arch/sparc/kernel/signal_64.c

Source file repositories/reference/linux-study-clean/arch/sparc/kernel/signal_64.c

File Facts

System
Linux kernel
Corpus path
arch/sparc/kernel/signal_64.c
Extension
.c
Size
18792 bytes
Lines
596
Domain
Architecture Layer
Bucket
arch/sparc
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct rt_signal_frame {
	struct sparc_stackf	ss;
	siginfo_t		info;
	struct pt_regs		regs;
	__siginfo_fpu_t __user	*fpu_save;
	stack_t			stack;
	sigset_t		mask;
	__siginfo_rwin_t	*rwin_save;
};

void do_rt_sigreturn(struct pt_regs *regs)
{
	unsigned long tpc, tnpc, tstate, ufp;
	struct rt_signal_frame __user *sf;
	__siginfo_fpu_t __user *fpu_save;
	__siginfo_rwin_t __user *rwin_save;
	sigset_t set;
	int err;

	/* Always make any pending restarted system calls return -EINTR */
	current->restart_block.fn = do_no_restart_syscall;

	synchronize_user_stack ();
	sf = (struct rt_signal_frame __user *)
		(regs->u_regs [UREG_FP] + STACK_BIAS);

	/* 1. Make sure we are not getting garbage from the user */
	if (invalid_frame_pointer(sf))
		goto segv;

	if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
		goto segv;

	if ((ufp + STACK_BIAS) & 0x7)
		goto segv;

	err = __get_user(tpc, &sf->regs.tpc);
	err |= __get_user(tnpc, &sf->regs.tnpc);
	if (test_thread_flag(TIF_32BIT)) {
		tpc &= 0xffffffff;
		tnpc &= 0xffffffff;
	}
	err |= ((tpc | tnpc) & 3);

	/* 2. Restore the state */
	err |= __get_user(regs->y, &sf->regs.y);
	err |= __get_user(tstate, &sf->regs.tstate);
	err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));

	/* User can only change condition codes and %asi in %tstate. */
	regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
	regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));

	err |= __get_user(fpu_save, &sf->fpu_save);
	if (!err && fpu_save)
		err |= restore_fpu_state(regs, fpu_save);

	err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
	err |= restore_altstack(&sf->stack);
	if (err)
		goto segv;

	err |= __get_user(rwin_save, &sf->rwin_save);
	if (!err && rwin_save) {
		if (restore_rwin_state(rwin_save))
			goto segv;
	}

	regs->tpc = tpc;
	regs->tnpc = tnpc;

	/* Prevent syscall restart.  */
	pt_regs_clear_syscall(regs);

	set_current_blocked(&set);
	return;
segv:
	force_sig(SIGSEGV);
}

static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
{
	unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;

	/*
	 * If we are on the alternate signal stack and would overflow it, don't.
	 * Return an always-bogus address instead so we will die with SIGSEGV.
	 */
	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
		return (void __user *) -1L;

Annotation

Implementation Notes