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/*
* arch/s390/kernel/signal.c
*
* S390 version
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
*
* Based on Intel version
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
*/
#include <linux/config.h>
#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>
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
typedef struct
{
__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
struct sigcontext sc;
_sigregs sregs;
__u8 retcode[S390_SYSCALL_SIZE];
} sigframe;
typedef struct
{
__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
__u8 retcode[S390_SYSCALL_SIZE];
struct siginfo info;
struct ucontext uc;
} rt_sigframe;
asmlinkage int FASTCALL(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(struct pt_regs * regs,int history0, int history1, old_sigset_t mask)
{
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->gprs[2] = -EINTR;
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
schedule();
if (do_signal(regs, &saveset))
return -EINTR;
}
}
asmlinkage int
sys_rt_sigsuspend(struct pt_regs * regs,sigset_t *unewset, size_t sigsetsize)
{
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->gprs[2] = -EINTR;
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
schedule();
if (do_signal(regs, &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, struct pt_regs *regs)
{
return do_sigaltstack(uss, uoss, regs->gprs[15]);
}
static int save_sigregs(struct pt_regs *regs,_sigregs *sregs)
{
int err;
s390_fp_regs fpregs;
err = __copy_to_user(&sregs->regs,regs,sizeof(_s390_regs_common));
if(!err)
{
save_fp_regs(&fpregs);
err=__copy_to_user(&sregs->fpregs,&fpregs,sizeof(fpregs));
}
return(err);
}
static int restore_sigregs(struct pt_regs *regs,_sigregs *sregs)
{
int err;
s390_fp_regs fpregs;
psw_t saved_psw=regs->psw;
err=__copy_from_user(regs,&sregs->regs,sizeof(_s390_regs_common));
if(!err)
{
regs->trap = -1; /* disable syscall checks */
regs->psw.mask=(saved_psw.mask&~PSW_MASK_DEBUGCHANGE)|
(regs->psw.mask&PSW_MASK_DEBUGCHANGE);
regs->psw.addr=(saved_psw.addr&~PSW_ADDR_DEBUGCHANGE)|
(regs->psw.addr&PSW_ADDR_DEBUGCHANGE);
err=__copy_from_user(&fpregs,&sregs->fpregs,sizeof(fpregs));
if(!err)
restore_fp_regs(&fpregs);
}
return(err);
}
asmlinkage long sys_sigreturn(struct pt_regs *regs)
{
sigframe *frame = (sigframe *)regs->gprs[15];
sigset_t set;
if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
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_sigregs(regs, &frame->sregs))
goto badframe;
return regs->gprs[2];
badframe:
force_sig(SIGSEGV, current);
return 0;
}
asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
{
rt_sigframe *frame = (rt_sigframe *)regs->gprs[15];
sigset_t set;
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_sigregs(regs, &frame->uc.uc_mcontext))
goto badframe;
/* It is more difficult to avoid calling this function than to
call it and ignore errors. */
do_sigaltstack(&frame->uc.uc_stack, NULL, regs->gprs[15]);
return regs->gprs[2];
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame.
*/
/*
* Determine which stack to use..
*/
static inline void *
get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
{
unsigned long sp;
/* Default to using normal stack */
sp = regs->gprs[15];
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (! on_sig_stack(sp))
sp = current->sas_ss_sp + current->sas_ss_size;
}
/* This is the legacy signal stack switching. */
else if (!user_mode(regs) &&
!(ka->sa.sa_flags & SA_RESTORER) &&
ka->sa.sa_restorer) {
sp = (unsigned long) ka->sa.sa_restorer;
}
return (void *)((sp - frame_size) & -8ul);
}
static inline int map_signal(int sig)
{
if (current->exec_domain
&& current->exec_domain->signal_invmap
&& sig < 32)
return current->exec_domain->signal_invmap[sig];
else
return sig;
}
static void setup_frame(int sig, struct k_sigaction *ka,
sigset_t *set, struct pt_regs * regs)
{
sigframe *frame = get_sigframe(ka, regs, sizeof(sigframe));
if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
goto give_sigsegv;
if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
goto give_sigsegv;
if (save_sigregs(regs, &frame->sregs))
goto give_sigsegv;
if (__put_user(&frame->sregs, &frame->sc.sregs))
goto give_sigsegv;
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->gprs[14] = FIX_PSW(ka->sa.sa_restorer);
} else {
regs->gprs[14] = FIX_PSW(frame->retcode);
if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
(u16 *)(frame->retcode)))
goto give_sigsegv;
}
/* Set up registers for signal handler */
regs->gprs[15] = (addr_t)frame;
regs->psw.addr = FIX_PSW(ka->sa.sa_handler);
regs->psw.mask = _USER_PSW_MASK;
regs->gprs[2] = map_signal(sig);
regs->gprs[3] = (addr_t)&frame->sc;
/* We forgot to include these in the sigcontext.
To avoid breaking binary compatibility, they are passed as args. */
regs->gprs[4] = current->thread.trap_no;
regs->gprs[5] = current->thread.prot_addr;
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)
{
int err = 0;
rt_sigframe *frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
goto give_sigsegv;
if (copy_siginfo_to_user(&frame->info, info))
goto give_sigsegv;
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->gprs[15]),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= save_sigregs(regs, &frame->uc.uc_mcontext);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
goto give_sigsegv;
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
regs->gprs[14] = FIX_PSW(ka->sa.sa_restorer);
} else {
regs->gprs[14] = FIX_PSW(frame->retcode);
err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
(u16 *)(frame->retcode));
}
/* Set up registers for signal handler */
regs->gprs[15] = (addr_t)frame;
regs->psw.addr = FIX_PSW(ka->sa.sa_handler);
regs->psw.mask = _USER_PSW_MASK;
regs->gprs[2] = map_signal(sig);
regs->gprs[3] = (addr_t)&frame->info;
regs->gprs[4] = (addr_t)&frame->uc;
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->trap == __LC_SVC_OLD_PSW) {
/* If so, check system call restarting.. */
switch (regs->gprs[2]) {
case -ERESTARTNOHAND:
regs->gprs[2] = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
regs->gprs[2] = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->gprs[2] = regs->orig_gpr2;
regs->psw.addr -= 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;
#ifdef CONFIG_S390_SUPPORT
if (current->thread.flags & S390_FLAG_31BIT) {
extern asmlinkage int do_signal32(struct pt_regs *regs, sigset_t *oldset);
return do_signal32(regs, oldset);
}
#endif
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;
set_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: {
struct signal_struct *sig;
set_current_state(TASK_STOPPED);
current->exit_code = signr;
sig = current->p_pptr->sig;
if (sig && !(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->trap == __LC_SVC_OLD_PSW /* System Call! */ ) {
/* Restart the system call - no handlers present */
if (regs->gprs[2] == -ERESTARTNOHAND ||
regs->gprs[2] == -ERESTARTSYS ||
regs->gprs[2] == -ERESTARTNOINTR) {
regs->gprs[2] = regs->orig_gpr2;
regs->psw.addr -= 2;
}
}
return 0;
}
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