1 files changed, 517 insertions, 0 deletions

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
new file mode 100644
index 000000000000..508026ae5842
--- /dev/null
+++ b/arch/mips/kernel/signal.c
@@ -0,0 +1,517 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1991, 1992  Linus Torvalds
+ * Copyright (C) 1994 - 2000  Ralf Baechle
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ */
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/personality.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/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/compiler.h>
+
+#include <asm/asm.h>
+#include <linux/bitops.h>
+#include <asm/cacheflush.h>
+#include <asm/fpu.h>
+#include <asm/sim.h>
+#include <asm/uaccess.h>
+#include <asm/ucontext.h>
+#include <asm/cpu-features.h>
+
+#include "signal-common.h"
+
+#define DEBUG_SIG 0
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+static int do_signal(sigset_t *oldset, struct pt_regs *regs);
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+
+#ifdef CONFIG_TRAD_SIGNALS
+save_static_function(sys_sigsuspend);
+__attribute_used__ noinline static int
+_sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
+{
+        sigset_t *uset, saveset, newset;
+
+        uset = (sigset_t *) regs.regs[4];
+        if (copy_from_user(&newset, uset, sizeof(sigset_t)))
+                return -EFAULT;
+        sigdelsetmask(&newset, ~_BLOCKABLE);
+
+        spin_lock_irq(&current->sighand->siglock);
+        saveset = current->blocked;
+        current->blocked = newset;
+        recalc_sigpending();
+        spin_unlock_irq(&current->sighand->siglock);
+
+        regs.regs[2] = EINTR;
+        regs.regs[7] = 1;
+        while (1) {
+                current->state = TASK_INTERRUPTIBLE;
+                schedule();
+                if (do_signal(&saveset, &regs))
+                        return -EINTR;
+        }
+}
+#endif
+
+save_static_function(sys_rt_sigsuspend);
+__attribute_used__ noinline static int
+_sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
+{
+        sigset_t *unewset, saveset, newset;
+        size_t sigsetsize;
+
+        /* XXX Don't preclude handling different sized sigset_t's.  */
+        sigsetsize = regs.regs[5];
+        if (sigsetsize != sizeof(sigset_t))
+                return -EINVAL;
+
+        unewset = (sigset_t *) regs.regs[4];
+        if (copy_from_user(&newset, unewset, sizeof(newset)))
+                return -EFAULT;
+        sigdelsetmask(&newset, ~_BLOCKABLE);
+
+        spin_lock_irq(&current->sighand->siglock);
+        saveset = current->blocked;
+        current->blocked = newset;
+        recalc_sigpending();
+        spin_unlock_irq(&current->sighand->siglock);
+
+        regs.regs[2] = EINTR;
+        regs.regs[7] = 1;
+        while (1) {
+                current->state = TASK_INTERRUPTIBLE;
+                schedule();
+                if (do_signal(&saveset, &regs))
+                        return -EINTR;
+        }
+}
+
+#ifdef CONFIG_TRAD_SIGNALS
+asmlinkage int sys_sigaction(int sig, const struct sigaction *act,
+        struct sigaction *oact)
+{
+        struct k_sigaction new_ka, old_ka;
+        int ret;
+        int err = 0;
+
+        if (act) {
+                old_sigset_t mask;
+
+                if (!access_ok(VERIFY_READ, act, sizeof(*act)))
+                        return -EFAULT;
+                err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
+                err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
+                err |= __get_user(mask, &act->sa_mask.sig[0]);
+                if (err)
+                        return -EFAULT;
+
+                siginitset(&new_ka.sa.sa_mask, mask);
+        }
+
+        ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
+
+        if (!ret && oact) {
+                if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
+                        return -EFAULT;
+                err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
+                err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
+                err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
+                err |= __put_user(0, &oact->sa_mask.sig[1]);
+                err |= __put_user(0, &oact->sa_mask.sig[2]);
+                err |= __put_user(0, &oact->sa_mask.sig[3]);
+                if (err)
+                        return -EFAULT;
+        }
+
+        return ret;
+}
+#endif
+
+asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)
+{
+        const stack_t *uss = (const stack_t *) regs.regs[4];
+        stack_t *uoss = (stack_t *) regs.regs[5];
+        unsigned long usp = regs.regs[29];
+
+        return do_sigaltstack(uss, uoss, usp);
+}
+
+#if PLAT_TRAMPOLINE_STUFF_LINE
+#define __tramp __attribute__((aligned(PLAT_TRAMPOLINE_STUFF_LINE)))
+#else
+#define __tramp
+#endif
+
+#ifdef CONFIG_TRAD_SIGNALS
+struct sigframe {
+        u32 sf_ass[4];                  /* argument save space for o32 */
+        u32 sf_code[2] __tramp;         /* signal trampoline */
+        struct sigcontext sf_sc __tramp;
+        sigset_t sf_mask;
+};
+#endif
+
+struct rt_sigframe {
+        u32 rs_ass[4];                  /* argument save space for o32 */
+        u32 rs_code[2] __tramp;         /* signal trampoline */
+        struct siginfo rs_info __tramp;
+        struct ucontext rs_uc;
+};
+
+#ifdef CONFIG_TRAD_SIGNALS
+save_static_function(sys_sigreturn);
+__attribute_used__ noinline static void
+_sys_sigreturn(nabi_no_regargs struct pt_regs regs)
+{
+        struct sigframe *frame;
+        sigset_t blocked;
+
+        frame = (struct sigframe *) regs.regs[29];
+        if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+                goto badframe;
+        if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
+                goto badframe;
+
+        sigdelsetmask(&blocked, ~_BLOCKABLE);
+        spin_lock_irq(&current->sighand->siglock);
+        current->blocked = blocked;
+        recalc_sigpending();
+        spin_unlock_irq(&current->sighand->siglock);
+
+        if (restore_sigcontext(&regs, &frame->sf_sc))
+                goto badframe;
+
+        /*
+         * Don't let your children do this ...
+         */
+        if (current_thread_info()->flags & TIF_SYSCALL_TRACE)
+                do_syscall_trace(&regs, 1);
+        __asm__ __volatile__(
+                "move\t$29, %0\n\t"
+                "j\tsyscall_exit"
+                :/* no outputs */
+                :"r" (&regs));
+        /* Unreached */
+
+badframe:
+        force_sig(SIGSEGV, current);
+}
+#endif
+
+save_static_function(sys_rt_sigreturn);
+__attribute_used__ noinline static void
+_sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
+{
+        struct rt_sigframe *frame;
+        sigset_t set;
+        stack_t st;
+
+        frame = (struct rt_sigframe *) regs.regs[29];
+        if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+                goto badframe;
+        if (__copy_from_user(&set, &frame->rs_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->rs_uc.uc_mcontext))
+                goto badframe;
+
+        if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
+                goto badframe;
+        /* It is more difficult to avoid calling this function than to
+           call it and ignore errors.  */
+        do_sigaltstack(&st, NULL, regs.regs[29]);
+
+        /*
+         * Don't let your children do this ...
+         */
+        __asm__ __volatile__(
+                "move\t$29, %0\n\t"
+                "j\tsyscall_exit"
+                :/* no outputs */
+                :"r" (&regs));
+        /* Unreached */
+
+badframe:
+        force_sig(SIGSEGV, current);
+}
+
+#ifdef CONFIG_TRAD_SIGNALS
+static void inline setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
+        int signr, sigset_t *set)
+{
+        struct sigframe *frame;
+        int err = 0;
+
+        frame = get_sigframe(ka, regs, sizeof(*frame));
+        if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+                goto give_sigsegv;
+
+        /*
+         * Set up the return code ...
+         *
+         *         li      v0, __NR_sigreturn
+         *         syscall
+         */
+        if (PLAT_TRAMPOLINE_STUFF_LINE)
+                __clear_user(frame->sf_code, PLAT_TRAMPOLINE_STUFF_LINE);
+        err |= __put_user(0x24020000 + __NR_sigreturn, frame->sf_code + 0);
+        err |= __put_user(0x0000000c                 , frame->sf_code + 1);
+        flush_cache_sigtramp((unsigned long) frame->sf_code);
+
+        err |= setup_sigcontext(regs, &frame->sf_sc);
+        err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
+        if (err)
+                goto give_sigsegv;
+
+        /*
+         * Arguments to signal handler:
+         *
+         *   a0 = signal number
+         *   a1 = 0 (should be cause)
+         *   a2 = pointer to struct sigcontext
+         *
+         * $25 and c0_epc point to the signal handler, $29 points to the
+         * struct sigframe.
+         */
+        regs->regs[ 4] = signr;
+        regs->regs[ 5] = 0;
+        regs->regs[ 6] = (unsigned long) &frame->sf_sc;
+        regs->regs[29] = (unsigned long) frame;
+        regs->regs[31] = (unsigned long) frame->sf_code;
+        regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
+
+#if DEBUG_SIG
+        printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
+               current->comm, current->pid,
+               frame, regs->cp0_epc, frame->regs[31]);
+#endif
+        return;
+
+give_sigsegv:
+        force_sigsegv(signr, current);
+}
+#endif
+
+static void inline setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
+        int signr, sigset_t *set, siginfo_t *info)
+{
+        struct rt_sigframe *frame;
+        int err = 0;
+
+        frame = get_sigframe(ka, regs, sizeof(*frame));
+        if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+                goto give_sigsegv;
+
+        /*
+         * Set up the return code ...
+         *
+         *         li      v0, __NR_rt_sigreturn
+         *         syscall
+         */
+        if (PLAT_TRAMPOLINE_STUFF_LINE)
+                __clear_user(frame->rs_code, PLAT_TRAMPOLINE_STUFF_LINE);
+        err |= __put_user(0x24020000 + __NR_rt_sigreturn, frame->rs_code + 0);
+        err |= __put_user(0x0000000c                    , frame->rs_code + 1);
+        flush_cache_sigtramp((unsigned long) frame->rs_code);
+
+        /* Create siginfo.  */
+        err |= copy_siginfo_to_user(&frame->rs_info, info);
+
+        /* Create the ucontext.  */
+        err |= __put_user(0, &frame->rs_uc.uc_flags);
+        err |= __put_user(0, &frame->rs_uc.uc_link);
+        err |= __put_user((void *)current->sas_ss_sp,
+                          &frame->rs_uc.uc_stack.ss_sp);
+        err |= __put_user(sas_ss_flags(regs->regs[29]),
+                          &frame->rs_uc.uc_stack.ss_flags);
+        err |= __put_user(current->sas_ss_size,
+                          &frame->rs_uc.uc_stack.ss_size);
+        err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
+        err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
+
+        if (err)
+                goto give_sigsegv;
+
+        /*
+         * Arguments to signal handler:
+         *
+         *   a0 = signal number
+         *   a1 = 0 (should be cause)
+         *   a2 = pointer to ucontext
+         *
+         * $25 and c0_epc point to the signal handler, $29 points to
+         * the struct rt_sigframe.
+         */
+        regs->regs[ 4] = signr;
+        regs->regs[ 5] = (unsigned long) &frame->rs_info;
+        regs->regs[ 6] = (unsigned long) &frame->rs_uc;
+        regs->regs[29] = (unsigned long) frame;
+        regs->regs[31] = (unsigned long) frame->rs_code;
+        regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
+
+#if DEBUG_SIG
+        printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
+               current->comm, current->pid,
+               frame, regs->cp0_epc, regs->regs[31]);
+#endif
+        return;
+
+give_sigsegv:
+        force_sigsegv(signr, current);
+}
+
+extern void setup_rt_frame_n32(struct k_sigaction * ka,
+        struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info);
+
+static inline void handle_signal(unsigned long sig, siginfo_t *info,
+        struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
+{
+        switch(regs->regs[0]) {
+        case ERESTART_RESTARTBLOCK:
+        case ERESTARTNOHAND:
+                regs->regs[2] = EINTR;
+                break;
+        case ERESTARTSYS:
+                if(!(ka->sa.sa_flags & SA_RESTART)) {
+                        regs->regs[2] = EINTR;
+                        break;
+                }
+        /* fallthrough */
+        case ERESTARTNOINTR:            /* Userland will reload $v0.  */
+                regs->regs[7] = regs->regs[26];
+                regs->cp0_epc -= 8;
+        }
+
+        regs->regs[0] = 0;              /* Don't deal with this again.  */
+
+#ifdef CONFIG_TRAD_SIGNALS
+        if (ka->sa.sa_flags & SA_SIGINFO) {
+#else
+        if (1) {
+#endif
+#ifdef CONFIG_MIPS32_N32
+                if ((current->thread.mflags & MF_ABI_MASK) == MF_N32)
+                        setup_rt_frame_n32 (ka, regs, sig, oldset, info);
+                else
+#endif
+                        setup_rt_frame(ka, regs, sig, oldset, info);
+        }
+#ifdef CONFIG_TRAD_SIGNALS
+        else
+                setup_frame(ka, regs, sig, oldset);
+#endif
+
+        if (!(ka->sa.sa_flags & SA_NODEFER)) {
+                spin_lock_irq(&current->sighand->siglock);
+                sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+                sigaddset(&current->blocked,sig);
+                recalc_sigpending();
+                spin_unlock_irq(&current->sighand->siglock);
+        }
+}
+
+extern int do_signal32(sigset_t *oldset, struct pt_regs *regs);
+extern int do_irix_signal(sigset_t *oldset, struct pt_regs *regs);
+
+static int do_signal(sigset_t *oldset, struct pt_regs *regs)
+{
+        struct k_sigaction ka;
+        siginfo_t info;
+        int signr;
+
+#ifdef CONFIG_BINFMT_ELF32
+        if ((current->thread.mflags & MF_ABI_MASK) == MF_O32) {
+                return do_signal32(oldset, regs);
+        }
+#endif
+
+        /*
+         * 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 1;
+
+        if (try_to_freeze(0))
+                goto no_signal;
+
+        if (!oldset)
+                oldset = &current->blocked;
+
+        signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+        if (signr > 0) {
+                handle_signal(signr, &info, &ka, oldset, regs);
+                return 1;
+        }
+
+no_signal:
+        /*
+         * Who's code doesn't conform to the restartable syscall convention
+         * dies here!!!  The li instruction, a single machine instruction,
+         * must directly be followed by the syscall instruction.
+         */
+        if (regs->regs[0]) {
+                if (regs->regs[2] == ERESTARTNOHAND ||
+                    regs->regs[2] == ERESTARTSYS ||
+                    regs->regs[2] == ERESTARTNOINTR) {
+                        regs->regs[7] = regs->regs[26];
+                        regs->cp0_epc -= 8;
+                }
+                if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
+                        regs->regs[2] = __NR_restart_syscall;
+                        regs->regs[7] = regs->regs[26];
+                        regs->cp0_epc -= 4;
+                }
+        }
+        return 0;
+}
+
+/*
+ * notification of userspace execution resumption
+ * - triggered by current->work.notify_resume
+ */
+asmlinkage void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
+        __u32 thread_info_flags)
+{
+        /* deal with pending signal delivery */
+        if (thread_info_flags & _TIF_SIGPENDING) {
+#ifdef CONFIG_BINFMT_ELF32
+                if (likely((current->thread.mflags & MF_ABI_MASK) == MF_O32)) {
+                        do_signal32(oldset, regs);
+                        return;
+                }
+#endif
+#ifdef CONFIG_BINFMT_IRIX
+                if (unlikely(current->personality != PER_LINUX)) {
+                        do_irix_signal(oldset, regs);
+                        return;
+                }
+#endif
+                do_signal(oldset, regs);
+        }
+}