--- /dev/null
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * Based on linux/arch/sh/kernel/signal.c
+ * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * 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/sched.h>
+#include <linux/mm.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/freezer.h>
+
+#include <asm/uaccess.h>
+#include <asm/ucontext.h>
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
+ struct pt_regs *regs)
+{
+ return do_sigaltstack(uss, uoss, regs->sp);
+}
+
+struct rt_sigframe
+{
+ struct siginfo info;
+ struct ucontext uc;
+ unsigned long retcode;
+};
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+ int err = 0;
+
+#define COPY(x) err |= __get_user(regs->x, &sc->x)
+ COPY(sr);
+ COPY(pc);
+ COPY(lr);
+ COPY(sp);
+ COPY(r12);
+ COPY(r11);
+ COPY(r10);
+ COPY(r9);
+ COPY(r8);
+ COPY(r7);
+ COPY(r6);
+ COPY(r5);
+ COPY(r4);
+ COPY(r3);
+ COPY(r2);
+ COPY(r1);
+ COPY(r0);
+#undef COPY
+
+ /*
+ * Don't allow anyone to pretend they're running in supervisor
+ * mode or something...
+ */
+ err |= !valid_user_regs(regs);
+
+ return err;
+}
+
+
+asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+ sigset_t set;
+
+ frame = (struct rt_sigframe __user *)regs->sp;
+ pr_debug("SIG return: frame = %p\n", frame);
+
+ 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(¤t->sighand->siglock);
+ current->blocked = set;
+ recalc_sigpending();
+ spin_unlock_irq(¤t->sighand->siglock);
+
+ if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
+ goto badframe;
+
+ pr_debug("Context restored: pc = %08lx, lr = %08lx, sp = %08lx\n",
+ regs->pc, regs->lr, regs->sp);
+
+ return regs->r12;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+static int
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
+{
+ int err = 0;
+
+#define COPY(x) err |= __put_user(regs->x, &sc->x)
+ COPY(sr);
+ COPY(pc);
+ COPY(lr);
+ COPY(sp);
+ COPY(r12);
+ COPY(r11);
+ COPY(r10);
+ COPY(r9);
+ COPY(r8);
+ COPY(r7);
+ COPY(r6);
+ COPY(r5);
+ COPY(r4);
+ COPY(r3);
+ COPY(r2);
+ COPY(r1);
+ COPY(r0);
+#undef COPY
+
+ return err;
+}
+
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
+{
+ unsigned long sp = regs->sp;
+
+ if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
+ sp = current->sas_ss_sp + current->sas_ss_size;
+
+ return (void __user *)((sp - framesize) & ~3);
+}
+
+static int
+setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *set, struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+ int err = 0;
+
+ frame = get_sigframe(ka, regs, sizeof(*frame));
+ err = -EFAULT;
+ if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+ goto out;
+
+ /*
+ * Set up the return code:
+ *
+ * mov r8, __NR_rt_sigreturn
+ * scall
+ *
+ * Note: This will blow up since we're using a non-executable
+ * stack. Better use SA_RESTORER.
+ */
+#if __NR_rt_sigreturn > 127
+# error __NR_rt_sigreturn must be < 127 to fit in a short mov
+#endif
+ err = __put_user(0x3008d733 | (__NR_rt_sigreturn << 20),
+ &frame->retcode);
+
+ err |= copy_siginfo_to_user(&frame->info, info);
+
+ /* Set up the ucontext */
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(NULL, &frame->uc.uc_link);
+ err |= __put_user((void __user *)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 out;
+
+ regs->r12 = sig;
+ regs->r11 = (unsigned long) &frame->info;
+ regs->r10 = (unsigned long) &frame->uc;
+ regs->sp = (unsigned long) frame;
+ if (ka->sa.sa_flags & SA_RESTORER)
+ regs->lr = (unsigned long)ka->sa.sa_restorer;
+ else {
+ printk(KERN_NOTICE "[%s:%d] did not set SA_RESTORER\n",
+ current->comm, current->pid);
+ regs->lr = (unsigned long) &frame->retcode;
+ }
+
+ pr_debug("SIG deliver [%s:%d]: sig=%d sp=0x%lx pc=0x%lx->0x%p lr=0x%lx\n",
+ current->comm, current->pid, sig, regs->sp,
+ regs->pc, ka->sa.sa_handler, regs->lr);
+
+ regs->pc = (unsigned long) ka->sa.sa_handler;
+
+out:
+ return err;
+}
+
+static inline void restart_syscall(struct pt_regs *regs)
+{
+ if (regs->r12 == -ERESTART_RESTARTBLOCK)
+ regs->r8 = __NR_restart_syscall;
+ else
+ regs->r12 = regs->r12_orig;
+ regs->pc -= 2;
+}
+
+static inline void
+handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *oldset, struct pt_regs *regs, int syscall)
+{
+ int ret;
+
+ /*
+ * Set up the stack frame
+ */
+ ret = setup_rt_frame(sig, ka, info, oldset, regs);
+
+ /*
+ * Check that the resulting registers are sane
+ */
+ ret |= !valid_user_regs(regs);
+
+ /*
+ * Block the signal if we were unsuccessful.
+ */
+ if (ret != 0 || !(ka->sa.sa_flags & SA_NODEFER)) {
+ spin_lock_irq(¤t->sighand->siglock);
+ sigorsets(¤t->blocked, ¤t->blocked,
+ &ka->sa.sa_mask);
+ sigaddset(¤t->blocked, sig);
+ recalc_sigpending();
+ spin_unlock_irq(¤t->sighand->siglock);
+ }
+
+ if (ret == 0)
+ return;
+
+ force_sigsegv(sig, current);
+}
+
+/*
+ * 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(struct pt_regs *regs, sigset_t *oldset, int syscall)
+{
+ siginfo_t info;
+ int signr;
+ struct k_sigaction ka;
+
+ /*
+ * 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 (try_to_freeze()) {
+ signr = 0;
+ if (!signal_pending(current))
+ goto no_signal;
+ }
+
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ oldset = ¤t->saved_sigmask;
+ else if (!oldset)
+ oldset = ¤t->blocked;
+
+ signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+no_signal:
+ if (syscall) {
+ switch (regs->r12) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ if (signr > 0) {
+ regs->r12 = -EINTR;
+ break;
+ }
+ /* fall through */
+ case -ERESTARTSYS:
+ if (signr > 0 && !(ka.sa.sa_flags & SA_RESTART)) {
+ regs->r12 = -EINTR;
+ break;
+ }
+ /* fall through */
+ case -ERESTARTNOINTR:
+ restart_syscall(regs);
+ }
+ }
+
+ if (signr == 0) {
+ /* No signal to deliver -- put the saved sigmask back */
+ if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+ sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
+ }
+ return 0;
+ }
+
+ handle_signal(signr, &ka, &info, oldset, regs, syscall);
+ return 1;
+}
+
+asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti)
+{
+ int syscall = 0;
+
+ if ((sysreg_read(SR) & MODE_MASK) == MODE_SUPERVISOR)
+ syscall = 1;
+
+ if (ti->flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+ do_signal(regs, ¤t->blocked, syscall);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff