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/*
* 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.
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1994 - 1999 Ralf Baechle
* Copyright (C) 1999 Silicon Graphics, Inc.
*/
#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 <asm/asm.h>
#include <asm/bitops.h>
#include <asm/pgalloc.h>
#include <asm/stackframe.h>
#include <asm/uaccess.h>
#include <asm/ucontext.h>
#define DEBUG_SIG 0
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
extern asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs);
extern asmlinkage int (*save_fp_context)(struct sigcontext *sc);
extern asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
extern asmlinkage void syscall_trace(void);
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.
*/
save_static_function(sys_sigsuspend);
static_unused int
_sys_sigsuspend(struct pt_regs regs)
{
sigset_t *uset, saveset, newset;
uset = (sigset_t *) regs.regs[4];
if (copy_from_user(&newset, uset, sizeof(sigset_t)))
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[2] = EINTR;
regs.regs[7] = 1;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(&saveset, ®s))
return -EINTR;
}
}
save_static_function(sys_rt_sigsuspend);
static_unused int
_sys_rt_sigsuspend(struct pt_regs regs)
{
sigset_t *unewset, saveset, newset;
size_t sigsetsize;
/* XXX Don't preclude handling different sized sigset_t's. */
sigsetsize = regs.regs[5];
if (sigsetsize != sizeof(sigset_t))
return -EINVAL;
unewset = (sigset_t *) regs.regs[4];
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[2] = EINTR;
regs.regs[7] = 1;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(&saveset, ®s))
return -EINTR;
}
}
asmlinkage int
sys_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
{
struct k_sigaction new_ka, old_ka;
int ret;
int err = 0;
if (act) {
old_sigset_t mask;
if (!access_ok(VERIFY_READ, act, sizeof(*act)))
return -EFAULT;
err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
err |= __get_user(mask, &act->sa_mask.sig[0]);
err |= __get_user(new_ka.sa.sa_restorer, &act->sa_restorer);
if (err)
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)))
return -EFAULT;
err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
err |= __put_user(0, &oact->sa_mask.sig[1]);
err |= __put_user(0, &oact->sa_mask.sig[2]);
err |= __put_user(0, &oact->sa_mask.sig[3]);
err |= __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer);
if (err)
return -EFAULT;
}
return ret;
}
asmlinkage int
sys_sigaltstack(struct pt_regs regs)
{
const stack_t *uss = (const stack_t *) regs.regs[4];
stack_t *uoss = (stack_t *) regs.regs[5];
unsigned long usp = regs.regs[29];
return do_sigaltstack(uss, uoss, usp);
}
asmlinkage int
restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
{
int owned_fp;
int err = 0;
u64 reg;
err |= __get_user(regs->cp0_epc, &sc->sc_pc);
err |= __get_user(reg, &sc->sc_mdhi);
regs->hi = (int) reg;
err |= __get_user(reg, &sc->sc_mdlo);
regs->lo = (int) reg;
#define restore_gp_reg(i) do { \
err |= __get_user(reg, &sc->sc_regs[i]); \
regs->regs[i] = reg; \
} while(0);
restore_gp_reg( 1); restore_gp_reg( 2); restore_gp_reg( 3);
restore_gp_reg( 4); restore_gp_reg( 5); restore_gp_reg( 6);
restore_gp_reg( 7); restore_gp_reg( 8); restore_gp_reg( 9);
restore_gp_reg(10); restore_gp_reg(11); restore_gp_reg(12);
restore_gp_reg(13); restore_gp_reg(14); restore_gp_reg(15);
restore_gp_reg(16); restore_gp_reg(17); restore_gp_reg(18);
restore_gp_reg(19); restore_gp_reg(20); restore_gp_reg(21);
restore_gp_reg(22); restore_gp_reg(23); restore_gp_reg(24);
restore_gp_reg(25); restore_gp_reg(26); restore_gp_reg(27);
restore_gp_reg(28); restore_gp_reg(29); restore_gp_reg(30);
restore_gp_reg(31);
#undef restore_gp_reg
err |= __get_user(owned_fp, &sc->sc_ownedfp);
if (owned_fp) {
err |= restore_fp_context(sc);
last_task_used_math = current;
}
return err;
}
struct sigframe {
u32 sf_ass[4]; /* argument save space for o32 */
u32 sf_code[2]; /* signal trampoline */
struct sigcontext sf_sc;
sigset_t sf_mask;
};
struct rt_sigframe {
u32 rs_ass[4]; /* argument save space for o32 */
u32 rs_code[2]; /* signal trampoline */
struct siginfo rs_info;
struct ucontext rs_uc;
};
asmlinkage void
sys_sigreturn(struct pt_regs regs)
{
struct sigframe *frame;
sigset_t blocked;
frame = (struct sigframe *) regs.regs[29];
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
goto badframe;
sigdelsetmask(&blocked, ~_BLOCKABLE);
spin_lock_irq(¤t->sigmask_lock);
current->blocked = blocked;
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
if (restore_sigcontext(®s, &frame->sf_sc))
goto badframe;
/*
* Don't let your children do this ...
*/
if (current->ptrace & PT_TRACESYS)
syscall_trace();
__asm__ __volatile__(
"move\t$29, %0\n\t"
"j\tret_from_sys_call"
:/* no outputs */
:"r" (®s));
/* Unreached */
badframe:
force_sig(SIGSEGV, current);
}
asmlinkage void
sys_rt_sigreturn(struct pt_regs regs)
{
struct rt_sigframe *frame;
sigset_t set;
stack_t st;
frame = (struct rt_sigframe *) regs.regs[29];
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->rs_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->rs_uc.uc_mcontext))
goto badframe;
if (__copy_from_user(&st, &frame->rs_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[29]);
/*
* Don't let your children do this ...
*/
__asm__ __volatile__(
"move\t$29, %0\n\t"
"j\tret_from_sys_call"
:/* no outputs */
:"r" (®s));
/* Unreached */
badframe:
force_sig(SIGSEGV, current);
}
static int inline
setup_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
{
int owned_fp;
int err = 0;
u64 reg;
err |= __put_user(regs->cp0_epc, &sc->sc_pc);
err |= __put_user(regs->cp0_status, &sc->sc_status);
#define save_gp_reg(i) { \
reg = regs->regs[i]; \
err |= __put_user(reg, &sc->sc_regs[i]); \
} while(0)
__put_user(0, &sc->sc_regs[0]); save_gp_reg(1); save_gp_reg(2);
save_gp_reg(3); save_gp_reg(4); save_gp_reg(5); save_gp_reg(6);
save_gp_reg(7); save_gp_reg(8); save_gp_reg(9); save_gp_reg(10);
save_gp_reg(11); save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
save_gp_reg(15); save_gp_reg(16); save_gp_reg(17); save_gp_reg(18);
save_gp_reg(19); save_gp_reg(20); save_gp_reg(21); save_gp_reg(22);
save_gp_reg(23); save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
save_gp_reg(27); save_gp_reg(28); save_gp_reg(29); save_gp_reg(30);
save_gp_reg(31);
#undef save_gp_reg
err |= __put_user(regs->hi, &sc->sc_mdhi);
err |= __put_user(regs->lo, &sc->sc_mdlo);
err |= __put_user(regs->cp0_cause, &sc->sc_cause);
err |= __put_user(regs->cp0_badvaddr, &sc->sc_badvaddr);
owned_fp = (current == last_task_used_math);
err |= __put_user(owned_fp, &sc->sc_ownedfp);
if (current->used_math) { /* fp is active. */
set_cp0_status(ST0_CU1);
err |= save_fp_context(sc);
last_task_used_math = NULL;
regs->cp0_status &= ~ST0_CU1;
current->used_math = 0;
}
return err;
}
/*
* 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->regs[29];
/* This is the X/Open sanctioned signal stack switching. */
if ((ka->sa.sa_flags & SA_ONSTACK) && ! on_sig_stack(sp))
sp = current->sas_ss_sp + current->sas_ss_size;
return (void *)((sp - frame_size) & ALMASK);
}
static void inline
setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
int signr, sigset_t *set)
{
struct sigframe *frame;
int err = 0;
frame = get_sigframe(ka, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
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->regs[31] = (unsigned long) ka->sa.sa_restorer;
else {
/*
* Set up the return code ...
*
* li v0, __NR_sigreturn
* syscall
*/
err |= __put_user(0x24020000 + __NR_sigreturn,
frame->sf_code + 0);
err |= __put_user(0x0000000c ,
frame->sf_code + 1);
flush_cache_sigtramp((unsigned long) frame->sf_code);
}
err |= setup_sigcontext(regs, &frame->sf_sc);
err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
if (err)
goto give_sigsegv;
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = 0 (should be cause)
* a2 = pointer to struct sigcontext
*
* $25 and c0_epc point to the signal handler, $29 points to the
* struct sigframe.
*/
regs->regs[ 4] = signr;
regs->regs[ 5] = 0;
regs->regs[ 6] = (unsigned long) &frame->sf_sc;
regs->regs[29] = (unsigned long) frame;
regs->regs[31] = (unsigned long) frame->sf_code;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%p ra=0x%p\n",
current->comm, current->pid, frame, regs->cp0_epc, frame->code);
#endif
return;
give_sigsegv:
if (signr == SIGSEGV)
ka->sa.sa_handler = SIG_DFL;
force_sig(SIGSEGV, current);
}
static void inline
setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
int signr, sigset_t *set, siginfo_t *info)
{
struct rt_sigframe *frame;
int err = 0;
frame = get_sigframe(ka, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
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->regs[31] = (unsigned long) ka->sa.sa_restorer;
else {
/*
* Set up the return code ...
*
* li v0, __NR_rt_sigreturn
* syscall
*/
err |= __put_user(0x24020000 + __NR_rt_sigreturn,
frame->rs_code + 0);
err |= __put_user(0x0000000c ,
frame->rs_code + 1);
flush_cache_sigtramp((unsigned long) frame->rs_code);
}
/* Create siginfo. */
err |= copy_siginfo_to_user(&frame->rs_info, info);
/* Create the ucontext. */
err |= __put_user(0, &frame->rs_uc.uc_flags);
err |= __put_user(0, &frame->rs_uc.uc_link);
err |= __put_user((void *)current->sas_ss_sp,
&frame->rs_uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->regs[29]),
&frame->rs_uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size,
&frame->rs_uc.uc_stack.ss_size);
err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
if (err)
goto give_sigsegv;
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = 0 (should be cause)
* a2 = pointer to ucontext
*
* $25 and c0_epc point to the signal handler, $29 points to
* the struct rt_sigframe.
*/
regs->regs[ 4] = signr;
regs->regs[ 5] = (unsigned long) &frame->rs_info;
regs->regs[ 6] = (unsigned long) &frame->rs_uc;
regs->regs[29] = (unsigned long) frame;
regs->regs[31] = (unsigned long) frame->rs_code;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%p ra=0x%p\n",
current->comm, current->pid, frame, regs->cp0_epc, frame->code);
#endif
return;
give_sigsegv:
if (signr == SIGSEGV)
ka->sa.sa_handler = SIG_DFL;
force_sig(SIGSEGV, current);
}
static inline void
handle_signal(unsigned long sig, struct k_sigaction *ka,
siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
{
if (ka->sa.sa_flags & SA_SIGINFO)
setup_rt_frame(ka, regs, sig, oldset, info);
else
setup_frame(ka, regs, sig, oldset);
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);
}
}
static inline void
syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
{
switch(regs->regs[0]) {
case ERESTARTNOHAND:
regs->regs[2] = EINTR;
break;
case ERESTARTSYS:
if(!(ka->sa.sa_flags & SA_RESTART)) {
regs->regs[2] = EINTR;
break;
}
/* fallthrough */
case ERESTARTNOINTR: /* Userland will reload $v0. */
regs->regs[7] = regs->regs[26];
regs->cp0_epc -= 8;
}
regs->regs[0] = 0; /* Don't deal with this again. */
}
extern int do_irix_signal(sigset_t *oldset, struct pt_regs *regs);
asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs)
{
struct k_sigaction *ka;
siginfo_t info;
#ifdef CONFIG_BINFMT_IRIX
if (current->personality != PER_LINUX)
return do_irix_signal(oldset, regs);
#endif
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 */
}
}
if (regs->regs[0])
syscall_restart(regs, ka);
/* Whee! Actually deliver the signal. */
handle_signal(signr, ka, &info, oldset, regs);
return 1;
}
/*
* Who's code doesn't conform to the restartable syscall convention
* dies here!!! The li instruction, a single machine instruction,
* must directly be followed by the syscall instruction.
*/
if (regs->regs[0]) {
if (regs->regs[2] == ERESTARTNOHAND ||
regs->regs[2] == ERESTARTSYS ||
regs->regs[2] == ERESTARTNOINTR) {
regs->regs[7] = regs->regs[26];
regs->cp0_epc -= 8;
}
}
return 0;
}
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