1 files changed, 540 insertions, 0 deletions

diff --git a/arch/arm26/kernel/signal.c b/arch/arm26/kernel/signal.c
new file mode 100644
index 000000000000..356d9809cc0b
--- /dev/null
+++ b/arch/arm26/kernel/signal.c
@@ -0,0 +1,540 @@
+/*
+ *  linux/arch/arm26/kernel/signal.c
+ *
+ *  Copyright (C) 1995-2002 Russell King
+ *  Copyright (C) 2003 Ian Molton (ARM26)
+ *
+ * FIXME!!! This is probably very broken (13/05/2003)
+ *
+ * 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/config.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/personality.h>
+#include <linux/tty.h>
+#include <linux/binfmts.h>
+#include <linux/elf.h>
+
+#include <asm/pgalloc.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+
+#include "ptrace.h"
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+/*
+ * For ARM syscalls, we encode the syscall number into the instruction.
+ */
+#define SWI_SYS_SIGRETURN       (0xef000000|(__NR_sigreturn))
+#define SWI_SYS_RT_SIGRETURN    (0xef000000|(__NR_rt_sigreturn))
+
+static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);
+
+/*
+ * atomically swap in the new signal mask, and wait for a signal.
+ */
+asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
+{
+        sigset_t saveset;
+
+        mask &= _BLOCKABLE;
+        spin_lock_irq(&current->sighand->siglock);
+        saveset = current->blocked;
+        siginitset(&current->blocked, mask);
+        recalc_sigpending();
+        spin_unlock_irq(&current->sighand->siglock);
+        regs->ARM_r0 = -EINTR;
+
+        while (1) {
+                current->state = TASK_INTERRUPTIBLE;
+                schedule();
+                if (do_signal(&saveset, regs, 0))
+                        return regs->ARM_r0;
+        }
+}
+
+asmlinkage int
+sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, struct pt_regs *regs)
+{
+        sigset_t saveset, newset;
+
+        /* XXX: Don't preclude handling different sized sigset_t's. */
+        if (sigsetsize != sizeof(sigset_t))
+                return -EINVAL;
+
+        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->ARM_r0 = -EINTR;
+
+        while (1) {
+                current->state = TASK_INTERRUPTIBLE;
+                schedule();
+                if (do_signal(&saveset, regs, 0))
+                        return regs->ARM_r0;
+        }
+}
+
+asmlinkage int 
+sys_sigaction(int sig, const struct old_sigaction *act,
+              struct old_sigaction *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_restorer, &act->sa_restorer))
+                        return -EFAULT;
+                __get_user(new_ka.sa.sa_flags, &act->sa_flags);
+                __get_user(mask, &act->sa_mask);
+                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)) ||
+                    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
+                    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+                        return -EFAULT;
+                __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
+                __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
+        }
+
+        return ret;
+}
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+struct sigframe
+{
+        struct sigcontext sc;
+        unsigned long extramask[_NSIG_WORDS-1];
+        unsigned long retcode;
+};
+
+struct rt_sigframe
+{
+        struct siginfo *pinfo;
+        void *puc;
+        struct siginfo info;
+        struct ucontext uc;
+        unsigned long retcode;
+};
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
+{
+        int err = 0;
+
+        __get_user_error(regs->ARM_r0, &sc->arm_r0, err);
+        __get_user_error(regs->ARM_r1, &sc->arm_r1, err);
+        __get_user_error(regs->ARM_r2, &sc->arm_r2, err);
+        __get_user_error(regs->ARM_r3, &sc->arm_r3, err);
+        __get_user_error(regs->ARM_r4, &sc->arm_r4, err);
+        __get_user_error(regs->ARM_r5, &sc->arm_r5, err);
+        __get_user_error(regs->ARM_r6, &sc->arm_r6, err);
+        __get_user_error(regs->ARM_r7, &sc->arm_r7, err);
+        __get_user_error(regs->ARM_r8, &sc->arm_r8, err);
+        __get_user_error(regs->ARM_r9, &sc->arm_r9, err);
+        __get_user_error(regs->ARM_r10, &sc->arm_r10, err);
+        __get_user_error(regs->ARM_fp, &sc->arm_fp, err);
+        __get_user_error(regs->ARM_ip, &sc->arm_ip, err);
+        __get_user_error(regs->ARM_sp, &sc->arm_sp, err);
+        __get_user_error(regs->ARM_lr, &sc->arm_lr, err);
+        __get_user_error(regs->ARM_pc, &sc->arm_pc, err);
+
+        err |= !valid_user_regs(regs);
+
+        return err;
+}
+
+asmlinkage int sys_sigreturn(struct pt_regs *regs)
+{
+        struct sigframe *frame;
+        sigset_t set;
+
+        /*
+         * Since we stacked the signal on a 64-bit boundary,
+         * then 'sp' should be word aligned here.  If it's
+         * not, then the user is trying to mess with us.
+         */
+        if (regs->ARM_sp & 7)
+                goto badframe;
+
+        frame = (struct sigframe *)regs->ARM_sp;
+
+        if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
+                goto badframe;
+        if (__get_user(set.sig[0], &frame->sc.oldmask)
+            || (_NSIG_WORDS > 1
+                && __copy_from_user(&set.sig[1], &frame->extramask,
+                                    sizeof(frame->extramask))))
+                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->sc))
+                goto badframe;
+
+        /* Send SIGTRAP if we're single-stepping */
+        if (current->ptrace & PT_SINGLESTEP) {
+                ptrace_cancel_bpt(current);
+                send_sig(SIGTRAP, current, 1);
+        }
+
+        return regs->ARM_r0;
+
+badframe:
+        force_sig(SIGSEGV, current);
+        return 0;
+}
+
+asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
+{
+        struct rt_sigframe *frame;
+        sigset_t set;
+
+        /*
+         * Since we stacked the signal on a 64-bit boundary,
+         * then 'sp' should be word aligned here.  If it's
+         * not, then the user is trying to mess with us.
+         */
+        if (regs->ARM_sp & 7)
+                goto badframe;
+
+        frame = (struct rt_sigframe *)regs->ARM_sp;
+
+        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))
+                goto badframe;
+
+        /* Send SIGTRAP if we're single-stepping */
+        if (current->ptrace & PT_SINGLESTEP) {
+                ptrace_cancel_bpt(current);
+                send_sig(SIGTRAP, current, 1);
+        }
+
+        return regs->ARM_r0;
+
+badframe:
+        force_sig(SIGSEGV, current);
+        return 0;
+}
+
+static int
+setup_sigcontext(struct sigcontext *sc, /*struct _fpstate *fpstate,*/
+                 struct pt_regs *regs, unsigned long mask)
+{
+        int err = 0;
+
+        __put_user_error(regs->ARM_r0, &sc->arm_r0, err);
+        __put_user_error(regs->ARM_r1, &sc->arm_r1, err);
+        __put_user_error(regs->ARM_r2, &sc->arm_r2, err);
+        __put_user_error(regs->ARM_r3, &sc->arm_r3, err);
+        __put_user_error(regs->ARM_r4, &sc->arm_r4, err);
+        __put_user_error(regs->ARM_r5, &sc->arm_r5, err);
+        __put_user_error(regs->ARM_r6, &sc->arm_r6, err);
+        __put_user_error(regs->ARM_r7, &sc->arm_r7, err);
+        __put_user_error(regs->ARM_r8, &sc->arm_r8, err);
+        __put_user_error(regs->ARM_r9, &sc->arm_r9, err);
+        __put_user_error(regs->ARM_r10, &sc->arm_r10, err);
+        __put_user_error(regs->ARM_fp, &sc->arm_fp, err);
+        __put_user_error(regs->ARM_ip, &sc->arm_ip, err);
+        __put_user_error(regs->ARM_sp, &sc->arm_sp, err);
+        __put_user_error(regs->ARM_lr, &sc->arm_lr, err);
+        __put_user_error(regs->ARM_pc, &sc->arm_pc, err);
+
+        __put_user_error(current->thread.trap_no, &sc->trap_no, err);
+        __put_user_error(current->thread.error_code, &sc->error_code, err);
+        __put_user_error(current->thread.address, &sc->fault_address, err);
+        __put_user_error(mask, &sc->oldmask, err);
+
+        return err;
+}
+
+static inline void *
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
+{
+        unsigned long sp = regs->ARM_sp;
+
+        /*
+         * This is the X/Open sanctioned signal stack switching.
+         */
+        if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
+                sp = current->sas_ss_sp + current->sas_ss_size;
+
+        /*
+         * ATPCS B01 mandates 8-byte alignment
+         */
+        return (void *)((sp - framesize) & ~7);
+}
+
+static int
+setup_return(struct pt_regs *regs, struct k_sigaction *ka,
+             unsigned long *rc, void *frame, int usig)
+{
+        unsigned long handler = (unsigned long)ka->sa.sa_handler;
+        unsigned long retcode;
+
+        if (ka->sa.sa_flags & SA_RESTORER) {
+                retcode = (unsigned long)ka->sa.sa_restorer;
+        } else {
+
+                if (__put_user((ka->sa.sa_flags & SA_SIGINFO)?SWI_SYS_RT_SIGRETURN:SWI_SYS_SIGRETURN, rc))
+                        return 1;
+
+                retcode = ((unsigned long)rc);
+        }
+
+        regs->ARM_r0 = usig;
+        regs->ARM_sp = (unsigned long)frame;
+        regs->ARM_lr = retcode;
+        regs->ARM_pc = handler & ~3;
+
+        return 0;
+}
+
+static int
+setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs)
+{
+        struct sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
+        int err = 0;
+
+        if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+                return 1;
+
+        err |= setup_sigcontext(&frame->sc, /*&frame->fpstate,*/ regs, set->sig[0]);
+
+        if (_NSIG_WORDS > 1) {
+                err |= __copy_to_user(frame->extramask, &set->sig[1],
+                                      sizeof(frame->extramask));
+        }
+
+        if (err == 0)
+                err = setup_return(regs, ka, &frame->retcode, frame, usig);
+
+        return err;
+}
+
+static int
+setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info,
+               sigset_t *set, struct pt_regs *regs)
+{
+        struct rt_sigframe *frame = get_sigframe(ka, regs, sizeof(*frame));
+        int err = 0;
+
+        if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+                return 1;
+
+        __put_user_error(&frame->info, &frame->pinfo, err);
+        __put_user_error(&frame->uc, &frame->puc, err);
+        err |= copy_siginfo_to_user(&frame->info, info);
+
+        /* Clear all the bits of the ucontext we don't use.  */
+        err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
+
+        err |= setup_sigcontext(&frame->uc.uc_mcontext, /*&frame->fpstate,*/
+                                regs, set->sig[0]);
+        err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+        if (err == 0)
+                err = setup_return(regs, ka, &frame->retcode, frame, usig);
+
+        if (err == 0) {
+                /*
+                 * For realtime signals we must also set the second and third
+                 * arguments for the signal handler.
+                 *   -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
+                 */
+                regs->ARM_r1 = (unsigned long)frame->pinfo;
+                regs->ARM_r2 = (unsigned long)frame->puc;
+        }
+
+        return err;
+}
+
+static inline void restart_syscall(struct pt_regs *regs)
+{
+        regs->ARM_r0 = regs->ARM_ORIG_r0;
+        regs->ARM_pc -= 4;
+}
+
+/*
+ * OK, we're invoking a handler
+ */     
+static void
+handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
+              struct pt_regs * regs, int syscall)
+{
+        struct thread_info *thread = current_thread_info();
+        struct task_struct *tsk = current;
+        struct k_sigaction *ka = &tsk->sighand->action[sig-1];
+        int usig = sig;
+        int ret;
+
+        /*
+         * If we were from a system call, check for system call restarting...
+         */
+        if (syscall) {
+                switch (regs->ARM_r0) {
+                case -ERESTART_RESTARTBLOCK:
+                        current_thread_info()->restart_block.fn =
+                                do_no_restart_syscall;
+                case -ERESTARTNOHAND:
+                        regs->ARM_r0 = -EINTR;
+                        break;
+                case -ERESTARTSYS:
+                        if (!(ka->sa.sa_flags & SA_RESTART)) {
+                                regs->ARM_r0 = -EINTR;
+                                break;
+                        }
+                        /* fallthrough */
+                case -ERESTARTNOINTR:
+                        restart_syscall(regs);
+                }
+        }
+
+        /*
+         * translate the signal
+         */
+        if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
+                usig = thread->exec_domain->signal_invmap[usig];
+
+        /*
+         * Set up the stack frame
+         */
+        if (ka->sa.sa_flags & SA_SIGINFO)
+                ret = setup_rt_frame(usig, ka, info, oldset, regs);
+        else
+                ret = setup_frame(usig, ka, oldset, regs);
+
+        /*
+         * Check that the resulting registers are actually sane.
+         */
+        ret |= !valid_user_regs(regs);
+
+        if (ret == 0) {
+                if (ka->sa.sa_flags & SA_ONESHOT)
+                        ka->sa.sa_handler = SIG_DFL;
+
+                if (!(ka->sa.sa_flags & SA_NODEFER)) {
+                        spin_lock_irq(&tsk->sighand->siglock);
+                        sigorsets(&tsk->blocked, &tsk->blocked,
+                                  &ka->sa.sa_mask);
+                        sigaddset(&tsk->blocked, sig);
+                        recalc_sigpending();
+                        spin_unlock_irq(&tsk->sighand->siglock);
+                }
+                return;
+        }
+
+        force_sigsegv(sig, tsk);
+}
+
+/*
+ * 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.
+ */
+static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
+{
+        siginfo_t info;
+        int signr;
+
+        /*
+         * 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 0;
+
+        if (current->ptrace & PT_SINGLESTEP)
+                ptrace_cancel_bpt(current);
+        
+        signr = get_signal_to_deliver(&info, regs, NULL);
+        if (signr > 0) {
+                handle_signal(signr, &info, oldset, regs, syscall);
+                if (current->ptrace & PT_SINGLESTEP)
+                        ptrace_set_bpt(current);
+                return 1;
+        }
+
+        /*
+         * No signal to deliver to the process - restart the syscall.
+         */
+        if (syscall) {
+                if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
+                        u32 *usp;
+
+                        regs->ARM_sp -= 12;
+                        usp = (u32 *)regs->ARM_sp;
+
+                        put_user(regs->ARM_pc, &usp[0]);
+                        /* swi __NR_restart_syscall */
+                        put_user(0xef000000 | __NR_restart_syscall, &usp[1]);
+                        /* ldr  pc, [sp], #12 */
+// FIXME!!! is #12 correct there?
+                        put_user(0xe49df00c, &usp[2]);
+
+                        regs->ARM_pc = regs->ARM_sp + 4;
+                }
+                if (regs->ARM_r0 == -ERESTARTNOHAND ||
+                    regs->ARM_r0 == -ERESTARTSYS ||
+                    regs->ARM_r0 == -ERESTARTNOINTR) {
+                        restart_syscall(regs);
+                }
+        }
+        if (current->ptrace & PT_SINGLESTEP)
+                ptrace_set_bpt(current);
+        return 0;
+}
+
+asmlinkage void
+do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
+{
+        if (thread_flags & _TIF_SIGPENDING)
+                do_signal(&current->blocked, regs, syscall);
+}