2 * arch/xtensa/kernel/signal.c
4 * Default platform functions.
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
10 * Copyright (C) 2005, 2006 Tensilica Inc.
11 * Copyright (C) 1991, 1992 Linus Torvalds
12 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
14 * Chris Zankel <chris@zankel.net>
15 * Joe Taylor <joe@tensilica.com>
18 #include <linux/signal.h>
19 #include <linux/errno.h>
20 #include <linux/ptrace.h>
21 #include <linux/personality.h>
22 #include <linux/tracehook.h>
24 #include <asm/ucontext.h>
25 #include <asm/uaccess.h>
26 #include <asm/cacheflush.h>
27 #include <asm/coprocessor.h>
28 #include <asm/unistd.h>
32 extern struct task_struct *coproc_owners[];
41 #if XTENSA_HAVE_COPROCESSORS
42 xtregs_coprocessor_t cp;
45 unsigned char retcode[6];
46 unsigned int window[4];
50 * Flush register windows stored in pt_regs to stack.
51 * Returns 1 for errors.
55 flush_window_regs_user(struct pt_regs *regs)
57 const unsigned long ws = regs->windowstart;
58 const unsigned long wb = regs->windowbase;
64 /* Return if no other frames. */
69 /* Rotate windowmask and skip empty frames. */
71 wm = (ws >> wb) | (ws << (XCHAL_NUM_AREGS / 4 - wb));
72 base = (XCHAL_NUM_AREGS / 4) - (regs->wmask >> 4);
74 /* For call8 or call12 frames, we need the previous stack pointer. */
76 if ((regs->wmask & 2) == 0)
77 if (__get_user(sp, (int*)(regs->areg[base * 4 + 1] - 12)))
80 /* Spill frames to stack. */
82 while (base < XCHAL_NUM_AREGS / 4) {
87 /* Save registers a4..a7 (call8) or a4...a11 (call12) */
89 if (m & 2) { /* call4 */
92 } else if (m & 4) { /* call8 */
93 if (copy_to_user((void*)(sp - 32),
94 ®s->areg[(base + 1) * 4], 16))
98 } else if (m & 8) { /* call12 */
99 if (copy_to_user((void*)(sp - 48),
100 ®s->areg[(base + 1) * 4], 32))
105 /* Save current frame a0..a3 under next SP */
107 sp = regs->areg[((base + inc) * 4 + 1) % XCHAL_NUM_AREGS];
108 if (copy_to_user((void*)(sp - 16), ®s->areg[base * 4], 16))
111 /* Get current stack pointer for next loop iteration. */
113 sp = regs->areg[base * 4 + 1];
118 regs->windowstart = 1 << wb;
127 * Note: We don't copy double exception 'regs', we have to finish double exc.
128 * first before we return to signal handler! This dbl.exc.handler might cause
129 * another double exception, but I think we are fine as the situation is the
130 * same as if we had returned to the signal handerl and got an interrupt
135 setup_sigcontext(struct rt_sigframe __user *frame, struct pt_regs *regs)
137 struct sigcontext __user *sc = &frame->uc.uc_mcontext;
138 struct thread_info *ti = current_thread_info();
141 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
150 err |= flush_window_regs_user(regs);
151 err |= __copy_to_user (sc->sc_a, regs->areg, 16 * 4);
152 err |= __put_user(0, &sc->sc_xtregs);
157 #if XTENSA_HAVE_COPROCESSORS
158 coprocessor_flush_all(ti);
159 coprocessor_release_all(ti);
160 err |= __copy_to_user(&frame->xtregs.cp, &ti->xtregs_cp,
161 sizeof (frame->xtregs.cp));
163 err |= __copy_to_user(&frame->xtregs.opt, ®s->xtregs_opt,
164 sizeof (xtregs_opt_t));
165 err |= __copy_to_user(&frame->xtregs.user, &ti->xtregs_user,
166 sizeof (xtregs_user_t));
168 err |= __put_user(err ? NULL : &frame->xtregs, &sc->sc_xtregs);
174 restore_sigcontext(struct pt_regs *regs, struct rt_sigframe __user *frame)
176 struct sigcontext __user *sc = &frame->uc.uc_mcontext;
177 struct thread_info *ti = current_thread_info();
178 unsigned int err = 0;
181 #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
189 /* All registers were flushed to stack. Start with a prestine frame. */
192 regs->windowbase = 0;
193 regs->windowstart = 1;
195 regs->syscall = -1; /* disable syscall checks */
197 /* For PS, restore only PS.CALLINC.
198 * Assume that all other bits are either the same as for the signal
199 * handler, or the user mode value doesn't matter (e.g. PS.OWB).
201 err |= __get_user(ps, &sc->sc_ps);
202 regs->ps = (regs->ps & ~PS_CALLINC_MASK) | (ps & PS_CALLINC_MASK);
204 /* Additional corruption checks */
206 if ((regs->lcount > 0)
207 && ((regs->lbeg > TASK_SIZE) || (regs->lend > TASK_SIZE)) )
210 err |= __copy_from_user(regs->areg, sc->sc_a, 16 * 4);
215 /* The signal handler may have used coprocessors in which
216 * case they are still enabled. We disable them to force a
217 * reloading of the original task's CP state by the lazy
218 * context-switching mechanisms of CP exception handling.
219 * Also, we essentially discard any coprocessor state that the
220 * signal handler created. */
222 #if XTENSA_HAVE_COPROCESSORS
223 coprocessor_release_all(ti);
224 err |= __copy_from_user(&ti->xtregs_cp, &frame->xtregs.cp,
225 sizeof (frame->xtregs.cp));
227 err |= __copy_from_user(&ti->xtregs_user, &frame->xtregs.user,
228 sizeof (xtregs_user_t));
229 err |= __copy_from_user(®s->xtregs_opt, &frame->xtregs.opt,
230 sizeof (xtregs_opt_t));
237 * Do a signal return; undo the signal stack.
240 asmlinkage long xtensa_rt_sigreturn(long a0, long a1, long a2, long a3,
241 long a4, long a5, struct pt_regs *regs)
243 struct rt_sigframe __user *frame;
247 /* Always make any pending restarted system calls return -EINTR */
248 current_thread_info()->restart_block.fn = do_no_restart_syscall;
251 panic("rt_sigreturn in double exception!\n");
253 frame = (struct rt_sigframe __user *) regs->areg[1];
255 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
258 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
261 set_current_blocked(&set);
263 if (restore_sigcontext(regs, frame))
268 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->areg[1]) == -EFAULT)
274 force_sig(SIGSEGV, current);
281 * Set up a signal frame.
285 gen_return_code(unsigned char *codemem)
290 * The 12-bit immediate is really split up within the 24-bit MOVI
291 * instruction. As long as the above system call numbers fit within
292 * 8-bits, the following code works fine. See the Xtensa ISA for
296 #if __NR_rt_sigreturn > 255
297 # error Generating the MOVI instruction below breaks!
300 #ifdef __XTENSA_EB__ /* Big Endian version */
301 /* Generate instruction: MOVI a2, __NR_rt_sigreturn */
302 err |= __put_user(0x22, &codemem[0]);
303 err |= __put_user(0x0a, &codemem[1]);
304 err |= __put_user(__NR_rt_sigreturn, &codemem[2]);
305 /* Generate instruction: SYSCALL */
306 err |= __put_user(0x00, &codemem[3]);
307 err |= __put_user(0x05, &codemem[4]);
308 err |= __put_user(0x00, &codemem[5]);
310 #elif defined __XTENSA_EL__ /* Little Endian version */
311 /* Generate instruction: MOVI a2, __NR_rt_sigreturn */
312 err |= __put_user(0x22, &codemem[0]);
313 err |= __put_user(0xa0, &codemem[1]);
314 err |= __put_user(__NR_rt_sigreturn, &codemem[2]);
315 /* Generate instruction: SYSCALL */
316 err |= __put_user(0x00, &codemem[3]);
317 err |= __put_user(0x50, &codemem[4]);
318 err |= __put_user(0x00, &codemem[5]);
320 # error Must use compiler for Xtensa processors.
323 /* Flush generated code out of the data cache */
326 __invalidate_icache_range((unsigned long)codemem, 6UL);
327 __flush_invalidate_dcache_range((unsigned long)codemem, 6UL);
334 static int setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
335 sigset_t *set, struct pt_regs *regs)
337 struct rt_sigframe *frame;
340 unsigned long sp, ra;
344 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) {
345 sp = current->sas_ss_sp + current->sas_ss_size;
348 frame = (void *)((sp - sizeof(*frame)) & -16ul);
351 panic ("Double exception sys_sigreturn\n");
353 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) {
357 signal = current_thread_info()->exec_domain
358 && current_thread_info()->exec_domain->signal_invmap
360 ? current_thread_info()->exec_domain->signal_invmap[sig]
363 if (ka->sa.sa_flags & SA_SIGINFO) {
364 err |= copy_siginfo_to_user(&frame->info, info);
367 /* Create the user context. */
369 err |= __put_user(0, &frame->uc.uc_flags);
370 err |= __put_user(0, &frame->uc.uc_link);
371 err |= __put_user((void *)current->sas_ss_sp,
372 &frame->uc.uc_stack.ss_sp);
373 err |= __put_user(sas_ss_flags(regs->areg[1]),
374 &frame->uc.uc_stack.ss_flags);
375 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
376 err |= setup_sigcontext(frame, regs);
377 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
379 if (ka->sa.sa_flags & SA_RESTORER) {
380 ra = (unsigned long)ka->sa.sa_restorer;
383 /* Create sys_rt_sigreturn syscall in stack frame */
385 err |= gen_return_code(frame->retcode);
390 ra = (unsigned long) frame->retcode;
394 * Create signal handler execution context.
395 * Return context not modified until this point.
398 /* Set up registers for signal handler */
399 start_thread(regs, (unsigned long) ka->sa.sa_handler,
400 (unsigned long) frame);
402 /* Set up a stack frame for a call4
403 * Note: PS.CALLINC is set to one by start_thread
405 regs->areg[4] = (((unsigned long) ra) & 0x3fffffff) | 0x40000000;
406 regs->areg[6] = (unsigned long) signal;
407 regs->areg[7] = (unsigned long) &frame->info;
408 regs->areg[8] = (unsigned long) &frame->uc;
410 /* Set access mode to USER_DS. Nomenclature is outdated, but
411 * functionality is used in uaccess.h
416 printk("SIG rt deliver (%s:%d): signal=%d sp=%p pc=%08x\n",
417 current->comm, current->pid, signal, frame, regs->pc);
423 force_sigsegv(sig, current);
427 asmlinkage long xtensa_sigaltstack(const stack_t __user *uss,
428 stack_t __user *uoss,
429 long a2, long a3, long a4, long a5,
430 struct pt_regs *regs)
432 return do_sigaltstack(uss, uoss, regs->areg[1]);
438 * Note that 'init' is a special process: it doesn't get signals it doesn't
439 * want to handle. Thus you cannot kill init even with a SIGKILL even by
442 * Note that we go through the signals twice: once to check the signals that
443 * the kernel can handle, and then we build all the user-level signal handling
444 * stack-frames in one go after that.
446 static void do_signal(struct pt_regs *regs)
450 struct k_sigaction ka;
452 task_pt_regs(current)->icountlevel = 0;
454 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
459 /* Are we from a system call? */
461 if ((signed)regs->syscall >= 0) {
463 /* If so, check system call restarting.. */
465 switch (regs->areg[2]) {
466 case -ERESTARTNOHAND:
467 case -ERESTART_RESTARTBLOCK:
468 regs->areg[2] = -EINTR;
472 if (!(ka.sa.sa_flags & SA_RESTART)) {
473 regs->areg[2] = -EINTR;
477 case -ERESTARTNOINTR:
478 regs->areg[2] = regs->syscall;
484 if (regs->areg[2] != 0)
489 /* Whee! Actually deliver the signal. */
490 /* Set up the stack frame */
491 ret = setup_frame(signr, &ka, &info, sigmask_to_save(), regs);
495 signal_delivered(signr, &info, &ka, regs, 0);
496 if (current->ptrace & PT_SINGLESTEP)
497 task_pt_regs(current)->icountlevel = 1;
502 /* Did we come from a system call? */
503 if ((signed) regs->syscall >= 0) {
504 /* Restart the system call - no handlers present */
505 switch (regs->areg[2]) {
506 case -ERESTARTNOHAND:
508 case -ERESTARTNOINTR:
509 regs->areg[2] = regs->syscall;
512 case -ERESTART_RESTARTBLOCK:
513 regs->areg[2] = __NR_restart_syscall;
519 /* If there's no signal to deliver, we just restore the saved mask. */
520 restore_saved_sigmask();
522 if (current->ptrace & PT_SINGLESTEP)
523 task_pt_regs(current)->icountlevel = 1;
527 void do_notify_resume(struct pt_regs *regs)
529 if (test_thread_flag(TIF_SIGPENDING))
532 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
533 tracehook_notify_resume(regs);