swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: ae64f9bd1d3621b5e60d7363bc20afb46aede215 authored by Linus Torvalds on 03 December 2017, 16:01:47 UTC
Linux 4.15-rc2
Linux 4.15-rc2
Tip revision: ae64f9b
signal.c
// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/m32r/kernel/signal.c
*
* Copyright (c) 2003 Hitoshi Yamamoto
*
* Taken from i386 version.
* Copyright (C) 1991, 1992 Linus Torvalds
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
*/
#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/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/tracehook.h>
#include <asm/cacheflush.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>
#define DEBUG_SIG 0
/*
* Do a signal return; undo the signal stack.
*/
struct rt_sigframe
{
int sig;
struct siginfo __user *pinfo;
void __user *puc;
struct siginfo info;
struct ucontext uc;
// struct _fpstate fpstate;
};
static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
int *r0_p)
{
unsigned int err = 0;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
COPY(r4);
COPY(r5);
COPY(r6);
COPY(pt_regs);
/* COPY(r0); Skip r0 */
COPY(r1);
COPY(r2);
COPY(r3);
COPY(r7);
COPY(r8);
COPY(r9);
COPY(r10);
COPY(r11);
COPY(r12);
COPY(acc0h);
COPY(acc0l);
COPY(acc1h); /* ISA_DSP_LEVEL2 only */
COPY(acc1l); /* ISA_DSP_LEVEL2 only */
COPY(psw);
COPY(bpc);
COPY(bbpsw);
COPY(bbpc);
COPY(spu);
COPY(fp);
COPY(lr);
COPY(spi);
#undef COPY
regs->syscall_nr = -1; /* disable syscall checks */
err |= __get_user(*r0_p, &sc->sc_r0);
return err;
}
asmlinkage int
sys_rt_sigreturn(unsigned long r0, unsigned long r1,
unsigned long r2, unsigned long r3, unsigned long r4,
unsigned long r5, unsigned long r6, struct pt_regs *regs)
{
struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
sigset_t set;
int result;
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(regs, &frame->uc.uc_mcontext, &result))
goto badframe;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return result;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Set up a signal frame.
*/
static int
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
unsigned long mask)
{
int err = 0;
#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
COPY(r4);
COPY(r5);
COPY(r6);
COPY(pt_regs);
COPY(r0);
COPY(r1);
COPY(r2);
COPY(r3);
COPY(r7);
COPY(r8);
COPY(r9);
COPY(r10);
COPY(r11);
COPY(r12);
COPY(acc0h);
COPY(acc0l);
COPY(acc1h); /* ISA_DSP_LEVEL2 only */
COPY(acc1l); /* ISA_DSP_LEVEL2 only */
COPY(psw);
COPY(bpc);
COPY(bbpsw);
COPY(bbpc);
COPY(spu);
COPY(fp);
COPY(lr);
COPY(spi);
#undef COPY
err |= __put_user(mask, &sc->oldmask);
return err;
}
/*
* Determine which stack to use..
*/
static inline void __user *
get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size)
{
return (void __user *)((sigsp(sp, ksig) - frame_size) & -8ul);
}
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
int err = 0;
int sig = ksig->sig;
frame = get_sigframe(ksig, regs->spu, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
err |= __put_user(sig, &frame->sig);
if (err)
return -EFAULT;
err |= __put_user(&frame->info, &frame->pinfo);
err |= __put_user(&frame->uc, &frame->puc);
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
if (err)
return -EFAULT;
/* 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, regs->spu);
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
/* Set up to return from userspace. */
regs->lr = (unsigned long)ksig->ka.sa.sa_restorer;
/* Set up registers for signal handler */
regs->spu = (unsigned long)frame;
regs->r0 = sig; /* Arg for signal handler */
regs->r1 = (unsigned long)&frame->info;
regs->r2 = (unsigned long)&frame->uc;
regs->bpc = (unsigned long)ksig->ka.sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
current->comm, current->pid, frame, regs->pc);
#endif
return 0;
}
static int prev_insn(struct pt_regs *regs)
{
u16 inst;
if (get_user(inst, (u16 __user *)(regs->bpc - 2)))
return -EFAULT;
if ((inst & 0xfff0) == 0x10f0) /* trap ? */
regs->bpc -= 2;
else
regs->bpc -= 4;
regs->syscall_nr = -1;
return 0;
}
/*
* OK, we're invoking a handler
*/
static void
handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
int ret;
/* Are we from a system call? */
if (regs->syscall_nr >= 0) {
/* If so, check system call restarting.. */
switch (regs->r0) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->r0 = -EINTR;
break;
case -ERESTARTSYS:
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
regs->r0 = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->r0 = regs->orig_r0;
if (prev_insn(regs) < 0)
return;
}
}
/* Set up the stack frame */
ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
signal_setup_done(ret, ksig, 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)
{
struct ksignal ksig;
/*
* 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(regs))
return;
if (get_signal(&ksig)) {
/* Re-enable any watchpoints before delivering the
* signal to user space. The processor register will
* have been cleared if the watchpoint triggered
* inside the kernel.
*/
/* Whee! Actually deliver the signal. */
handle_signal(&ksig, regs);
return;
}
/* Did we come from a system call? */
if (regs->syscall_nr >= 0) {
/* Restart the system call - no handlers present */
if (regs->r0 == -ERESTARTNOHAND ||
regs->r0 == -ERESTARTSYS ||
regs->r0 == -ERESTARTNOINTR) {
regs->r0 = regs->orig_r0;
prev_insn(regs);
} else if (regs->r0 == -ERESTART_RESTARTBLOCK){
regs->r0 = regs->orig_r0;
regs->r7 = __NR_restart_syscall;
prev_insn(regs);
}
}
restore_saved_sigmask();
}
/*
* notification of userspace execution resumption
* - triggered by current->work.notify_resume
*/
void do_notify_resume(struct pt_regs *regs, __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(regs);
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
}