
221 err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
222 err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
223 DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n",
224 regs->iaoq[0], regs->iaoq[1]);
225 }
226
227 err |= __put_user(flags, &sc->sc_flags);
228 err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
229 err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
230 err |= __put_user(regs->sar, &sc->sc_sar);
231 DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]);
232
233 return err;
234}
235
236static long
237setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
238 sigset_t *set, struct pt_regs *regs, int in_syscall)
239{
240 struct rt_sigframe __user *frame;
241 unsigned long rp, usp;
242 unsigned long haddr, sigframe_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 int err = 0;
Helge Dellera8f44e32007-01-28 14:58:52 +0100244#ifdef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 compat_int_t compat_val;
246 struct compat_rt_sigframe __user * compat_frame;
247 compat_sigset_t compat_set;
248#endif
249
250 usp = (regs->gr[30] & ~(0x01UL));
251 /*FIXME: frame_size parameter is unused, remove it. */
252 frame = get_sigframe(ka, usp, sizeof(*frame));
253
254 DBG(1,"SETUP_RT_FRAME: START\n");
255 DBG(1,"setup_rt_frame: frame %p info %p\n", frame, info);
256
257
Helge Dellera8f44e32007-01-28 14:58:52 +0100258#ifdef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
260 compat_frame = (struct compat_rt_sigframe __user *)frame;
261
Kyle McMartina3ea84f2006-06-16 19:10:02 +0000262 if (is_compat_task()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
Kyle McMartinf671c452006-01-15 14:10:29 -0500264 err |= copy_siginfo_to_user32(&compat_frame->info, info);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 DBG(1,"SETUP_RT_FRAME: 1\n");
266 compat_val = (compat_int_t)current->sas_ss_sp;
267 err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_sp);
268 DBG(1,"SETUP_RT_FRAME: 2\n");
269 compat_val = (compat_int_t)current->sas_ss_size;
270 err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_size);
271 DBG(1,"SETUP_RT_FRAME: 3\n");
272 compat_val = sas_ss_flags(regs->gr[30]);
273 err |= __put_user(compat_val, &compat_frame->uc.uc_stack.ss_flags);
274 DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
275 DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
276 err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext,
277 &compat_frame->regs, regs, in_syscall);
278 sigset_64to32(&compat_set,set);
279 err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set));
280 } else
281#endif
282 {
283 DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
284 err |= copy_siginfo_to_user(&frame->info, info);
285 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
286 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
287 err |= __put_user(sas_ss_flags(regs->gr[30]),
288 &frame->uc.uc_stack.ss_flags);
289 DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
290 DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
291 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300292 /* FIXME: Should probably be converted as well for the compat case */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
294 }
295
296 if (err)
297 goto give_sigsegv;
298
299 /* Set up to return from userspace. If provided, use a stub
300 already in userspace. The first words of tramp are used to
301 save the previous sigrestartblock trampoline that might be
302 on the stack. We start the sigreturn trampoline at
303 SIGRESTARTBLOCK_TRAMP+X. */
304 err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
305 &frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
306 err |= __put_user(INSN_LDI_R20,
307 &frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
308 err |= __put_user(INSN_BLE_SR2_R0,
309 &frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
310 err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
311
312#if DEBUG_SIG
313 /* Assert that we're flushing in the correct space... */
314 {
315 int sid;
316 asm ("mfsp %%sr3,%0" : "=r" (sid));
317 DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
318 sid, frame->tramp);
319 }
320#endif
321
322 flush_user_dcache_range((unsigned long) &frame->tramp[0],
323 (unsigned long) &frame->tramp[TRAMP_SIZE]);
324 flush_user_icache_range((unsigned long) &frame->tramp[0],
325 (unsigned long) &frame->tramp[TRAMP_SIZE]);
326
Paulius Zaleckasefad798b2008-02-03 15:42:53 +0200327 /* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 * TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
329 * So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
330 */
331 rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
332
333 if (err)
334 goto give_sigsegv;
335
336 haddr = A(ka->sa.sa_handler);
337 /* The sa_handler may be a pointer to a function descriptor */
Helge Dellera8f44e32007-01-28 14:58:52 +0100338#ifdef CONFIG_64BIT
Kyle McMartina3ea84f2006-06-16 19:10:02 +0000339 if (is_compat_task()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340#endif
341 if (haddr & PA_PLABEL_FDESC) {
342 Elf32_Fdesc fdesc;
343 Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
344
345 err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
346
347 if (err)
348 goto give_sigsegv;
349
350 haddr = fdesc.addr;
351 regs->gr[19] = fdesc.gp;
352 }
Helge Dellera8f44e32007-01-28 14:58:52 +0100353#ifdef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 } else {
355 Elf64_Fdesc fdesc;
356 Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
357
358 err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
359
360 if (err)
361 goto give_sigsegv;
362
363 haddr = fdesc.addr;
364 regs->gr[19] = fdesc.gp;
365 DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
366 haddr, regs->gr[19], in_syscall);
367 }
368#endif
369
370 /* The syscall return path will create IAOQ values from r31.
371 */
372 sigframe_size = PARISC_RT_SIGFRAME_SIZE;
Helge Dellera8f44e32007-01-28 14:58:52 +0100373#ifdef CONFIG_64BIT
Kyle McMartina3ea84f2006-06-16 19:10:02 +0000374 if (is_compat_task())
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
376#endif
377 if (in_syscall) {
378 regs->gr[31] = haddr;
Helge Dellera8f44e32007-01-28 14:58:52 +0100379#ifdef CONFIG_64BIT
Kyle McMartindf570b92006-08-27 11:04:26 -0400380 if (!test_thread_flag(TIF_32BIT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 sigframe_size |= 1;
382#endif
383 } else {
384 unsigned long psw = USER_PSW;
Helge Dellera8f44e32007-01-28 14:58:52 +0100385#ifdef CONFIG_64BIT
Kyle McMartindf570b92006-08-27 11:04:26 -0400386 if (!test_thread_flag(TIF_32BIT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 psw |= PSW_W;
388#endif
389
390 /* If we are singlestepping, arrange a trap to be delivered
391 when we return to userspace. Note the semantics -- we
392 should trap before the first insn in the handler is
393 executed. Ref:
394 http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
395 */
396 if (pa_psw(current)->r) {
397 pa_psw(current)->r = 0;
398 psw |= PSW_R;
399 mtctl(-1, 0);
400 }
401
402 regs->gr[0] = psw;
403 regs->iaoq[0] = haddr | 3;
404 regs->iaoq[1] = regs->iaoq[0] + 4;
405 }
406
407 regs->gr[2] = rp; /* userland return pointer */
408 regs->gr[26] = sig; /* signal number */
409
Helge Dellera8f44e32007-01-28 14:58:52 +0100410#ifdef CONFIG_64BIT
Kyle McMartina3ea84f2006-06-16 19:10:02 +0000411 if (is_compat_task()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
413 regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */
414 } else
415#endif
416 {
417 regs->gr[25] = A(&frame->info); /* siginfo pointer */
418 regs->gr[24] = A(&frame->uc); /* ucontext pointer */
419 }
420
421 DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
422 regs->gr[30], sigframe_size,
423 regs->gr[30] + sigframe_size);
424 /* Raise the user stack pointer to make a proper call frame. */
425 regs->gr[30] = (A(frame) + sigframe_size);
426
427
428 DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
429 current->comm, current->pid, frame, regs->gr[30],
430 regs->iaoq[0], regs->iaoq[1], rp);
431
432 return 1;
433
434give_sigsegv:
435 DBG(1,"setup_rt_frame: sending SIGSEGV\n");
Randolph Chung40c72f22005-10-21 22:49:47 -0400436 force_sigsegv(sig, current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 return 0;
438}
439
440/*
441 * OK, we're invoking a handler.
442 */
443
444static long
445handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
Al Virob7f9a112012-05-02 09:59:21 -0400446 struct pt_regs *regs, int in_syscall)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447{
Al Virob7f9a112012-05-02 09:59:21 -0400448 sigset_t *oldset = sigmask_to_save();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
450 sig, ka, info, oldset, regs);
451
452 /* Set up the stack frame */
453 if (!setup_rt_frame(sig, ka, info, oldset, regs, in_syscall))
454 return 0;
455
Matt Flemingade77282012-05-11 10:58:58 +1000456 block_sigmask(ka, sig);
Kyle McMartinecf02de2009-04-27 00:29:53 -0400457
Kyle McMartin22a8cdd2010-02-12 10:53:08 -0500458 tracehook_signal_handler(sig, info, ka, regs,
459 test_thread_flag(TIF_SINGLESTEP) ||
460 test_thread_flag(TIF_BLOCKSTEP));
Kyle McMartinecf02de2009-04-27 00:29:53 -0400461
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 return 1;
463}
464
Kyle McMartin2b163b72007-01-15 00:36:26 -0500465static inline void
466syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
467{
468 /* Check the return code */
469 switch (regs->gr[28]) {
470 case -ERESTART_RESTARTBLOCK:
Kyle McMartin2b163b72007-01-15 00:36:26 -0500471 case -ERESTARTNOHAND:
472 DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
473 regs->gr[28] = -EINTR;
474 break;
475
476 case -ERESTARTSYS:
477 if (!(ka->sa.sa_flags & SA_RESTART)) {
478 DBG(1,"ERESTARTSYS: putting -EINTR\n");
479 regs->gr[28] = -EINTR;
480 break;
481 }
482 /* fallthrough */
483 case -ERESTARTNOINTR:
484 /* A syscall is just a branch, so all
485 * we have to do is fiddle the return pointer.
486 */
487 regs->gr[31] -= 8; /* delayed branching */
488 /* Preserve original r28. */
489 regs->gr[28] = regs->orig_r28;
490 break;
491 }
492}
493
494static inline void
495insert_restart_trampoline(struct pt_regs *regs)
496{
497 switch(regs->gr[28]) {
498 case -ERESTART_RESTARTBLOCK: {
499 /* Restart the system call - no handlers present */
500 unsigned int *usp = (unsigned int *)regs->gr[30];
501
502 /* Setup a trampoline to restart the syscall
503 * with __NR_restart_syscall
504 *
505 * 0: <return address (orig r31)>
506 * 4: <2nd half for 64-bit>
507 * 8: ldw 0(%sp), %r31
508 * 12: be 0x100(%sr2, %r0)
509 * 16: ldi __NR_restart_syscall, %r20
510 */
511#ifdef CONFIG_64BIT
512 put_user(regs->gr[31] >> 32, &usp[0]);
513 put_user(regs->gr[31] & 0xffffffff, &usp[1]);
514 put_user(0x0fc010df, &usp[2]);
515#else
516 put_user(regs->gr[31], &usp[0]);
517 put_user(0x0fc0109f, &usp[2]);
518#endif
519 put_user(0xe0008200, &usp[3]);
520 put_user(0x34140000, &usp[4]);
521
522 /* Stack is 64-byte aligned, and we only need
523 * to flush 1 cache line.
524 * Flushing one cacheline is cheap.
525 * "sync" on bigger (> 4 way) boxes is not.
526 */
Kyle McMartincf39cc32008-04-15 18:36:38 -0400527 flush_user_dcache_range(regs->gr[30], regs->gr[30] + 4);
528 flush_user_icache_range(regs->gr[30], regs->gr[30] + 4);
Kyle McMartin2b163b72007-01-15 00:36:26 -0500529
530 regs->gr[31] = regs->gr[30] + 8;
531 /* Preserve original r28. */
532 regs->gr[28] = regs->orig_r28;
533
534 return;
535 }
536 case -ERESTARTNOHAND:
537 case -ERESTARTSYS:
538 case -ERESTARTNOINTR: {
539 /* Hooray for delayed branching. We don't
540 * have to restore %r20 (the system call
541 * number) because it gets loaded in the delay
542 * slot of the branch external instruction.
543 */
544 regs->gr[31] -= 8;
545 /* Preserve original r28. */
546 regs->gr[28] = regs->orig_r28;
547
548 return;
549 }
550 default:
551 break;
552 }
553}
554
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555/*
556 * Note that 'init' is a special process: it doesn't get signals it doesn't
557 * want to handle. Thus you cannot kill init even with a SIGKILL even by
558 * mistake.
559 *
560 * We need to be able to restore the syscall arguments (r21-r26) to
561 * restart syscalls. Thus, the syscall path should save them in the
562 * pt_regs structure (it's okay to do so since they are caller-save
563 * registers). As noted below, the syscall number gets restored for
564 * us due to the magic of delayed branching.
565 */
Kyle McMartin4650f0a2007-01-08 16:28:06 -0500566asmlinkage void
567do_signal(struct pt_regs *regs, long in_syscall)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568{
569 siginfo_t info;
570 struct k_sigaction ka;
571 int signr;
572
Al Virob7f9a112012-05-02 09:59:21 -0400573 DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n",
574 regs, regs->sr[7], in_syscall);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575
576 /* Everyone else checks to see if they are in kernel mode at
577 this point and exits if that's the case. I'm not sure why
578 we would be called in that case, but for some reason we
579 are. */
580
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 /* May need to force signal if handle_signal failed to deliver */
582 while (1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
584 DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]);
585
586 if (signr <= 0)
587 break;
588
589 /* Restart a system call if necessary. */
Kyle McMartin2b163b72007-01-15 00:36:26 -0500590 if (in_syscall)
591 syscall_restart(regs, &ka);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 /* Whee! Actually deliver the signal. If the
594 delivery failed, we need to continue to iterate in
595 this loop so we can deliver the SIGSEGV... */
Al Virob7f9a112012-05-02 09:59:21 -0400596 if (handle_signal(signr, &info, &ka, regs, in_syscall)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
598 regs->gr[28]);
Kyle McMartin4650f0a2007-01-08 16:28:06 -0500599 if (test_thread_flag(TIF_RESTORE_SIGMASK))
600 clear_thread_flag(TIF_RESTORE_SIGMASK);
601 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 }
603 }
604 /* end of while(1) looping forever if we can't force a signal */
605
606 /* Did we come from a system call? */
Kyle McMartin2b163b72007-01-15 00:36:26 -0500607 if (in_syscall)
608 insert_restart_trampoline(regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
610 DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n",
611 regs->gr[28]);
612
Al Viro51a7b442012-05-21 23:33:55 -0400613 restore_saved_sigmask();
Kyle McMartin4650f0a2007-01-08 16:28:06 -0500614}
615
616void do_notify_resume(struct pt_regs *regs, long in_syscall)
617{
618 if (test_thread_flag(TIF_SIGPENDING) ||
619 test_thread_flag(TIF_RESTORE_SIGMASK))
620 do_signal(regs, in_syscall);
David Howellsd0420c82009-09-02 09:14:16 +0100621
622 if (test_thread_flag(TIF_NOTIFY_RESUME)) {
623 clear_thread_flag(TIF_NOTIFY_RESUME);
624 tracehook_notify_resume(regs);
625 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626}