2 * Signal support for Hexagon processor
4 * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 and
8 * only version 2 as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 #include <linux/linkage.h>
22 #include <linux/syscalls.h>
23 #include <linux/freezer.h>
24 #include <linux/tracehook.h>
25 #include <asm/registers.h>
26 #include <asm/thread_info.h>
27 #include <asm/unistd.h>
28 #include <asm/uaccess.h>
29 #include <asm/ucontext.h>
30 #include <asm/cacheflush.h>
31 #include <asm/signal.h>
34 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
37 unsigned long tramp[2];
42 static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
45 unsigned long sp = regs->r29;
47 /* Switch to signal stack if appropriate */
48 if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
49 sp = current->sas_ss_sp + current->sas_ss_size;
51 return (void __user *)((sp - frame_size) & ~(sizeof(long long) - 1));
54 static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
59 err |= copy_to_user(&sc->sc_regs.r0, ®s->r00,
60 32*sizeof(unsigned long));
62 err |= __put_user(regs->sa0, &sc->sc_regs.sa0);
63 err |= __put_user(regs->lc0, &sc->sc_regs.lc0);
64 err |= __put_user(regs->sa1, &sc->sc_regs.sa1);
65 err |= __put_user(regs->lc1, &sc->sc_regs.lc1);
66 err |= __put_user(regs->m0, &sc->sc_regs.m0);
67 err |= __put_user(regs->m1, &sc->sc_regs.m1);
68 err |= __put_user(regs->usr, &sc->sc_regs.usr);
69 err |= __put_user(regs->preds, &sc->sc_regs.p3_0);
70 err |= __put_user(regs->gp, &sc->sc_regs.gp);
71 err |= __put_user(regs->ugp, &sc->sc_regs.ugp);
73 tmp = pt_elr(regs); err |= __put_user(tmp, &sc->sc_regs.pc);
74 tmp = pt_cause(regs); err |= __put_user(tmp, &sc->sc_regs.cause);
75 tmp = pt_badva(regs); err |= __put_user(tmp, &sc->sc_regs.badva);
80 static int restore_sigcontext(struct pt_regs *regs,
81 struct sigcontext __user *sc)
86 err |= copy_from_user(®s->r00, &sc->sc_regs.r0,
87 32 * sizeof(unsigned long));
89 err |= __get_user(regs->sa0, &sc->sc_regs.sa0);
90 err |= __get_user(regs->lc0, &sc->sc_regs.lc0);
91 err |= __get_user(regs->sa1, &sc->sc_regs.sa1);
92 err |= __get_user(regs->lc1, &sc->sc_regs.lc1);
93 err |= __get_user(regs->m0, &sc->sc_regs.m0);
94 err |= __get_user(regs->m1, &sc->sc_regs.m1);
95 err |= __get_user(regs->usr, &sc->sc_regs.usr);
96 err |= __get_user(regs->preds, &sc->sc_regs.p3_0);
97 err |= __get_user(regs->gp, &sc->sc_regs.gp);
98 err |= __get_user(regs->ugp, &sc->sc_regs.ugp);
100 err |= __get_user(tmp, &sc->sc_regs.pc); pt_set_elr(regs, tmp);
106 * Setup signal stack frame with siginfo structure
108 static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
109 sigset_t *set, struct pt_regs *regs)
112 struct rt_sigframe __user *frame;
113 struct hexagon_vdso *vdso = current->mm->context.vdso;
115 frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe));
117 if (!access_ok(VERIFY_WRITE, frame, sizeof(struct rt_sigframe)))
120 if (copy_siginfo_to_user(&frame->info, info))
123 /* The on-stack signal trampoline is no longer executed;
124 * however, the libgcc signal frame unwinding code checks for
125 * the presence of these two numeric magic values.
127 err |= __put_user(0x7800d166, &frame->tramp[0]);
128 err |= __put_user(0x5400c004, &frame->tramp[1]);
129 err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
130 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
134 /* Load r0/r1 pair with signumber/siginfo pointer... */
135 regs->r0100 = ((unsigned long long)((unsigned long)&frame->info) << 32)
136 | (unsigned long long)signr;
137 regs->r02 = (unsigned long) &frame->uc;
138 regs->r31 = (unsigned long) vdso->rt_signal_trampoline;
139 pt_psp(regs) = (unsigned long) frame;
140 pt_set_elr(regs, (unsigned long)ka->sa.sa_handler);
145 force_sigsegv(signr, current);
150 * Setup invocation of signal handler
152 static int handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka,
153 sigset_t *oldset, struct pt_regs *regs)
158 * If we're handling a signal that aborted a system call,
159 * set up the error return value before adding the signal
160 * frame to the stack.
163 if (regs->syscall_nr >= 0) {
165 case -ERESTART_RESTARTBLOCK:
166 case -ERESTARTNOHAND:
170 if (!(ka->sa.sa_flags & SA_RESTART)) {
175 case -ERESTARTNOINTR:
176 regs->r06 = regs->syscall_nr;
177 pt_set_elr(regs, pt_elr(regs) - 4);
178 regs->r00 = regs->restart_r0;
186 * Set up the stack frame; not doing the SA_SIGINFO thing. We
187 * only set up the rt_frame flavor.
189 rc = setup_rt_frame(sig, ka, info, oldset, regs);
191 /* If there was an error on setup, no signal was delivered. */
195 block_sigmask(ka, sig);
201 * Called from return-from-event code.
203 static void do_signal(struct pt_regs *regs)
205 struct k_sigaction sigact;
209 if (!user_mode(regs))
215 signo = get_signal_to_deliver(&info, &sigact, regs, NULL);
220 if (test_thread_flag(TIF_RESTORE_SIGMASK))
221 oldset = ¤t->saved_sigmask;
223 oldset = ¤t->blocked;
225 if (handle_signal(signo, &info, &sigact, oldset, regs) == 0) {
227 * Successful delivery case. The saved sigmask is
228 * stored in the signal frame, and will be restored
229 * by sigreturn. We can clear the TIF flag.
231 clear_thread_flag(TIF_RESTORE_SIGMASK);
233 tracehook_signal_handler(signo, &info, &sigact, regs,
234 test_thread_flag(TIF_SINGLESTEP));
241 * If we came from a system call, handle the restart.
243 if (regs->syscall_nr >= 0) {
245 case -ERESTARTNOHAND:
247 case -ERESTARTNOINTR:
248 regs->r06 = regs->syscall_nr;
250 case -ERESTART_RESTARTBLOCK:
251 regs->r06 = __NR_restart_syscall;
256 pt_set_elr(regs, pt_elr(regs) - 4);
257 regs->r00 = regs->restart_r0;
261 /* If there's no signal to deliver, put the saved sigmask back */
262 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
263 clear_thread_flag(TIF_RESTORE_SIGMASK);
264 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
268 void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
270 if (thread_info_flags & _TIF_SIGPENDING)
273 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
274 clear_thread_flag(TIF_NOTIFY_RESUME);
275 tracehook_notify_resume(regs);
280 * Architecture-specific wrappers for signal-related system calls
282 asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
284 struct pt_regs *regs = current_thread_info()->regs;
286 return do_sigaltstack(uss, uoss, regs->r29);
289 asmlinkage int sys_rt_sigreturn(void)
291 struct pt_regs *regs = current_thread_info()->regs;
292 struct rt_sigframe __user *frame;
295 /* Always make any pending restarted system calls return -EINTR */
296 current_thread_info()->restart_block.fn = do_no_restart_syscall;
298 frame = (struct rt_sigframe __user *)pt_psp(regs);
299 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
301 if (__copy_from_user(&blocked, &frame->uc.uc_sigmask, sizeof(blocked)))
304 sigdelsetmask(&blocked, ~_BLOCKABLE);
305 set_current_blocked(&blocked);
307 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
310 /* Restore the user's stack as well */
311 pt_psp(regs) = regs->r29;
314 * Leave a trace in the stack frame that this was a sigreturn.
315 * If the system call is to replay, we've already restored the
316 * number in the GPR slot and it will be regenerated on the
317 * new system call trap entry. Note that if restore_sigcontext()
318 * did something other than a bulk copy of the pt_regs struct,
319 * we could avoid this assignment by simply not overwriting
322 regs->syscall_nr = __NR_rt_sigreturn;
325 * If we were meticulous, we'd only call this if we knew that
326 * we were actually going to use an alternate stack, and we'd
327 * consider any error to be fatal. What we do here, in common
328 * with many other architectures, is call it blindly and only
329 * consider the -EFAULT return case to be proof of a problem.
331 if (do_sigaltstack(&frame->uc.uc_stack, NULL, pt_psp(regs)) == -EFAULT)
337 force_sig(SIGSEGV, current);