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-rw-r--r--arch/ppc/kernel/signal.c775
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;
+}
+