--- /dev/null
+/* signal.c: FRV specific bits of signal handling
+ *
+ * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * - Derived from arch/m68k/kernel/signal.c
+ *
+ * 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/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/personality.h>
+#include <linux/tracehook.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/cacheflush.h>
+
+#define DEBUG_SIG 0
+
+struct fdpic_func_descriptor {
+ unsigned long text;
+ unsigned long GOT;
+};
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+struct sigframe
+{
+ __sigrestore_t pretcode;
+ int sig;
+ struct sigcontext sc;
+ unsigned long extramask[_NSIG_WORDS-1];
+ uint32_t retcode[2];
+};
+
+struct rt_sigframe
+{
+ __sigrestore_t pretcode;
+ int sig;
+ struct siginfo __user *pinfo;
+ void __user *puc;
+ struct siginfo info;
+ struct ucontext uc;
+ uint32_t retcode[2];
+};
+
+static int restore_sigcontext(struct sigcontext __user *sc, int *_gr8)
+{
+ struct user_context *user = current->thread.user;
+ unsigned long tbr, psr;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ tbr = user->i.tbr;
+ psr = user->i.psr;
+ if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context)))
+ goto badframe;
+ user->i.tbr = tbr;
+ user->i.psr = psr;
+
+ restore_user_regs(user);
+
+ user->i.syscallno = -1; /* disable syscall checks */
+
+ *_gr8 = user->i.gr[8];
+ return 0;
+
+ badframe:
+ return 1;
+}
+
+asmlinkage int sys_sigreturn(void)
+{
+ struct sigframe __user *frame = (struct sigframe __user *) __frame->sp;
+ sigset_t set;
+ int gr8;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__get_user(set.sig[0], &frame->sc.sc_oldmask))
+ goto badframe;
+
+ if (_NSIG_WORDS > 1 &&
+ __copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (restore_sigcontext(&frame->sc, &gr8))
+ goto badframe;
+ return gr8;
+
+ badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+asmlinkage int sys_rt_sigreturn(void)
+{
+ struct rt_sigframe __user *frame = (struct rt_sigframe __user *) __frame->sp;
+ sigset_t set;
+ int gr8;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (restore_sigcontext(&frame->uc.uc_mcontext, &gr8))
+ goto badframe;
+
+ if (restore_altstack(&frame->uc.uc_stack))
+ goto badframe;
+
+ return gr8;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+/*
+ * Set up a signal frame
+ */
+static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask)
+{
+ save_user_regs(current->thread.user);
+
+ if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0)
+ goto badframe;
+
+ /* non-iBCS2 extensions.. */
+ if (__put_user(mask, &sc->sc_oldmask) < 0)
+ goto badframe;
+
+ return 0;
+
+ badframe:
+ return 1;
+}
+
+/*****************************************************************************/
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *get_sigframe(struct ksignal *ksig,
+ size_t frame_size)
+{
+ unsigned long sp = sigsp(__frame->sp, ksig);
+
+ return (void __user *) ((sp - frame_size) & ~7UL);
+
+} /* end get_sigframe() */
+
+/*****************************************************************************/
+/*
+ *
+ */
+static int setup_frame(struct ksignal *ksig, sigset_t *set)
+{
+ struct sigframe __user *frame;
+ int sig = ksig->sig;
+
+ frame = get_sigframe(ksig, sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ if (__put_user(sig, &frame->sig) < 0)
+ return -EFAULT;
+
+ if (setup_sigcontext(&frame->sc, set->sig[0]))
+ return -EFAULT;
+
+ if (_NSIG_WORDS > 1) {
+ if (__copy_to_user(frame->extramask, &set->sig[1],
+ sizeof(frame->extramask)))
+ return -EFAULT;
+ }
+
+ /* Set up to return from userspace. If provided, use a stub
+ * already in userspace. */
+ if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+ if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode) < 0)
+ return -EFAULT;
+ }
+ else {
+ /* Set up the following code on the stack:
+ * setlos #__NR_sigreturn,gr7
+ * tira gr0,0
+ */
+ if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) ||
+ __put_user(0x8efc0000|__NR_sigreturn, &frame->retcode[0]) ||
+ __put_user(0xc0700000, &frame->retcode[1]))
+ return -EFAULT;
+
+ flush_icache_range((unsigned long) frame->retcode,
+ (unsigned long) (frame->retcode + 2));
+ }
+
+ /* Set up registers for the signal handler */
+ if (current->personality & FDPIC_FUNCPTRS) {
+ struct fdpic_func_descriptor __user *funcptr =
+ (struct fdpic_func_descriptor __user *) ksig->ka.sa.sa_handler;
+ struct fdpic_func_descriptor desc;
+ if (copy_from_user(&desc, funcptr, sizeof(desc)))
+ return -EFAULT;
+ __frame->pc = desc.text;
+ __frame->gr15 = desc.GOT;
+ } else {
+ __frame->pc = (unsigned long) ksig->ka.sa.sa_handler;
+ __frame->gr15 = 0;
+ }
+
+ __frame->sp = (unsigned long) frame;
+ __frame->lr = (unsigned long) &frame->retcode;
+ __frame->gr8 = sig;
+
+#if DEBUG_SIG
+ printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
+ sig, current->comm, current->pid, frame, __frame->pc,
+ frame->pretcode);
+#endif
+
+ return 0;
+} /* end setup_frame() */
+
+/*****************************************************************************/
+/*
+ *
+ */
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set)
+{
+ struct rt_sigframe __user *frame;
+ int sig = ksig->sig;
+
+ frame = get_sigframe(ksig, sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ if (__put_user(sig, &frame->sig) ||
+ __put_user(&frame->info, &frame->pinfo) ||
+ __put_user(&frame->uc, &frame->puc))
+ return -EFAULT;
+
+ if (copy_siginfo_to_user(&frame->info, &ksig->info))
+ return -EFAULT;
+
+ /* Create the ucontext. */
+ if (__put_user(0, &frame->uc.uc_flags) ||
+ __put_user(NULL, &frame->uc.uc_link) ||
+ __save_altstack(&frame->uc.uc_stack, __frame->sp))
+ return -EFAULT;
+
+ if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0]))
+ return -EFAULT;
+
+ if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
+ return -EFAULT;
+
+ /* Set up to return from userspace. If provided, use a stub
+ * already in userspace. */
+ if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+ if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode))
+ return -EFAULT;
+ }
+ else {
+ /* Set up the following code on the stack:
+ * setlos #__NR_sigreturn,gr7
+ * tira gr0,0
+ */
+ if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) ||
+ __put_user(0x8efc0000|__NR_rt_sigreturn, &frame->retcode[0]) ||
+ __put_user(0xc0700000, &frame->retcode[1]))
+ return -EFAULT;
+
+ flush_icache_range((unsigned long) frame->retcode,
+ (unsigned long) (frame->retcode + 2));
+ }
+
+ /* Set up registers for signal handler */
+ if (current->personality & FDPIC_FUNCPTRS) {
+ struct fdpic_func_descriptor __user *funcptr =
+ (struct fdpic_func_descriptor __user *) ksig->ka.sa.sa_handler;
+ struct fdpic_func_descriptor desc;
+ if (copy_from_user(&desc, funcptr, sizeof(desc)))
+ return -EFAULT;
+ __frame->pc = desc.text;
+ __frame->gr15 = desc.GOT;
+ } else {
+ __frame->pc = (unsigned long) ksig->ka.sa.sa_handler;
+ __frame->gr15 = 0;
+ }
+
+ __frame->sp = (unsigned long) frame;
+ __frame->lr = (unsigned long) &frame->retcode;
+ __frame->gr8 = sig;
+ __frame->gr9 = (unsigned long) &frame->info;
+
+#if DEBUG_SIG
+ printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
+ sig, current->comm, current->pid, frame, __frame->pc,
+ frame->pretcode);
+#endif
+ return 0;
+
+} /* end setup_rt_frame() */
+
+/*****************************************************************************/
+/*
+ * OK, we're invoking a handler
+ */
+static void handle_signal(struct ksignal *ksig)
+{
+ sigset_t *oldset = sigmask_to_save();
+ int ret;
+
+ /* Are we from a system call? */
+ if (__frame->syscallno != -1) {
+ /* If so, check system call restarting.. */
+ switch (__frame->gr8) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ __frame->gr8 = -EINTR;
+ break;
+
+ case -ERESTARTSYS:
+ if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+ __frame->gr8 = -EINTR;
+ break;
+ }
+
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ __frame->gr8 = __frame->orig_gr8;
+ __frame->pc -= 4;
+ }
+ __frame->syscallno = -1;
+ }
+
+ /* Set up the stack frame */
+ if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+ ret = setup_rt_frame(ksig, oldset);
+ else
+ ret = setup_frame(ksig, oldset);
+
+ signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
+} /* end handle_signal() */
+
+/*****************************************************************************/
+/*
+ * 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.
+ */
+static void do_signal(void)
+{
+ struct ksignal ksig;
+
+ if (get_signal(&ksig)) {
+ handle_signal(&ksig);
+ return;
+ }
+
+ /* Did we come from a system call? */
+ if (__frame->syscallno != -1) {
+ /* Restart the system call - no handlers present */
+ switch (__frame->gr8) {
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ __frame->gr8 = __frame->orig_gr8;
+ __frame->pc -= 4;
+ break;
+
+ case -ERESTART_RESTARTBLOCK:
+ __frame->gr7 = __NR_restart_syscall;
+ __frame->pc -= 4;
+ break;
+ }
+ __frame->syscallno = -1;
+ }
+
+ /* if there's no signal to deliver, we just put the saved sigmask
+ * back */
+ restore_saved_sigmask();
+} /* end do_signal() */
+
+/*****************************************************************************/
+/*
+ * notification of userspace execution resumption
+ * - triggered by the TIF_WORK_MASK flags
+ */
+asmlinkage void do_notify_resume(__u32 thread_info_flags)
+{
+ /* pending single-step? */
+ if (thread_info_flags & _TIF_SINGLESTEP)
+ clear_thread_flag(TIF_SINGLESTEP);
+
+ /* deal with pending signal delivery */
+ if (thread_info_flags & _TIF_SIGPENDING)
+ do_signal();
+
+ /* deal with notification on about to resume userspace execution */
+ if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(__frame);
+ }
+
+} /* end do_notify_resume() */
Code Review / kvmfornfv.git / blobdiff