1 files changed, 286 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/signal.c b/arch/blackfin/kernel/signal.c
new file mode 100644
index 000000000..ea570db59
--- /dev/null
+++ b/arch/blackfin/kernel/signal.c
@@ -0,0 +1,286 @@
+/*
+ * Copyright 2004-2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later
+ */
+
+#include <linux/signal.h>
+#include <linux/syscalls.h>
+#include <linux/ptrace.h>
+#include <linux/tty.h>
+#include <linux/personality.h>
+#include <linux/binfmts.h>
+#include <linux/uaccess.h>
+#include <linux/tracehook.h>
+
+#include <asm/cacheflush.h>
+#include <asm/ucontext.h>
+#include <asm/fixed_code.h>
+#include <asm/syscall.h>
+
+/* Location of the trace bit in SYSCFG. */
+#define TRACE_BITS 0x0001
+
+struct fdpic_func_descriptor {
+	unsigned long	text;
+	unsigned long	GOT;
+};
+
+struct rt_sigframe {
+	int sig;
+	struct siginfo *pinfo;
+	void *puc;
+	/* This is no longer needed by the kernel, but unfortunately userspace
+	 * code expects it to be there.  */
+	char retcode[8];
+	struct siginfo info;
+	struct ucontext uc;
+};
+
+static inline int
+rt_restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *pr0)
+{
+	unsigned long usp = 0;
+	int err = 0;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+#define RESTORE(x) err |= __get_user(regs->x, &sc->sc_##x)
+
+	/* restore passed registers */
+	RESTORE(r0); RESTORE(r1); RESTORE(r2); RESTORE(r3);
+	RESTORE(r4); RESTORE(r5); RESTORE(r6); RESTORE(r7);
+	RESTORE(p0); RESTORE(p1); RESTORE(p2); RESTORE(p3);
+	RESTORE(p4); RESTORE(p5);
+	err |= __get_user(usp, &sc->sc_usp);
+	wrusp(usp);
+	RESTORE(a0w); RESTORE(a1w);
+	RESTORE(a0x); RESTORE(a1x);
+	RESTORE(astat);
+	RESTORE(rets);
+	RESTORE(pc);
+	RESTORE(retx);
+	RESTORE(fp);
+	RESTORE(i0); RESTORE(i1); RESTORE(i2); RESTORE(i3);
+	RESTORE(m0); RESTORE(m1); RESTORE(m2); RESTORE(m3);
+	RESTORE(l0); RESTORE(l1); RESTORE(l2); RESTORE(l3);
+	RESTORE(b0); RESTORE(b1); RESTORE(b2); RESTORE(b3);
+	RESTORE(lc0); RESTORE(lc1);
+	RESTORE(lt0); RESTORE(lt1);
+	RESTORE(lb0); RESTORE(lb1);
+	RESTORE(seqstat);
+
+	regs->orig_p0 = -1;	/* disable syscall checks */
+
+	*pr0 = regs->r0;
+	return err;
+}
+
+asmlinkage int sys_rt_sigreturn(void)
+{
+	struct pt_regs *regs = current_pt_regs();
+	unsigned long usp = rdusp();
+	struct rt_sigframe *frame = (struct rt_sigframe *)(usp);
+	sigset_t set;
+	int r0;
+
+	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 (rt_restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return r0;
+
+ badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+static inline int rt_setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs)
+{
+	int err = 0;
+
+#define SETUP(x) err |= __put_user(regs->x, &sc->sc_##x)
+
+	SETUP(r0); SETUP(r1); SETUP(r2); SETUP(r3);
+	SETUP(r4); SETUP(r5); SETUP(r6); SETUP(r7);
+	SETUP(p0); SETUP(p1); SETUP(p2); SETUP(p3);
+	SETUP(p4); SETUP(p5);
+	err |= __put_user(rdusp(), &sc->sc_usp);
+	SETUP(a0w); SETUP(a1w);
+	SETUP(a0x); SETUP(a1x);
+	SETUP(astat);
+	SETUP(rets);
+	SETUP(pc);
+	SETUP(retx);
+	SETUP(fp);
+	SETUP(i0); SETUP(i1); SETUP(i2); SETUP(i3);
+	SETUP(m0); SETUP(m1); SETUP(m2); SETUP(m3);
+	SETUP(l0); SETUP(l1); SETUP(l2); SETUP(l3);
+	SETUP(b0); SETUP(b1); SETUP(b2); SETUP(b3);
+	SETUP(lc0); SETUP(lc1);
+	SETUP(lt0); SETUP(lt1);
+	SETUP(lb0); SETUP(lb1);
+	SETUP(seqstat);
+
+	return err;
+}
+
+static inline void *get_sigframe(struct ksignal *ksig,
+				 size_t frame_size)
+{
+	unsigned long usp = sigsp(rdusp(), ksig);
+
+	return (void *)((usp - frame_size) & -8UL);
+}
+
+static int
+setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
+{
+	struct rt_sigframe *frame;
+	int err = 0;
+
+	frame = get_sigframe(ksig, sizeof(*frame));
+
+	err |= __put_user(ksig->sig, &frame->sig);
+
+	err |= __put_user(&frame->info, &frame->pinfo);
+	err |= __put_user(&frame->uc, &frame->puc);
+	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+
+	/* Create the ucontext.  */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(0, &frame->uc.uc_link);
+	err |= __save_altstack(&frame->uc.uc_stack, rdusp());
+	err |= rt_setup_sigcontext(&frame->uc.uc_mcontext, regs);
+	err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+	if (err)
+		return -EFAULT;
+
+	/* Set up registers for signal handler */
+	if (current->personality & FDPIC_FUNCPTRS) {
+		struct fdpic_func_descriptor __user *funcptr =
+			(struct fdpic_func_descriptor *) ksig->ka.sa.sa_handler;
+		u32 pc, p3;
+		err |= __get_user(pc, &funcptr->text);
+		err |= __get_user(p3, &funcptr->GOT);
+		if (err)
+			return -EFAULT;
+		regs->pc = pc;
+		regs->p3 = p3;
+	} else
+		regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
+	wrusp((unsigned long)frame);
+	regs->rets = SIGRETURN_STUB;
+
+	regs->r0 = frame->sig;
+	regs->r1 = (unsigned long)(&frame->info);
+	regs->r2 = (unsigned long)(&frame->uc);
+
+	return 0;
+}
+
+static inline void
+handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
+{
+	switch (regs->r0) {
+	case -ERESTARTNOHAND:
+		if (!has_handler)
+			goto do_restart;
+		regs->r0 = -EINTR;
+		break;
+
+	case -ERESTARTSYS:
+		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
+			regs->r0 = -EINTR;
+			break;
+		}
+		/* fallthrough */
+	case -ERESTARTNOINTR:
+ do_restart:
+		regs->p0 = regs->orig_p0;
+		regs->r0 = regs->orig_r0;
+		regs->pc -= 2;
+		break;
+
+	case -ERESTART_RESTARTBLOCK:
+		regs->p0 = __NR_restart_syscall;
+		regs->pc -= 2;
+		break;
+	}
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	int ret;
+
+	/* are we from a system call? to see pt_regs->orig_p0 */
+	if (regs->orig_p0 >= 0)
+		/* If so, check system call restarting.. */
+		handle_restart(regs, &ksig->ka, 1);
+
+	/* set up the stack frame */
+	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
+
+	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
+}
+
+/*
+ * 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.
+ *
+ * Note that we go through the signals twice: once to check the signals
+ * that the kernel can handle, and then we build all the user-level signal
+ * handling stack-frames in one go after that.
+ */
+asmlinkage void do_signal(struct pt_regs *regs)
+{
+	struct ksignal ksig;
+
+	current->thread.esp0 = (unsigned long)regs;
+
+	if (get_signal(&ksig)) {
+		/* Whee!  Actually deliver the signal.  */
+		handle_signal(&ksig, regs);
+		return;
+	}
+
+	/* Did we come from a system call? */
+	if (regs->orig_p0 >= 0)
+		/* Restart the system call - no handlers present */
+		handle_restart(regs, NULL, 0);
+
+	/* if there's no signal to deliver, we just put the saved sigmask
+	 * back */
+	restore_saved_sigmask();
+}
+
+/*
+ * notification of userspace execution resumption
+ */
+asmlinkage void do_notify_resume(struct pt_regs *regs)
+{
+	if (test_thread_flag(TIF_SIGPENDING))
+		do_signal(regs);
+
+	if (test_thread_flag(TIF_NOTIFY_RESUME)) {
+		clear_thread_flag(TIF_NOTIFY_RESUME);
+		tracehook_notify_resume(regs);
+	}
+}
+