x86_64: move kernel

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 495 insertions, 0 deletions

diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
new file mode 100644
index 00000000000..739175b01e0
--- /dev/null
+++ b/arch/x86/kernel/signal_64.c
@@ -0,0 +1,495 @@
+/*
+ *  linux/arch/x86_64/kernel/signal.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
+ *
+ *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
+ *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
+ *  2000-2002   x86-64 support by Andi Kleen
+ */
+
+#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/stddef.h>
+#include <linux/personality.h>
+#include <linux/compiler.h>
+#include <asm/ucontext.h>
+#include <asm/uaccess.h>
+#include <asm/i387.h>
+#include <asm/proto.h>
+#include <asm/ia32_unistd.h>
+#include <asm/mce.h>
+
+/* #define DEBUG_SIG 1 */
+
+#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+
+int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+               sigset_t *set, struct pt_regs * regs); 
+int ia32_setup_frame(int sig, struct k_sigaction *ka,
+            sigset_t *set, struct pt_regs * regs); 
+
+asmlinkage long
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
+		struct pt_regs *regs)
+{
+	return do_sigaltstack(uss, uoss, regs->rsp);
+}
+
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+struct rt_sigframe
+{
+	char __user *pretcode;
+	struct ucontext uc;
+	struct siginfo info;
+};
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, unsigned long *prax)
+{
+	unsigned int err = 0;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+#define COPY(x)		err |= __get_user(regs->x, &sc->x)
+
+	COPY(rdi); COPY(rsi); COPY(rbp); COPY(rsp); COPY(rbx);
+	COPY(rdx); COPY(rcx); COPY(rip);
+	COPY(r8);
+	COPY(r9);
+	COPY(r10);
+	COPY(r11);
+	COPY(r12);
+	COPY(r13);
+	COPY(r14);
+	COPY(r15);
+
+	/* Kernel saves and restores only the CS segment register on signals,
+	 * which is the bare minimum needed to allow mixed 32/64-bit code.
+	 * App's signal handler can save/restore other segments if needed. */
+	{
+		unsigned cs;
+		err |= __get_user(cs, &sc->cs);
+		regs->cs = cs | 3;	/* Force into user mode */
+	}
+
+	{
+		unsigned int tmpflags;
+		err |= __get_user(tmpflags, &sc->eflags);
+		regs->eflags = (regs->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
+		regs->orig_rax = -1;		/* disable syscall checks */
+	}
+
+	{
+		struct _fpstate __user * buf;
+		err |= __get_user(buf, &sc->fpstate);
+
+		if (buf) {
+			if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
+				goto badframe;
+			err |= restore_i387(buf);
+		} else {
+			struct task_struct *me = current;
+			if (used_math()) {
+				clear_fpu(me);
+				clear_used_math();
+			}
+		}
+	}
+
+	err |= __get_user(*prax, &sc->rax);
+	return err;
+
+badframe:
+	return 1;
+}
+
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+	sigset_t set;
+	unsigned long eax;
+
+	frame = (struct rt_sigframe __user *)(regs->rsp - 8);
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) {
+		goto badframe;
+	} 
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) { 
+		goto badframe;
+	} 
+
+	sigdelsetmask(&set, ~_BLOCKABLE);
+	spin_lock_irq(&current->sighand->siglock);
+	current->blocked = set;
+	recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+	
+	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &eax))
+		goto badframe;
+
+#ifdef DEBUG_SIG
+	printk("%d sigreturn rip:%lx rsp:%lx frame:%p rax:%lx\n",current->pid,regs->rip,regs->rsp,frame,eax);
+#endif
+
+	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->rsp) == -EFAULT)
+		goto badframe;
+
+	return eax;
+
+badframe:
+	signal_fault(regs,frame,"sigreturn");
+	return 0;
+}	
+
+/*
+ * Set up a signal frame.
+ */
+
+static inline int
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask, struct task_struct *me)
+{
+	int err = 0;
+
+	err |= __put_user(regs->cs, &sc->cs);
+	err |= __put_user(0, &sc->gs);
+	err |= __put_user(0, &sc->fs);
+
+	err |= __put_user(regs->rdi, &sc->rdi);
+	err |= __put_user(regs->rsi, &sc->rsi);
+	err |= __put_user(regs->rbp, &sc->rbp);
+	err |= __put_user(regs->rsp, &sc->rsp);
+	err |= __put_user(regs->rbx, &sc->rbx);
+	err |= __put_user(regs->rdx, &sc->rdx);
+	err |= __put_user(regs->rcx, &sc->rcx);
+	err |= __put_user(regs->rax, &sc->rax);
+	err |= __put_user(regs->r8, &sc->r8);
+	err |= __put_user(regs->r9, &sc->r9);
+	err |= __put_user(regs->r10, &sc->r10);
+	err |= __put_user(regs->r11, &sc->r11);
+	err |= __put_user(regs->r12, &sc->r12);
+	err |= __put_user(regs->r13, &sc->r13);
+	err |= __put_user(regs->r14, &sc->r14);
+	err |= __put_user(regs->r15, &sc->r15);
+	err |= __put_user(me->thread.trap_no, &sc->trapno);
+	err |= __put_user(me->thread.error_code, &sc->err);
+	err |= __put_user(regs->rip, &sc->rip);
+	err |= __put_user(regs->eflags, &sc->eflags);
+	err |= __put_user(mask, &sc->oldmask);
+	err |= __put_user(me->thread.cr2, &sc->cr2);
+
+	return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+
+static void __user *
+get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size)
+{
+	unsigned long rsp;
+
+	/* Default to using normal stack - redzone*/
+	rsp = regs->rsp - 128;
+
+	/* This is the X/Open sanctioned signal stack switching.  */
+	if (ka->sa.sa_flags & SA_ONSTACK) {
+		if (sas_ss_flags(rsp) == 0)
+			rsp = current->sas_ss_sp + current->sas_ss_size;
+	}
+
+	return (void __user *)round_down(rsp - size, 16); 
+}
+
+static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+			   sigset_t *set, struct pt_regs * regs)
+{
+	struct rt_sigframe __user *frame;
+	struct _fpstate __user *fp = NULL; 
+	int err = 0;
+	struct task_struct *me = current;
+
+	if (used_math()) {
+		fp = get_stack(ka, regs, sizeof(struct _fpstate)); 
+		frame = (void __user *)round_down(
+			(unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
+
+		if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
+			goto give_sigsegv;
+
+		if (save_i387(fp) < 0) 
+			err |= -1; 
+	} else
+		frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		goto give_sigsegv;
+
+	if (ka->sa.sa_flags & SA_SIGINFO) { 
+		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 |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+	err |= __put_user(sas_ss_flags(regs->rsp),
+			  &frame->uc.uc_stack.ss_flags);
+	err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
+	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
+	err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
+	if (sizeof(*set) == 16) { 
+		__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
+		__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]); 
+	} else
+		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	/* x86-64 should always use SA_RESTORER. */
+	if (ka->sa.sa_flags & SA_RESTORER) {
+		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
+	} else {
+		/* could use a vstub here */
+		goto give_sigsegv; 
+	}
+
+	if (err)
+		goto give_sigsegv;
+
+#ifdef DEBUG_SIG
+	printk("%d old rip %lx old rsp %lx old rax %lx\n", current->pid,regs->rip,regs->rsp,regs->rax);
+#endif
+
+	/* Set up registers for signal handler */
+	regs->rdi = sig;
+	/* In case the signal handler was declared without prototypes */ 
+	regs->rax = 0;	
+
+	/* This also works for non SA_SIGINFO handlers because they expect the
+	   next argument after the signal number on the stack. */
+	regs->rsi = (unsigned long)&frame->info; 
+	regs->rdx = (unsigned long)&frame->uc; 
+	regs->rip = (unsigned long) ka->sa.sa_handler;
+
+	regs->rsp = (unsigned long)frame;
+
+	/* Set up the CS register to run signal handlers in 64-bit mode,
+	   even if the handler happens to be interrupting 32-bit code. */
+	regs->cs = __USER_CS;
+
+	/* This, by contrast, has nothing to do with segment registers -
+	   see include/asm-x86_64/uaccess.h for details. */
+	set_fs(USER_DS);
+
+	regs->eflags &= ~TF_MASK;
+	if (test_thread_flag(TIF_SINGLESTEP))
+		ptrace_notify(SIGTRAP);
+#ifdef DEBUG_SIG
+	printk("SIG deliver (%s:%d): sp=%p pc=%lx ra=%p\n",
+		current->comm, current->pid, frame, regs->rip, frame->pretcode);
+#endif
+
+	return 0;
+
+give_sigsegv:
+	force_sigsegv(sig, current);
+	return -EFAULT;
+}
+
+/*
+ * OK, we're invoking a handler
+ */	
+
+static int
+handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
+		sigset_t *oldset, struct pt_regs *regs)
+{
+	int ret;
+
+#ifdef DEBUG_SIG
+	printk("handle_signal pid:%d sig:%lu rip:%lx rsp:%lx regs=%p\n",
+		current->pid, sig,
+		regs->rip, regs->rsp, regs);
+#endif
+
+	/* Are we from a system call? */
+	if ((long)regs->orig_rax >= 0) {
+		/* If so, check system call restarting.. */
+		switch (regs->rax) {
+		        case -ERESTART_RESTARTBLOCK:
+			case -ERESTARTNOHAND:
+				regs->rax = -EINTR;
+				break;
+
+			case -ERESTARTSYS:
+				if (!(ka->sa.sa_flags & SA_RESTART)) {
+					regs->rax = -EINTR;
+					break;
+				}
+				/* fallthrough */
+			case -ERESTARTNOINTR:
+				regs->rax = regs->orig_rax;
+				regs->rip -= 2;
+				break;
+		}
+	}
+
+	/*
+	 * If TF is set due to a debugger (PT_DTRACE), clear the TF
+	 * flag so that register information in the sigcontext is
+	 * correct.
+	 */
+	if (unlikely(regs->eflags & TF_MASK)) {
+		if (likely(current->ptrace & PT_DTRACE)) {
+			current->ptrace &= ~PT_DTRACE;
+			regs->eflags &= ~TF_MASK;
+		}
+	}
+
+#ifdef CONFIG_IA32_EMULATION
+	if (test_thread_flag(TIF_IA32)) {
+		if (ka->sa.sa_flags & SA_SIGINFO)
+			ret = ia32_setup_rt_frame(sig, ka, info, oldset, regs);
+		else
+			ret = ia32_setup_frame(sig, ka, oldset, regs);
+	} else 
+#endif
+	ret = setup_rt_frame(sig, ka, info, oldset, regs);
+
+	if (ret == 0) {
+		spin_lock_irq(&current->sighand->siglock);
+		sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+		if (!(ka->sa.sa_flags & SA_NODEFER))
+			sigaddset(&current->blocked,sig);
+		recalc_sigpending();
+		spin_unlock_irq(&current->sighand->siglock);
+	}
+
+	return ret;
+}
+
+/*
+ * 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 k_sigaction ka;
+	siginfo_t info;
+	int signr;
+	sigset_t *oldset;
+
+	/*
+	 * 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 (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else
+		oldset = &current->blocked;
+
+	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+	if (signr > 0) {
+		/* Reenable any watchpoints before delivering the
+		 * signal to user space. The processor register will
+		 * have been cleared if the watchpoint triggered
+		 * inside the kernel.
+		 */
+		if (current->thread.debugreg7)
+			set_debugreg(current->thread.debugreg7, 7);
+
+		/* Whee!  Actually deliver the signal.  */
+		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
+			/* a signal was successfully delivered; the saved
+			 * sigmask will have been stored in the signal frame,
+			 * and will be restored by sigreturn, so we can simply
+			 * clear the TIF_RESTORE_SIGMASK flag */
+			clear_thread_flag(TIF_RESTORE_SIGMASK);
+		}
+		return;
+	}
+
+	/* Did we come from a system call? */
+	if ((long)regs->orig_rax >= 0) {
+		/* Restart the system call - no handlers present */
+		long res = regs->rax;
+		switch (res) {
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+			regs->rax = regs->orig_rax;
+			regs->rip -= 2;
+			break;
+		case -ERESTART_RESTARTBLOCK:
+			regs->rax = test_thread_flag(TIF_IA32) ?
+					__NR_ia32_restart_syscall :
+					__NR_restart_syscall;
+			regs->rip -= 2;
+			break;
+		}
+	}
+
+	/* if there's no signal to deliver, we just put the saved sigmask
+	   back. */
+	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+		clear_thread_flag(TIF_RESTORE_SIGMASK);
+		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+	}
+}
+
+void
+do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
+{
+#ifdef DEBUG_SIG
+	printk("do_notify_resume flags:%x rip:%lx rsp:%lx caller:%p pending:%x\n",
+	       thread_info_flags, regs->rip, regs->rsp, __builtin_return_address(0),signal_pending(current)); 
+#endif
+	       
+	/* Pending single-step? */
+	if (thread_info_flags & _TIF_SINGLESTEP) {
+		regs->eflags |= TF_MASK;
+		clear_thread_flag(TIF_SINGLESTEP);
+	}
+
+#ifdef CONFIG_X86_MCE
+	/* notify userspace of pending MCEs */
+	if (thread_info_flags & _TIF_MCE_NOTIFY)
+		mce_notify_user();
+#endif /* CONFIG_X86_MCE */
+
+	/* deal with pending signal delivery */
+	if (thread_info_flags & (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK))
+		do_signal(regs);
+}
+
+void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
+{ 
+	struct task_struct *me = current; 
+	if (show_unhandled_signals && printk_ratelimit())
+		printk("%s[%d] bad frame in %s frame:%p rip:%lx rsp:%lx orax:%lx\n",
+	       me->comm,me->pid,where,frame,regs->rip,regs->rsp,regs->orig_rax); 
+
+	force_sig(SIGSEGV, me); 
+}