diff options
Diffstat (limited to 'arch/avr32/kernel/signal.c')
| -rw-r--r-- | arch/avr32/kernel/signal.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/arch/avr32/kernel/signal.c b/arch/avr32/kernel/signal.c new file mode 100644 index 000000000000..33096651c24f --- /dev/null +++ b/arch/avr32/kernel/signal.c @@ -0,0 +1,328 @@ +/* + * Copyright (C) 2004-2006 Atmel Corporation + * + * Based on linux/arch/sh/kernel/signal.c + * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima + * Copyright (C) 1991, 1992 Linus Torvalds + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/errno.h> +#include <linux/ptrace.h> +#include <linux/unistd.h> +#include <linux/suspend.h> + +#include <asm/uaccess.h> +#include <asm/ucontext.h> + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, + struct pt_regs *regs) +{ + return do_sigaltstack(uss, uoss, regs->sp); +} + +struct rt_sigframe +{ + struct siginfo info; + struct ucontext uc; + unsigned long retcode; +}; + +static int +restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) +{ + int err = 0; + +#define COPY(x) err |= __get_user(regs->x, &sc->x) + COPY(sr); + COPY(pc); + COPY(lr); + COPY(sp); + COPY(r12); + COPY(r11); + COPY(r10); + COPY(r9); + COPY(r8); + COPY(r7); + COPY(r6); + COPY(r5); + COPY(r4); + COPY(r3); + COPY(r2); + COPY(r1); + COPY(r0); +#undef COPY + + /* + * Don't allow anyone to pretend they're running in supervisor + * mode or something... + */ + err |= !valid_user_regs(regs); + + return err; +} + + +asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) +{ + struct rt_sigframe __user *frame; + sigset_t set; + + frame = (struct rt_sigframe __user *)regs->sp; + pr_debug("SIG return: frame = %p\n", frame); + + if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) + goto badframe; + + if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) + goto badframe; + + sigdelsetmask(&set, ~_BLOCKABLE); + spin_lock_irq(¤t->sighand->siglock); + current->blocked = set; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) + goto badframe; + + pr_debug("Context restored: pc = %08lx, lr = %08lx, sp = %08lx\n", + regs->pc, regs->lr, regs->sp); + + return regs->r12; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +static int +setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) +{ + int err = 0; + +#define COPY(x) err |= __put_user(regs->x, &sc->x) + COPY(sr); + COPY(pc); + COPY(lr); + COPY(sp); + COPY(r12); + COPY(r11); + COPY(r10); + COPY(r9); + COPY(r8); + COPY(r7); + COPY(r6); + COPY(r5); + COPY(r4); + COPY(r3); + COPY(r2); + COPY(r1); + COPY(r0); +#undef COPY + + return err; +} + +static inline void __user * +get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) +{ + unsigned long sp = regs->sp; + + if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) + sp = current->sas_ss_sp + current->sas_ss_size; + + return (void __user *)((sp - framesize) & ~3); +} + +static int +setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, + sigset_t *set, struct pt_regs *regs) +{ + struct rt_sigframe __user *frame; + int err = 0; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + err = -EFAULT; + if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) + goto out; + + /* + * Set up the return code: + * + * mov r8, __NR_rt_sigreturn + * scall + * + * Note: This will blow up since we're using a non-executable + * stack. Better use SA_RESTORER. + */ +#if __NR_rt_sigreturn > 127 +# error __NR_rt_sigreturn must be < 127 to fit in a short mov +#endif + err = __put_user(0x3008d733 | (__NR_rt_sigreturn << 20), + &frame->retcode); + + err |= copy_siginfo_to_user(&frame->info, info); + + /* Set up the ucontext */ + err |= __put_user(0, &frame->uc.uc_flags); + err |= __put_user(NULL, &frame->uc.uc_link); + err |= __put_user((void __user *)current->sas_ss_sp, + &frame->uc.uc_stack.ss_sp); + err |= __put_user(sas_ss_flags(regs->sp), + &frame->uc.uc_stack.ss_flags); + err |= __put_user(current->sas_ss_size, + &frame->uc.uc_stack.ss_size); + err |= setup_sigcontext(&frame->uc.uc_mcontext, regs); + err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + + if (err) + goto out; + + regs->r12 = sig; + regs->r11 = (unsigned long) &frame->info; + regs->r10 = (unsigned long) &frame->uc; + regs->sp = (unsigned long) frame; + if (ka->sa.sa_flags & SA_RESTORER) + regs->lr = (unsigned long)ka->sa.sa_restorer; + else { + printk(KERN_NOTICE "[%s:%d] did not set SA_RESTORER\n", + current->comm, current->pid); + regs->lr = (unsigned long) &frame->retcode; + } + + pr_debug("SIG deliver [%s:%d]: sig=%d sp=0x%lx pc=0x%lx->0x%p lr=0x%lx\n", + current->comm, current->pid, sig, regs->sp, + regs->pc, ka->sa.sa_handler, regs->lr); + + regs->pc = (unsigned long) ka->sa.sa_handler; + +out: + return err; +} + +static inline void restart_syscall(struct pt_regs *regs) +{ + if (regs->r12 == -ERESTART_RESTARTBLOCK) + regs->r8 = __NR_restart_syscall; + else + regs->r12 = regs->r12_orig; + regs->pc -= 2; +} + +static inline void +handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, + sigset_t *oldset, struct pt_regs *regs, int syscall) +{ + int ret; + + /* + * Set up the stack frame + */ + ret = setup_rt_frame(sig, ka, info, oldset, regs); + + /* + * Check that the resulting registers are sane + */ + ret |= !valid_user_regs(regs); + + /* + * Block the signal if we were unsuccessful. + */ + if (ret != 0 || !(ka->sa.sa_flags & SA_NODEFER)) { + spin_lock_irq(¤t->sighand->siglock); + sigorsets(¤t->blocked, ¤t->blocked, + &ka->sa.sa_mask); + sigaddset(¤t->blocked, sig); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + } + + if (ret == 0) + return; + + force_sigsegv(sig, current); +} + +/* + * Note that 'init' is a special process: it doesn't get signals it + * doesn't want to handle. Thus you cannot kill init even with a + * SIGKILL even by mistake. + */ +int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall) +{ + siginfo_t info; + int signr; + struct k_sigaction ka; + + /* + * We want the common case to go fast, which is why we may in + * certain cases get here from kernel mode. Just return + * without doing anything if so. + */ + if (!user_mode(regs)) + return 0; + + if (try_to_freeze()) { + signr = 0; + if (!signal_pending(current)) + goto no_signal; + } + + if (test_thread_flag(TIF_RESTORE_SIGMASK)) + oldset = ¤t->saved_sigmask; + else if (!oldset) + oldset = ¤t->blocked; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); +no_signal: + if (syscall) { + switch (regs->r12) { + case -ERESTART_RESTARTBLOCK: + case -ERESTARTNOHAND: + if (signr > 0) { + regs->r12 = -EINTR; + break; + } + /* fall through */ + case -ERESTARTSYS: + if (signr > 0 && !(ka.sa.sa_flags & SA_RESTART)) { + regs->r12 = -EINTR; + break; + } + /* fall through */ + case -ERESTARTNOINTR: + restart_syscall(regs); + } + } + + if (signr == 0) { + /* No signal to deliver -- put the saved sigmask back */ + if (test_thread_flag(TIF_RESTORE_SIGMASK)) { + clear_thread_flag(TIF_RESTORE_SIGMASK); + sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); + } + return 0; + } + + handle_signal(signr, &ka, &info, oldset, regs, syscall); + return 1; +} + +asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti) +{ + int syscall = 0; + + if ((sysreg_read(SR) & MODE_MASK) == MODE_SUPERVISOR) + syscall = 1; + + if (ti->flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) + do_signal(regs, ¤t->blocked, syscall); +} |