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Diffstat (limited to 'arch/m68k/kernel/signal_no.c')
-rw-r--r--arch/m68k/kernel/signal_no.c765
1 files changed, 765 insertions, 0 deletions
diff --git a/arch/m68k/kernel/signal_no.c b/arch/m68k/kernel/signal_no.c
new file mode 100644
index 000000000000..36a81bb6835a
--- /dev/null
+++ b/arch/m68k/kernel/signal_no.c
@@ -0,0 +1,765 @@
+/*
+ * linux/arch/m68knommu/kernel/signal.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+/*
+ * Linux/m68k support by Hamish Macdonald
+ *
+ * 68060 fixes by Jesper Skov
+ *
+ * 1997-12-01 Modified for POSIX.1b signals by Andreas Schwab
+ *
+ * mathemu support by Roman Zippel
+ * (Note: fpstate in the signal context is completely ignored for the emulator
+ * and the internal floating point format is put on stack)
+ */
+
+/*
+ * ++roman (07/09/96): implemented signal stacks (specially for tosemu on
+ * Atari :-) Current limitation: Only one sigstack can be active at one time.
+ * If a second signal with SA_ONSTACK set arrives while working on a sigstack,
+ * SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
+ * signal handlers!
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/syscalls.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/highuid.h>
+#include <linux/tty.h>
+#include <linux/personality.h>
+#include <linux/binfmts.h>
+
+#include <asm/setup.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/traps.h>
+#include <asm/ucontext.h>
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+void ret_from_user_signal(void);
+void ret_from_user_rt_signal(void);
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+asmlinkage int
+sys_sigsuspend(int unused0, int unused1, old_sigset_t mask)
+{
+ mask &= _BLOCKABLE;
+ spin_lock_irq(&current->sighand->siglock);
+ current->saved_sigmask = current->blocked;
+ siginitset(&current->blocked, mask);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ current->state = TASK_INTERRUPTIBLE;
+ schedule();
+ set_restore_sigmask();
+
+ return -ERESTARTNOHAND;
+}
+
+asmlinkage 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) ||
+ __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+ __get_user(mask, &act->sa_mask))
+ return -EFAULT;
+ 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) ||
+ __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+ __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
+ return -EFAULT;
+ }
+
+ return ret;
+}
+
+asmlinkage int
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
+{
+ return do_sigaltstack(uss, uoss, rdusp());
+}
+
+
+/*
+ * Do a signal return; undo the signal stack.
+ *
+ * Keep the return code on the stack quadword aligned!
+ * That makes the cache flush below easier.
+ */
+
+struct sigframe
+{
+ char __user *pretcode;
+ int sig;
+ int code;
+ struct sigcontext __user *psc;
+ char retcode[8];
+ unsigned long extramask[_NSIG_WORDS-1];
+ struct sigcontext sc;
+};
+
+struct rt_sigframe
+{
+ char __user *pretcode;
+ int sig;
+ struct siginfo __user *pinfo;
+ void __user *puc;
+ char retcode[8];
+ struct siginfo info;
+ struct ucontext uc;
+};
+
+#ifdef CONFIG_FPU
+
+static unsigned char fpu_version = 0; /* version number of fpu, set by setup_frame */
+
+static inline int restore_fpu_state(struct sigcontext *sc)
+{
+ int err = 1;
+
+ if (FPU_IS_EMU) {
+ /* restore registers */
+ memcpy(current->thread.fpcntl, sc->sc_fpcntl, 12);
+ memcpy(current->thread.fp, sc->sc_fpregs, 24);
+ return 0;
+ }
+
+ if (sc->sc_fpstate[0]) {
+ /* Verify the frame format. */
+ if (sc->sc_fpstate[0] != fpu_version)
+ goto out;
+
+ __asm__ volatile (".chip 68k/68881\n\t"
+ "fmovemx %0,%%fp0-%%fp1\n\t"
+ "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
+ ".chip 68k"
+ : /* no outputs */
+ : "m" (*sc->sc_fpregs), "m" (*sc->sc_fpcntl));
+ }
+ __asm__ volatile (".chip 68k/68881\n\t"
+ "frestore %0\n\t"
+ ".chip 68k" : : "m" (*sc->sc_fpstate));
+ err = 0;
+
+out:
+ return err;
+}
+
+#define FPCONTEXT_SIZE 216
+#define uc_fpstate uc_filler[0]
+#define uc_formatvec uc_filler[FPCONTEXT_SIZE/4]
+#define uc_extra uc_filler[FPCONTEXT_SIZE/4+1]
+
+static inline int rt_restore_fpu_state(struct ucontext __user *uc)
+{
+ unsigned char fpstate[FPCONTEXT_SIZE];
+ int context_size = 0;
+ fpregset_t fpregs;
+ int err = 1;
+
+ if (FPU_IS_EMU) {
+ /* restore fpu control register */
+ if (__copy_from_user(current->thread.fpcntl,
+ uc->uc_mcontext.fpregs.f_fpcntl, 12))
+ goto out;
+ /* restore all other fpu register */
+ if (__copy_from_user(current->thread.fp,
+ uc->uc_mcontext.fpregs.f_fpregs, 96))
+ goto out;
+ return 0;
+ }
+
+ if (__get_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate))
+ goto out;
+ if (fpstate[0]) {
+ context_size = fpstate[1];
+
+ /* Verify the frame format. */
+ if (fpstate[0] != fpu_version)
+ goto out;
+ if (__copy_from_user(&fpregs, &uc->uc_mcontext.fpregs,
+ sizeof(fpregs)))
+ goto out;
+ __asm__ volatile (".chip 68k/68881\n\t"
+ "fmovemx %0,%%fp0-%%fp7\n\t"
+ "fmoveml %1,%%fpcr/%%fpsr/%%fpiar\n\t"
+ ".chip 68k"
+ : /* no outputs */
+ : "m" (*fpregs.f_fpregs),
+ "m" (*fpregs.f_fpcntl));
+ }
+ if (context_size &&
+ __copy_from_user(fpstate + 4, (long __user *)&uc->uc_fpstate + 1,
+ context_size))
+ goto out;
+ __asm__ volatile (".chip 68k/68881\n\t"
+ "frestore %0\n\t"
+ ".chip 68k" : : "m" (*fpstate));
+ err = 0;
+
+out:
+ return err;
+}
+
+#endif
+
+static inline int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp,
+ int *pd0)
+{
+ int formatvec;
+ struct sigcontext context;
+ int err = 0;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+ /* get previous context */
+ if (copy_from_user(&context, usc, sizeof(context)))
+ goto badframe;
+
+ /* restore passed registers */
+ regs->d1 = context.sc_d1;
+ regs->a0 = context.sc_a0;
+ regs->a1 = context.sc_a1;
+ ((struct switch_stack *)regs - 1)->a5 = context.sc_a5;
+ regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
+ regs->pc = context.sc_pc;
+ regs->orig_d0 = -1; /* disable syscall checks */
+ wrusp(context.sc_usp);
+ formatvec = context.sc_formatvec;
+ regs->format = formatvec >> 12;
+ regs->vector = formatvec & 0xfff;
+
+#ifdef CONFIG_FPU
+ err = restore_fpu_state(&context);
+#endif
+
+ *pd0 = context.sc_d0;
+ return err;
+
+badframe:
+ return 1;
+}
+
+static inline int
+rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
+ struct ucontext __user *uc, int *pd0)
+{
+ int temp;
+ greg_t __user *gregs = uc->uc_mcontext.gregs;
+ unsigned long usp;
+ int err;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+ err = __get_user(temp, &uc->uc_mcontext.version);
+ if (temp != MCONTEXT_VERSION)
+ goto badframe;
+ /* restore passed registers */
+ err |= __get_user(regs->d0, &gregs[0]);
+ err |= __get_user(regs->d1, &gregs[1]);
+ err |= __get_user(regs->d2, &gregs[2]);
+ err |= __get_user(regs->d3, &gregs[3]);
+ err |= __get_user(regs->d4, &gregs[4]);
+ err |= __get_user(regs->d5, &gregs[5]);
+ err |= __get_user(sw->d6, &gregs[6]);
+ err |= __get_user(sw->d7, &gregs[7]);
+ err |= __get_user(regs->a0, &gregs[8]);
+ err |= __get_user(regs->a1, &gregs[9]);
+ err |= __get_user(regs->a2, &gregs[10]);
+ err |= __get_user(sw->a3, &gregs[11]);
+ err |= __get_user(sw->a4, &gregs[12]);
+ err |= __get_user(sw->a5, &gregs[13]);
+ err |= __get_user(sw->a6, &gregs[14]);
+ err |= __get_user(usp, &gregs[15]);
+ wrusp(usp);
+ err |= __get_user(regs->pc, &gregs[16]);
+ err |= __get_user(temp, &gregs[17]);
+ regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
+ regs->orig_d0 = -1; /* disable syscall checks */
+ regs->format = temp >> 12;
+ regs->vector = temp & 0xfff;
+
+ if (do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
+ goto badframe;
+
+ *pd0 = regs->d0;
+ return err;
+
+badframe:
+ return 1;
+}
+
+asmlinkage int do_sigreturn(unsigned long __unused)
+{
+ struct switch_stack *sw = (struct switch_stack *) &__unused;
+ struct pt_regs *regs = (struct pt_regs *) (sw + 1);
+ unsigned long usp = rdusp();
+ struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
+ sigset_t set;
+ int d0;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
+ (_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, frame + 1, &d0))
+ goto badframe;
+ return d0;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+asmlinkage int do_rt_sigreturn(unsigned long __unused)
+{
+ struct switch_stack *sw = (struct switch_stack *) &__unused;
+ struct pt_regs *regs = (struct pt_regs *) (sw + 1);
+ unsigned long usp = rdusp();
+ struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
+ sigset_t set;
+ int d0;
+
+ 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 (rt_restore_ucontext(regs, sw, &frame->uc, &d0))
+ goto badframe;
+ return d0;
+
+badframe:
+ force_sig(SIGSEGV, current);
+ return 0;
+}
+
+#ifdef CONFIG_FPU
+/*
+ * Set up a signal frame.
+ */
+
+static inline void save_fpu_state(struct sigcontext *sc, struct pt_regs *regs)
+{
+ if (FPU_IS_EMU) {
+ /* save registers */
+ memcpy(sc->sc_fpcntl, current->thread.fpcntl, 12);
+ memcpy(sc->sc_fpregs, current->thread.fp, 24);
+ return;
+ }
+
+ __asm__ volatile (".chip 68k/68881\n\t"
+ "fsave %0\n\t"
+ ".chip 68k"
+ : : "m" (*sc->sc_fpstate) : "memory");
+
+ if (sc->sc_fpstate[0]) {
+ fpu_version = sc->sc_fpstate[0];
+ __asm__ volatile (".chip 68k/68881\n\t"
+ "fmovemx %%fp0-%%fp1,%0\n\t"
+ "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
+ ".chip 68k"
+ : "=m" (*sc->sc_fpregs),
+ "=m" (*sc->sc_fpcntl)
+ : /* no inputs */
+ : "memory");
+ }
+}
+
+static inline int rt_save_fpu_state(struct ucontext __user *uc, struct pt_regs *regs)
+{
+ unsigned char fpstate[FPCONTEXT_SIZE];
+ int context_size = 0;
+ int err = 0;
+
+ if (FPU_IS_EMU) {
+ /* save fpu control register */
+ err |= copy_to_user(uc->uc_mcontext.fpregs.f_pcntl,
+ current->thread.fpcntl, 12);
+ /* save all other fpu register */
+ err |= copy_to_user(uc->uc_mcontext.fpregs.f_fpregs,
+ current->thread.fp, 96);
+ return err;
+ }
+
+ __asm__ volatile (".chip 68k/68881\n\t"
+ "fsave %0\n\t"
+ ".chip 68k"
+ : : "m" (*fpstate) : "memory");
+
+ err |= __put_user(*(long *)fpstate, (long __user *)&uc->uc_fpstate);
+ if (fpstate[0]) {
+ fpregset_t fpregs;
+ context_size = fpstate[1];
+ fpu_version = fpstate[0];
+ __asm__ volatile (".chip 68k/68881\n\t"
+ "fmovemx %%fp0-%%fp7,%0\n\t"
+ "fmoveml %%fpcr/%%fpsr/%%fpiar,%1\n\t"
+ ".chip 68k"
+ : "=m" (*fpregs.f_fpregs),
+ "=m" (*fpregs.f_fpcntl)
+ : /* no inputs */
+ : "memory");
+ err |= copy_to_user(&uc->uc_mcontext.fpregs, &fpregs,
+ sizeof(fpregs));
+ }
+ if (context_size)
+ err |= copy_to_user((long __user *)&uc->uc_fpstate + 1, fpstate + 4,
+ context_size);
+ return err;
+}
+
+#endif
+
+static void setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
+ unsigned long mask)
+{
+ sc->sc_mask = mask;
+ sc->sc_usp = rdusp();
+ sc->sc_d0 = regs->d0;
+ sc->sc_d1 = regs->d1;
+ sc->sc_a0 = regs->a0;
+ sc->sc_a1 = regs->a1;
+ sc->sc_a5 = ((struct switch_stack *)regs - 1)->a5;
+ sc->sc_sr = regs->sr;
+ sc->sc_pc = regs->pc;
+ sc->sc_formatvec = regs->format << 12 | regs->vector;
+#ifdef CONFIG_FPU
+ save_fpu_state(sc, regs);
+#endif
+}
+
+static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
+{
+ struct switch_stack *sw = (struct switch_stack *)regs - 1;
+ greg_t __user *gregs = uc->uc_mcontext.gregs;
+ int err = 0;
+
+ err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
+ err |= __put_user(regs->d0, &gregs[0]);
+ err |= __put_user(regs->d1, &gregs[1]);
+ err |= __put_user(regs->d2, &gregs[2]);
+ err |= __put_user(regs->d3, &gregs[3]);
+ err |= __put_user(regs->d4, &gregs[4]);
+ err |= __put_user(regs->d5, &gregs[5]);
+ err |= __put_user(sw->d6, &gregs[6]);
+ err |= __put_user(sw->d7, &gregs[7]);
+ err |= __put_user(regs->a0, &gregs[8]);
+ err |= __put_user(regs->a1, &gregs[9]);
+ err |= __put_user(regs->a2, &gregs[10]);
+ err |= __put_user(sw->a3, &gregs[11]);
+ err |= __put_user(sw->a4, &gregs[12]);
+ err |= __put_user(sw->a5, &gregs[13]);
+ err |= __put_user(sw->a6, &gregs[14]);
+ err |= __put_user(rdusp(), &gregs[15]);
+ err |= __put_user(regs->pc, &gregs[16]);
+ err |= __put_user(regs->sr, &gregs[17]);
+#ifdef CONFIG_FPU
+ err |= rt_save_fpu_state(uc, regs);
+#endif
+ return err;
+}
+
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
+{
+ unsigned long usp;
+
+ /* Default to using normal stack. */
+ usp = rdusp();
+
+ /* This is the X/Open sanctioned signal stack switching. */
+ if (ka->sa.sa_flags & SA_ONSTACK) {
+ if (!sas_ss_flags(usp))
+ usp = current->sas_ss_sp + current->sas_ss_size;
+ }
+ return (void __user *)((usp - frame_size) & -8UL);
+}
+
+static int setup_frame (int sig, struct k_sigaction *ka,
+ sigset_t *set, struct pt_regs *regs)
+{
+ struct sigframe __user *frame;
+ struct sigcontext context;
+ int err = 0;
+
+ frame = get_sigframe(ka, regs, sizeof(*frame));
+
+ err |= __put_user((current_thread_info()->exec_domain
+ && current_thread_info()->exec_domain->signal_invmap
+ && sig < 32
+ ? current_thread_info()->exec_domain->signal_invmap[sig]
+ : sig),
+ &frame->sig);
+
+ err |= __put_user(regs->vector, &frame->code);
+ err |= __put_user(&frame->sc, &frame->psc);
+
+ if (_NSIG_WORDS > 1)
+ err |= copy_to_user(frame->extramask, &set->sig[1],
+ sizeof(frame->extramask));
+
+ setup_sigcontext(&context, regs, set->sig[0]);
+ err |= copy_to_user (&frame->sc, &context, sizeof(context));
+
+ /* Set up to return from userspace. */
+ err |= __put_user((void *) ret_from_user_signal, &frame->pretcode);
+
+ if (err)
+ goto give_sigsegv;
+
+ /* Set up registers for signal handler */
+ wrusp ((unsigned long) frame);
+ regs->pc = (unsigned long) ka->sa.sa_handler;
+ ((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
+ regs->format = 0x4; /*set format byte to make stack appear modulo 4
+ which it will be when doing the rte */
+
+adjust_stack:
+ /* Prepare to skip over the extra stuff in the exception frame. */
+ if (regs->stkadj) {
+ struct pt_regs *tregs =
+ (struct pt_regs *)((ulong)regs + regs->stkadj);
+#if defined(DEBUG)
+ printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj);
+#endif
+ /* This must be copied with decreasing addresses to
+ handle overlaps. */
+ tregs->vector = 0;
+ tregs->format = 0;
+ tregs->pc = regs->pc;
+ tregs->sr = regs->sr;
+ }
+ return err;
+
+give_sigsegv:
+ force_sigsegv(sig, current);
+ goto adjust_stack;
+}
+
+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 |= __put_user((current_thread_info()->exec_domain
+ && current_thread_info()->exec_domain->signal_invmap
+ && sig < 32
+ ? current_thread_info()->exec_domain->signal_invmap[sig]
+ : sig),
+ &frame->sig);
+ err |= __put_user(&frame->info, &frame->pinfo);
+ err |= __put_user(&frame->uc, &frame->puc);
+ err |= copy_siginfo_to_user(&frame->info, info);
+
+ /* Create 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(rdusp()),
+ &frame->uc.uc_stack.ss_flags);
+ err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= rt_setup_ucontext(&frame->uc, regs);
+ err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
+
+ /* Set up to return from userspace. */
+ err |= __put_user((void *) ret_from_user_rt_signal, &frame->pretcode);
+
+ if (err)
+ goto give_sigsegv;
+
+ /* Set up registers for signal handler */
+ wrusp ((unsigned long) frame);
+ regs->pc = (unsigned long) ka->sa.sa_handler;
+ ((struct switch_stack *)regs - 1)->a5 = current->mm->start_data;
+ regs->format = 0x4; /*set format byte to make stack appear modulo 4
+ which it will be when doing the rte */
+
+adjust_stack:
+ /* Prepare to skip over the extra stuff in the exception frame. */
+ if (regs->stkadj) {
+ struct pt_regs *tregs =
+ (struct pt_regs *)((ulong)regs + regs->stkadj);
+#if defined(DEBUG)
+ printk(KERN_DEBUG "Performing stackadjust=%04x\n", regs->stkadj);
+#endif
+ /* This must be copied with decreasing addresses to
+ handle overlaps. */
+ tregs->vector = 0;
+ tregs->format = 0;
+ tregs->pc = regs->pc;
+ tregs->sr = regs->sr;
+ }
+ return err;
+
+give_sigsegv:
+ force_sigsegv(sig, current);
+ goto adjust_stack;
+}
+
+static inline void
+handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
+{
+ switch (regs->d0) {
+ case -ERESTARTNOHAND:
+ if (!has_handler)
+ goto do_restart;
+ regs->d0 = -EINTR;
+ break;
+
+ case -ERESTART_RESTARTBLOCK:
+ if (!has_handler) {
+ regs->d0 = __NR_restart_syscall;
+ regs->pc -= 2;
+ break;
+ }
+ regs->d0 = -EINTR;
+ break;
+
+ case -ERESTARTSYS:
+ if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
+ regs->d0 = -EINTR;
+ break;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ do_restart:
+ regs->d0 = regs->orig_d0;
+ regs->pc -= 2;
+ break;
+ }
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static void
+handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *oldset, struct pt_regs *regs)
+{
+ int err;
+ /* are we from a system call? */
+ if (regs->orig_d0 >= 0)
+ /* If so, check system call restarting.. */
+ handle_restart(regs, ka, 1);
+
+ /* set up the stack frame */
+ if (ka->sa.sa_flags & SA_SIGINFO)
+ err = setup_rt_frame(sig, ka, info, oldset, regs);
+ else
+ err = setup_frame(sig, ka, oldset, regs);
+
+ if (err)
+ return;
+
+ spin_lock_irq(&current->sighand->siglock);
+ sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+ if (!(ka->sa.sa_flags & SA_NODEFER))
+ sigaddset(&current->blocked,sig);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+}
+
+/*
+ * 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.
+ */
+asmlinkage void do_signal(struct pt_regs *regs)
+{
+ struct k_sigaction ka;
+ siginfo_t info;
+ int signr;
+ sigset_t *oldset;
+
+ /*
+ * 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;
+
+ if (test_thread_flag(TIF_RESTORE_SIGMASK))
+ oldset = &current->saved_sigmask;
+ else
+ oldset = &current->blocked;
+
+ signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+ if (signr > 0) {
+ /* Whee! Actually deliver the signal. */
+ handle_signal(signr, &ka, &info, oldset, regs);
+ return;
+ }
+
+ /* Did we come from a system call? */
+ if (regs->orig_d0 >= 0) {
+ /* Restart the system call - no handlers present */
+ handle_restart(regs, NULL, 0);
+ }
+
+ /* If there's no signal to deliver, we just restore the saved mask. */
+ if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+ clear_thread_flag(TIF_RESTORE_SIGMASK);
+ sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+ }
+}
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