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/*
* Architecture-specific signal handling support.
*
* Copyright (C) 1999-2001 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* Derived from i386 and Alpha versions.
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/wait.h>
#include <asm/ia32.h>
#include <asm/uaccess.h>
#include <asm/rse.h>
#include <asm/sigcontext.h>
#include "sigframe.h"
#define DEBUG_SIG 0
#define STACK_ALIGN 16 /* minimal alignment for stack pointer */
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
#if _NSIG_WORDS > 1
# define PUT_SIGSET(k,u) __copy_to_user((u)->sig, (k)->sig, sizeof(sigset_t))
# define GET_SIGSET(k,u) __copy_from_user((k)->sig, (u)->sig, sizeof(sigset_t))
#else
# define PUT_SIGSET(k,u) __put_user((k)->sig[0], &(u)->sig[0])
# define GET_SIGSET(k,u) __get_user((k)->sig[0], &(u)->sig[0])
#endif
extern long ia64_do_signal (sigset_t *, struct sigscratch *, long); /* forward decl */
long
ia64_rt_sigsuspend (sigset_t *uset, size_t sigsetsize, struct sigscratch *scr)
{
sigset_t oldset, set;
/* XXX: Don't preclude handling different sized sigset_t's. */
if (sigsetsize != sizeof(sigset_t))
return -EINVAL;
if (!access_ok(VERIFY_READ, uset, sigsetsize))
return -EFAULT;
if (GET_SIGSET(&set, uset))
return -EFAULT;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(¤t->sigmask_lock);
{
oldset = current->blocked;
current->blocked = set;
recalc_sigpending(current);
}
spin_unlock_irq(¤t->sigmask_lock);
/*
* The return below usually returns to the signal handler. We need to
* pre-set the correct error code here to ensure that the right values
* get saved in sigcontext by ia64_do_signal.
*/
scr->pt.r8 = EINTR;
scr->pt.r10 = -1;
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (ia64_do_signal(&oldset, scr, 1))
return -EINTR;
}
}
asmlinkage long
sys_sigaltstack (const stack_t *uss, stack_t *uoss, long arg2, long arg3, long arg4,
long arg5, long arg6, long arg7, long stack)
{
struct pt_regs *pt = (struct pt_regs *) &stack;
return do_sigaltstack(uss, uoss, pt->r12);
}
static long
restore_sigcontext (struct sigcontext *sc, struct sigscratch *scr)
{
unsigned long ip, flags, nat, um, cfm;
long err;
/* restore scratch that always needs gets updated during signal delivery: */
err = __get_user(flags, &sc->sc_flags);
err |= __get_user(nat, &sc->sc_nat);
err |= __get_user(ip, &sc->sc_ip); /* instruction pointer */
err |= __get_user(cfm, &sc->sc_cfm);
err |= __get_user(um, &sc->sc_um); /* user mask */
err |= __get_user(scr->pt.ar_rsc, &sc->sc_ar_rsc);
err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv);
err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat);
err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr);
err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs);
err |= __get_user(scr->pt.pr, &sc->sc_pr); /* predicates */
err |= __get_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */
err |= __get_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */
err |= __get_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */
err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 3*8); /* r1-r3 */
err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8); /* r8-r11 */
err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 4*8); /* r12-r15 */
err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8); /* r16-r31 */
scr->pt.cr_ifs = cfm | (1UL << 63);
/* establish new instruction pointer: */
scr->pt.cr_iip = ip & ~0x3UL;
ia64_psr(&scr->pt)->ri = ip & 0x3;
scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM);
scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat);
if ((flags & IA64_SC_FLAG_FPH_VALID) != 0) {
struct ia64_psr *psr = ia64_psr(&scr->pt);
__copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16);
psr->mfh = 0; /* drop signal handler's fph contents... */
if (!psr->dfh)
__ia64_load_fpu(current->thread.fph);
}
return err;
}
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);
switch (from->si_code >> 16) {
case __SI_FAULT >> 16:
err |= __put_user(from->si_isr, &to->si_isr);
case __SI_POLL >> 16:
err |= __put_user(from->si_addr, &to->si_addr);
err |= __put_user(from->si_imm, &to->si_imm);
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);
case __SI_PROF >> 16:
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(from->si_pid, &to->si_pid);
err |= __put_user(from->si_pfm_ovfl, &to->si_pfm_ovfl);
break;
default:
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(from->si_pid, &to->si_pid);
break;
/* case __SI_RT: This is not generated by the kernel as of now. */
}
return err;
}
}
int
copy_siginfo_from_user (siginfo_t *to, siginfo_t *from)
{
if (!access_ok(VERIFY_READ, from, sizeof(siginfo_t)))
return -EFAULT;
if (__copy_from_user(to, from, sizeof(siginfo_t)) != 0)
return -EFAULT;
if (SI_FROMUSER(to))
return 0;
to->si_code &= ~__SI_MASK;
if (to->si_code != 0) {
switch (to->si_signo) {
case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: case SIGTRAP:
to->si_code |= __SI_FAULT;
break;
case SIGCHLD:
to->si_code |= __SI_CHLD;
break;
case SIGPOLL:
to->si_code |= __SI_POLL;
break;
case SIGPROF:
to->si_code |= __SI_PROF;
break;
default:
break;
}
}
return 0;
}
long
ia64_rt_sigreturn (struct sigscratch *scr)
{
extern char ia64_strace_leave_kernel, ia64_leave_kernel;
struct sigcontext *sc;
struct siginfo si;
sigset_t set;
long retval;
sc = &((struct sigframe *) (scr->pt.r12 + 16))->sc;
/*
* When we return to the previously executing context, r8 and r10 have already
* been setup the way we want them. Indeed, if the signal wasn't delivered while
* in a system call, we must not touch r8 or r10 as otherwise user-level state
* could be corrupted.
*/
retval = (long) &ia64_leave_kernel;
if (current->ptrace & PT_TRACESYS)
/*
* strace expects to be notified after sigreturn returns even though the
* context to which we return may not be in the middle of a syscall.
* Thus, the return-value that strace displays for sigreturn is
* meaningless.
*/
retval = (long) &ia64_strace_leave_kernel;
if (!access_ok(VERIFY_READ, sc, sizeof(*sc)))
goto give_sigsegv;
if (GET_SIGSET(&set, &sc->sc_mask))
goto give_sigsegv;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(¤t->sigmask_lock);
{
current->blocked = set;
recalc_sigpending(current);
}
spin_unlock_irq(¤t->sigmask_lock);
if (restore_sigcontext(sc, scr))
goto give_sigsegv;
#if DEBUG_SIG
printk("SIG return (%s:%d): sp=%lx ip=%lx\n",
current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip);
#endif
/*
* It is more difficult to avoid calling this function than to
* call it and ignore errors.
*/
do_sigaltstack(&sc->sc_stack, 0, scr->pt.r12);
return retval;
give_sigsegv:
si.si_signo = SIGSEGV;
si.si_errno = 0;
si.si_code = SI_KERNEL;
si.si_pid = current->pid;
si.si_uid = current->uid;
si.si_addr = sc;
force_sig_info(SIGSEGV, &si, current);
return retval;
}
/*
* This does just the minimum required setup of sigcontext.
* Specifically, it only installs data that is either not knowable at
* the user-level or that gets modified before execution in the
* trampoline starts. Everything else is done at the user-level.
*/
static long
setup_sigcontext (struct sigcontext *sc, sigset_t *mask, struct sigscratch *scr)
{
unsigned long flags = 0, ifs, nat;
long err;
ifs = scr->pt.cr_ifs;
if (on_sig_stack((unsigned long) sc))
flags |= IA64_SC_FLAG_ONSTACK;
if ((ifs & (1UL << 63)) == 0) {
/* if cr_ifs isn't valid, we got here through a syscall */
flags |= IA64_SC_FLAG_IN_SYSCALL;
}
ia64_flush_fph(current);
if ((current->thread.flags & IA64_THREAD_FPH_VALID)) {
flags |= IA64_SC_FLAG_FPH_VALID;
__copy_to_user(&sc->sc_fr[32], current->thread.fph, 96*16);
}
/*
* Note: sw->ar_unat is UNDEFINED unless the process is being
* PTRACED. However, this is OK because the NaT bits of the
* preserved registers (r4-r7) are never being looked at by
* the signal handler (registers r4-r7 are used instead).
*/
nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat);
err = __put_user(flags, &sc->sc_flags);
err |= __put_user(nat, &sc->sc_nat);
err |= PUT_SIGSET(mask, &sc->sc_mask);
err |= __put_user(scr->pt.cr_ipsr & IA64_PSR_UM, &sc->sc_um);
err |= __put_user(scr->pt.ar_rsc, &sc->sc_ar_rsc);
err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv);
err |= __put_user(scr->pt.ar_unat, &sc->sc_ar_unat); /* ar.unat */
err |= __put_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); /* ar.fpsr */
err |= __put_user(scr->pt.ar_pfs, &sc->sc_ar_pfs);
err |= __put_user(scr->pt.pr, &sc->sc_pr); /* predicates */
err |= __put_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */
err |= __put_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */
err |= __put_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */
err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 3*8); /* r1-r3 */
err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8); /* r8-r11 */
err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 4*8); /* r12-r15 */
err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8); /* r16-r31 */
err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip);
return err;
}
static long
setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set,
struct sigscratch *scr)
{
extern char ia64_sigtramp[], __start_gate_section[];
unsigned long tramp_addr, new_rbs = 0;
struct sigframe *frame;
struct siginfo si;
long err;
frame = (void *) scr->pt.r12;
tramp_addr = GATE_ADDR + (ia64_sigtramp - __start_gate_section);
if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack((unsigned long) frame)) {
new_rbs = (current->sas_ss_sp + sizeof(long) - 1) & ~(sizeof(long) - 1);
frame = (void *) ((current->sas_ss_sp + current->sas_ss_size)
& ~(STACK_ALIGN - 1));
}
frame = (void *) frame - ((sizeof(*frame) + STACK_ALIGN - 1) & ~(STACK_ALIGN - 1));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
err = __put_user(sig, &frame->arg0);
err |= __put_user(&frame->info, &frame->arg1);
err |= __put_user(&frame->sc, &frame->arg2);
err |= __put_user(new_rbs, &frame->sc.sc_rbs_base);
err |= __put_user(0, &frame->sc.sc_loadrs); /* initialize to zero */
err |= __put_user(ka->sa.sa_handler, &frame->handler);
err |= copy_siginfo_to_user(&frame->info, info);
err |= __put_user(current->sas_ss_sp, &frame->sc.sc_stack.ss_sp);
err |= __put_user(current->sas_ss_size, &frame->sc.sc_stack.ss_size);
err |= __put_user(sas_ss_flags(scr->pt.r12), &frame->sc.sc_stack.ss_flags);
err |= setup_sigcontext(&frame->sc, set, scr);
if (err)
goto give_sigsegv;
scr->pt.r12 = (unsigned long) frame - 16; /* new stack pointer */
scr->pt.ar_fpsr = FPSR_DEFAULT; /* reset fpsr for signal handler */
scr->pt.cr_iip = tramp_addr;
ia64_psr(&scr->pt)->ri = 0; /* start executing in first slot */
/*
* Note: this affects only the NaT bits of the scratch regs (the ones saved in
* pt_regs), which is exactly what we want.
*/
scr->scratch_unat = 0; /* ensure NaT bits of r12 is clear */
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%lx\n",
current->comm, current->pid, sig, scr->pt.r12, scr->pt.cr_iip, scr->pt.r3);
#endif
return 1;
give_sigsegv:
if (sig == SIGSEGV)
ka->sa.sa_handler = SIG_DFL;
si.si_signo = SIGSEGV;
si.si_errno = 0;
si.si_code = SI_KERNEL;
si.si_pid = current->pid;
si.si_uid = current->uid;
si.si_addr = frame;
force_sig_info(SIGSEGV, &si, current);
return 0;
}
static long
handle_signal (unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset,
struct sigscratch *scr)
{
#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(&scr->pt)) {
/* send signal to IA-32 process */
if (!ia32_setup_frame1(sig, ka, info, oldset, &scr->pt))
return 0;
} else
#endif
/* send signal to IA-64 process */
if (!setup_frame(sig, ka, info, oldset, scr))
return 0;
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);
}
return 1;
}
/*
* 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.
*/
long
ia64_do_signal (sigset_t *oldset, struct sigscratch *scr, long in_syscall)
{
struct signal_struct *sig;
struct k_sigaction *ka;
siginfo_t info;
long restart = in_syscall;
long errno = scr->pt.r8;
/*
* In the ia64_leave_kernel code path, 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(&scr->pt))
return 0;
if (!oldset)
oldset = ¤t->blocked;
#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(&scr->pt)) {
if (in_syscall) {
if (errno >= 0)
restart = 0;
else
errno = -errno;
}
} else
#endif
if (scr->pt.r10 != -1) {
/*
* A system calls has to be restarted only if one of the error codes
* ERESTARTNOHAND, ERESTARTSYS, or ERESTARTNOINTR is returned. If r10
* isn't -1 then r8 doesn't hold an error code and we don't need to
* restart the syscall, so we can clear the "restart" flag here.
*/
restart = 0;
}
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->thread.siginfo = &info;
current->state = TASK_STOPPED;
notify_parent(current, SIGCHLD);
schedule();
signr = current->exit_code;
current->thread.siginfo = 0;
/* We're back. Did the debugger cancel the sig? */
if (!signr)
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;
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, &scr->pt))
exit_code |= 0x80;
/* FALLTHRU */
default:
sigaddset(¤t->pending.signal, signr);
recalc_sigpending(current);
current->flags |= PF_SIGNALED;
do_exit(exit_code);
/* NOTREACHED */
}
}
if (restart) {
switch (errno) {
case ERESTARTSYS:
if ((ka->sa.sa_flags & SA_RESTART) == 0) {
case ERESTARTNOHAND:
#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(&scr->pt))
scr->pt.r8 = -EINTR;
else
#endif
scr->pt.r8 = EINTR;
/* note: scr->pt.r10 is already -1 */
break;
}
case ERESTARTNOINTR:
#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(&scr->pt)) {
scr->pt.r8 = scr->pt.r1;
scr->pt.cr_iip -= 2;
} else
#endif
ia64_decrement_ip(&scr->pt);
}
}
/* Whee! Actually deliver the signal. If the
delivery failed, we need to continue to iterate in
this loop so we can deliver the SIGSEGV... */
if (handle_signal(signr, ka, &info, oldset, scr))
return 1;
}
/* Did we come from a system call? */
if (restart) {
/* Restart the system call - no handlers present */
if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR) {
#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(&scr->pt)) {
scr->pt.r8 = scr->pt.r1;
scr->pt.cr_iip -= 2;
} else
#endif
/*
* Note: the syscall number is in r15 which is
* saved in pt_regs so all we need to do here
* is adjust ip so that the "break"
* instruction gets re-executed.
*/
ia64_decrement_ip(&scr->pt);
}
}
return 0;
}
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