290 lines
8.1 KiB
C
290 lines
8.1 KiB
C
/*
|
|
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
|
|
* Licensed under the GPL
|
|
*/
|
|
|
|
#include "linux/config.h"
|
|
#include "linux/stddef.h"
|
|
#include "linux/sys.h"
|
|
#include "linux/sched.h"
|
|
#include "linux/wait.h"
|
|
#include "linux/kernel.h"
|
|
#include "linux/smp_lock.h"
|
|
#include "linux/module.h"
|
|
#include "linux/slab.h"
|
|
#include "linux/tty.h"
|
|
#include "linux/binfmts.h"
|
|
#include "linux/ptrace.h"
|
|
#include "asm/signal.h"
|
|
#include "asm/uaccess.h"
|
|
#include "asm/unistd.h"
|
|
#include "user_util.h"
|
|
#include "asm/ucontext.h"
|
|
#include "kern_util.h"
|
|
#include "signal_kern.h"
|
|
#include "signal_user.h"
|
|
#include "kern.h"
|
|
#include "frame_kern.h"
|
|
#include "sigcontext.h"
|
|
#include "mode.h"
|
|
|
|
EXPORT_SYMBOL(block_signals);
|
|
EXPORT_SYMBOL(unblock_signals);
|
|
|
|
#define _S(nr) (1<<((nr)-1))
|
|
|
|
#define _BLOCKABLE (~(_S(SIGKILL) | _S(SIGSTOP)))
|
|
|
|
/*
|
|
* OK, we're invoking a handler
|
|
*/
|
|
static int handle_signal(struct pt_regs *regs, unsigned long signr,
|
|
struct k_sigaction *ka, siginfo_t *info,
|
|
sigset_t *oldset)
|
|
{
|
|
unsigned long sp;
|
|
int err;
|
|
|
|
/* Always make any pending restarted system calls return -EINTR */
|
|
current_thread_info()->restart_block.fn = do_no_restart_syscall;
|
|
|
|
/* Did we come from a system call? */
|
|
if(PT_REGS_SYSCALL_NR(regs) >= 0){
|
|
/* If so, check system call restarting.. */
|
|
switch(PT_REGS_SYSCALL_RET(regs)){
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
PT_REGS_SYSCALL_RET(regs) = -EINTR;
|
|
break;
|
|
|
|
case -ERESTARTSYS:
|
|
if (!(ka->sa.sa_flags & SA_RESTART)) {
|
|
PT_REGS_SYSCALL_RET(regs) = -EINTR;
|
|
break;
|
|
}
|
|
/* fallthrough */
|
|
case -ERESTARTNOINTR:
|
|
PT_REGS_RESTART_SYSCALL(regs);
|
|
PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
|
|
break;
|
|
}
|
|
}
|
|
|
|
sp = PT_REGS_SP(regs);
|
|
if((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
|
|
sp = current->sas_ss_sp + current->sas_ss_size;
|
|
|
|
if(ka->sa.sa_flags & SA_SIGINFO)
|
|
err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset);
|
|
else
|
|
err = setup_signal_stack_sc(sp, signr, ka, regs, oldset);
|
|
|
|
if(err){
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
current->blocked = *oldset;
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
force_sigsegv(signr, current);
|
|
}
|
|
else if(!(ka->sa.sa_flags & SA_NODEFER)){
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
sigorsets(¤t->blocked, ¤t->blocked,
|
|
&ka->sa.sa_mask);
|
|
sigaddset(¤t->blocked, signr);
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int kern_do_signal(struct pt_regs *regs, sigset_t *oldset)
|
|
{
|
|
struct k_sigaction ka_copy;
|
|
siginfo_t info;
|
|
int sig, handled_sig = 0;
|
|
|
|
while((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0){
|
|
handled_sig = 1;
|
|
/* Whee! Actually deliver the signal. */
|
|
if(!handle_signal(regs, sig, &ka_copy, &info, oldset))
|
|
break;
|
|
}
|
|
|
|
/* Did we come from a system call? */
|
|
if(!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)){
|
|
/* Restart the system call - no handlers present */
|
|
if(PT_REGS_SYSCALL_RET(regs) == -ERESTARTNOHAND ||
|
|
PT_REGS_SYSCALL_RET(regs) == -ERESTARTSYS ||
|
|
PT_REGS_SYSCALL_RET(regs) == -ERESTARTNOINTR){
|
|
PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
|
|
PT_REGS_RESTART_SYSCALL(regs);
|
|
}
|
|
else if(PT_REGS_SYSCALL_RET(regs) == -ERESTART_RESTARTBLOCK){
|
|
PT_REGS_SYSCALL_RET(regs) = __NR_restart_syscall;
|
|
PT_REGS_RESTART_SYSCALL(regs);
|
|
}
|
|
}
|
|
|
|
/* This closes a way to execute a system call on the host. If
|
|
* you set a breakpoint on a system call instruction and singlestep
|
|
* from it, the tracing thread used to PTRACE_SINGLESTEP the process
|
|
* rather than PTRACE_SYSCALL it, allowing the system call to execute
|
|
* on the host. The tracing thread will check this flag and
|
|
* PTRACE_SYSCALL if necessary.
|
|
*/
|
|
if(current->ptrace & PT_DTRACE)
|
|
current->thread.singlestep_syscall =
|
|
is_syscall(PT_REGS_IP(¤t->thread.regs));
|
|
return(handled_sig);
|
|
}
|
|
|
|
int do_signal(void)
|
|
{
|
|
return(kern_do_signal(¤t->thread.regs, ¤t->blocked));
|
|
}
|
|
|
|
/*
|
|
* Atomically swap in the new signal mask, and wait for a signal.
|
|
*/
|
|
long sys_sigsuspend(int history0, int history1, old_sigset_t mask)
|
|
{
|
|
sigset_t saveset;
|
|
|
|
mask &= _BLOCKABLE;
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
saveset = current->blocked;
|
|
siginitset(¤t->blocked, mask);
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
|
|
PT_REGS_SYSCALL_RET(¤t->thread.regs) = -EINTR;
|
|
while (1) {
|
|
current->state = TASK_INTERRUPTIBLE;
|
|
schedule();
|
|
if(kern_do_signal(¤t->thread.regs, &saveset))
|
|
return(-EINTR);
|
|
}
|
|
}
|
|
|
|
long sys_rt_sigsuspend(sigset_t __user *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->sighand->siglock);
|
|
saveset = current->blocked;
|
|
current->blocked = newset;
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
|
|
PT_REGS_SYSCALL_RET(¤t->thread.regs) = -EINTR;
|
|
while (1) {
|
|
current->state = TASK_INTERRUPTIBLE;
|
|
schedule();
|
|
if (kern_do_signal(¤t->thread.regs, &saveset))
|
|
return(-EINTR);
|
|
}
|
|
}
|
|
|
|
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 (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;
|
|
}
|
|
|
|
long sys_sigaltstack(const stack_t *uss, stack_t *uoss)
|
|
{
|
|
return(do_sigaltstack(uss, uoss, PT_REGS_SP(¤t->thread.regs)));
|
|
}
|
|
|
|
extern int userspace_pid[];
|
|
|
|
static int copy_sc_from_user(struct pt_regs *to, void *from,
|
|
struct arch_frame_data *arch)
|
|
{
|
|
int ret;
|
|
|
|
ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from, arch),
|
|
copy_sc_from_user_skas(userspace_pid[0],
|
|
&to->regs, from));
|
|
return(ret);
|
|
}
|
|
|
|
long sys_sigreturn(struct pt_regs regs)
|
|
{
|
|
void __user *sc = sp_to_sc(PT_REGS_SP(¤t->thread.regs));
|
|
void __user *mask = sp_to_mask(PT_REGS_SP(¤t->thread.regs));
|
|
int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
|
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
copy_from_user(¤t->blocked.sig[0], sc_sigmask(sc),
|
|
sizeof(current->blocked.sig[0]));
|
|
copy_from_user(¤t->blocked.sig[1], mask, sig_size);
|
|
sigdelsetmask(¤t->blocked, ~_BLOCKABLE);
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
copy_sc_from_user(¤t->thread.regs, sc,
|
|
&signal_frame_sc.common.arch);
|
|
return(PT_REGS_SYSCALL_RET(¤t->thread.regs));
|
|
}
|
|
|
|
long sys_rt_sigreturn(struct pt_regs regs)
|
|
{
|
|
unsigned long sp = PT_REGS_SP(¤t->thread.regs);
|
|
struct ucontext __user *uc = sp_to_uc(sp);
|
|
int sig_size = _NSIG_WORDS * sizeof(unsigned long);
|
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
copy_from_user(¤t->blocked, &uc->uc_sigmask, sig_size);
|
|
sigdelsetmask(¤t->blocked, ~_BLOCKABLE);
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext,
|
|
&signal_frame_si.common.arch);
|
|
return(PT_REGS_SYSCALL_RET(¤t->thread.regs));
|
|
}
|
|
|
|
/*
|
|
* Overrides for Emacs so that we follow Linus's tabbing style.
|
|
* Emacs will notice this stuff at the end of the file and automatically
|
|
* adjust the settings for this buffer only. This must remain at the end
|
|
* of the file.
|
|
* ---------------------------------------------------------------------------
|
|
* Local variables:
|
|
* c-file-style: "linux"
|
|
* End:
|
|
*/
|