- 根目录:
- arch
- frv
- kernel
- signal.c
/* signal.c: FRV specific bits of signal handling
*
* Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* - Derived from arch/m68k/kernel/signal.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.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/personality.h>
#include <linux/tracehook.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#define DEBUG_SIG 0
struct fdpic_func_descriptor {
unsigned long text;
unsigned long GOT;
};
/*
* Do a signal return; undo the signal stack.
*/
struct sigframe
{
__sigrestore_t pretcode;
int sig;
struct sigcontext sc;
unsigned long extramask[_NSIG_WORDS-1];
uint32_t retcode[2];
};
struct rt_sigframe
{
__sigrestore_t pretcode;
int sig;
struct siginfo __user *pinfo;
void __user *puc;
struct siginfo info;
struct ucontext uc;
uint32_t retcode[2];
};
static int restore_sigcontext(struct sigcontext __user *sc, int *_gr8)
{
struct user_context *user = current->thread.user;
unsigned long tbr, psr;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
tbr = user->i.tbr;
psr = user->i.psr;
if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context)))
goto badframe;
user->i.tbr = tbr;
user->i.psr = psr;
restore_user_regs(user);
user->i.syscallno = -1; /* disable syscall checks */
*_gr8 = user->i.gr[8];
return 0;
badframe:
return 1;
}
asmlinkage int sys_sigreturn(void)
{
struct sigframe __user *frame = (struct sigframe __user *) __frame->sp;
sigset_t set;
int gr8;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.sc_oldmask))
goto badframe;
if (_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, &gr8))
goto badframe;
return gr8;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
asmlinkage int sys_rt_sigreturn(void)
{
struct rt_sigframe __user *frame = (struct rt_sigframe __user *) __frame->sp;
sigset_t set;
int gr8;
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, &gr8))
goto badframe;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return gr8;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame
*/
static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask)
{
save_user_regs(current->thread.user);
if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0)
goto badframe;
/* non-iBCS2 extensions.. */
if (__put_user(mask, &sc->sc_oldmask) < 0)
goto badframe;
return 0;
badframe:
return 1;
}
/*****************************************************************************/
/*
* Determine which stack to use..
*/
static inline void __user *get_sigframe(struct k_sigaction *ka,
size_t frame_size)
{
unsigned long sp;
/* Default to using normal stack */
sp = __frame->sp;
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (! sas_ss_flags(sp))
sp = current->sas_ss_sp + current->sas_ss_size;
}
return (void __user *) ((sp - frame_size) & ~7UL);
} /* end get_sigframe() */
/*****************************************************************************/
/*
*
*/
static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set)
{
struct sigframe __user *frame;
int rsig;
set_fs(USER_DS);
frame = get_sigframe(ka, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
rsig = sig;
if (sig < 32 &&
__current_thread_info->exec_domain &&
__current_thread_info->exec_domain->signal_invmap)
rsig = __current_thread_info->exec_domain->signal_invmap[sig];
if (__put_user(rsig, &frame->sig) < 0)
goto give_sigsegv;
if (setup_sigcontext(&frame->sc, set->sig[0]))
goto give_sigsegv;
if (_NSIG_WORDS > 1) {
if (__copy_to_user(frame->extramask, &set->sig[1],
sizeof(frame->extramask)))
goto give_sigsegv;
}
/* Set up to return from userspace. If provided, use a stub
* already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
if (__put_user(ka->sa.sa_restorer, &frame->pretcode) < 0)
goto give_sigsegv;
}
else {
/* Set up the following code on the stack:
* setlos #__NR_sigreturn,gr7
* tira gr0,0
*/
if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) ||
__put_user(0x8efc0000|__NR_sigreturn, &frame->retcode[0]) ||
__put_user(0xc0700000, &frame->retcode[1]))
goto give_sigsegv;
flush_icache_range((unsigned long) frame->retcode,
(unsigned long) (frame->retcode + 2));
}
/* Set up registers for the signal handler */
if (current->personality & FDPIC_FUNCPTRS) {
struct fdpic_func_descriptor __user *funcptr =
(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
struct fdpic_func_descriptor desc;
if (copy_from_user(&desc, funcptr, sizeof(desc)))
goto give_sigsegv;
__frame->pc = desc.text;
__frame->gr15 = desc.GOT;
} else {
__frame->pc = (unsigned long) ka->sa.sa_handler;
__frame->gr15 = 0;
}
__frame->sp = (unsigned long) frame;
__frame->lr = (unsigned long) &frame->retcode;
__frame->gr8 = sig;
#if DEBUG_SIG
printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
sig, current->comm, current->pid, frame, __frame->pc,
frame->pretcode);
#endif
return 0;
give_sigsegv:
force_sigsegv(sig, current);
return -EFAULT;
} /* end setup_frame() */
/*****************************************************************************/
/*
*
*/
static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set)
{
struct rt_sigframe __user *frame;
int rsig;
set_fs(USER_DS);
frame = get_sigframe(ka, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
rsig = sig;
if (sig < 32 &&
__current_thread_info->exec_domain &&
__current_thread_info->exec_domain->signal_invmap)
rsig = __current_thread_info->exec_domain->signal_invmap[sig];
if (__put_user(rsig, &frame->sig) ||
__put_user(&frame->info, &frame->pinfo) ||
__put_user(&frame->uc, &frame->puc))
goto give_sigsegv;
if (copy_siginfo_to_user(&frame->info, info))
goto give_sigsegv;
/* Create the ucontext. */
if (__put_user(0, &frame->uc.uc_flags) ||
__put_user(NULL, &frame->uc.uc_link) ||
__save_altstack(&frame->uc.uc_stack, __frame->sp))
goto give_sigsegv;
if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0]))
goto give_sigsegv;
if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
goto give_sigsegv;
/* Set up to return from userspace. If provided, use a stub
* already in userspace. */
if (ka->sa.sa_flags & SA_RESTORER) {
if (__put_user(ka->sa.sa_restorer, &frame->pretcode))
goto give_sigsegv;
}
else {
/* Set up the following code on the stack:
* setlos #__NR_sigreturn,gr7
* tira gr0,0
*/
if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) ||
__put_user(0x8efc0000|__NR_rt_sigreturn, &frame->retcode[0]) ||
__put_user(0xc0700000, &frame->retcode[1]))
goto give_sigsegv;
flush_icache_range((unsigned long) frame->retcode,
(unsigned long) (frame->retcode + 2));
}
/* Set up registers for signal handler */
if (current->personality & FDPIC_FUNCPTRS) {
struct fdpic_func_descriptor __user *funcptr =
(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
struct fdpic_func_descriptor desc;
if (copy_from_user(&desc, funcptr, sizeof(desc)))
goto give_sigsegv;
__frame->pc = desc.text;
__frame->gr15 = desc.GOT;
} else {
__frame->pc = (unsigned long) ka->sa.sa_handler;
__frame->gr15 = 0;
}
__frame->sp = (unsigned long) frame;
__frame->lr = (unsigned long) &frame->retcode;
__frame->gr8 = sig;
__frame->gr9 = (unsigned long) &frame->info;
#if DEBUG_SIG
printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
sig, current->comm, current->pid, frame, __frame->pc,
frame->pretcode);
#endif
return 0;
give_sigsegv:
force_sigsegv(sig, current);
return -EFAULT;
} /* end setup_rt_frame() */
/*****************************************************************************/
/*
* OK, we're invoking a handler
*/
static void handle_signal(unsigned long sig, siginfo_t *info,
struct k_sigaction *ka)
{
sigset_t *oldset = sigmask_to_save();
int ret;
/* Are we from a system call? */
if (__frame->syscallno != -1) {
/* If so, check system call restarting.. */
switch (__frame->gr8) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
__frame->gr8 = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
__frame->gr8 = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
__frame->gr8 = __frame->orig_gr8;
__frame->pc -= 4;
}
__frame->syscallno = -1;
}
/* Set up the stack frame */
if (ka->sa.sa_flags & SA_SIGINFO)
ret = setup_rt_frame(sig, ka, info, oldset);
else
ret = setup_frame(sig, ka, oldset);
if (ret)
return;
signal_delivered(sig, info, ka, __frame,
test_thread_flag(TIF_SINGLESTEP));
} /* end handle_signal() */
/*****************************************************************************/
/*
* 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(void)
{
struct k_sigaction ka;
siginfo_t info;
int signr;
signr = get_signal_to_deliver(&info, &ka, __frame, NULL);
if (signr > 0) {
handle_signal(signr, &info, &ka);
return;
}
/* Did we come from a system call? */
if (__frame->syscallno != -1) {
/* Restart the system call - no handlers present */
switch (__frame->gr8) {
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
__frame->gr8 = __frame->orig_gr8;
__frame->pc -= 4;
break;
case -ERESTART_RESTARTBLOCK:
__frame->gr7 = __NR_restart_syscall;
__frame->pc -= 4;
break;
}
__frame->syscallno = -1;
}
/* if there's no signal to deliver, we just put the saved sigmask
* back */
restore_saved_sigmask();
} /* end do_signal() */
/*****************************************************************************/
/*
* notification of userspace execution resumption
* - triggered by the TIF_WORK_MASK flags
*/
asmlinkage void do_notify_resume(__u32 thread_info_flags)
{
/* pending single-step? */
if (thread_info_flags & _TIF_SINGLESTEP)
clear_thread_flag(TIF_SINGLESTEP);
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal();
/* deal with notification on about to resume userspace execution */
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(__frame);
}
} /* end do_notify_resume() */