Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  x86: Fix atomic64_xxx_cx8() functions
  x86: Fix and improve cmpxchg_double{,_local}()
  x86_64, asm: Optimise fls(), ffs() and fls64()
  x86, bitops: Move fls64.h inside __KERNEL__
  x86: Fix and improve percpu_cmpxchg{8,16}b_double()
  x86: Report cpb and eff_freq_ro flags correctly
  x86/i386: Use less assembly in strlen(), speed things up a bit
  x86: Use the same node_distance for 32 and 64-bit
  x86: Fix rflags in FAKE_STACK_FRAME
  x86: Clean up and extend do_int3()
  x86: Call do_notify_resume() with interrupts enabled
  x86/div64: Add a micro-optimization shortcut if base is power of two
  x86-64: Cleanup some assembly entry points
  x86-64: Slightly shorten line system call entry and exit paths
  x86-64: Reduce amount of redundant code generated for invalidate_interruptNN
  x86-64: Slightly shorten int_ret_from_sys_call
  x86, efi: Convert efi_phys_get_time() args to physical addresses
  x86: Default to vsyscall=emulate
  x86-64: Set siginfo and context on vsyscall emulation faults
  x86: consolidate xchg and xadd macros
  ...

6 files changed, 94 insertions, 30 deletions

diff --git a/arch/x86/kernel/cpu/powerflags.c b/arch/x86/kernel/cpu/powerflags.c
index 5abbea2..7b3fe56 100644
--- a/arch/x86/kernel/cpu/powerflags.c
+++ b/arch/x86/kernel/cpu/powerflags.c
@@ -16,5 +16,6 @@ const char *const x86_power_flags[32] = {
 	"100mhzsteps",
 	"hwpstate",
 	"",	/* tsc invariant mapped to constant_tsc */
-		/* nothing */
+	"cpb",  /* core performance boost */
+	"eff_freq_ro", /* Readonly aperf/mperf */
 };
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index f3f6f53..22d0e21 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -625,6 +625,8 @@ work_notifysig:				# deal with pending signals and
 	movl %esp, %eax
 	jne work_notifysig_v86		# returning to kernel-space or
 					# vm86-space
+	TRACE_IRQS_ON
+	ENABLE_INTERRUPTS(CLBR_NONE)
 	xorl %edx, %edx
 	call do_notify_resume
 	jmp resume_userspace_sig
@@ -638,6 +640,8 @@ work_notifysig_v86:
 #else
 	movl %esp, %eax
 #endif
+	TRACE_IRQS_ON
+	ENABLE_INTERRUPTS(CLBR_NONE)
 	xorl %edx, %edx
 	call do_notify_resume
 	jmp resume_userspace_sig
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index faf8d5e..a20e1cb 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -221,7 +221,7 @@ ENDPROC(native_usergs_sysret64)
 	/*CFI_REL_OFFSET	ss,0*/
 	pushq_cfi %rax /* rsp */
 	CFI_REL_OFFSET	rsp,0
-	pushq_cfi $X86_EFLAGS_IF /* eflags - interrupts on */
+	pushq_cfi $(X86_EFLAGS_IF|X86_EFLAGS_BIT1) /* eflags - interrupts on */
 	/*CFI_REL_OFFSET	rflags,0*/
 	pushq_cfi $__KERNEL_CS /* cs */
 	/*CFI_REL_OFFSET	cs,0*/
@@ -411,7 +411,7 @@ ENTRY(ret_from_fork)
 	RESTORE_REST
 
 	testl $3, CS-ARGOFFSET(%rsp)		# from kernel_thread?
-	je   int_ret_from_sys_call
+	jz   retint_restore_args
 
 	testl $_TIF_IA32, TI_flags(%rcx)	# 32-bit compat task needs IRET
 	jnz  int_ret_from_sys_call
@@ -465,7 +465,7 @@ ENTRY(system_call)
 	 * after the swapgs, so that it can do the swapgs
 	 * for the guest and jump here on syscall.
 	 */
-ENTRY(system_call_after_swapgs)
+GLOBAL(system_call_after_swapgs)
 
 	movq	%rsp,PER_CPU_VAR(old_rsp)
 	movq	PER_CPU_VAR(kernel_stack),%rsp
@@ -478,8 +478,7 @@ ENTRY(system_call_after_swapgs)
 	movq  %rax,ORIG_RAX-ARGOFFSET(%rsp)
 	movq  %rcx,RIP-ARGOFFSET(%rsp)
 	CFI_REL_OFFSET rip,RIP-ARGOFFSET
-	GET_THREAD_INFO(%rcx)
-	testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags(%rcx)
+	testl $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
 	jnz tracesys
 system_call_fastpath:
 	cmpq $__NR_syscall_max,%rax
@@ -496,10 +495,9 @@ ret_from_sys_call:
 	/* edi:	flagmask */
 sysret_check:
 	LOCKDEP_SYS_EXIT
-	GET_THREAD_INFO(%rcx)
 	DISABLE_INTERRUPTS(CLBR_NONE)
 	TRACE_IRQS_OFF
-	movl TI_flags(%rcx),%edx
+	movl TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET),%edx
 	andl %edi,%edx
 	jnz  sysret_careful
 	CFI_REMEMBER_STATE
@@ -583,7 +581,7 @@ sysret_audit:
 	/* Do syscall tracing */
 tracesys:
 #ifdef CONFIG_AUDITSYSCALL
-	testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags(%rcx)
+	testl $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
 	jz auditsys
 #endif
 	SAVE_REST
@@ -612,8 +610,6 @@ tracesys:
 GLOBAL(int_ret_from_sys_call)
 	DISABLE_INTERRUPTS(CLBR_NONE)
 	TRACE_IRQS_OFF
-	testl $3,CS-ARGOFFSET(%rsp)
-	je retint_restore_args
 	movl $_TIF_ALLWORK_MASK,%edi
 	/* edi:	mask to check */
 GLOBAL(int_with_check)
@@ -953,6 +949,7 @@ END(common_interrupt)
 ENTRY(\sym)
 	INTR_FRAME
 	pushq_cfi $~(\num)
+.Lcommon_\sym:
 	interrupt \do_sym
 	jmp ret_from_intr
 	CFI_ENDPROC
@@ -976,13 +973,21 @@ apicinterrupt X86_PLATFORM_IPI_VECTOR \
 	x86_platform_ipi smp_x86_platform_ipi
 
 #ifdef CONFIG_SMP
-.irp idx,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15, \
+	ALIGN
+	INTR_FRAME
+.irp idx,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15, \
 	16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
 .if NUM_INVALIDATE_TLB_VECTORS > \idx
-apicinterrupt (INVALIDATE_TLB_VECTOR_START)+\idx \
-	invalidate_interrupt\idx smp_invalidate_interrupt
+ENTRY(invalidate_interrupt\idx)
+	pushq_cfi $~(INVALIDATE_TLB_VECTOR_START+\idx)
+	jmp .Lcommon_invalidate_interrupt0
+	CFI_ADJUST_CFA_OFFSET -8
+END(invalidate_interrupt\idx)
 .endif
 .endr
+	CFI_ENDPROC
+apicinterrupt INVALIDATE_TLB_VECTOR_START, \
+	invalidate_interrupt0, smp_invalidate_interrupt
 #endif
 
 apicinterrupt THRESHOLD_APIC_VECTOR \
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index ee5d4fb..15763af 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -293,7 +293,7 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 	regs.orig_ax = -1;
 	regs.ip = (unsigned long) kernel_thread_helper;
 	regs.cs = __KERNEL_CS | get_kernel_rpl();
-	regs.flags = X86_EFLAGS_IF | 0x2;
+	regs.flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
 
 	/* Ok, create the new process.. */
 	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index a8e3eb8..fa1191f 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -306,15 +306,10 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
 			== NOTIFY_STOP)
 		return;
 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
-#ifdef CONFIG_KPROBES
+
 	if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
 			== NOTIFY_STOP)
 		return;
-#else
-	if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP)
-			== NOTIFY_STOP)
-		return;
-#endif
 
 	preempt_conditional_sti(regs);
 	do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c
index e4d4a22..b07ba93 100644
--- a/arch/x86/kernel/vsyscall_64.c
+++ b/arch/x86/kernel/vsyscall_64.c
@@ -57,7 +57,7 @@ DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data) =
 	.lock = __SEQLOCK_UNLOCKED(__vsyscall_gtod_data.lock),
 };
 
-static enum { EMULATE, NATIVE, NONE } vsyscall_mode = NATIVE;
+static enum { EMULATE, NATIVE, NONE } vsyscall_mode = EMULATE;
 
 static int __init vsyscall_setup(char *str)
 {
@@ -140,11 +140,40 @@ static int addr_to_vsyscall_nr(unsigned long addr)
 	return nr;
 }
 
+static bool write_ok_or_segv(unsigned long ptr, size_t size)
+{
+	/*
+	 * XXX: if access_ok, get_user, and put_user handled
+	 * sig_on_uaccess_error, this could go away.
+	 */
+
+	if (!access_ok(VERIFY_WRITE, (void __user *)ptr, size)) {
+		siginfo_t info;
+		struct thread_struct *thread = &current->thread;
+
+		thread->error_code	= 6;  /* user fault, no page, write */
+		thread->cr2		= ptr;
+		thread->trap_no		= 14;
+
+		memset(&info, 0, sizeof(info));
+		info.si_signo		= SIGSEGV;
+		info.si_errno		= 0;
+		info.si_code		= SEGV_MAPERR;
+		info.si_addr		= (void __user *)ptr;
+
+		force_sig_info(SIGSEGV, &info, current);
+		return false;
+	} else {
+		return true;
+	}
+}
+
 bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 {
 	struct task_struct *tsk;
 	unsigned long caller;
 	int vsyscall_nr;
+	int prev_sig_on_uaccess_error;
 	long ret;
 
 	/*
@@ -180,35 +209,65 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	if (seccomp_mode(&tsk->seccomp))
 		do_exit(SIGKILL);
 
+	/*
+	 * With a real vsyscall, page faults cause SIGSEGV.  We want to
+	 * preserve that behavior to make writing exploits harder.
+	 */
+	prev_sig_on_uaccess_error = current_thread_info()->sig_on_uaccess_error;
+	current_thread_info()->sig_on_uaccess_error = 1;
+
+	/*
+	 * 0 is a valid user pointer (in the access_ok sense) on 32-bit and
+	 * 64-bit, so we don't need to special-case it here.  For all the
+	 * vsyscalls, 0 means "don't write anything" not "write it at
+	 * address 0".
+	 */
+	ret = -EFAULT;
 	switch (vsyscall_nr) {
 	case 0:
+		if (!write_ok_or_segv(regs->di, sizeof(struct timeval)) ||
+		    !write_ok_or_segv(regs->si, sizeof(struct timezone)))
+			break;
+
 		ret = sys_gettimeofday(
 			(struct timeval __user *)regs->di,
 			(struct timezone __user *)regs->si);
 		break;
 
 	case 1:
+		if (!write_ok_or_segv(regs->di, sizeof(time_t)))
+			break;
+
 		ret = sys_time((time_t __user *)regs->di);
 		break;
 
 	case 2:
+		if (!write_ok_or_segv(regs->di, sizeof(unsigned)) ||
+		    !write_ok_or_segv(regs->si, sizeof(unsigned)))
+			break;
+
 		ret = sys_getcpu((unsigned __user *)regs->di,
 				 (unsigned __user *)regs->si,
 				 0);
 		break;
 	}
 
+	current_thread_info()->sig_on_uaccess_error = prev_sig_on_uaccess_error;
+
 	if (ret == -EFAULT) {
-		/*
-		 * Bad news -- userspace fed a bad pointer to a vsyscall.
-		 *
-		 * With a real vsyscall, that would have caused SIGSEGV.
-		 * To make writing reliable exploits using the emulated
-		 * vsyscalls harder, generate SIGSEGV here as well.
-		 */
+		/* Bad news -- userspace fed a bad pointer to a vsyscall. */
 		warn_bad_vsyscall(KERN_INFO, regs,
 				  "vsyscall fault (exploit attempt?)");
-		goto sigsegv;
+
+		/*
+		 * If we failed to generate a signal for any reason,
+		 * generate one here.  (This should be impossible.)
+		 */
+		if (WARN_ON_ONCE(!sigismember(&tsk->pending.signal, SIGBUS) &&
+				 !sigismember(&tsk->pending.signal, SIGSEGV)))
+			goto sigsegv;
+
+		return true;  /* Don't emulate the ret. */
 	}
 
 	regs->ax = ret;