Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 775 insertions, 0 deletions

diff --git a/arch/ppc/kernel/signal.c b/arch/ppc/kernel/signal.c
new file mode 100644
index 000000000000..9567d3041ea7
--- /dev/null
+++ b/arch/ppc/kernel/signal.c
@@ -0,0 +1,775 @@
+/*
+ *  arch/ppc/kernel/signal.c
+ *
+ *  PowerPC version
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ *  Derived from "arch/i386/kernel/signal.c"
+ *    Copyright (C) 1991, 1992 Linus Torvalds
+ *    1997-11-28  Modified for POSIX.1b signals by Richard Henderson
+ *
+ *  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; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+
+#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/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/elf.h>
+#include <linux/tty.h>
+#include <linux/binfmts.h>
+#include <linux/suspend.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+
+#undef DEBUG_SIG
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+extern void sigreturn_exit(struct pt_regs *);
+
+#define GP_REGS_SIZE    min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
+
+int do_signal(sigset_t *oldset, struct pt_regs *regs);
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+int
+sys_sigsuspend(old_sigset_t mask, int p2, int p3, int p4, int p6, int p7,
+               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->result = -EINTR;
+        regs->gpr[3] = EINTR;
+        regs->ccr |= 0x10000000;
+        while (1) {
+                current->state = TASK_INTERRUPTIBLE;
+                schedule();
+                if (do_signal(&saveset, regs))
+                        sigreturn_exit(regs);
+        }
+}
+
+int
+sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, int p3, int p4,
+                  int p6, int p7, 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->result = -EINTR;
+        regs->gpr[3] = EINTR;
+        regs->ccr |= 0x10000000;
+        while (1) {
+                current->state = TASK_INTERRUPTIBLE;
+                schedule();
+                if (do_signal(&saveset, regs))
+                        sigreturn_exit(regs);
+        }
+}
+
+
+int
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, int r5,
+                int r6, int r7, int r8, struct pt_regs *regs)
+{
+        return do_sigaltstack(uss, uoss, regs->gpr[1]);
+}
+
+int
+sys_sigaction(int sig, const struct old_sigaction __user *act,
+              struct old_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_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;
+}
+
+/*
+ * When we have signals to deliver, we set up on the
+ * user stack, going down from the original stack pointer:
+ *      a sigregs struct
+ *      a sigcontext struct
+ *      a gap of __SIGNAL_FRAMESIZE bytes
+ *
+ * Each of these things must be a multiple of 16 bytes in size.
+ *
+ */
+struct sigregs {
+        struct mcontext mctx;           /* all the register values */
+        /* Programs using the rs6000/xcoff abi can save up to 19 gp regs
+           and 18 fp regs below sp before decrementing it. */
+        int             abigap[56];
+};
+
+/* We use the mc_pad field for the signal return trampoline. */
+#define tramp   mc_pad
+
+/*
+ *  When we have rt signals to deliver, we set up on the
+ *  user stack, going down from the original stack pointer:
+ *      one rt_sigframe struct (siginfo + ucontext + ABI gap)
+ *      a gap of __SIGNAL_FRAMESIZE+16 bytes
+ *  (the +16 is to get the siginfo and ucontext in the same
+ *  positions as in older kernels).
+ *
+ *  Each of these things must be a multiple of 16 bytes in size.
+ *
+ */
+struct rt_sigframe
+{
+        struct siginfo info;
+        struct ucontext uc;
+        /* Programs using the rs6000/xcoff abi can save up to 19 gp regs
+           and 18 fp regs below sp before decrementing it. */
+        int             abigap[56];
+};
+
+/*
+ * Save the current user registers on the user stack.
+ * We only save the altivec/spe registers if the process has used
+ * altivec/spe instructions at some point.
+ */
+static int
+save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, int sigret)
+{
+        /* save general and floating-point registers */
+        CHECK_FULL_REGS(regs);
+        preempt_disable();
+        if (regs->msr & MSR_FP)
+                giveup_fpu(current);
+#ifdef CONFIG_ALTIVEC
+        if (current->thread.used_vr && (regs->msr & MSR_VEC))
+                giveup_altivec(current);
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_SPE
+        if (current->thread.used_spe && (regs->msr & MSR_SPE))
+                giveup_spe(current);
+#endif /* CONFIG_ALTIVEC */
+        preempt_enable();
+
+        if (__copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE)
+            || __copy_to_user(&frame->mc_fregs, current->thread.fpr,
+                              ELF_NFPREG * sizeof(double)))
+                return 1;
+
+        current->thread.fpscr = 0;      /* turn off all fp exceptions */
+
+#ifdef CONFIG_ALTIVEC
+        /* save altivec registers */
+        if (current->thread.used_vr) {
+                if (__copy_to_user(&frame->mc_vregs, current->thread.vr,
+                                   ELF_NVRREG * sizeof(vector128)))
+                        return 1;
+                /* set MSR_VEC in the saved MSR value to indicate that
+                   frame->mc_vregs contains valid data */
+                if (__put_user(regs->msr | MSR_VEC, &frame->mc_gregs[PT_MSR]))
+                        return 1;
+        }
+        /* else assert((regs->msr & MSR_VEC) == 0) */
+
+        /* We always copy to/from vrsave, it's 0 if we don't have or don't
+         * use altivec. Since VSCR only contains 32 bits saved in the least
+         * significant bits of a vector, we "cheat" and stuff VRSAVE in the
+         * most significant bits of that same vector. --BenH
+         */
+        if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
+                return 1;
+#endif /* CONFIG_ALTIVEC */
+
+#ifdef CONFIG_SPE
+        /* save spe registers */
+        if (current->thread.used_spe) {
+                if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
+                                   ELF_NEVRREG * sizeof(u32)))
+                        return 1;
+                /* set MSR_SPE in the saved MSR value to indicate that
+                   frame->mc_vregs contains valid data */
+                if (__put_user(regs->msr | MSR_SPE, &frame->mc_gregs[PT_MSR]))
+                        return 1;
+        }
+        /* else assert((regs->msr & MSR_SPE) == 0) */
+
+        /* We always copy to/from spefscr */
+        if (__put_user(current->thread.spefscr, (u32 *)&frame->mc_vregs + ELF_NEVRREG))
+                return 1;
+#endif /* CONFIG_SPE */
+
+        if (sigret) {
+                /* Set up the sigreturn trampoline: li r0,sigret; sc */
+                if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
+                    || __put_user(0x44000002UL, &frame->tramp[1]))
+                        return 1;
+                flush_icache_range((unsigned long) &frame->tramp[0],
+                                   (unsigned long) &frame->tramp[2]);
+        }
+
+        return 0;
+}
+
+/*
+ * Restore the current user register values from the user stack,
+ * (except for MSR).
+ */
+static int
+restore_user_regs(struct pt_regs *regs, struct mcontext __user *sr, int sig)
+{
+        unsigned long save_r2 = 0;
+#if defined(CONFIG_ALTIVEC) || defined(CONFIG_SPE)
+        unsigned long msr;
+#endif
+
+        /* backup/restore the TLS as we don't want it to be modified */
+        if (!sig)
+                save_r2 = regs->gpr[2];
+        /* copy up to but not including MSR */
+        if (__copy_from_user(regs, &sr->mc_gregs, PT_MSR * sizeof(elf_greg_t)))
+                return 1;
+        /* copy from orig_r3 (the word after the MSR) up to the end */
+        if (__copy_from_user(&regs->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3],
+                             GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t)))
+                return 1;
+        if (!sig)
+                regs->gpr[2] = save_r2;
+
+        /* force the process to reload the FP registers from
+           current->thread when it next does FP instructions */
+        regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);
+        if (__copy_from_user(current->thread.fpr, &sr->mc_fregs,
+                             sizeof(sr->mc_fregs)))
+                return 1;
+
+#ifdef CONFIG_ALTIVEC
+        /* force the process to reload the altivec registers from
+           current->thread when it next does altivec instructions */
+        regs->msr &= ~MSR_VEC;
+        if (!__get_user(msr, &sr->mc_gregs[PT_MSR]) && (msr & MSR_VEC) != 0) {
+                /* restore altivec registers from the stack */
+                if (__copy_from_user(current->thread.vr, &sr->mc_vregs,
+                                     sizeof(sr->mc_vregs)))
+                        return 1;
+        } else if (current->thread.used_vr)
+                memset(&current->thread.vr, 0, ELF_NVRREG * sizeof(vector128));
+
+        /* Always get VRSAVE back */
+        if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32]))
+                return 1;
+#endif /* CONFIG_ALTIVEC */
+
+#ifdef CONFIG_SPE
+        /* force the process to reload the spe registers from
+           current->thread when it next does spe instructions */
+        regs->msr &= ~MSR_SPE;
+        if (!__get_user(msr, &sr->mc_gregs[PT_MSR]) && (msr & MSR_SPE) != 0) {
+                /* restore spe registers from the stack */
+                if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
+                                     ELF_NEVRREG * sizeof(u32)))
+                        return 1;
+        } else if (current->thread.used_spe)
+                memset(&current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
+
+        /* Always get SPEFSCR back */
+        if (__get_user(current->thread.spefscr, (u32 *)&sr->mc_vregs + ELF_NEVRREG))
+                return 1;
+#endif /* CONFIG_SPE */
+
+#ifndef CONFIG_SMP
+        preempt_disable();
+        if (last_task_used_math == current)
+                last_task_used_math = NULL;
+        if (last_task_used_altivec == current)
+                last_task_used_altivec = NULL;
+        if (last_task_used_spe == current)
+                last_task_used_spe = NULL;
+        preempt_enable();
+#endif
+        return 0;
+}
+
+/*
+ * Restore the user process's signal mask
+ */
+static void
+restore_sigmask(sigset_t *set)
+{
+        sigdelsetmask(set, ~_BLOCKABLE);
+        spin_lock_irq(&current->sighand->siglock);
+        current->blocked = *set;
+        recalc_sigpending();
+        spin_unlock_irq(&current->sighand->siglock);
+}
+
+/*
+ * Set up a signal frame for a "real-time" signal handler
+ * (one which gets siginfo).
+ */
+static void
+handle_rt_signal(unsigned long sig, struct k_sigaction *ka,
+                 siginfo_t *info, sigset_t *oldset, struct pt_regs * regs,
+                 unsigned long newsp)
+{
+        struct rt_sigframe __user *rt_sf;
+        struct mcontext __user *frame;
+        unsigned long origsp = newsp;
+
+        /* Set up Signal Frame */
+        /* Put a Real Time Context onto stack */
+        newsp -= sizeof(*rt_sf);
+        rt_sf = (struct rt_sigframe __user *) newsp;
+
+        /* create a stack frame for the caller of the handler */
+        newsp -= __SIGNAL_FRAMESIZE + 16;
+
+        if (!access_ok(VERIFY_WRITE, (void __user *) newsp, origsp - newsp))
+                goto badframe;
+
+        /* Put the siginfo & fill in most of the ucontext */
+        if (copy_siginfo_to_user(&rt_sf->info, info)
+            || __put_user(0, &rt_sf->uc.uc_flags)
+            || __put_user(0, &rt_sf->uc.uc_link)
+            || __put_user(current->sas_ss_sp, &rt_sf->uc.uc_stack.ss_sp)
+            || __put_user(sas_ss_flags(regs->gpr[1]),
+                          &rt_sf->uc.uc_stack.ss_flags)
+            || __put_user(current->sas_ss_size, &rt_sf->uc.uc_stack.ss_size)
+            || __put_user(&rt_sf->uc.uc_mcontext, &rt_sf->uc.uc_regs)
+            || __copy_to_user(&rt_sf->uc.uc_sigmask, oldset, sizeof(*oldset)))
+                goto badframe;
+
+        /* Save user registers on the stack */
+        frame = &rt_sf->uc.uc_mcontext;
+        if (save_user_regs(regs, frame, __NR_rt_sigreturn))
+                goto badframe;
+
+        if (put_user(regs->gpr[1], (unsigned long __user *)newsp))
+                goto badframe;
+        regs->gpr[1] = newsp;
+        regs->gpr[3] = sig;
+        regs->gpr[4] = (unsigned long) &rt_sf->info;
+        regs->gpr[5] = (unsigned long) &rt_sf->uc;
+        regs->gpr[6] = (unsigned long) rt_sf;
+        regs->nip = (unsigned long) ka->sa.sa_handler;
+        regs->link = (unsigned long) frame->tramp;
+        regs->trap = 0;
+
+        return;
+
+badframe:
+#ifdef DEBUG_SIG
+        printk("badframe in handle_rt_signal, regs=%p frame=%p newsp=%lx\n",
+               regs, frame, newsp);
+#endif
+        force_sigsegv(sig, current);
+}
+
+static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
+{
+        sigset_t set;
+        struct mcontext __user *mcp;
+
+        if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(set))
+            || __get_user(mcp, &ucp->uc_regs))
+                return -EFAULT;
+        restore_sigmask(&set);
+        if (restore_user_regs(regs, mcp, sig))
+                return -EFAULT;
+
+        return 0;
+}
+
+int sys_swapcontext(struct ucontext __user *old_ctx,
+                    struct ucontext __user *new_ctx,
+                    int ctx_size, int r6, int r7, int r8, struct pt_regs *regs)
+{
+        unsigned char tmp;
+
+        /* Context size is for future use. Right now, we only make sure
+         * we are passed something we understand
+         */
+        if (ctx_size < sizeof(struct ucontext))
+                return -EINVAL;
+
+        if (old_ctx != NULL) {
+                if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
+                    || save_user_regs(regs, &old_ctx->uc_mcontext, 0)
+                    || __copy_to_user(&old_ctx->uc_sigmask,
+                                      &current->blocked, sizeof(sigset_t))
+                    || __put_user(&old_ctx->uc_mcontext, &old_ctx->uc_regs))
+                        return -EFAULT;
+        }
+        if (new_ctx == NULL)
+                return 0;
+        if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
+            || __get_user(tmp, (u8 __user *) new_ctx)
+            || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
+                return -EFAULT;
+
+        /*
+         * If we get a fault copying the context into the kernel's
+         * image of the user's registers, we can't just return -EFAULT
+         * because the user's registers will be corrupted.  For instance
+         * the NIP value may have been updated but not some of the
+         * other registers.  Given that we have done the access_ok
+         * and successfully read the first and last bytes of the region
+         * above, this should only happen in an out-of-memory situation
+         * or if another thread unmaps the region containing the context.
+         * We kill the task with a SIGSEGV in this situation.
+         */
+        if (do_setcontext(new_ctx, regs, 0))
+                do_exit(SIGSEGV);
+        sigreturn_exit(regs);
+        /* doesn't actually return back to here */
+        return 0;
+}
+
+int sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
+                     struct pt_regs *regs)
+{
+        struct rt_sigframe __user *rt_sf;
+
+        /* Always make any pending restarted system calls return -EINTR */
+        current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+        rt_sf = (struct rt_sigframe __user *)
+                (regs->gpr[1] + __SIGNAL_FRAMESIZE + 16);
+        if (!access_ok(VERIFY_READ, rt_sf, sizeof(struct rt_sigframe)))
+                goto bad;
+        if (do_setcontext(&rt_sf->uc, regs, 1))
+                goto bad;
+
+        /*
+         * It's not clear whether or why it is desirable to save the
+         * sigaltstack setting on signal delivery and restore it on
+         * signal return.  But other architectures do this and we have
+         * always done it up until now so it is probably better not to
+         * change it.  -- paulus
+         */
+        do_sigaltstack(&rt_sf->uc.uc_stack, NULL, regs->gpr[1]);
+
+        sigreturn_exit(regs);           /* doesn't return here */
+        return 0;
+
+ bad:
+        force_sig(SIGSEGV, current);
+        return 0;
+}
+
+int sys_debug_setcontext(struct ucontext __user *ctx,
+                         int ndbg, struct sig_dbg_op *dbg,
+                         int r6, int r7, int r8,
+                         struct pt_regs *regs)
+{
+        struct sig_dbg_op op;
+        int i;
+        unsigned long new_msr = regs->msr;
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+        unsigned long new_dbcr0 = current->thread.dbcr0;
+#endif
+
+        for (i=0; i<ndbg; i++) {
+                if (__copy_from_user(&op, dbg, sizeof(op)))
+                        return -EFAULT;
+                switch (op.dbg_type) {
+                case SIG_DBG_SINGLE_STEPPING:
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+                        if (op.dbg_value) {
+                                new_msr |= MSR_DE;
+                                new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
+                        } else {
+                                new_msr &= ~MSR_DE;
+                                new_dbcr0 &= ~(DBCR0_IDM | DBCR0_IC);
+                        }
+#else
+                        if (op.dbg_value)
+                                new_msr |= MSR_SE;
+                        else
+                                new_msr &= ~MSR_SE;
+#endif
+                        break;
+                case SIG_DBG_BRANCH_TRACING:
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+                        return -EINVAL;
+#else
+                        if (op.dbg_value)
+                                new_msr |= MSR_BE;
+                        else
+                                new_msr &= ~MSR_BE;
+#endif
+                        break;
+
+                default:
+                        return -EINVAL;
+                }
+        }
+
+        /* We wait until here to actually install the values in the
+           registers so if we fail in the above loop, it will not
+           affect the contents of these registers.  After this point,
+           failure is a problem, anyway, and it's very unlikely unless
+           the user is really doing something wrong. */
+        regs->msr = new_msr;
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+        current->thread.dbcr0 = new_dbcr0;
+#endif
+
+        /*
+         * If we get a fault copying the context into the kernel's
+         * image of the user's registers, we can't just return -EFAULT
+         * because the user's registers will be corrupted.  For instance
+         * the NIP value may have been updated but not some of the
+         * other registers.  Given that we have done the access_ok
+         * and successfully read the first and last bytes of the region
+         * above, this should only happen in an out-of-memory situation
+         * or if another thread unmaps the region containing the context.
+         * We kill the task with a SIGSEGV in this situation.
+         */
+        if (do_setcontext(ctx, regs, 1)) {
+                force_sig(SIGSEGV, current);
+                goto out;
+        }
+
+        /*
+         * It's not clear whether or why it is desirable to save the
+         * sigaltstack setting on signal delivery and restore it on
+         * signal return.  But other architectures do this and we have
+         * always done it up until now so it is probably better not to
+         * change it.  -- paulus
+         */
+        do_sigaltstack(&ctx->uc_stack, NULL, regs->gpr[1]);
+
+        sigreturn_exit(regs);
+        /* doesn't actually return back to here */
+
+ out:
+        return 0;
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static void
+handle_signal(unsigned long sig, struct k_sigaction *ka,
+              siginfo_t *info, sigset_t *oldset, struct pt_regs * regs,
+              unsigned long newsp)
+{
+        struct sigcontext __user *sc;
+        struct sigregs __user *frame;
+        unsigned long origsp = newsp;
+
+        /* Set up Signal Frame */
+        newsp -= sizeof(struct sigregs);
+        frame = (struct sigregs __user *) newsp;
+
+        /* Put a sigcontext on the stack */
+        newsp -= sizeof(*sc);
+        sc = (struct sigcontext __user *) newsp;
+
+        /* create a stack frame for the caller of the handler */
+        newsp -= __SIGNAL_FRAMESIZE;
+
+        if (!access_ok(VERIFY_WRITE, (void __user *) newsp, origsp - newsp))
+                goto badframe;
+
+#if _NSIG != 64
+#error "Please adjust handle_signal()"
+#endif
+        if (__put_user((unsigned long) ka->sa.sa_handler, &sc->handler)
+            || __put_user(oldset->sig[0], &sc->oldmask)
+            || __put_user(oldset->sig[1], &sc->_unused[3])
+            || __put_user((struct pt_regs *)frame, &sc->regs)
+            || __put_user(sig, &sc->signal))
+                goto badframe;
+
+        if (save_user_regs(regs, &frame->mctx, __NR_sigreturn))
+                goto badframe;
+
+        if (put_user(regs->gpr[1], (unsigned long __user *)newsp))
+                goto badframe;
+        regs->gpr[1] = newsp;
+        regs->gpr[3] = sig;
+        regs->gpr[4] = (unsigned long) sc;
+        regs->nip = (unsigned long) ka->sa.sa_handler;
+        regs->link = (unsigned long) frame->mctx.tramp;
+        regs->trap = 0;
+
+        return;
+
+badframe:
+#ifdef DEBUG_SIG
+        printk("badframe in handle_signal, regs=%p frame=%p newsp=%lx\n",
+               regs, frame, newsp);
+#endif
+        force_sigsegv(sig, current);
+}
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+int sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
+                  struct pt_regs *regs)
+{
+        struct sigcontext __user *sc;
+        struct sigcontext sigctx;
+        struct mcontext __user *sr;
+        sigset_t set;
+
+        /* Always make any pending restarted system calls return -EINTR */
+        current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+        sc = (struct sigcontext __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
+        if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
+                goto badframe;
+
+        set.sig[0] = sigctx.oldmask;
+        set.sig[1] = sigctx._unused[3];
+        restore_sigmask(&set);
+
+        sr = (struct mcontext __user *) sigctx.regs;
+        if (!access_ok(VERIFY_READ, sr, sizeof(*sr))
+            || restore_user_regs(regs, sr, 1))
+                goto badframe;
+
+        sigreturn_exit(regs);           /* doesn't return */
+        return 0;
+
+badframe:
+        force_sig(SIGSEGV, current);
+        return 0;
+}
+
+/*
+ * 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.
+ */
+int do_signal(sigset_t *oldset, struct pt_regs *regs)
+{
+        siginfo_t info;
+        struct k_sigaction ka;
+        unsigned long frame, newsp;
+        int signr, ret;
+
+        if (current->flags & PF_FREEZE) {
+                refrigerator(PF_FREEZE);
+                signr = 0;
+                ret = regs->gpr[3];
+                if (!signal_pending(current))
+                        goto no_signal;
+        }
+
+        if (!oldset)
+                oldset = &current->blocked;
+
+        newsp = frame = 0;
+
+        signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+
+        if (TRAP(regs) == 0x0C00                /* System Call! */
+            && regs->ccr & 0x10000000           /* error signalled */
+            && ((ret = regs->gpr[3]) == ERESTARTSYS
+                || ret == ERESTARTNOHAND || ret == ERESTARTNOINTR
+                || ret == ERESTART_RESTARTBLOCK)) {
+
+                if (signr > 0
+                    && (ret == ERESTARTNOHAND || ret == ERESTART_RESTARTBLOCK
+                        || (ret == ERESTARTSYS
+                            && !(ka.sa.sa_flags & SA_RESTART)))) {
+                        /* make the system call return an EINTR error */
+                        regs->result = -EINTR;
+                        regs->gpr[3] = EINTR;
+                        /* note that the cr0.SO bit is already set */
+                } else {
+no_signal:
+                        regs->nip -= 4; /* Back up & retry system call */
+                        regs->result = 0;
+                        regs->trap = 0;
+                        if (ret == ERESTART_RESTARTBLOCK)
+                                regs->gpr[0] = __NR_restart_syscall;
+                        else
+                                regs->gpr[3] = regs->orig_gpr3;
+                }
+        }
+
+        if (signr == 0)
+                return 0;               /* no signals delivered */
+
+        if ((ka.sa.sa_flags & SA_ONSTACK) && current->sas_ss_size
+            && !on_sig_stack(regs->gpr[1]))
+                newsp = current->sas_ss_sp + current->sas_ss_size;
+        else
+                newsp = regs->gpr[1];
+        newsp &= ~0xfUL;
+
+        /* Whee!  Actually deliver the signal.  */
+        if (ka.sa.sa_flags & SA_SIGINFO)
+                handle_rt_signal(signr, &ka, &info, oldset, regs, newsp);
+        else
+                handle_signal(signr, &ka, &info, oldset, regs, newsp);
+
+        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, signr);
+                recalc_sigpending();
+                spin_unlock_irq(&current->sighand->siglock);
+        }
+
+        return 1;
+}
+