2 * Signal support for Hexagon processor
4 * Copyright (c) 2010-2011, The Linux Foundation. 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/tracehook.h>
24 #include <asm/registers.h>
25 #include <asm/thread_info.h>
26 #include <asm/unistd.h>
27 #include <asm/uaccess.h>
28 #include <asm/ucontext.h>
29 #include <asm/cacheflush.h>
30 #include <asm/signal.h>
34 unsigned long tramp[2];
39 static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
42 unsigned long sp = regs->r29;
44 /* Switch to signal stack if appropriate */
45 if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
46 sp = current->sas_ss_sp + current->sas_ss_size;
48 return (void __user *)((sp - frame_size) & ~(sizeof(long long) - 1));
51 static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
56 err |= copy_to_user(&sc->sc_regs.r0, ®s->r00,
57 32*sizeof(unsigned long));
59 err |= __put_user(regs->sa0, &sc->sc_regs.sa0);
60 err |= __put_user(regs->lc0, &sc->sc_regs.lc0);
61 err |= __put_user(regs->sa1, &sc->sc_regs.sa1);
62 err |= __put_user(regs->lc1, &sc->sc_regs.lc1);
63 err |= __put_user(regs->m0, &sc->sc_regs.m0);
64 err |= __put_user(regs->m1, &sc->sc_regs.m1);
65 err |= __put_user(regs->usr, &sc->sc_regs.usr);
66 err |= __put_user(regs->preds, &sc->sc_regs.p3_0);
67 err |= __put_user(regs->gp, &sc->sc_regs.gp);
68 err |= __put_user(regs->ugp, &sc->sc_regs.ugp);
70 tmp = pt_elr(regs); err |= __put_user(tmp, &sc->sc_regs.pc);
71 tmp = pt_cause(regs); err |= __put_user(tmp, &sc->sc_regs.cause);
72 tmp = pt_badva(regs); err |= __put_user(tmp, &sc->sc_regs.badva);
77 static int restore_sigcontext(struct pt_regs *regs,
78 struct sigcontext __user *sc)
83 err |= copy_from_user(®s->r00, &sc->sc_regs.r0,
84 32 * sizeof(unsigned long));
86 err |= __get_user(regs->sa0, &sc->sc_regs.sa0);
87 err |= __get_user(regs->lc0, &sc->sc_regs.lc0);
88 err |= __get_user(regs->sa1, &sc->sc_regs.sa1);
89 err |= __get_user(regs->lc1, &sc->sc_regs.lc1);
90 err |= __get_user(regs->m0, &sc->sc_regs.m0);
91 err |= __get_user(regs->m1, &sc->sc_regs.m1);
92 err |= __get_user(regs->usr, &sc->sc_regs.usr);
93 err |= __get_user(regs->preds, &sc->sc_regs.p3_0);
94 err |= __get_user(regs->gp, &sc->sc_regs.gp);
95 err |= __get_user(regs->ugp, &sc->sc_regs.ugp);
97 err |= __get_user(tmp, &sc->sc_regs.pc); pt_set_elr(regs, tmp);
103 * Setup signal stack frame with siginfo structure
105 static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
106 sigset_t *set, struct pt_regs *regs)
109 struct rt_sigframe __user *frame;
110 struct hexagon_vdso *vdso = current->mm->context.vdso;
112 frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe));
114 if (!access_ok(VERIFY_WRITE, frame, sizeof(struct rt_sigframe)))
117 if (copy_siginfo_to_user(&frame->info, info))
120 /* The on-stack signal trampoline is no longer executed;
121 * however, the libgcc signal frame unwinding code checks for
122 * the presence of these two numeric magic values.
124 err |= __put_user(0x7800d166, &frame->tramp[0]);
125 err |= __put_user(0x5400c004, &frame->tramp[1]);
126 err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
127 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
128 err |= __save_altstack(&frame->uc.uc_stack, user_stack_pointer(regs));
132 /* Load r0/r1 pair with signumber/siginfo pointer... */
133 regs->r0100 = ((unsigned long long)((unsigned long)&frame->info) << 32)
134 | (unsigned long long)signr;
135 regs->r02 = (unsigned long) &frame->uc;
136 regs->r31 = (unsigned long) vdso->rt_signal_trampoline;
137 pt_psp(regs) = (unsigned long) frame;
138 pt_set_elr(regs, (unsigned long)ka->sa.sa_handler);
143 force_sigsegv(signr, current);
148 * Setup invocation of signal handler
150 static void handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka,
151 struct pt_regs *regs)
154 * If we're handling a signal that aborted a system call,
155 * set up the error return value before adding the signal
156 * frame to the stack.
159 if (regs->syscall_nr >= 0) {
161 case -ERESTART_RESTARTBLOCK:
162 case -ERESTARTNOHAND:
166 if (!(ka->sa.sa_flags & SA_RESTART)) {
171 case -ERESTARTNOINTR:
172 regs->r06 = regs->syscall_nr;
173 pt_set_elr(regs, pt_elr(regs) - 4);
174 regs->r00 = regs->restart_r0;
182 * Set up the stack frame; not doing the SA_SIGINFO thing. We
183 * only set up the rt_frame flavor.
185 /* If there was an error on setup, no signal was delivered. */
186 if (setup_rt_frame(sig, ka, info, sigmask_to_save(), regs) < 0)
189 signal_delivered(sig, info, ka, regs,
190 test_thread_flag(TIF_SINGLESTEP));
194 * Called from return-from-event code.
196 static void do_signal(struct pt_regs *regs)
198 struct k_sigaction sigact;
202 if (!user_mode(regs))
205 signo = get_signal_to_deliver(&info, &sigact, regs, NULL);
208 handle_signal(signo, &info, &sigact, regs);
213 * If we came from a system call, handle the restart.
215 if (regs->syscall_nr >= 0) {
217 case -ERESTARTNOHAND:
219 case -ERESTARTNOINTR:
220 regs->r06 = regs->syscall_nr;
222 case -ERESTART_RESTARTBLOCK:
223 regs->r06 = __NR_restart_syscall;
228 pt_set_elr(regs, pt_elr(regs) - 4);
229 regs->r00 = regs->restart_r0;
233 /* If there's no signal to deliver, put the saved sigmask back */
234 restore_saved_sigmask();
237 void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
239 if (thread_info_flags & _TIF_SIGPENDING)
242 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
243 clear_thread_flag(TIF_NOTIFY_RESUME);
244 tracehook_notify_resume(regs);
249 * Architecture-specific wrappers for signal-related system calls
252 asmlinkage int sys_rt_sigreturn(void)
254 struct pt_regs *regs = current_pt_regs();
255 struct rt_sigframe __user *frame;
258 /* Always make any pending restarted system calls return -EINTR */
259 current_thread_info()->restart_block.fn = do_no_restart_syscall;
261 frame = (struct rt_sigframe __user *)pt_psp(regs);
262 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
264 if (__copy_from_user(&blocked, &frame->uc.uc_sigmask, sizeof(blocked)))
267 set_current_blocked(&blocked);
269 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
272 /* Restore the user's stack as well */
273 pt_psp(regs) = regs->r29;
276 * Leave a trace in the stack frame that this was a sigreturn.
277 * If the system call is to replay, we've already restored the
278 * number in the GPR slot and it will be regenerated on the
279 * new system call trap entry. Note that if restore_sigcontext()
280 * did something other than a bulk copy of the pt_regs struct,
281 * we could avoid this assignment by simply not overwriting
284 regs->syscall_nr = __NR_rt_sigreturn;
286 if (restore_altstack(&frame->uc.uc_stack))
292 force_sig(SIGSEGV, current);