https://jxself.org/git/linux-libre.git
Tip revision: 1a05fe3feb7c3880b9c2e1b4c7759866192b44db authored by Jason Self on 10 March 2014, 16:45:11 UTC
Linux-libre 3.12.14-gnu
Linux-libre 3.12.14-gnu
Tip revision: 1a05fe3
signal.c
/*
* linux/arch/h8300/kernel/signal.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 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.
*/
/*
* uClinux H8/300 support by Yoshinori Sato <ysato@users.sourceforge.jp>
* and David McCullough <davidm@snapgear.com>
*
* Based on
* Linux/m68k by Hamish Macdonald
*/
/*
* ++roman (07/09/96): implemented signal stacks (specially for tosemu on
* Atari :-) Current limitation: Only one sigstack can be active at one time.
* If a second signal with SA_ONSTACK set arrives while working on a sigstack,
* SA_ONSTACK is ignored. This behaviour avoids lots of trouble with nested
* signal handlers!
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/syscalls.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/highuid.h>
#include <linux/personality.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
#include <linux/tracehook.h>
#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/traps.h>
#include <asm/ucontext.h>
/*
* Do a signal return; undo the signal stack.
*
* Keep the return code on the stack quadword aligned!
* That makes the cache flush below easier.
*/
struct sigframe
{
long dummy_er0;
long dummy_vector;
#if defined(CONFIG_CPU_H8S)
short dummy_exr;
#endif
long dummy_pc;
char *pretcode;
unsigned char retcode[8];
unsigned long extramask[_NSIG_WORDS-1];
struct sigcontext sc;
int sig;
} __attribute__((aligned(2),packed));
struct rt_sigframe
{
long dummy_er0;
long dummy_vector;
#if defined(CONFIG_CPU_H8S)
short dummy_exr;
#endif
long dummy_pc;
char *pretcode;
struct siginfo *pinfo;
void *puc;
unsigned char retcode[8];
struct siginfo info;
struct ucontext uc;
int sig;
} __attribute__((aligned(2),packed));
static inline int
restore_sigcontext(struct sigcontext *usc, int *pd0)
{
struct pt_regs *regs = current_pt_regs();
int err = 0;
unsigned int ccr;
unsigned int usp;
unsigned int er0;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
#define COPY(r) err |= __get_user(regs->r, &usc->sc_##r) /* restore passed registers */
COPY(er1);
COPY(er2);
COPY(er3);
COPY(er5);
COPY(pc);
ccr = regs->ccr & 0x10;
COPY(ccr);
#undef COPY
regs->ccr &= 0xef;
regs->ccr |= ccr;
regs->orig_er0 = -1; /* disable syscall checks */
err |= __get_user(usp, &usc->sc_usp);
wrusp(usp);
err |= __get_user(er0, &usc->sc_er0);
*pd0 = er0;
return err;
}
asmlinkage int sys_sigreturn(void)
{
unsigned long usp = rdusp();
struct sigframe *frame = (struct sigframe *)(usp - 4);
sigset_t set;
int er0;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.sc_mask) ||
(_NSIG_WORDS > 1 &&
__copy_from_user(&set.sig[1], &frame->extramask,
sizeof(frame->extramask))))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(&frame->sc, &er0))
goto badframe;
return er0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
asmlinkage int sys_rt_sigreturn(void)
{
unsigned long usp = rdusp();
struct rt_sigframe *frame = (struct rt_sigframe *)(usp - 4);
sigset_t set;
int er0;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(&frame->uc.uc_mcontext, &er0))
goto badframe;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return er0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
unsigned long mask)
{
int err = 0;
err |= __put_user(regs->er0, &sc->sc_er0);
err |= __put_user(regs->er1, &sc->sc_er1);
err |= __put_user(regs->er2, &sc->sc_er2);
err |= __put_user(regs->er3, &sc->sc_er3);
err |= __put_user(regs->er4, &sc->sc_er4);
err |= __put_user(regs->er5, &sc->sc_er5);
err |= __put_user(regs->er6, &sc->sc_er6);
err |= __put_user(rdusp(), &sc->sc_usp);
err |= __put_user(regs->pc, &sc->sc_pc);
err |= __put_user(regs->ccr, &sc->sc_ccr);
err |= __put_user(mask, &sc->sc_mask);
return err;
}
static inline void *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
{
unsigned long usp;
/* Default to using normal stack. */
usp = rdusp();
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (!sas_ss_flags(usp))
usp = current->sas_ss_sp + current->sas_ss_size;
}
return (void *)((usp - frame_size) & -8UL);
}
static int setup_frame (int sig, struct k_sigaction *ka,
sigset_t *set, struct pt_regs *regs)
{
struct sigframe *frame;
int err = 0;
int usig;
unsigned char *ret;
frame = get_sigframe(ka, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
usig = current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig;
err |= __put_user(usig, &frame->sig);
if (err)
goto give_sigsegv;
err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
if (err)
goto give_sigsegv;
if (_NSIG_WORDS > 1) {
err |= copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask));
if (err)
goto give_sigsegv;
}
ret = frame->retcode;
if (ka->sa.sa_flags & SA_RESTORER)
ret = (unsigned char *)(ka->sa.sa_restorer);
else {
/* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
(unsigned long *)(frame->retcode + 0));
err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
}
/* Set up to return from userspace. */
err |= __put_user(ret, &frame->pretcode);
if (err)
goto give_sigsegv;
/* Set up registers for signal handler */
wrusp ((unsigned long) frame);
regs->pc = (unsigned long) ka->sa.sa_handler;
regs->er0 = (current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig);
regs->er1 = (unsigned long)&(frame->sc);
regs->er5 = current->mm->start_data; /* GOT base */
return 0;
give_sigsegv:
force_sigsegv(sig, current);
return -EFAULT;
}
static int 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 usig;
unsigned char *ret;
frame = get_sigframe(ka, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
usig = current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig;
err |= __put_user(usig, &frame->sig);
if (err)
goto give_sigsegv;
err |= __put_user(&frame->info, &frame->pinfo);
err |= __put_user(&frame->uc, &frame->puc);
err |= copy_siginfo_to_user(&frame->info, info);
if (err)
goto give_sigsegv;
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __save_altstack(&frame->uc.uc_stack, rdusp());
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
err |= copy_to_user (&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
goto give_sigsegv;
/* Set up to return from userspace. */
ret = frame->retcode;
if (ka->sa.sa_flags & SA_RESTORER)
ret = (unsigned char *)(ka->sa.sa_restorer);
else {
/* sub.l er0,er0; mov.b #__NR_sigreturn,r0l; trapa #0 */
err |= __put_user(0x1a80f800 + (__NR_sigreturn & 0xff),
(unsigned long *)(frame->retcode + 0));
err |= __put_user(0x5700, (unsigned short *)(frame->retcode + 4));
}
err |= __put_user(ret, &frame->pretcode);
if (err)
goto give_sigsegv;
/* Set up registers for signal handler */
wrusp ((unsigned long) frame);
regs->pc = (unsigned long) ka->sa.sa_handler;
regs->er0 = (current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig);
regs->er1 = (unsigned long)&(frame->info);
regs->er2 = (unsigned long)&frame->uc;
regs->er5 = current->mm->start_data; /* GOT base */
return 0;
give_sigsegv:
force_sigsegv(sig, current);
return -EFAULT;
}
/*
* OK, we're invoking a handler
*/
static void
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
struct pt_regs * regs)
{
sigset_t *oldset = sigmask_to_save();
int ret;
/* are we from a system call? */
if (regs->orig_er0 >= 0) {
switch (regs->er0) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->er0 = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
regs->er0 = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->er0 = regs->orig_er0;
regs->pc -= 2;
}
}
/* set up the stack frame */
if (ka->sa.sa_flags & SA_SIGINFO)
ret = setup_rt_frame(sig, ka, info, oldset, regs);
else
ret = setup_frame(sig, ka, oldset, regs);
if (!ret)
signal_delivered(sig, info, ka, regs, 0);
}
/*
* 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.
*/
static void do_signal(struct pt_regs *regs)
{
siginfo_t info;
int signr;
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 ((regs->ccr & 0x10))
return;
current->thread.esp0 = (unsigned long) regs;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
/* Whee! Actually deliver the signal. */
handle_signal(signr, &info, &ka, regs);
return;
}
/* Did we come from a system call? */
if (regs->orig_er0 >= 0) {
/* Restart the system call - no handlers present */
if (regs->er0 == -ERESTARTNOHAND ||
regs->er0 == -ERESTARTSYS ||
regs->er0 == -ERESTARTNOINTR) {
regs->er0 = regs->orig_er0;
regs->pc -= 2;
}
if (regs->er0 == -ERESTART_RESTARTBLOCK){
regs->er0 = __NR_restart_syscall;
regs->pc -= 2;
}
}
/* If there's no signal to deliver, we just restore the saved mask. */
restore_saved_sigmask();
}
asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags)
{
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
}