2 * Copyright (C) 2004-2006 Atmel Corporation
4 * Based on linux/arch/sh/kernel/signal.c
5 * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
6 * Copyright (C) 1991, 1992 Linus Torvalds
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/sched.h>
15 #include <linux/errno.h>
16 #include <linux/ptrace.h>
17 #include <linux/unistd.h>
18 #include <linux/tracehook.h>
20 #include <asm/uaccess.h>
21 #include <asm/ucontext.h>
22 #include <asm/syscalls.h>
24 asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
27 return do_sigaltstack(uss, uoss, regs->sp);
34 unsigned long retcode;
38 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
42 #define COPY(x) err |= __get_user(regs->x, &sc->x)
63 * Don't allow anyone to pretend they're running in supervisor
64 * mode or something...
66 err |= !valid_user_regs(regs);
72 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
74 struct rt_sigframe __user *frame;
77 /* Always make any pending restarted system calls return -EINTR */
78 current_thread_info()->restart_block.fn = do_no_restart_syscall;
80 frame = (struct rt_sigframe __user *)regs->sp;
81 pr_debug("SIG return: frame = %p\n", frame);
83 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
86 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
89 set_current_blocked(&set);
91 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
94 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
97 pr_debug("Context restored: pc = %08lx, lr = %08lx, sp = %08lx\n",
98 regs->pc, regs->lr, regs->sp);
103 force_sig(SIGSEGV, current);
108 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
112 #define COPY(x) err |= __put_user(regs->x, &sc->x)
135 static inline void __user *
136 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
138 unsigned long sp = regs->sp;
140 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
141 sp = current->sas_ss_sp + current->sas_ss_size;
143 return (void __user *)((sp - framesize) & ~3);
147 setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
148 sigset_t *set, struct pt_regs *regs)
150 struct rt_sigframe __user *frame;
153 frame = get_sigframe(ka, regs, sizeof(*frame));
155 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
159 * Set up the return code:
161 * mov r8, __NR_rt_sigreturn
164 * Note: This will blow up since we're using a non-executable
165 * stack. Better use SA_RESTORER.
167 #if __NR_rt_sigreturn > 127
168 # error __NR_rt_sigreturn must be < 127 to fit in a short mov
170 err = __put_user(0x3008d733 | (__NR_rt_sigreturn << 20),
173 err |= copy_siginfo_to_user(&frame->info, info);
175 /* Set up the ucontext */
176 err |= __put_user(0, &frame->uc.uc_flags);
177 err |= __put_user(NULL, &frame->uc.uc_link);
178 err |= __put_user((void __user *)current->sas_ss_sp,
179 &frame->uc.uc_stack.ss_sp);
180 err |= __put_user(sas_ss_flags(regs->sp),
181 &frame->uc.uc_stack.ss_flags);
182 err |= __put_user(current->sas_ss_size,
183 &frame->uc.uc_stack.ss_size);
184 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs);
185 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
191 regs->r11 = (unsigned long) &frame->info;
192 regs->r10 = (unsigned long) &frame->uc;
193 regs->sp = (unsigned long) frame;
194 if (ka->sa.sa_flags & SA_RESTORER)
195 regs->lr = (unsigned long)ka->sa.sa_restorer;
197 printk(KERN_NOTICE "[%s:%d] did not set SA_RESTORER\n",
198 current->comm, current->pid);
199 regs->lr = (unsigned long) &frame->retcode;
202 pr_debug("SIG deliver [%s:%d]: sig=%d sp=0x%lx pc=0x%lx->0x%p lr=0x%lx\n",
203 current->comm, current->pid, sig, regs->sp,
204 regs->pc, ka->sa.sa_handler, regs->lr);
206 regs->pc = (unsigned long) ka->sa.sa_handler;
212 static inline void setup_syscall_restart(struct pt_regs *regs)
214 if (regs->r12 == -ERESTART_RESTARTBLOCK)
215 regs->r8 = __NR_restart_syscall;
217 regs->r12 = regs->r12_orig;
222 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
223 struct pt_regs *regs, int syscall)
228 * Set up the stack frame
230 ret = setup_rt_frame(sig, ka, info, sigmask_to_save(), regs);
233 * Check that the resulting registers are sane
235 ret |= !valid_user_regs(regs);
238 * Block the signal if we were successful.
241 force_sigsegv(sig, current);
243 signal_delivered(sig, info, ka, regs, 0);
247 * Note that 'init' is a special process: it doesn't get signals it
248 * doesn't want to handle. Thus you cannot kill init even with a
249 * SIGKILL even by mistake.
251 static void do_signal(struct pt_regs *regs, int syscall)
255 struct k_sigaction ka;
258 * We want the common case to go fast, which is why we may in
259 * certain cases get here from kernel mode. Just return
260 * without doing anything if so.
262 if (!user_mode(regs))
265 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
268 case -ERESTART_RESTARTBLOCK:
269 case -ERESTARTNOHAND:
276 if (signr > 0 && !(ka.sa.sa_flags & SA_RESTART)) {
281 case -ERESTARTNOINTR:
282 setup_syscall_restart(regs);
287 /* No signal to deliver -- put the saved sigmask back */
288 restore_saved_sigmask();
292 handle_signal(signr, &ka, &info, regs, syscall);
295 asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti)
299 if ((sysreg_read(SR) & MODE_MASK) == MODE_SUPERVISOR)
302 if (ti->flags & _TIF_SIGPENDING)
303 do_signal(regs, syscall);
305 if (ti->flags & _TIF_NOTIFY_RESUME) {
306 clear_thread_flag(TIF_NOTIFY_RESUME);
307 tracehook_notify_resume(regs);