1 files changed, 162 insertions, 111 deletions

diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 6fb5bcdd8933..d6dd057d0f22 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -17,6 +17,7 @@
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
+#include <linux/tracehook.h>
 #include <linux/elf.h>
 #include <linux/smp.h>
 #include <linux/mm.h>
@@ -26,6 +27,8 @@
 #include <asm/uaccess.h>
 #include <asm/i387.h>
 #include <asm/vdso.h>
+#include <asm/syscall.h>
+#include <asm/syscalls.h>
 
 #include "sigframe.h"
 
@@ -110,6 +113,27 @@ asmlinkage int sys_sigaltstack(unsigned long bx)
 	return do_sigaltstack(uss, uoss, regs->sp);
 }
 
+#define COPY(x)			{		\
+	err |= __get_user(regs->x, &sc->x);	\
+}
+
+#define COPY_SEG(seg)		{			\
+		unsigned short tmp;			\
+		err |= __get_user(tmp, &sc->seg);	\
+		regs->seg = tmp;			\
+}
+
+#define COPY_SEG_STRICT(seg)	{			\
+		unsigned short tmp;			\
+		err |= __get_user(tmp, &sc->seg);	\
+		regs->seg = tmp | 3;			\
+}
+
+#define GET_SEG(seg)		{			\
+		unsigned short tmp;			\
+		err |= __get_user(tmp, &sc->seg);	\
+		loadsegment(seg, tmp);			\
+}
 
 /*
  * Do a signal return; undo the signal stack.
@@ -118,28 +142,13 @@ static int
 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
 		   unsigned long *pax)
 {
+	void __user *buf;
+	unsigned int tmpflags;
 	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)
-
-#define COPY_SEG(seg)							\
-	{ unsigned short tmp;						\
-	  err |= __get_user(tmp, &sc->seg);				\
-	  regs->seg = tmp; }
-
-#define COPY_SEG_STRICT(seg)						\
-	{ unsigned short tmp;						\
-	  err |= __get_user(tmp, &sc->seg);				\
-	  regs->seg = tmp|3; }
-
-#define GET_SEG(seg)							\
-	{ unsigned short tmp;						\
-	  err |= __get_user(tmp, &sc->seg);				\
-	  loadsegment(seg, tmp); }
-
 	GET_SEG(gs);
 	COPY_SEG(fs);
 	COPY_SEG(es);
@@ -149,38 +158,15 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
 	COPY_SEG_STRICT(cs);
 	COPY_SEG_STRICT(ss);
 
-	{
-		unsigned int tmpflags;
-
-		err |= __get_user(tmpflags, &sc->flags);
-		regs->flags = (regs->flags & ~FIX_EFLAGS) |
-						(tmpflags & FIX_EFLAGS);
-		regs->orig_ax = -1;		/* disable syscall checks */
-	}
+	err |= __get_user(tmpflags, &sc->flags);
+	regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
+	regs->orig_ax = -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(buf, &sc->fpstate);
+	err |= restore_i387_xstate(buf);
 
 	err |= __get_user(*pax, &sc->ax);
 	return err;
-
-badframe:
-	return 1;
 }
 
 asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
@@ -226,9 +212,8 @@ badframe:
 	return 0;
 }
 
-asmlinkage int sys_rt_sigreturn(unsigned long __unused)
+static long do_rt_sigreturn(struct pt_regs *regs)
 {
-	struct pt_regs *regs = (struct pt_regs *)&__unused;
 	struct rt_sigframe __user *frame;
 	unsigned long ax;
 	sigset_t set;
@@ -254,15 +239,22 @@ asmlinkage int sys_rt_sigreturn(unsigned long __unused)
 	return ax;
 
 badframe:
-	force_sig(SIGSEGV, current);
+	signal_fault(regs, frame, "rt_sigreturn");
 	return 0;
 }
 
+asmlinkage int sys_rt_sigreturn(unsigned long __unused)
+{
+	struct pt_regs *regs = (struct pt_regs *)&__unused;
+
+	return do_rt_sigreturn(regs);
+}
+
 /*
  * Set up a signal frame.
  */
 static int
-setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
+setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 		 struct pt_regs *regs, unsigned long mask)
 {
 	int tmp, err = 0;
@@ -289,7 +281,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
 	err |= __put_user(regs->sp, &sc->sp_at_signal);
 	err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
 
-	tmp = save_i387(fpstate);
+	tmp = save_i387_xstate(fpstate);
 	if (tmp < 0)
 		err = 1;
 	else
@@ -306,7 +298,8 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
  * Determine which stack to use..
  */
 static inline void __user *
-get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
+	     void **fpstate)
 {
 	unsigned long sp;
 
@@ -332,6 +325,11 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
 			sp = (unsigned long) ka->sa.sa_restorer;
 	}
 
+	if (used_math()) {
+		sp = sp - sig_xstate_size;
+		*fpstate = (struct _fpstate *) sp;
+	}
+
 	sp -= frame_size;
 	/*
 	 * Align the stack pointer according to the i386 ABI,
@@ -343,38 +341,29 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
 }
 
 static int
-setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
-	    struct pt_regs *regs)
+__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
+	      struct pt_regs *regs)
 {
 	struct sigframe __user *frame;
 	void __user *restorer;
 	int err = 0;
-	int usig;
+	void __user *fpstate = NULL;
 
-	frame = get_sigframe(ka, regs, sizeof(*frame));
+	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
 
 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
-		goto give_sigsegv;
+		return -EFAULT;
 
-	usig = current_thread_info()->exec_domain
-		&& current_thread_info()->exec_domain->signal_invmap
-		&& sig < 32
-		? current_thread_info()->exec_domain->signal_invmap[sig]
-		: sig;
+	if (__put_user(sig, &frame->sig))
+		return -EFAULT;
 
-	err = __put_user(usig, &frame->sig);
-	if (err)
-		goto give_sigsegv;
-
-	err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]);
-	if (err)
-		goto give_sigsegv;
+	if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
+		return -EFAULT;
 
 	if (_NSIG_WORDS > 1) {
-		err = __copy_to_user(&frame->extramask, &set->sig[1],
-				      sizeof(frame->extramask));
-		if (err)
-			goto give_sigsegv;
+		if (__copy_to_user(&frame->extramask, &set->sig[1],
+				   sizeof(frame->extramask)))
+			return -EFAULT;
 	}
 
 	if (current->mm->context.vdso)
@@ -399,7 +388,7 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
 	err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
 
 	if (err)
-		goto give_sigsegv;
+		return -EFAULT;
 
 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long)frame;
@@ -414,50 +403,43 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
 	regs->cs = __USER_CS;
 
 	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)
+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;
 	void __user *restorer;
 	int err = 0;
-	int usig;
+	void __user *fpstate = NULL;
 
-	frame = get_sigframe(ka, regs, sizeof(*frame));
+	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
 
 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
-		goto give_sigsegv;
+		return -EFAULT;
 
-	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);
+	err |= __put_user(sig, &frame->sig);
 	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;
+		return -EFAULT;
 
 	/* Create the ucontext.  */
-	err |= __put_user(0, &frame->uc.uc_flags);
+	if (cpu_has_xsave)
+		err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
+	else
+		err |= __put_user(0, &frame->uc.uc_flags);
 	err |= __put_user(0, &frame->uc.uc_link);
 	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 	err |= __put_user(sas_ss_flags(regs->sp),
 			  &frame->uc.uc_stack.ss_flags);
 	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
-	err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
+	err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
 				regs, set->sig[0]);
 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 	if (err)
-		goto give_sigsegv;
+		return -EFAULT;
 
 	/* Set up to return from userspace.  */
 	restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
@@ -477,12 +459,12 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
 
 	if (err)
-		goto give_sigsegv;
+		return -EFAULT;
 
 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long)frame;
 	regs->ip = (unsigned long)ka->sa.sa_handler;
-	regs->ax = (unsigned long)usig;
+	regs->ax = (unsigned long)sig;
 	regs->dx = (unsigned long)&frame->info;
 	regs->cx = (unsigned long)&frame->uc;
 
@@ -492,15 +474,48 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	regs->cs = __USER_CS;
 
 	return 0;
-
-give_sigsegv:
-	force_sigsegv(sig, current);
-	return -EFAULT;
 }
 
 /*
  * OK, we're invoking a handler:
  */
+static int signr_convert(int sig)
+{
+	struct thread_info *info = current_thread_info();
+
+	if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
+		return info->exec_domain->signal_invmap[sig];
+	return sig;
+}
+
+#define is_ia32	1
+#define ia32_setup_frame	__setup_frame
+#define ia32_setup_rt_frame	__setup_rt_frame
+
+static int
+setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+	       sigset_t *set, struct pt_regs *regs)
+{
+	int usig = signr_convert(sig);
+	int ret;
+
+	/* Set up the stack frame */
+	if (is_ia32) {
+		if (ka->sa.sa_flags & SA_SIGINFO)
+			ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
+		else
+			ret = ia32_setup_frame(usig, ka, set, regs);
+	} else
+		ret = __setup_rt_frame(sig, ka, info, set, regs);
+
+	if (ret) {
+		force_sigsegv(sig, current);
+		return -EFAULT;
+	}
+
+	return ret;
+}
+
 static int
 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 	      sigset_t *oldset, struct pt_regs *regs)
@@ -508,9 +523,9 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 	int ret;
 
 	/* Are we from a system call? */
-	if ((long)regs->orig_ax >= 0) {
+	if (syscall_get_nr(current, regs) >= 0) {
 		/* If so, check system call restarting.. */
-		switch (regs->ax) {
+		switch (syscall_get_error(current, regs)) {
 		case -ERESTART_RESTARTBLOCK:
 		case -ERESTARTNOHAND:
 			regs->ax = -EINTR;
@@ -537,15 +552,20 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 	    likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
 		regs->flags &= ~X86_EFLAGS_TF;
 
-	/* 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);
+	ret = setup_rt_frame(sig, ka, info, oldset, regs);
 
 	if (ret)
 		return ret;
 
+#ifdef CONFIG_X86_64
+	/*
+	 * This has nothing to do with segment registers,
+	 * despite the name.  This magic affects uaccess.h
+	 * macros' behavior.  Reset it to the normal setting.
+	 */
+	set_fs(USER_DS);
+#endif
+
 	/*
 	 * Clear the direction flag as per the ABI for function entry.
 	 */
@@ -558,8 +578,6 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 	 * handler too.
 	 */
 	regs->flags &= ~X86_EFLAGS_TF;
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
 
 	spin_lock_irq(&current->sighand->siglock);
 	sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
@@ -568,9 +586,13 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
+	tracehook_signal_handler(sig, info, ka, regs,
+				 test_thread_flag(TIF_SINGLESTEP));
+
 	return 0;
 }
 
+#define NR_restart_syscall	__NR_restart_syscall
 /*
  * 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
@@ -623,9 +645,9 @@ static void do_signal(struct pt_regs *regs)
 	}
 
 	/* Did we come from a system call? */
-	if ((long)regs->orig_ax >= 0) {
+	if (syscall_get_nr(current, regs) >= 0) {
 		/* Restart the system call - no handlers present */
-		switch (regs->ax) {
+		switch (syscall_get_error(current, regs)) {
 		case -ERESTARTNOHAND:
 		case -ERESTARTSYS:
 		case -ERESTARTNOINTR:
@@ -634,7 +656,7 @@ static void do_signal(struct pt_regs *regs)
 			break;
 
 		case -ERESTART_RESTARTBLOCK:
-			regs->ax = __NR_restart_syscall;
+			regs->ax = NR_restart_syscall;
 			regs->ip -= 2;
 			break;
 		}
@@ -657,9 +679,38 @@ static void do_signal(struct pt_regs *regs)
 void
 do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
 {
+#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
+	/* notify userspace of pending MCEs */
+	if (thread_info_flags & _TIF_MCE_NOTIFY)
+		mce_notify_user();
+#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
+
 	/* 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);
+	}
+
+#ifdef CONFIG_X86_32
 	clear_thread_flag(TIF_IRET);
+#endif /* CONFIG_X86_32 */
+}
+
+void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
+{
+	struct task_struct *me = current;
+
+	if (show_unhandled_signals && printk_ratelimit()) {
+		printk(KERN_INFO
+		       "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
+		       me->comm, me->pid, where, frame,
+		       regs->ip, regs->sp, regs->orig_ax);
+		print_vma_addr(" in ", regs->ip);
+		printk(KERN_CONT "\n");
+	}
+
+	force_sig(SIGSEGV, me);
 }