Initial import

1 files changed, 288 insertions, 0 deletions

diff --git a/arch/avr32/kernel/signal.c b/arch/avr32/kernel/signal.c
new file mode 100644
index 000000000..8f1c63b9b
--- /dev/null
+++ b/arch/avr32/kernel/signal.c
@@ -0,0 +1,288 @@
+/*
+ * 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/tracehook.h>
+
+#include <asm/uaccess.h>
+#include <asm/ucontext.h>
+#include <asm/syscalls.h>
+
+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;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	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;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		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 ksignal *ksig, struct pt_regs *regs, int framesize)
+{
+	unsigned long sp = sigsp(regs->sp, ksig);
+
+	return (void __user *)((sp - framesize) & ~3);
+}
+
+static int
+setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+	int err = 0;
+
+	frame = get_sigframe(ksig, 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, &ksig->info);
+
+	/* Set up the ucontext */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(NULL, &frame->uc.uc_link);
+	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
+	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 = ksig->sig;
+	regs->r11 = (unsigned long) &frame->info;
+	regs->r10 = (unsigned long) &frame->uc;
+	regs->sp = (unsigned long) frame;
+	if (ksig->ka.sa.sa_flags & SA_RESTORER)
+		regs->lr = (unsigned long)ksig->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, ksig->sig, regs->sp,
+		 regs->pc, ksig->ka.sa.sa_handler, regs->lr);
+
+	regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
+
+out:
+	return err;
+}
+
+static inline void setup_syscall_restart(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(struct ksignal *ksig, struct pt_regs *regs, int syscall)
+{
+	int ret;
+
+	/*
+	 * Set up the stack frame
+	 */
+	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
+
+	/*
+	 * Check that the resulting registers are sane
+	 */
+	ret |= !valid_user_regs(regs);
+
+	/*
+	 * Block the signal if we were successful.
+	 */
+	signal_setup_done(ret, ksig, 0);
+}
+
+/*
+ * 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.
+ */
+static void do_signal(struct pt_regs *regs, int syscall)
+{
+	struct ksignal ksig;
+
+	/*
+	 * 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;
+
+	get_signal(&ksig);
+	if (syscall) {
+		switch (regs->r12) {
+		case -ERESTART_RESTARTBLOCK:
+		case -ERESTARTNOHAND:
+			if (ksig.sig > 0) {
+				regs->r12 = -EINTR;
+				break;
+			}
+			/* fall through */
+		case -ERESTARTSYS:
+			if (ksig.sig > 0 && !(ksig.ka.sa.sa_flags & SA_RESTART)) {
+				regs->r12 = -EINTR;
+				break;
+			}
+			/* fall through */
+		case -ERESTARTNOINTR:
+			setup_syscall_restart(regs);
+		}
+	}
+
+	if (!ksig.sig) {
+		/* No signal to deliver -- put the saved sigmask back */
+		restore_saved_sigmask();
+		return;
+	}
+
+	handle_signal(&ksig, regs, syscall);
+}
+
+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)
+		do_signal(regs, syscall);
+
+	if (ti->flags & _TIF_NOTIFY_RESUME) {
+		clear_thread_flag(TIF_NOTIFY_RESUME);
+		tracehook_notify_resume(regs);
+	}
+}