1 files changed, 359 insertions, 0 deletions

diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c
new file mode 100644
index 000000000000..7ea85eb85242
--- /dev/null
+++ b/arch/tile/kernel/signal.c
@@ -0,0 +1,359 @@
+/*
+ * Copyright (C) 1991, 1992  Linus Torvalds
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/personality.h>
+#include <linux/suspend.h>
+#include <linux/ptrace.h>
+#include <linux/elf.h>
+#include <linux/compat.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <asm/processor.h>
+#include <asm/ucontext.h>
+#include <asm/sigframe.h>
+#include <arch/interrupts.h>
+
+#define DEBUG_SIG 0
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+
+/* Caller before callee in this file; other callee is in assembler */
+void do_signal(struct pt_regs *regs);
+
+int _sys_sigaltstack(const stack_t __user *uss,
+                     stack_t __user *uoss, struct pt_regs *regs)
+{
+        return do_sigaltstack(uss, uoss, regs->sp);
+}
+
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+int restore_sigcontext(struct pt_regs *regs,
+                       struct sigcontext __user *sc, long *pr0)
+{
+        int err = 0;
+        int i;
+
+        /* Always make any pending restarted system calls return -EINTR */
+        current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+        for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i)
+                err |= __get_user(((long *)regs)[i],
+                                  &((long *)(&sc->regs))[i]);
+
+        regs->faultnum = INT_SWINT_1_SIGRETURN;
+
+        err |= __get_user(*pr0, &sc->regs.regs[0]);
+        return err;
+}
+
+int _sys_rt_sigreturn(struct pt_regs *regs)
+{
+        struct rt_sigframe __user *frame =
+                (struct rt_sigframe __user *)(regs->sp);
+        sigset_t set;
+        long r0;
+
+        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(&current->sighand->siglock);
+        current->blocked = set;
+        recalc_sigpending();
+        spin_unlock_irq(&current->sighand->siglock);
+
+        if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
+                goto badframe;
+
+        if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
+                goto badframe;
+
+        return r0;
+
+badframe:
+        force_sig(SIGSEGV, current);
+        return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
+{
+        int i, err = 0;
+
+        for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i)
+                err |= __put_user(((long *)regs)[i],
+                                  &((long *)(&sc->regs))[i]);
+
+        return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *get_sigframe(struct k_sigaction *ka,
+                                        struct pt_regs *regs,
+                                        size_t frame_size)
+{
+        unsigned long sp;
+
+        /* Default to using normal stack */
+        sp = regs->sp;
+
+        /*
+         * If we are on the alternate signal stack and would overflow
+         * it, don't.  Return an always-bogus address instead so we
+         * will die with SIGSEGV.
+         */
+        if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
+                return (void __user *) -1L;
+
+        /* This is the X/Open sanctioned signal stack switching.  */
+        if (ka->sa.sa_flags & SA_ONSTACK) {
+                if (sas_ss_flags(sp) == 0)
+                        sp = current->sas_ss_sp + current->sas_ss_size;
+        }
+
+        sp -= frame_size;
+        /*
+         * Align the stack pointer according to the TILE ABI,
+         * i.e. so that on function entry (sp & 15) == 0.
+         */
+        sp &= -16UL;
+        return (void __user *) sp;
+}
+
+static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+                           sigset_t *set, struct pt_regs *regs)
+{
+        unsigned long restorer;
+        struct rt_sigframe __user *frame;
+        int err = 0;
+        int usig;
+
+        frame = get_sigframe(ka, regs, sizeof(*frame));
+
+        if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+                goto give_sigsegv;
+
+        usig = current_thread_info()->exec_domain
+                && current_thread_info()->exec_domain->signal_invmap
+                && sig < 32
+                ? current_thread_info()->exec_domain->signal_invmap[sig]
+                : sig;
+
+        /* Always write at least the signal number for the stack backtracer. */
+        if (ka->sa.sa_flags & SA_SIGINFO) {
+                /* At sigreturn time, restore the callee-save registers too. */
+                err |= copy_siginfo_to_user(&frame->info, info);
+                regs->flags |= PT_FLAGS_RESTORE_REGS;
+        } else {
+                err |= __put_user(info->si_signo, &frame->info.si_signo);
+        }
+
+        /* Create the ucontext.  */
+        err |= __clear_user(&frame->save_area, sizeof(frame->save_area));
+        err |= __put_user(0, &frame->uc.uc_flags);
+        err |= __put_user(0, &frame->uc.uc_link);
+        err |= __put_user((void *)(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 give_sigsegv;
+
+        restorer = VDSO_BASE;
+        if (ka->sa.sa_flags & SA_RESTORER)
+                restorer = (unsigned long) ka->sa.sa_restorer;
+
+        /*
+         * Set up registers for signal handler.
+         * Registers that we don't modify keep the value they had from
+         * user-space at the time we took the signal.
+         */
+        regs->pc = (unsigned long) ka->sa.sa_handler;
+        regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */
+        regs->sp = (unsigned long) frame;
+        regs->lr = restorer;
+        regs->regs[0] = (unsigned long) usig;
+
+        if (ka->sa.sa_flags & SA_SIGINFO) {
+                /* Need extra arguments, so mark to restore caller-saves. */
+                regs->regs[1] = (unsigned long) &frame->info;
+                regs->regs[2] = (unsigned long) &frame->uc;
+                regs->flags |= PT_FLAGS_CALLER_SAVES;
+        }
+
+        /*
+         * Notify any tracer that was single-stepping it.
+         * The tracer may want to single-step inside the
+         * handler too.
+         */
+        if (test_thread_flag(TIF_SINGLESTEP))
+                ptrace_notify(SIGTRAP);
+
+        return 0;
+
+give_sigsegv:
+        force_sigsegv(sig, current);
+        return -EFAULT;
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+
+static int handle_signal(unsigned long sig, siginfo_t *info,
+                         struct k_sigaction *ka, sigset_t *oldset,
+                         struct pt_regs *regs)
+{
+        int ret;
+
+
+        /* Are we from a system call? */
+        if (regs->faultnum == INT_SWINT_1) {
+                /* If so, check system call restarting.. */
+                switch (regs->regs[0]) {
+                case -ERESTART_RESTARTBLOCK:
+                case -ERESTARTNOHAND:
+                        regs->regs[0] = -EINTR;
+                        break;
+
+                case -ERESTARTSYS:
+                        if (!(ka->sa.sa_flags & SA_RESTART)) {
+                                regs->regs[0] = -EINTR;
+                                break;
+                        }
+                        /* fallthrough */
+                case -ERESTARTNOINTR:
+                        /* Reload caller-saves to restore r0..r5 and r10. */
+                        regs->flags |= PT_FLAGS_CALLER_SAVES;
+                        regs->regs[0] = regs->orig_r0;
+                        regs->pc -= 8;
+                }
+        }
+
+        /* Set up the stack frame */
+#ifdef CONFIG_COMPAT
+        if (is_compat_task())
+                ret = compat_setup_rt_frame(sig, ka, info, oldset, regs);
+        else
+#endif
+                ret = setup_rt_frame(sig, ka, info, oldset, regs);
+        if (ret == 0) {
+                /* This code is only called from system calls or from
+                 * the work_pending path in the return-to-user code, and
+                 * either way we can re-enable interrupts unconditionally.
+                 */
+                spin_lock_irq(&current->sighand->siglock);
+                sigorsets(&current->blocked,
+                          &current->blocked, &ka->sa.sa_mask);
+                if (!(ka->sa.sa_flags & SA_NODEFER))
+                        sigaddset(&current->blocked, sig);
+                recalc_sigpending();
+                spin_unlock_irq(&current->sighand->siglock);
+        }
+
+        return ret;
+}
+
+/*
+ * 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.
+ */
+void do_signal(struct pt_regs *regs)
+{
+        siginfo_t info;
+        int signr;
+        struct k_sigaction ka;
+        sigset_t *oldset;
+
+        /*
+         * i386 will check if we're coming from kernel mode and bail out
+         * here.  In my experience this just turns weird crashes into
+         * weird spin-hangs.  But if we find a case where this seems
+         * helpful, we can reinstate the check on "!user_mode(regs)".
+         */
+
+        if (current_thread_info()->status & TS_RESTORE_SIGMASK)
+                oldset = &current->saved_sigmask;
+        else
+                oldset = &current->blocked;
+
+        signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+        if (signr > 0) {
+                /* Whee! Actually deliver the signal.  */
+                if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
+                        /*
+                         * A signal was successfully delivered; the saved
+                         * sigmask will have been stored in the signal frame,
+                         * and will be restored by sigreturn, so we can simply
+                         * clear the TS_RESTORE_SIGMASK flag.
+                         */
+                        current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
+                }
+
+                return;
+        }
+
+        /* Did we come from a system call? */
+        if (regs->faultnum == INT_SWINT_1) {
+                /* Restart the system call - no handlers present */
+                switch (regs->regs[0]) {
+                case -ERESTARTNOHAND:
+                case -ERESTARTSYS:
+                case -ERESTARTNOINTR:
+                        regs->flags |= PT_FLAGS_CALLER_SAVES;
+                        regs->regs[0] = regs->orig_r0;
+                        regs->pc -= 8;
+                        break;
+
+                case -ERESTART_RESTARTBLOCK:
+                        regs->flags |= PT_FLAGS_CALLER_SAVES;
+                        regs->regs[TREG_SYSCALL_NR] = __NR_restart_syscall;
+                        regs->pc -= 8;
+                        break;
+                }
+        }
+
+        /* If there's no signal to deliver, just put the saved sigmask back. */
+        if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
+                current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
+                sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+        }
+}