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/* $Id: signal.c,v 1.21 2000/03/11 14:06:21 gniibe Exp $
*
* linux/arch/sh/kernel/signal.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
*
* SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
*
*/
#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/personality.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#define DEBUG_SIG 0
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
int copy_siginfo_to_user(siginfo_t *to, siginfo_t *from)
{
if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t)))
return -EFAULT;
if (from->si_code < 0)
return __copy_to_user(to, from, sizeof(siginfo_t));
else {
int err;
/* If you change siginfo_t structure, please be sure
this code is fixed accordingly.
It should never copy any pad contained in the structure
to avoid security leaks, but must copy the generic
3 ints plus the relevant union member. */
err = __put_user(from->si_signo, &to->si_signo);
err |= __put_user(from->si_errno, &to->si_errno);
err |= __put_user((short)from->si_code, &to->si_code);
/* First 32bits of unions are always present. */
err |= __put_user(from->si_pid, &to->si_pid);
switch (from->si_code >> 16) {
case __SI_FAULT >> 16:
break;
case __SI_CHLD >> 16:
err |= __put_user(from->si_utime, &to->si_utime);
err |= __put_user(from->si_stime, &to->si_stime);
err |= __put_user(from->si_status, &to->si_status);
default:
err |= __put_user(from->si_uid, &to->si_uid);
break;
/* case __SI_RT: This is not generated by the kernel as of now. */
}
return err;
}
}
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
asmlinkage int
sys_sigsuspend(old_sigset_t mask,
unsigned long r5, unsigned long r6, unsigned long r7,
struct pt_regs regs)
{
sigset_t saveset;
mask &= _BLOCKABLE;
spin_lock_irq(¤t->sigmask_lock);
saveset = current->blocked;
siginitset(¤t->blocked, mask);
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
regs.regs[0] = -EINTR;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(®s, &saveset))
return -EINTR;
}
}
asmlinkage int
sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
unsigned long r6, unsigned long r7,
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(¤t->sigmask_lock);
saveset = current->blocked;
current->blocked = newset;
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
regs.regs[0] = -EINTR;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(®s, &saveset))
return -EINTR;
}
}
asmlinkage int
sys_sigaction(int sig, const struct old_sigaction *act,
struct old_sigaction *oact)
{
struct k_sigaction new_ka, old_ka;
int ret;
if (act) {
old_sigset_t mask;
if (verify_area(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 (verify_area(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;
}
asmlinkage int
sys_sigaltstack(const stack_t *uss, stack_t *uoss,
unsigned long r6, unsigned long r7,
struct pt_regs regs)
{
return do_sigaltstack(uss, uoss, regs.regs[15]);
}
/*
* Do a signal return; undo the signal stack.
*/
struct sigframe
{
struct sigcontext sc;
unsigned long extramask[_NSIG_WORDS-1];
char retcode[4];
};
struct rt_sigframe
{
struct siginfo *pinfo;
void *puc;
struct siginfo info;
struct ucontext uc;
char retcode[4];
};
#if defined(__SH4__)
static inline int restore_sigcontext_fpu(struct sigcontext *sc)
{
struct task_struct *tsk = current;
tsk->used_math = 1;
return __copy_from_user(&tsk->thread.fpu.hard, &sc->sc_fpregs[0],
sizeof(long)*(16*2+2));
}
static inline int save_sigcontext_fpu(struct sigcontext *sc)
{
struct task_struct *tsk = current;
unsigned long flags;
int val;
if (!tsk->used_math) {
val = 0;
__copy_to_user(&sc->sc_ownedfp, &val, sizeof(int));
return 0;
}
val = 1;
__copy_to_user(&sc->sc_ownedfp, &val, sizeof(int));
/* This will cause a "finit" to be triggered by the next
attempted FPU operation by the 'current' process.
*/
tsk->used_math = 0;
save_and_cli(flags);
unlazy_fpu(tsk);
restore_flags(flags);
return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.fpu.hard,
sizeof(long)*(16*2+2));
}
#endif
static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *r0_p)
{
unsigned int err = 0;
#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
COPY(regs[1]);
COPY(regs[2]); COPY(regs[3]);
COPY(regs[4]); COPY(regs[5]);
COPY(regs[6]); COPY(regs[7]);
COPY(regs[8]); COPY(regs[9]);
COPY(regs[10]); COPY(regs[11]);
COPY(regs[12]); COPY(regs[13]);
COPY(regs[14]); COPY(regs[15]);
COPY(gbr); COPY(mach);
COPY(macl); COPY(pr);
COPY(sr); COPY(pc);
#undef COPY
#if defined(__SH4__)
{
int owned_fp;
struct task_struct *tsk = current;
regs->sr |= SR_FD; /* Release FPU */
clear_fpu(tsk);
current->used_math = 0;
__get_user (owned_fp, &sc->sc_ownedfp);
if (owned_fp)
err |= restore_sigcontext_fpu(sc);
}
#endif
regs->syscall_nr = -1; /* disable syscall checks */
err |= __get_user(*r0_p, &sc->sc_regs[0]);
return err;
}
asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs regs)
{
struct sigframe *frame = (struct sigframe *)regs.regs[15];
sigset_t set;
int r0;
if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask)
|| (_NSIG_WORDS > 1
&& __copy_from_user(&set.sig[1], &frame->extramask,
sizeof(frame->extramask))))
goto badframe;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(¤t->sigmask_lock);
current->blocked = set;
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
if (restore_sigcontext(®s, &frame->sc, &r0))
goto badframe;
return r0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7,
struct pt_regs regs)
{
struct rt_sigframe *frame = (struct rt_sigframe *)regs.regs[15];
sigset_t set;
stack_t st;
int r0;
if (verify_area(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->sigmask_lock);
current->blocked = set;
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
if (restore_sigcontext(®s, &frame->uc.uc_mcontext, &r0))
goto badframe;
if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
goto badframe;
/* It is more difficult to avoid calling this function than to
call it and ignore errors. */
do_sigaltstack(&st, NULL, regs.regs[15]);
return r0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame.
*/
static int
setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
unsigned long mask)
{
int err = 0;
#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
COPY(regs[0]); COPY(regs[1]);
COPY(regs[2]); COPY(regs[3]);
COPY(regs[4]); COPY(regs[5]);
COPY(regs[6]); COPY(regs[7]);
COPY(regs[8]); COPY(regs[9]);
COPY(regs[10]); COPY(regs[11]);
COPY(regs[12]); COPY(regs[13]);
COPY(regs[14]); COPY(regs[15]);
COPY(gbr); COPY(mach);
COPY(macl); COPY(pr);
COPY(sr); COPY(pc);
#undef COPY
#if defined(__SH4__)
err |= save_sigcontext_fpu(sc);
#endif
/* non-iBCS2 extensions.. */
err |= __put_user(mask, &sc->oldmask);
return err;
}
/*
* Determine which stack to use..
*/
static inline void *
get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
{
if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp))
sp = current->sas_ss_sp + current->sas_ss_size;
return (void *)((sp - frame_size) & -8ul);
}
static void setup_frame(int sig, struct k_sigaction *ka,
sigset_t *set, struct pt_regs *regs)
{
struct sigframe *frame;
int err = 0;
int signal;
frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
signal = current->exec_domain
&& current->exec_domain->signal_invmap
&& sig < 32
? current->exec_domain->signal_invmap[sig]
: sig;
err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
if (_NSIG_WORDS > 1) {
err |= __copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask));
}
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->pr = (unsigned long) ka->sa.sa_restorer;
} else {
/* This is : mov #__NR_sigreturn,r3 ; trapa #0x10 */
#ifdef __LITTLE_ENDIAN__
unsigned long code = 0xc310e300 | (__NR_sigreturn);
#else
unsigned long code = 0xe300c310 | (__NR_sigreturn << 16);
#endif
regs->pr = (unsigned long) frame->retcode;
err |= __put_user(code, (long *)(frame->retcode+0));
}
if (err)
goto give_sigsegv;
/* Set up registers for signal handler */
regs->regs[15] = (unsigned long) frame;
regs->regs[4] = signal; /* Arg for signal handler */
regs->pc = (unsigned long) ka->sa.sa_handler;
set_fs(USER_DS);
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
current->comm, current->pid, frame, regs->pc, regs->pr);
#endif
flush_cache_sigtramp(regs->pr);
return;
give_sigsegv:
if (sig == SIGSEGV)
ka->sa.sa_handler = SIG_DFL;
force_sig(SIGSEGV, current);
}
static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe *frame;
int err = 0;
int signal;
frame = get_sigframe(ka, regs->regs[15], sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
signal = current->exec_domain
&& current->exec_domain->signal_invmap
&& sig < 32
? current->exec_domain->signal_invmap[sig]
: 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(0, &frame->uc.uc_link);
err |= __put_user((void *)current->sas_ss_sp,
&frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->regs[15]),
&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, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->pr = (unsigned long) ka->sa.sa_restorer;
} else {
/* This is : mov #__NR_rt_sigreturn,r3 ; trapa #0x10 */
#ifdef __LITTLE_ENDIAN__
unsigned long code = 0xc310e300 | (__NR_rt_sigreturn);
#else
unsigned long code = 0xe300c310 | (__NR_rt_sigreturn << 16);
#endif
regs->pr = (unsigned long) frame->retcode;
err |= __put_user(code, (long *)(frame->retcode+0));
}
if (err)
goto give_sigsegv;
/* Set up registers for signal handler */
regs->regs[15] = (unsigned long) frame;
regs->regs[4] = signal; /* Arg for signal handler */
regs->pc = (unsigned long) ka->sa.sa_handler;
set_fs(USER_DS);
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
current->comm, current->pid, frame, regs->pc, regs->pr);
#endif
flush_cache_sigtramp(regs->pr);
return;
give_sigsegv:
if (sig == SIGSEGV)
ka->sa.sa_handler = SIG_DFL;
force_sig(SIGSEGV, current);
}
/*
* 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)
{
/* Are we from a system call? */
if (regs->syscall_nr >= 0) {
/* If so, check system call restarting.. */
switch (regs->regs[0]) {
case -ERESTARTNOHAND:
regs->regs[0] = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
regs->regs[0] = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->regs[0] = regs->syscall_nr;
regs->pc -= 2;
}
}
/* Set up the stack frame */
if (ka->sa.sa_flags & SA_SIGINFO)
setup_rt_frame(sig, ka, info, oldset, regs);
else
setup_frame(sig, ka, oldset, regs);
if (ka->sa.sa_flags & SA_ONESHOT)
ka->sa.sa_handler = SIG_DFL;
if (!(ka->sa.sa_flags & SA_NODEFER)) {
spin_lock_irq(¤t->sigmask_lock);
sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
sigaddset(¤t->blocked,sig);
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
}
}
/*
* 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.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
int do_signal(struct pt_regs *regs, sigset_t *oldset)
{
siginfo_t info;
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 1;
if (!oldset)
oldset = ¤t->blocked;
for (;;) {
unsigned long signr;
spin_lock_irq(¤t->sigmask_lock);
signr = dequeue_signal(¤t->blocked, &info);
spin_unlock_irq(¤t->sigmask_lock);
if (!signr)
break;
if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
/* Let the debugger run. */
current->exit_code = signr;
current->state = TASK_STOPPED;
notify_parent(current, SIGCHLD);
schedule();
/* We're back. Did the debugger cancel the sig? */
if (!(signr = current->exit_code))
continue;
current->exit_code = 0;
/* The debugger continued. Ignore SIGSTOP. */
if (signr == SIGSTOP)
continue;
/* Update the siginfo structure. Is this good? */
if (signr != info.si_signo) {
info.si_signo = signr;
info.si_errno = 0;
info.si_code = SI_USER;
info.si_pid = current->p_pptr->pid;
info.si_uid = current->p_pptr->uid;
}
/* If the (new) signal is now blocked, requeue it. */
if (sigismember(¤t->blocked, signr)) {
send_sig_info(signr, &info, current);
continue;
}
}
ka = ¤t->sig->action[signr-1];
if (ka->sa.sa_handler == SIG_IGN) {
if (signr != SIGCHLD)
continue;
/* Check for SIGCHLD: it's special. */
while (sys_wait4(-1, NULL, WNOHANG, NULL) > 0)
/* nothing */;
continue;
}
if (ka->sa.sa_handler == SIG_DFL) {
int exit_code = signr;
/* Init gets no signals it doesn't want. */
if (current->pid == 1)
continue;
switch (signr) {
case SIGCONT: case SIGCHLD: case SIGWINCH:
continue;
case SIGTSTP: case SIGTTIN: case SIGTTOU:
if (is_orphaned_pgrp(current->pgrp))
continue;
/* FALLTHRU */
case SIGSTOP:
current->state = TASK_STOPPED;
current->exit_code = signr;
if (!(current->p_pptr->sig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP))
notify_parent(current, SIGCHLD);
schedule();
continue;
case SIGQUIT: case SIGILL: case SIGTRAP:
case SIGABRT: case SIGFPE: case SIGSEGV:
case SIGBUS: case SIGSYS: case SIGXCPU: case SIGXFSZ:
if (do_coredump(signr, regs))
exit_code |= 0x80;
/* FALLTHRU */
default:
sigaddset(¤t->pending.signal, signr);
recalc_sigpending(current);
current->flags |= PF_SIGNALED;
do_exit(exit_code);
/* NOTREACHED */
}
}
/* Whee! Actually deliver the signal. */
handle_signal(signr, ka, &info, oldset, regs);
return 1;
}
/* Did we come from a system call? */
if (regs->syscall_nr >= 0) {
/* Restart the system call - no handlers present */
if (regs->regs[0] == -ERESTARTNOHAND ||
regs->regs[0] == -ERESTARTSYS ||
regs->regs[0] == -ERESTARTNOINTR) {
regs->regs[0] = regs->syscall_nr;
regs->pc -= 2;
}
}
return 0;
}
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