Initial import

1 files changed, 551 insertions, 0 deletions

diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
new file mode 100644
index 000000000..8dbfb15f1
--- /dev/null
+++ b/arch/alpha/kernel/signal.c
@@ -0,0 +1,551 @@
+/*
+ *  linux/arch/alpha/kernel/signal.c
+ *
+ *  Copyright (C) 1995  Linus Torvalds
+ *
+ *  1997-11-02  Modified for POSIX.1b signals by Richard Henderson
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/stddef.h>
+#include <linux/tty.h>
+#include <linux/binfmts.h>
+#include <linux/bitops.h>
+#include <linux/syscalls.h>
+#include <linux/tracehook.h>
+
+#include <asm/uaccess.h>
+#include <asm/sigcontext.h>
+#include <asm/ucontext.h>
+
+#include "proto.h"
+
+
+#define DEBUG_SIG 0
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+asmlinkage void ret_from_sys_call(void);
+
+/*
+ * The OSF/1 sigprocmask calling sequence is different from the
+ * C sigprocmask() sequence..
+ */
+SYSCALL_DEFINE2(osf_sigprocmask, int, how, unsigned long, newmask)
+{
+	sigset_t oldmask;
+	sigset_t mask;
+	unsigned long res;
+
+	siginitset(&mask, newmask & _BLOCKABLE);
+	res = sigprocmask(how, &mask, &oldmask);
+	if (!res) {
+		force_successful_syscall_return();
+		res = oldmask.sig[0];
+	}
+	return res;
+}
+
+SYSCALL_DEFINE3(osf_sigaction, int, sig,
+		const struct osf_sigaction __user *, act,
+		struct osf_sigaction __user *, oact)
+{
+	struct k_sigaction new_ka, old_ka;
+	int ret;
+
+	if (act) {
+		old_sigset_t mask;
+		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
+		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
+		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+		    __get_user(mask, &act->sa_mask))
+			return -EFAULT;
+		siginitset(&new_ka.sa.sa_mask, mask);
+		new_ka.ka_restorer = NULL;
+	}
+
+	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
+
+	if (!ret && oact) {
+		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
+		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
+		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
+			return -EFAULT;
+	}
+
+	return ret;
+}
+
+SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
+		struct sigaction __user *, oact,
+		size_t, sigsetsize, void __user *, restorer)
+{
+	struct k_sigaction new_ka, old_ka;
+	int ret;
+
+	/* XXX: Don't preclude handling different sized sigset_t's.  */
+	if (sigsetsize != sizeof(sigset_t))
+		return -EINVAL;
+
+	if (act) {
+		new_ka.ka_restorer = restorer;
+		if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
+			return -EFAULT;
+	}
+
+	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
+
+	if (!ret && oact) {
+		if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
+			return -EFAULT;
+	}
+
+	return ret;
+}
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+#if _NSIG_WORDS > 1
+# error "Non SA_SIGINFO frame needs rearranging"
+#endif
+
+struct sigframe
+{
+	struct sigcontext sc;
+	unsigned int retcode[3];
+};
+
+struct rt_sigframe
+{
+	struct siginfo info;
+	struct ucontext uc;
+	unsigned int retcode[3];
+};
+
+/* If this changes, userland unwinders that Know Things about our signal
+   frame will break.  Do not undertake lightly.  It also implies an ABI
+   change wrt the size of siginfo_t, which may cause some pain.  */
+extern char compile_time_assert
+        [offsetof(struct rt_sigframe, uc.uc_mcontext) == 176 ? 1 : -1];
+
+#define INSN_MOV_R30_R16	0x47fe0410
+#define INSN_LDI_R0		0x201f0000
+#define INSN_CALLSYS		0x00000083
+
+static long
+restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
+{
+	unsigned long usp;
+	struct switch_stack *sw = (struct switch_stack *)regs - 1;
+	long i, err = __get_user(regs->pc, &sc->sc_pc);
+
+	current->restart_block.fn = do_no_restart_syscall;
+
+	sw->r26 = (unsigned long) ret_from_sys_call;
+
+	err |= __get_user(regs->r0, sc->sc_regs+0);
+	err |= __get_user(regs->r1, sc->sc_regs+1);
+	err |= __get_user(regs->r2, sc->sc_regs+2);
+	err |= __get_user(regs->r3, sc->sc_regs+3);
+	err |= __get_user(regs->r4, sc->sc_regs+4);
+	err |= __get_user(regs->r5, sc->sc_regs+5);
+	err |= __get_user(regs->r6, sc->sc_regs+6);
+	err |= __get_user(regs->r7, sc->sc_regs+7);
+	err |= __get_user(regs->r8, sc->sc_regs+8);
+	err |= __get_user(sw->r9, sc->sc_regs+9);
+	err |= __get_user(sw->r10, sc->sc_regs+10);
+	err |= __get_user(sw->r11, sc->sc_regs+11);
+	err |= __get_user(sw->r12, sc->sc_regs+12);
+	err |= __get_user(sw->r13, sc->sc_regs+13);
+	err |= __get_user(sw->r14, sc->sc_regs+14);
+	err |= __get_user(sw->r15, sc->sc_regs+15);
+	err |= __get_user(regs->r16, sc->sc_regs+16);
+	err |= __get_user(regs->r17, sc->sc_regs+17);
+	err |= __get_user(regs->r18, sc->sc_regs+18);
+	err |= __get_user(regs->r19, sc->sc_regs+19);
+	err |= __get_user(regs->r20, sc->sc_regs+20);
+	err |= __get_user(regs->r21, sc->sc_regs+21);
+	err |= __get_user(regs->r22, sc->sc_regs+22);
+	err |= __get_user(regs->r23, sc->sc_regs+23);
+	err |= __get_user(regs->r24, sc->sc_regs+24);
+	err |= __get_user(regs->r25, sc->sc_regs+25);
+	err |= __get_user(regs->r26, sc->sc_regs+26);
+	err |= __get_user(regs->r27, sc->sc_regs+27);
+	err |= __get_user(regs->r28, sc->sc_regs+28);
+	err |= __get_user(regs->gp, sc->sc_regs+29);
+	err |= __get_user(usp, sc->sc_regs+30);
+	wrusp(usp);
+
+	for (i = 0; i < 31; i++)
+		err |= __get_user(sw->fp[i], sc->sc_fpregs+i);
+	err |= __get_user(sw->fp[31], &sc->sc_fpcr);
+
+	return err;
+}
+
+/* Note that this syscall is also used by setcontext(3) to install
+   a given sigcontext.  This because it's impossible to set *all*
+   registers and transfer control from userland.  */
+
+asmlinkage void
+do_sigreturn(struct sigcontext __user *sc)
+{
+	struct pt_regs *regs = current_pt_regs();
+	sigset_t set;
+
+	/* Verify that it's a good sigcontext before using it */
+	if (!access_ok(VERIFY_READ, sc, sizeof(*sc)))
+		goto give_sigsegv;
+	if (__get_user(set.sig[0], &sc->sc_mask))
+		goto give_sigsegv;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(sc, regs))
+		goto give_sigsegv;
+
+	/* Send SIGTRAP if we're single-stepping: */
+	if (ptrace_cancel_bpt (current)) {
+		siginfo_t info;
+
+		info.si_signo = SIGTRAP;
+		info.si_errno = 0;
+		info.si_code = TRAP_BRKPT;
+		info.si_addr = (void __user *) regs->pc;
+		info.si_trapno = 0;
+		send_sig_info(SIGTRAP, &info, current);
+	}
+	return;
+
+give_sigsegv:
+	force_sig(SIGSEGV, current);
+}
+
+asmlinkage void
+do_rt_sigreturn(struct rt_sigframe __user *frame)
+{
+	struct pt_regs *regs = current_pt_regs();
+	sigset_t set;
+
+	/* Verify that it's a good ucontext_t before using it */
+	if (!access_ok(VERIFY_READ, &frame->uc, sizeof(frame->uc)))
+		goto give_sigsegv;
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto give_sigsegv;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
+		goto give_sigsegv;
+
+	/* Send SIGTRAP if we're single-stepping: */
+	if (ptrace_cancel_bpt (current)) {
+		siginfo_t info;
+
+		info.si_signo = SIGTRAP;
+		info.si_errno = 0;
+		info.si_code = TRAP_BRKPT;
+		info.si_addr = (void __user *) regs->pc;
+		info.si_trapno = 0;
+		send_sig_info(SIGTRAP, &info, current);
+	}
+	return;
+
+give_sigsegv:
+	force_sig(SIGSEGV, current);
+}
+
+
+/*
+ * Set up a signal frame.
+ */
+
+static inline void __user *
+get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size)
+{
+	return (void __user *)((sigsp(sp, ksig) - frame_size) & -32ul);
+}
+
+static long
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, 
+		 unsigned long mask, unsigned long sp)
+{
+	struct switch_stack *sw = (struct switch_stack *)regs - 1;
+	long i, err = 0;
+
+	err |= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack);
+	err |= __put_user(mask, &sc->sc_mask);
+	err |= __put_user(regs->pc, &sc->sc_pc);
+	err |= __put_user(8, &sc->sc_ps);
+
+	err |= __put_user(regs->r0 , sc->sc_regs+0);
+	err |= __put_user(regs->r1 , sc->sc_regs+1);
+	err |= __put_user(regs->r2 , sc->sc_regs+2);
+	err |= __put_user(regs->r3 , sc->sc_regs+3);
+	err |= __put_user(regs->r4 , sc->sc_regs+4);
+	err |= __put_user(regs->r5 , sc->sc_regs+5);
+	err |= __put_user(regs->r6 , sc->sc_regs+6);
+	err |= __put_user(regs->r7 , sc->sc_regs+7);
+	err |= __put_user(regs->r8 , sc->sc_regs+8);
+	err |= __put_user(sw->r9   , sc->sc_regs+9);
+	err |= __put_user(sw->r10  , sc->sc_regs+10);
+	err |= __put_user(sw->r11  , sc->sc_regs+11);
+	err |= __put_user(sw->r12  , sc->sc_regs+12);
+	err |= __put_user(sw->r13  , sc->sc_regs+13);
+	err |= __put_user(sw->r14  , sc->sc_regs+14);
+	err |= __put_user(sw->r15  , sc->sc_regs+15);
+	err |= __put_user(regs->r16, sc->sc_regs+16);
+	err |= __put_user(regs->r17, sc->sc_regs+17);
+	err |= __put_user(regs->r18, sc->sc_regs+18);
+	err |= __put_user(regs->r19, sc->sc_regs+19);
+	err |= __put_user(regs->r20, sc->sc_regs+20);
+	err |= __put_user(regs->r21, sc->sc_regs+21);
+	err |= __put_user(regs->r22, sc->sc_regs+22);
+	err |= __put_user(regs->r23, sc->sc_regs+23);
+	err |= __put_user(regs->r24, sc->sc_regs+24);
+	err |= __put_user(regs->r25, sc->sc_regs+25);
+	err |= __put_user(regs->r26, sc->sc_regs+26);
+	err |= __put_user(regs->r27, sc->sc_regs+27);
+	err |= __put_user(regs->r28, sc->sc_regs+28);
+	err |= __put_user(regs->gp , sc->sc_regs+29);
+	err |= __put_user(sp, sc->sc_regs+30);
+	err |= __put_user(0, sc->sc_regs+31);
+
+	for (i = 0; i < 31; i++)
+		err |= __put_user(sw->fp[i], sc->sc_fpregs+i);
+	err |= __put_user(0, sc->sc_fpregs+31);
+	err |= __put_user(sw->fp[31], &sc->sc_fpcr);
+
+	err |= __put_user(regs->trap_a0, &sc->sc_traparg_a0);
+	err |= __put_user(regs->trap_a1, &sc->sc_traparg_a1);
+	err |= __put_user(regs->trap_a2, &sc->sc_traparg_a2);
+
+	return err;
+}
+
+static int
+setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
+{
+	unsigned long oldsp, r26, err = 0;
+	struct sigframe __user *frame;
+
+	oldsp = rdusp();
+	frame = get_sigframe(ksig, oldsp, sizeof(*frame));
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		return -EFAULT;
+
+	err |= setup_sigcontext(&frame->sc, regs, set->sig[0], oldsp);
+	if (err)
+		return -EFAULT;
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	r26 = (unsigned long) ksig->ka.ka_restorer;
+	if (!r26) {
+		err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
+		err |= __put_user(INSN_LDI_R0+__NR_sigreturn, frame->retcode+1);
+		err |= __put_user(INSN_CALLSYS, frame->retcode+2);
+		imb();
+		r26 = (unsigned long) frame->retcode;
+	}
+
+	/* Check that everything was written properly.  */
+	if (err)
+		return err;
+
+	/* "Return" to the handler */
+	regs->r26 = r26;
+	regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+	regs->r16 = ksig->sig;			/* a0: signal number */
+	regs->r17 = 0;				/* a1: exception code */
+	regs->r18 = (unsigned long) &frame->sc;	/* a2: sigcontext pointer */
+	wrusp((unsigned long) frame);
+	
+#if DEBUG_SIG
+	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
+		current->comm, current->pid, frame, regs->pc, regs->r26);
+#endif
+	return 0;
+}
+
+static int
+setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
+{
+	unsigned long oldsp, r26, err = 0;
+	struct rt_sigframe __user *frame;
+
+	oldsp = rdusp();
+	frame = get_sigframe(ksig, oldsp, sizeof(*frame));
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		return -EFAULT;
+
+	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 |= __put_user(set->sig[0], &frame->uc.uc_osf_sigmask);
+	err |= __save_altstack(&frame->uc.uc_stack, oldsp);
+	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, 
+				set->sig[0], oldsp);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+	if (err)
+		return -EFAULT;
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	r26 = (unsigned long) ksig->ka.ka_restorer;
+	if (!r26) {
+		err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
+		err |= __put_user(INSN_LDI_R0+__NR_rt_sigreturn,
+				  frame->retcode+1);
+		err |= __put_user(INSN_CALLSYS, frame->retcode+2);
+		imb();
+		r26 = (unsigned long) frame->retcode;
+	}
+
+	if (err)
+		return -EFAULT;
+
+	/* "Return" to the handler */
+	regs->r26 = r26;
+	regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+	regs->r16 = ksig->sig;			  /* a0: signal number */
+	regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */
+	regs->r18 = (unsigned long) &frame->uc;	  /* a2: ucontext pointer */
+	wrusp((unsigned long) frame);
+
+#if DEBUG_SIG
+	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
+		current->comm, current->pid, frame, regs->pc, regs->r26);
+#endif
+
+	return 0;
+}
+
+
+/*
+ * OK, we're invoking a handler.
+ */
+static inline void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	sigset_t *oldset = sigmask_to_save();
+	int ret;
+
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+		ret = setup_rt_frame(ksig, oldset, regs);
+	else
+		ret = setup_frame(ksig, oldset, regs);
+
+	signal_setup_done(ret, ksig, 0);
+}
+
+static inline void
+syscall_restart(unsigned long r0, unsigned long r19,
+		struct pt_regs *regs, struct k_sigaction *ka)
+{
+	switch (regs->r0) {
+	case ERESTARTSYS:
+		if (!(ka->sa.sa_flags & SA_RESTART)) {
+		case ERESTARTNOHAND:
+			regs->r0 = EINTR;
+			break;
+		}
+		/* fallthrough */
+	case ERESTARTNOINTR:
+		regs->r0 = r0;	/* reset v0 and a3 and replay syscall */
+		regs->r19 = r19;
+		regs->pc -= 4;
+		break;
+	case ERESTART_RESTARTBLOCK:
+		regs->r0 = EINTR;
+		break;
+	}
+}
+
+
+/*
+ * 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.
+ *
+ * "r0" and "r19" are the registers we need to restore for system call
+ * restart. "r0" is also used as an indicator whether we can restart at
+ * all (if we get here from anything but a syscall return, it will be 0)
+ */
+static void
+do_signal(struct pt_regs *regs, unsigned long r0, unsigned long r19)
+{
+	unsigned long single_stepping = ptrace_cancel_bpt(current);
+	struct ksignal ksig;
+
+	/* This lets the debugger run, ... */
+	if (get_signal(&ksig)) {
+		/* ... so re-check the single stepping. */
+		single_stepping |= ptrace_cancel_bpt(current);
+		/* Whee!  Actually deliver the signal.  */
+		if (r0)
+			syscall_restart(r0, r19, regs, &ksig.ka);
+		handle_signal(&ksig, regs);
+	} else {
+		single_stepping |= ptrace_cancel_bpt(current);
+		if (r0) {
+			switch (regs->r0) {
+			case ERESTARTNOHAND:
+			case ERESTARTSYS:
+			case ERESTARTNOINTR:
+				/* Reset v0 and a3 and replay syscall.  */
+				regs->r0 = r0;
+				regs->r19 = r19;
+				regs->pc -= 4;
+				break;
+			case ERESTART_RESTARTBLOCK:
+				/* Set v0 to the restart_syscall and replay */
+				regs->r0 = __NR_restart_syscall;
+				regs->pc -= 4;
+				break;
+			}
+		}
+		restore_saved_sigmask();
+	}
+	if (single_stepping)
+		ptrace_set_bpt(current);	/* re-set breakpoint */
+}
+
+void
+do_work_pending(struct pt_regs *regs, unsigned long thread_flags,
+		 unsigned long r0, unsigned long r19)
+{
+	do {
+		if (thread_flags & _TIF_NEED_RESCHED) {
+			schedule();
+		} else {
+			local_irq_enable();
+			if (thread_flags & _TIF_SIGPENDING) {
+				do_signal(regs, r0, r19);
+				r0 = 0;
+			} else {
+				clear_thread_flag(TIF_NOTIFY_RESUME);
+				tracehook_notify_resume(regs);
+			}
+		}
+		local_irq_disable();
+		thread_flags = current_thread_info()->flags;
+	} while (thread_flags & _TIF_WORK_MASK);
+}