Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

18 files changed, 257 insertions, 245 deletions

diff --git a/arch/tile/kernel/compat.c b/arch/tile/kernel/compat.c
index bf5e9d70266..d67459b9ac2 100644
--- a/arch/tile/kernel/compat.c
+++ b/arch/tile/kernel/compat.c
@@ -16,7 +16,6 @@
 #define __SYSCALL_COMPAT
 
 #include <linux/compat.h>
-#include <linux/msg.h>
 #include <linux/syscalls.h>
 #include <linux/kdev_t.h>
 #include <linux/fs.h>
@@ -95,52 +94,10 @@ long compat_sys_sched_rr_get_interval(compat_pid_t pid,
 	return ret;
 }
 
-/*
- * The usual compat_sys_msgsnd() and _msgrcv() seem to be assuming
- * some different calling convention than our normal 32-bit tile code.
- */
-
-/* Already defined in ipc/compat.c, but we need it here. */
-struct compat_msgbuf {
-	compat_long_t mtype;
-	char mtext[1];
-};
-
-long tile_compat_sys_msgsnd(int msqid,
-			    struct compat_msgbuf __user *msgp,
-			    size_t msgsz, int msgflg)
-{
-	compat_long_t mtype;
-
-	if (get_user(mtype, &msgp->mtype))
-		return -EFAULT;
-	return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
-}
-
-long tile_compat_sys_msgrcv(int msqid,
-			    struct compat_msgbuf __user *msgp,
-			    size_t msgsz, long msgtyp, int msgflg)
-{
-	long err, mtype;
-
-	err =  do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg);
-	if (err < 0)
-		goto out;
-
-	if (put_user(mtype, &msgp->mtype))
-		err = -EFAULT;
- out:
-	return err;
-}
-
 /* Provide the compat syscall number to call mapping. */
 #undef __SYSCALL
 #define __SYSCALL(nr, call) [nr] = (call),
 
-/* The generic versions of these don't work for Tile. */
-#define compat_sys_msgrcv tile_compat_sys_msgrcv
-#define compat_sys_msgsnd tile_compat_sys_msgsnd
-
 /* See comments in sys.c */
 #define compat_sys_fadvise64_64 sys32_fadvise64_64
 #define compat_sys_readahead sys32_readahead
diff --git a/arch/tile/kernel/compat_signal.c b/arch/tile/kernel/compat_signal.c
index a7869ad6277..77763ccd5a7 100644
--- a/arch/tile/kernel/compat_signal.c
+++ b/arch/tile/kernel/compat_signal.c
@@ -303,10 +303,7 @@ long compat_sys_rt_sigreturn(struct pt_regs *regs)
 		goto badframe;
 
 	sigdelsetmask(&set, ~_BLOCKABLE);
-	spin_lock_irq(&current->sighand->siglock);
-	current->blocked = set;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	set_current_blocked(&set);
 
 	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
 		goto badframe;
diff --git a/arch/tile/kernel/early_printk.c b/arch/tile/kernel/early_printk.c
index 493a0e66d91..afb9c9a0d88 100644
--- a/arch/tile/kernel/early_printk.c
+++ b/arch/tile/kernel/early_printk.c
@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/string.h>
+#include <linux/irqflags.h>
 #include <asm/setup.h>
 #include <hv/hypervisor.h>
 
diff --git a/arch/tile/kernel/entry.S b/arch/tile/kernel/entry.S
index 431e9ae6048..ec91568df88 100644
--- a/arch/tile/kernel/entry.S
+++ b/arch/tile/kernel/entry.S
@@ -85,6 +85,7 @@ STD_ENTRY(cpu_idle_on_new_stack)
 /* Loop forever on a nap during SMP boot. */
 STD_ENTRY(smp_nap)
 	nap
+	nop       /* avoid provoking the icache prefetch with a jump */
 	j smp_nap /* we are not architecturally guaranteed not to exit nap */
 	jrp lr    /* clue in the backtracer */
 	STD_ENDPROC(smp_nap)
@@ -105,5 +106,6 @@ STD_ENTRY(_cpu_idle)
 	.global _cpu_idle_nap
 _cpu_idle_nap:
 	nap
+	nop       /* avoid provoking the icache prefetch with a jump */
 	jrp lr
 	STD_ENDPROC(_cpu_idle)
diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S
index aecc8ed5f39..5d56a1ef5ba 100644
--- a/arch/tile/kernel/intvec_32.S
+++ b/arch/tile/kernel/intvec_32.S
@@ -799,6 +799,10 @@ handle_interrupt:
  * This routine takes a boolean in r30 indicating if this is an NMI.
  * If so, we also expect a boolean in r31 indicating whether to
  * re-enable the oprofile interrupts.
+ *
+ * Note that .Lresume_userspace is jumped to directly in several
+ * places, and we need to make sure r30 is set correctly in those
+ * callers as well.
  */
 STD_ENTRY(interrupt_return)
 	/* If we're resuming to kernel space, don't check thread flags. */
@@ -1237,7 +1241,10 @@ handle_syscall:
 	bzt     r30, 1f
 	jal	do_syscall_trace
 	FEEDBACK_REENTER(handle_syscall)
-1:	j       .Lresume_userspace   /* jump into middle of interrupt_return */
+1:	{
+	 movei  r30, 0               /* not an NMI */
+	 j      .Lresume_userspace   /* jump into middle of interrupt_return */
+	}
 
 .Linvalid_syscall:
 	/* Report an invalid syscall back to the user program */
@@ -1246,7 +1253,10 @@ handle_syscall:
 	 movei  r28, -ENOSYS
 	}
 	sw      r29, r28
-	j       .Lresume_userspace   /* jump into middle of interrupt_return */
+	{
+	 movei  r30, 0               /* not an NMI */
+	 j      .Lresume_userspace   /* jump into middle of interrupt_return */
+	}
 	STD_ENDPROC(handle_syscall)
 
 	/* Return the address for oprofile to suppress in backtraces. */
@@ -1262,7 +1272,10 @@ STD_ENTRY(ret_from_fork)
 	jal     sim_notify_fork
 	jal     schedule_tail
 	FEEDBACK_REENTER(ret_from_fork)
-	j       .Lresume_userspace   /* jump into middle of interrupt_return */
+	{
+	 movei  r30, 0               /* not an NMI */
+	 j      .Lresume_userspace   /* jump into middle of interrupt_return */
+	}
 	STD_ENDPROC(ret_from_fork)
 
 	/*
@@ -1376,7 +1389,10 @@ handle_ill:
 
 	jal     send_sigtrap    /* issue a SIGTRAP */
 	FEEDBACK_REENTER(handle_ill)
-	j       .Lresume_userspace   /* jump into middle of interrupt_return */
+	{
+	 movei  r30, 0               /* not an NMI */
+	 j      .Lresume_userspace   /* jump into middle of interrupt_return */
+	}
 
 .Ldispatch_normal_ill:
 	{
diff --git a/arch/tile/kernel/intvec_64.S b/arch/tile/kernel/intvec_64.S
index 79c93e10ba2..49d9d662168 100644
--- a/arch/tile/kernel/intvec_64.S
+++ b/arch/tile/kernel/intvec_64.S
@@ -22,6 +22,7 @@
 #include <asm/irqflags.h>
 #include <asm/asm-offsets.h>
 #include <asm/types.h>
+#include <asm/signal.h>
 #include <hv/hypervisor.h>
 #include <arch/abi.h>
 #include <arch/interrupts.h>
@@ -605,6 +606,10 @@ handle_interrupt:
  * This routine takes a boolean in r30 indicating if this is an NMI.
  * If so, we also expect a boolean in r31 indicating whether to
  * re-enable the oprofile interrupts.
+ *
+ * Note that .Lresume_userspace is jumped to directly in several
+ * places, and we need to make sure r30 is set correctly in those
+ * callers as well.
  */
 STD_ENTRY(interrupt_return)
 	/* If we're resuming to kernel space, don't check thread flags. */
@@ -1039,11 +1044,28 @@ handle_syscall:
 
 	/* Do syscall trace again, if requested. */
 	ld	r30, r31
-	andi    r30, r30, _TIF_SYSCALL_TRACE
-	beqzt	r30, 1f
+	andi    r0, r30, _TIF_SYSCALL_TRACE
+	{
+	 andi    r0, r30, _TIF_SINGLESTEP
+	 beqzt   r0, 1f
+	}
 	jal	do_syscall_trace
 	FEEDBACK_REENTER(handle_syscall)
-1:	j       .Lresume_userspace   /* jump into middle of interrupt_return */
+	andi    r0, r30, _TIF_SINGLESTEP
+
+1:	beqzt	r0, 2f
+
+	/* Single stepping -- notify ptrace. */
+	{
+	 movei   r0, SIGTRAP
+	 jal     ptrace_notify
+	}
+	FEEDBACK_REENTER(handle_syscall)
+
+2:	{
+	 movei  r30, 0               /* not an NMI */
+	 j      .Lresume_userspace   /* jump into middle of interrupt_return */
+	}
 
 .Lcompat_syscall:
 	/*
@@ -1077,7 +1099,10 @@ handle_syscall:
 	 movei  r28, -ENOSYS
 	}
 	st      r29, r28
-	j       .Lresume_userspace   /* jump into middle of interrupt_return */
+	{
+	 movei  r30, 0               /* not an NMI */
+	 j      .Lresume_userspace   /* jump into middle of interrupt_return */
+	}
 	STD_ENDPROC(handle_syscall)
 
 	/* Return the address for oprofile to suppress in backtraces. */
@@ -1093,7 +1118,10 @@ STD_ENTRY(ret_from_fork)
 	jal     sim_notify_fork
 	jal     schedule_tail
 	FEEDBACK_REENTER(ret_from_fork)
-	j       .Lresume_userspace
+	{
+	 movei  r30, 0               /* not an NMI */
+	 j      .Lresume_userspace   /* jump into middle of interrupt_return */
+	}
 	STD_ENDPROC(ret_from_fork)
 
 /* Various stub interrupt handlers and syscall handlers */
@@ -1156,6 +1184,18 @@ int_unalign:
 	push_extra_callee_saves r0
 	j       do_trap
 
+/* Fill the return address stack with nonzero entries. */
+STD_ENTRY(fill_ra_stack)
+	{
+	 move	r0, lr
+	 jal	1f
+	}
+1:	jal	2f
+2:	jal	3f
+3:	jal	4f
+4:	jrp	r0
+	STD_ENDPROC(fill_ra_stack)
+
 /* Include .intrpt1 array of interrupt vectors */
 	.section ".intrpt1", "ax"
 
@@ -1166,7 +1206,7 @@ int_unalign:
 #define do_hardwall_trap bad_intr
 #endif
 
-	int_hand     INT_MEM_ERROR, MEM_ERROR, bad_intr
+	int_hand     INT_MEM_ERROR, MEM_ERROR, do_trap
 	int_hand     INT_SINGLE_STEP_3, SINGLE_STEP_3, bad_intr
 #if CONFIG_KERNEL_PL == 2
 	int_hand     INT_SINGLE_STEP_2, SINGLE_STEP_2, gx_singlestep_handle
diff --git a/arch/tile/kernel/module.c b/arch/tile/kernel/module.c
index b90ab992567..98d47692010 100644
--- a/arch/tile/kernel/module.c
+++ b/arch/tile/kernel/module.c
@@ -67,6 +67,8 @@ void *module_alloc(unsigned long size)
 	area = __get_vm_area(size, VM_ALLOC, MEM_MODULE_START, MEM_MODULE_END);
 	if (!area)
 		goto error;
+	area->nr_pages = npages;
+	area->pages = pages;
 
 	if (map_vm_area(area, prot_rwx, &pages)) {
 		vunmap(area->addr);
diff --git a/arch/tile/kernel/proc.c b/arch/tile/kernel/proc.c
index 62d820833c6..7a932704640 100644
--- a/arch/tile/kernel/proc.c
+++ b/arch/tile/kernel/proc.c
@@ -23,6 +23,7 @@
 #include <linux/sysctl.h>
 #include <linux/hardirq.h>
 #include <linux/mman.h>
+#include <asm/unaligned.h>
 #include <asm/pgtable.h>
 #include <asm/processor.h>
 #include <asm/sections.h>
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index 4c1ac6e5347..2d5ef617bb3 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -27,16 +27,18 @@
 #include <linux/kernel.h>
 #include <linux/tracehook.h>
 #include <linux/signal.h>
-#include <asm/system.h>
 #include <asm/stack.h>
+#include <asm/switch_to.h>
 #include <asm/homecache.h>
 #include <asm/syscalls.h>
 #include <asm/traps.h>
+#include <asm/setup.h>
 #ifdef CONFIG_HARDWALL
 #include <asm/hardwall.h>
 #endif
 #include <arch/chip.h>
 #include <arch/abi.h>
+#include <arch/sim_def.h>
 
 
 /*
@@ -108,9 +110,7 @@ void cpu_idle(void)
 		}
 		rcu_idle_exit();
 		tick_nohz_idle_exit();
-		preempt_enable_no_resched();
-		schedule();
-		preempt_disable();
+		schedule_preempt_disabled();
 	}
 }
 
@@ -286,7 +286,7 @@ struct task_struct *validate_current(void)
 	static struct task_struct corrupt = { .comm = "<corrupt>" };
 	struct task_struct *tsk = current;
 	if (unlikely((unsigned long)tsk < PAGE_OFFSET ||
-		     (void *)tsk > high_memory ||
+		     (high_memory && (void *)tsk > high_memory) ||
 		     ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) {
 		pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer);
 		tsk = &corrupt;
diff --git a/arch/tile/kernel/regs_32.S b/arch/tile/kernel/regs_32.S
index caa13101c26..c12280c2d90 100644
--- a/arch/tile/kernel/regs_32.S
+++ b/arch/tile/kernel/regs_32.S
@@ -13,11 +13,11 @@
  */
 
 #include <linux/linkage.h>
-#include <asm/system.h>
 #include <asm/ptrace.h>
 #include <asm/asm-offsets.h>
 #include <arch/spr_def.h>
 #include <asm/processor.h>
+#include <asm/switch_to.h>
 
 /*
  * See <asm/system.h>; called with prev and next task_struct pointers.
diff --git a/arch/tile/kernel/regs_64.S b/arch/tile/kernel/regs_64.S
index f748c1e8528..0829fd01fa3 100644
--- a/arch/tile/kernel/regs_64.S
+++ b/arch/tile/kernel/regs_64.S
@@ -13,11 +13,11 @@
  */
 
 #include <linux/linkage.h>
-#include <asm/system.h>
 #include <asm/ptrace.h>
 #include <asm/asm-offsets.h>
 #include <arch/spr_def.h>
 #include <asm/processor.h>
+#include <asm/switch_to.h>
 
 /*
  * See <asm/system.h>; called with prev and next task_struct pointers.
diff --git a/arch/tile/kernel/setup.c b/arch/tile/kernel/setup.c
index 5f85d8b34db..bff23f47611 100644
--- a/arch/tile/kernel/setup.c
+++ b/arch/tile/kernel/setup.c
@@ -103,13 +103,11 @@ unsigned long __initdata pci_reserve_end_pfn = -1U;
 
 static int __init setup_maxmem(char *str)
 {
-	long maxmem_mb;
-	if (str == NULL || strict_strtol(str, 0, &maxmem_mb) != 0 ||
-	    maxmem_mb == 0)
+	unsigned long long maxmem;
+	if (str == NULL || (maxmem = memparse(str, NULL)) == 0)
 		return -EINVAL;
 
-	maxmem_pfn = (maxmem_mb >> (HPAGE_SHIFT - 20)) <<
-		(HPAGE_SHIFT - PAGE_SHIFT);
+	maxmem_pfn = (maxmem >> HPAGE_SHIFT) << (HPAGE_SHIFT - PAGE_SHIFT);
 	pr_info("Forcing RAM used to no more than %dMB\n",
 	       maxmem_pfn >> (20 - PAGE_SHIFT));
 	return 0;
@@ -119,14 +117,15 @@ early_param("maxmem", setup_maxmem);
 static int __init setup_maxnodemem(char *str)
 {
 	char *endp;
-	long maxnodemem_mb, node;
+	unsigned long long maxnodemem;
+	long node;
 
 	node = str ? simple_strtoul(str, &endp, 0) : INT_MAX;
-	if (node >= MAX_NUMNODES || *endp != ':' ||
-	    strict_strtol(endp+1, 0, &maxnodemem_mb) != 0)
+	if (node >= MAX_NUMNODES || *endp != ':')
 		return -EINVAL;
 
-	maxnodemem_pfn[node] = (maxnodemem_mb >> (HPAGE_SHIFT - 20)) <<
+	maxnodemem = memparse(endp+1, NULL);
+	maxnodemem_pfn[node] = (maxnodemem >> HPAGE_SHIFT) <<
 		(HPAGE_SHIFT - PAGE_SHIFT);
 	pr_info("Forcing RAM used on node %ld to no more than %dMB\n",
 	       node, maxnodemem_pfn[node] >> (20 - PAGE_SHIFT));
@@ -913,6 +912,13 @@ void __cpuinit setup_cpu(int boot)
 
 #ifdef CONFIG_BLK_DEV_INITRD
 
+/*
+ * Note that the kernel can potentially support other compression
+ * techniques than gz, though we don't do so by default.  If we ever
+ * decide to do so we can either look for other filename extensions,
+ * or just allow a file with this name to be compressed with an
+ * arbitrary compressor (somewhat counterintuitively).
+ */
 static int __initdata set_initramfs_file;
 static char __initdata initramfs_file[128] = "initramfs.cpio.gz";
 
@@ -928,9 +934,9 @@ static int __init setup_initramfs_file(char *str)
 early_param("initramfs_file", setup_initramfs_file);
 
 /*
- * We look for an additional "initramfs.cpio.gz" file in the hvfs.
+ * We look for an "initramfs.cpio.gz" file in the hvfs.
  * If there is one, we allocate some memory for it and it will be
- * unpacked to the initramfs after any built-in initramfs_data.
+ * unpacked to the initramfs.
  */
 static void __init load_hv_initrd(void)
 {
@@ -1100,7 +1106,7 @@ EXPORT_SYMBOL(hash_for_home_map);
 
 /*
  * cpu_cacheable_map lists all the cpus whose caches the hypervisor can
- * flush on our behalf.  It is set to cpu_possible_map OR'ed with
+ * flush on our behalf.  It is set to cpu_possible_mask OR'ed with
  * hash_for_home_map, and it is what should be passed to
  * hv_flush_remote() to flush all caches.  Note that if there are
  * dedicated hypervisor driver tiles that have authorized use of their
@@ -1186,7 +1192,7 @@ static void __init setup_cpu_maps(void)
 			      sizeof(cpu_lotar_map));
 	if (rc < 0) {
 		pr_err("warning: no HV_INQ_TILES_LOTAR; using AVAIL\n");
-		cpu_lotar_map = cpu_possible_map;
+		cpu_lotar_map = *cpu_possible_mask;
 	}
 
 #if CHIP_HAS_CBOX_HOME_MAP()
@@ -1196,9 +1202,9 @@ static void __init setup_cpu_maps(void)
 			      sizeof(hash_for_home_map));
 	if (rc < 0)
 		early_panic("hv_inquire_tiles(HFH_CACHE) failed: rc %d\n", rc);
-	cpumask_or(&cpu_cacheable_map, &cpu_possible_map, &hash_for_home_map);
+	cpumask_or(&cpu_cacheable_map, cpu_possible_mask, &hash_for_home_map);
 #else
-	cpu_cacheable_map = cpu_possible_map;
+	cpu_cacheable_map = *cpu_possible_mask;
 #endif
 }
 
diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c
index bedaf4e9f3a..f79d4b88c74 100644
--- a/arch/tile/kernel/signal.c
+++ b/arch/tile/kernel/signal.c
@@ -97,10 +97,7 @@ SYSCALL_DEFINE1(rt_sigreturn, struct pt_regs *, regs)
 		goto badframe;
 
 	sigdelsetmask(&set, ~_BLOCKABLE);
-	spin_lock_irq(&current->sighand->siglock);
-	current->blocked = set;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	set_current_blocked(&set);
 
 	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
 		goto badframe;
@@ -286,13 +283,7 @@ static int handle_signal(unsigned long sig, siginfo_t *info,
 		 * the work_pending path in the return-to-user code, and
 		 * either way we can re-enable interrupts unconditionally.
 		 */
-		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);
+		block_sigmask(ka, sig);
 	}
 
 	return ret;
diff --git a/arch/tile/kernel/single_step.c b/arch/tile/kernel/single_step.c
index b7a87950408..9efbc1391b3 100644
--- a/arch/tile/kernel/single_step.c
+++ b/arch/tile/kernel/single_step.c
@@ -25,6 +25,7 @@
 #include <linux/types.h>
 #include <linux/err.h>
 #include <asm/cacheflush.h>
+#include <asm/unaligned.h>
 #include <arch/abi.h>
 #include <arch/opcode.h>
 
@@ -152,6 +153,25 @@ static tile_bundle_bits rewrite_load_store_unaligned(
 	if (((unsigned long)addr % size) == 0)
 		return bundle;
 
+	/*
+	 * Return SIGBUS with the unaligned address, if requested.
+	 * Note that we return SIGBUS even for completely invalid addresses
+	 * as long as they are in fact unaligned; this matches what the
+	 * tilepro hardware would be doing, if it could provide us with the
+	 * actual bad address in an SPR, which it doesn't.
+	 */
+	if (unaligned_fixup == 0) {
+		siginfo_t info = {
+			.si_signo = SIGBUS,
+			.si_code = BUS_ADRALN,
+			.si_addr = addr
+		};
+		trace_unhandled_signal("unaligned trap", regs,
+				       (unsigned long)addr, SIGBUS);
+		force_sig_info(info.si_signo, &info, current);
+		return (tilepro_bundle_bits) 0;
+	}
+
 #ifndef __LITTLE_ENDIAN
 # error We assume little-endian representation with copy_xx_user size 2 here
 #endif
@@ -191,18 +211,6 @@ static tile_bundle_bits rewrite_load_store_unaligned(
 		return (tile_bundle_bits) 0;
 	}
 
-	if (unaligned_fixup == 0) {
-		siginfo_t info = {
-			.si_signo = SIGBUS,
-			.si_code = BUS_ADRALN,
-			.si_addr = addr
-		};
-		trace_unhandled_signal("unaligned trap", regs,
-				       (unsigned long)addr, SIGBUS);
-		force_sig_info(info.si_signo, &info, current);
-		return (tile_bundle_bits) 0;
-	}
-
 	if (unaligned_printk || unaligned_fixup_count == 0) {
 		pr_info("Process %d/%s: PC %#lx: Fixup of"
 			" unaligned %s at %#lx.\n",
diff --git a/arch/tile/kernel/smp.c b/arch/tile/kernel/smp.c
index c52224d5ed4..91da0f72195 100644
--- a/arch/tile/kernel/smp.c
+++ b/arch/tile/kernel/smp.c
@@ -87,25 +87,6 @@ void send_IPI_allbutself(int tag)
 	send_IPI_many(&mask, tag);
 }
 
-
-/*
- * Provide smp_call_function_mask, but also run function locally
- * if specified in the mask.
- */
-void on_each_cpu_mask(const struct cpumask *mask, void (*func)(void *),
-		      void *info, bool wait)
-{
-	int cpu = get_cpu();
-	smp_call_function_many(mask, func, info, wait);
-	if (cpumask_test_cpu(cpu, mask)) {
-		local_irq_disable();
-		func(info);
-		local_irq_enable();
-	}
-	put_cpu();
-}
-
-
 /*
  * Functions related to starting/stopping cpus.
  */
@@ -122,7 +103,7 @@ static void smp_stop_cpu_interrupt(void)
 	set_cpu_online(smp_processor_id(), 0);
 	arch_local_irq_disable_all();
 	for (;;)
-		asm("nap");
+		asm("nap; nop");
 }
 
 /* This function calls the 'stop' function on all other CPUs in the system. */
@@ -132,6 +113,12 @@ void smp_send_stop(void)
 	send_IPI_allbutself(MSG_TAG_STOP_CPU);
 }
 
+/* On panic, just wait; we may get an smp_send_stop() later on. */
+void panic_smp_self_stop(void)
+{
+	while (1)
+		asm("nap; nop");
+}
 
 /*
  * Dispatch code called from hv_message_intr() for HV_MSG_TILE hv messages.
diff --git a/arch/tile/kernel/stack.c b/arch/tile/kernel/stack.c
index 37ee4d037e0..b2f44c28dda 100644
--- a/arch/tile/kernel/stack.c
+++ b/arch/tile/kernel/stack.c
@@ -21,10 +21,12 @@
 #include <linux/stacktrace.h>
 #include <linux/uaccess.h>
 #include <linux/mmzone.h>
+#include <linux/dcache.h>
+#include <linux/fs.h>
 #include <asm/backtrace.h>
 #include <asm/page.h>
-#include <asm/tlbflush.h>
 #include <asm/ucontext.h>
+#include <asm/switch_to.h>
 #include <asm/sigframe.h>
 #include <asm/stack.h>
 #include <arch/abi.h>
@@ -44,72 +46,23 @@ static int in_kernel_stack(struct KBacktraceIterator *kbt, unsigned long sp)
 	return sp >= kstack_base && sp < kstack_base + THREAD_SIZE;
 }
 
-/* Is address valid for reading? */
-static int valid_address(struct KBacktraceIterator *kbt, unsigned long address)
-{
-	HV_PTE *l1_pgtable = kbt->pgtable;
-	HV_PTE *l2_pgtable;
-	unsigned long pfn;
-	HV_PTE pte;
-	struct page *page;
-
-	if (l1_pgtable == NULL)
-		return 0;	/* can't read user space in other tasks */
-
-#ifdef CONFIG_64BIT
-	/* Find the real l1_pgtable by looking in the l0_pgtable. */
-	pte = l1_pgtable[HV_L0_INDEX(address)];
-	if (!hv_pte_get_present(pte))
-		return 0;
-	pfn = hv_pte_get_pfn(pte);
-	if (pte_huge(pte)) {
-		if (!pfn_valid(pfn)) {
-			pr_err("L0 huge page has bad pfn %#lx\n", pfn);
-			return 0;
-		}
-		return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
-	}
-	page = pfn_to_page(pfn);
-	BUG_ON(PageHighMem(page));  /* No HIGHMEM on 64-bit. */
-	l1_pgtable = (HV_PTE *)pfn_to_kaddr(pfn);
-#endif
-	pte = l1_pgtable[HV_L1_INDEX(address)];
-	if (!hv_pte_get_present(pte))
-		return 0;
-	pfn = hv_pte_get_pfn(pte);
-	if (pte_huge(pte)) {
-		if (!pfn_valid(pfn)) {
-			pr_err("huge page has bad pfn %#lx\n", pfn);
-			return 0;
-		}
-		return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
-	}
-
-	page = pfn_to_page(pfn);
-	if (PageHighMem(page)) {
-		pr_err("L2 page table not in LOWMEM (%#llx)\n",
-		       HV_PFN_TO_CPA(pfn));
-		return 0;
-	}
-	l2_pgtable = (HV_PTE *)pfn_to_kaddr(pfn);
-	pte = l2_pgtable[HV_L2_INDEX(address)];
-	return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
-}
-
 /* Callback for backtracer; basically a glorified memcpy */
 static bool read_memory_func(void *result, unsigned long address,
 			     unsigned int size, void *vkbt)
 {
 	int retval;
 	struct KBacktraceIterator *kbt = (struct KBacktraceIterator *)vkbt;
+
+	if (address == 0)
+		return 0;
 	if (__kernel_text_address(address)) {
 		/* OK to read kernel code. */
 	} else if (address >= PAGE_OFFSET) {
 		/* We only tolerate kernel-space reads of this task's stack */
 		if (!in_kernel_stack(kbt, address))
 			return 0;
-	} else if (!valid_address(kbt, address)) {
-		return 0;	/* invalid user-space address */
+	} else if (!kbt->is_current) {
+		return 0;	/* can't read from other user address spaces */
 	}
 	pagefault_disable();
 	retval = __copy_from_user_inatomic(result,
@@ -127,6 +80,8 @@ static struct pt_regs *valid_fault_handler(struct KBacktraceIterator* kbt)
 	unsigned long sp = kbt->it.sp;
 	struct pt_regs *p;
 
+	if (sp % sizeof(long) != 0)
+		return NULL;
 	if (!in_kernel_stack(kbt, sp))
 		return NULL;
 	if (!in_kernel_stack(kbt, sp + C_ABI_SAVE_AREA_SIZE + PTREGS_SIZE-1))
@@ -169,27 +124,27 @@ static int is_sigreturn(unsigned long pc)
 }
 
 /* Return a pt_regs pointer for a valid signal handler frame */
-static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt)
+static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt,
+				      struct rt_sigframe* kframe)
 {
 	BacktraceIterator *b = &kbt->it;
 
-	if (b->pc == VDSO_BASE) {
-		struct rt_sigframe *frame;
-		unsigned long sigframe_top =
-			b->sp + sizeof(struct rt_sigframe) - 1;
-		if (!valid_address(kbt, b->sp) ||
-		    !valid_address(kbt, sigframe_top)) {
-			if (kbt->verbose)
-				pr_err("  (odd signal: sp %#lx?)\n",
-				       (unsigned long)(b->sp));
+	if (b->pc == VDSO_BASE && b->sp < PAGE_OFFSET &&
+	    b->sp % sizeof(long) == 0) {
+		int retval;
+		pagefault_disable();
+		retval = __copy_from_user_inatomic(
+			kframe, (void __user __force *)b->sp,
+			sizeof(*kframe));
+		pagefault_enable();
+		if (retval != 0 ||
+		    (unsigned int)(kframe->info.si_signo) >= _NSIG)
 			return NULL;
-		}
-		frame = (struct rt_sigframe *)b->sp;
 		if (kbt->verbose) {
 			pr_err("  <received signal %d>\n",
-			       frame->info.si_signo);
+			       kframe->info.si_signo);
 		}
-		return (struct pt_regs *)&frame->uc.uc_mcontext;
+		return (struct pt_regs *)&kframe->uc.uc_mcontext;
 	}
 	return NULL;
 }
@@ -202,10 +157,11 @@ static int KBacktraceIterator_is_sigreturn(struct KBacktraceIterator *kbt)
 static int KBacktraceIterator_restart(struct KBacktraceIterator *kbt)
 {
 	struct pt_regs *p;
+	struct rt_sigframe kframe;
 
 	p = valid_fault_handler(kbt);
 	if (p == NULL)
-		p = valid_sigframe(kbt);
+		p = valid_sigframe(kbt, &kframe);
 	if (p == NULL)
 		return 0;
 	backtrace_init(&kbt->it, read_memory_func, kbt,
@@ -265,41 +221,19 @@ void KBacktraceIterator_init(struct KBacktraceIterator *kbt,
 
 	/*
 	 * Set up callback information.  We grab the kernel stack base
-	 * so we will allow reads of that address range, and if we're
-	 * asking about the current process we grab the page table
-	 * so we can check user accesses before trying to read them.
-	 * We flush the TLB to avoid any weird skew issues.
+	 * so we will allow reads of that address range.
 	 */
-	is_current = (t == NULL);
+	is_current = (t == NULL || t == current);
 	kbt->is_current = is_current;
 	if (is_current)
 		t = validate_current();
 	kbt->task = t;
-	kbt->pgtable = NULL;
 	kbt->verbose = 0;   /* override in caller if desired */
 	kbt->profile = 0;   /* override in caller if desired */
 	kbt->end = KBT_ONGOING;
-	kbt->new_context = 0;
-	if (is_current) {
-		HV_PhysAddr pgdir_pa = hv_inquire_context().page_table;
-		if (pgdir_pa == (unsigned long)swapper_pg_dir - PAGE_OFFSET) {
-			/*
-			 * Not just an optimization: this also allows
-			 * this to work at all before va/pa mappings
-			 * are set up.
-			 */
-			kbt->pgtable = swapper_pg_dir;
-		} else {
-			struct page *page = pfn_to_page(PFN_DOWN(pgdir_pa));
-			if (!PageHighMem(page))
-				kbt->pgtable = __va(pgdir_pa);
-			else
-				pr_err("page table not in LOWMEM"
-				       " (%#llx)\n", pgdir_pa);
-		}
-		local_flush_tlb_all();
+	kbt->new_context = 1;
+	if (is_current)
 		validate_stack(regs);
-	}
 
 	if (regs == NULL) {
 		if (is_current || t->state == TASK_RUNNING) {
@@ -345,6 +279,78 @@ void KBacktraceIterator_next(struct KBacktraceIterator *kbt)
 }
 EXPORT_SYMBOL(KBacktraceIterator_next);
 
+static void describe_addr(struct KBacktraceIterator *kbt,
+			  unsigned long address,
+			  int have_mmap_sem, char *buf, size_t bufsize)
+{
+	struct vm_area_struct *vma;
+	size_t namelen, remaining;
+	unsigned long size, offset, adjust;
+	char *p, *modname;
+	const char *name;
+	int rc;
+
+	/*
+	 * Look one byte back for every caller frame (i.e. those that
+	 * aren't a new context) so we look up symbol data for the
+	 * call itself, not the following instruction, which may be on
+	 * a different line (or in a different function).
+	 */
+	adjust = !kbt->new_context;
+	address -= adjust;
+
+	if (address >= PAGE_OFFSET) {
+		/* Handle kernel symbols. */
+		BUG_ON(bufsize < KSYM_NAME_LEN);
+		name = kallsyms_lookup(address, &size, &offset,
+				       &modname, buf);
+		if (name == NULL) {
+			buf[0] = '\0';
+			return;
+		}
+		namelen = strlen(buf);
+		remaining = (bufsize - 1) - namelen;
+		p = buf + namelen;
+		rc = snprintf(p, remaining, "+%#lx/%#lx ",
+			      offset + adjust, size);
+		if (modname && rc < remaining)
+			snprintf(p + rc, remaining - rc, "[%s] ", modname);
+		buf[bufsize-1] = '\0';
+		return;
+	}
+
+	/* If we don't have the mmap_sem, we can't show any more info. */
+	buf[0] = '\0';
+	if (!have_mmap_sem)
+		return;
+
+	/* Find vma info. */
+	vma = find_vma(kbt->task->mm, address);
+	if (vma == NULL || address < vma->vm_start) {
+		snprintf(buf, bufsize, "[unmapped address] ");
+		return;
+	}
+
+	if (vma->vm_file) {
+		char *s;
+		p = d_path(&vma->vm_file->f_path, buf, bufsize);
+		if (IS_ERR(p))
+			p = "?";
+		s = strrchr(p, '/');
+		if (s)
+			p = s+1;
+	} else {
+		p = "anon";
+	}
+
+	/* Generate a string description of the vma info. */
+	namelen = strlen(p);
+	remaining = (bufsize - 1) - namelen;
+	memmove(buf, p, namelen);
+	snprintf(buf + namelen, remaining, "[%lx+%lx] ",
+		 vma->vm_start, vma->vm_end - vma->vm_start);
+}
+
 /*
  * This method wraps the backtracer's more generic support.
  * It is only invoked from the architecture-specific code; show_stack()
@@ -353,6 +359,7 @@ EXPORT_SYMBOL(KBacktraceIterator_next);
 void tile_show_stack(struct KBacktraceIterator *kbt, int headers)
 {
 	int i;
+	int have_mmap_sem = 0;
 
 	if (headers) {
 		/*
@@ -369,31 +376,16 @@ void tile_show_stack(struct KBacktraceIterator *kbt, int headers)
 	kbt->verbose = 1;
 	i = 0;
 	for (; !KBacktraceIterator_end(kbt); KBacktraceIterator_next(kbt)) {
-		char *modname;
-		const char *name;
-		unsigned long address = kbt->it.pc;
-		unsigned long offset, size;
 		char namebuf[KSYM_NAME_LEN+100];
+		unsigned long address = kbt->it.pc;
 
-		if (address >= PAGE_OFFSET)
-			name = kallsyms_lookup(address, &size, &offset,
-					       &modname, namebuf);
-		else
-			name = NULL;
-
-		if (!name)
-			namebuf[0] = '\0';
-		else {
-			size_t namelen = strlen(namebuf);
-			size_t remaining = (sizeof(namebuf) - 1) - namelen;
-			char *p = namebuf + namelen;
-			int rc = snprintf(p, remaining, "+%#lx/%#lx ",
-					  offset, size);
-			if (modname && rc < remaining)
-				snprintf(p + rc, remaining - rc,
-					 "[%s] ", modname);
-			namebuf[sizeof(namebuf)-1] = '\0';
-		}
+		/* Try to acquire the mmap_sem as we pass into userspace. */
+		if (address < PAGE_OFFSET && !have_mmap_sem && kbt->task->mm)
+			have_mmap_sem =
+				down_read_trylock(&kbt->task->mm->mmap_sem);
+
+		describe_addr(kbt, address, have_mmap_sem,
+			      namebuf, sizeof(namebuf));
 
 		pr_err("  frame %d: 0x%lx %s(sp 0x%lx)\n",
 		       i++, address, namebuf, (unsigned long)(kbt->it.sp));
@@ -408,6 +400,8 @@ void tile_show_stack(struct KBacktraceIterator *kbt, int headers)
 		pr_err("Stack dump stopped; next frame identical to this one\n");
 	if (headers)
 		pr_err("Stack dump complete\n");
+	if (have_mmap_sem)
+		up_read(&kbt->task->mm->mmap_sem);
 }
 EXPORT_SYMBOL(tile_show_stack);
 
diff --git a/arch/tile/kernel/sysfs.c b/arch/tile/kernel/sysfs.c
index f862b005eb7..71ae728e9d0 100644
--- a/arch/tile/kernel/sysfs.c
+++ b/arch/tile/kernel/sysfs.c
@@ -163,7 +163,7 @@ static int __init create_sysfs_entries(void)
 
 #define create_hv_attr(name)						\
 	if (!err)							\
-		err = sysfs_create_file(hypervisor_kobj, &dev_attr_##name);
+		err = sysfs_create_file(hypervisor_kobj, &dev_attr_##name.attr);
 	create_hv_attr(type);
 	create_hv_attr(version);
 	create_hv_attr(config_version);
diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c
index 4f47b8a356d..73cff814ac5 100644
--- a/arch/tile/kernel/traps.c
+++ b/arch/tile/kernel/traps.c
@@ -21,6 +21,7 @@
 #include <linux/ptrace.h>
 #include <asm/stack.h>
 #include <asm/traps.h>
+#include <asm/setup.h>
 
 #include <arch/interrupts.h>
 #include <arch/spr_def.h>
@@ -199,7 +200,7 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 {
 	siginfo_t info = { 0 };
 	int signo, code;
-	unsigned long address;
+	unsigned long address = 0;
 	bundle_bits instr;
 
 	/* Re-enable interrupts. */
@@ -222,6 +223,10 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 	}
 
 	switch (fault_num) {
+	case INT_MEM_ERROR:
+		signo = SIGBUS;
+		code = BUS_OBJERR;
+		break;
 	case INT_ILL:
 		if (copy_from_user(&instr, (void __user *)regs->pc,
 				   sizeof(instr))) {
@@ -288,7 +293,10 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 		address = regs->pc;
 		break;
 #ifdef __tilegx__
-	case INT_ILL_TRANS:
+	case INT_ILL_TRANS: {
+		/* Avoid a hardware erratum with the return address stack. */
+		fill_ra_stack();
+
 		signo = SIGSEGV;
 		code = SEGV_MAPERR;
 		if (reason & SPR_ILL_TRANS_REASON__I_STREAM_VA_RMASK)
@@ -296,6 +304,7 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 		else
 			address = 0;  /* FIXME: GX: single-step for address */
 		break;
+	}
 #endif
 	default:
 		panic("Unexpected do_trap interrupt number %d", fault_num);
@@ -307,7 +316,8 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 	info.si_addr = (void __user *)address;
 	if (signo == SIGILL)
 		info.si_trapno = fault_num;
-	trace_unhandled_signal("trap", regs, address, signo);
+	if (signo != SIGTRAP)
+		trace_unhandled_signal("trap", regs, address, signo);
 	force_sig_info(signo, &info, current);
 }