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

Pull perf updates from Ingo Molnar:
 "On the kernel side the main changes in this cycle were:

   - Add Intel Kaby Lake CPU support (Srinivas Pandruvada)

   - AMD uncore driver updates for fam17 (Janakarajan Natarajan)

   - Intel/PT updates and core events optimizations and cleanups
     (Alexander Shishkin)

   - cgroups events fixes (David Carrillo-Cisneros)

   - kprobes improvements (Masami Hiramatsu)

   - ... plus misc fixes and updates.

  On the tooling side the main changes were:

   - Support clang build in tools/{perf,lib/{bpf,traceevent,api}} with
     CC=clang, to, for instance, take advantage of better warnings
     (Arnaldo Carvalho de Melo):

   - Introduce the 'delta-abs' 'perf diff' compute method, that orders
     the histogram entries by the absolute value of the percentage delta
     for a function in two perf.data files, i.e. the functions that
     changed the most (increase or decrease in samples) comes first
     (Namhyung Kim)

   - Add support for parsing Intel uncore vendor event files and add
     uncore vendor events for the Intel server processors (Haswell,
     Broadwell, IvyBridge), Xeon Phi (Knights Landing) and Broadwell DE
     (Andi Kleen)

   - Introduce 'perf ftrace' a perf front end to the kernel's ftrace
     function and function_graph tracer, defaulting to the
     "function_graph" tracer, more work will be done in reviving this
     effort, forward porting it from its initial patch submission
     (Namhyung Kim)

   - Add 'e' and 'c' hotkeys to expand/collapse call chains for a single
     hist entry in the 'perf report' and 'perf top' TUI (Jiri Olsa)

   - Account thread wait time (off CPU time) separately: sleep, iowait
     and preempt, based on the prev_state of the last event, show the
     breakdown when using "perf sched timehist --state" (Namhyumg Kim)

   - Add more triggers to switch the output file (perf.data.TIMESTAMP).

     Now, in addition to switching to a different output file when
     receiving a SIGUSR2, one can also specify file size and time based
     triggers:

           perf record -a --switch-output=signal

     is equivalent to what we had before:

           perf record -a --switch-output

     While we can also ask for the file to be "sliced" by size, taking
     into account that that will happen only when we get woken up by the
     kernel, i.e. one has to take into account the --mmap-pages (the
     size of the perf mmap ring buffer):

           perf record -a --switch-output=2G

     will break the perf.data output into multiple files limited to 2GB
     of samples, right when generating the output.

     For time based samples, alert() will be used, so to have 1 minute
     limited perf.data output files:

          perf record -a --switch-output=1m

     (Jiri Olsa)

   - Improve 'perf trace' (Arnaldo Carvalho de Melo)

   - 'perf kallsyms' toy tool to look for extended symbol information on
     the running kernel and demonstrate the machine/thread/symbol APIs
     for use in other tools, such as 'perf probe' (Arnaldo Carvalho de
     Melo)

   - ... plus tons of other changes, see the shortlog and Git log for
     details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (131 commits)
  perf tools: Add missing parse_events_error() prototype
  perf pmu: Fix check for unset alias->unit array
  perf tools: Be consistent on the type of map->symbols[] interator
  perf intel pt decoder: clang has no -Wno-override-init
  perf evsel: Do not put a variable sized type not at the end of a struct
  perf probe: Avoid accessing uninitialized 'map' variable
  perf tools: Do not put a variable sized type not at the end of a struct
  perf record: Do not put a variable sized type not at the end of a struct
  perf tests: Synthesize struct instead of using field after variable sized type
  perf bench numa: Make sure dprintf() is not defined
  Revert "perf bench futex: Sanitize numeric parameters"
  tools lib subcmd: Make it an error to pass a signed value to OPTION_UINTEGER
  tools: Set the maximum optimization level according to the compiler being used
  tools: Suppress request for warning options not existent in clang
  samples/bpf: Reset global variables
  samples/bpf: Ignore already processed ELF sections
  samples/bpf: Add missing header
  perf symbols: dso->name is an array, no need to check it against NULL
  perf tests record: No need to test an array against NULL
  perf symbols: No need to check if sym->name is NULL
  ...

3 files changed, 219 insertions, 129 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index e235bb991bdd..77a932b54a64 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -355,6 +355,8 @@ enum event_type_t {
 	EVENT_FLEXIBLE = 0x1,
 	EVENT_PINNED = 0x2,
 	EVENT_TIME = 0x4,
+	/* see ctx_resched() for details */
+	EVENT_CPU = 0x8,
 	EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
 };
 
@@ -678,6 +680,8 @@ perf_cgroup_set_timestamp(struct task_struct *task,
 	info->timestamp = ctx->timestamp;
 }
 
+static DEFINE_PER_CPU(struct list_head, cgrp_cpuctx_list);
+
 #define PERF_CGROUP_SWOUT	0x1 /* cgroup switch out every event */
 #define PERF_CGROUP_SWIN	0x2 /* cgroup switch in events based on task */
 
@@ -690,61 +694,46 @@ perf_cgroup_set_timestamp(struct task_struct *task,
 static void perf_cgroup_switch(struct task_struct *task, int mode)
 {
 	struct perf_cpu_context *cpuctx;
-	struct pmu *pmu;
+	struct list_head *list;
 	unsigned long flags;
 
 	/*
-	 * disable interrupts to avoid geting nr_cgroup
-	 * changes via __perf_event_disable(). Also
-	 * avoids preemption.
+	 * Disable interrupts and preemption to avoid this CPU's
+	 * cgrp_cpuctx_entry to change under us.
 	 */
 	local_irq_save(flags);
 
-	/*
-	 * we reschedule only in the presence of cgroup
-	 * constrained events.
-	 */
+	list = this_cpu_ptr(&cgrp_cpuctx_list);
+	list_for_each_entry(cpuctx, list, cgrp_cpuctx_entry) {
+		WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0);
 
-	list_for_each_entry_rcu(pmu, &pmus, entry) {
-		cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
-		if (cpuctx->unique_pmu != pmu)
-			continue; /* ensure we process each cpuctx once */
-
-		/*
-		 * perf_cgroup_events says at least one
-		 * context on this CPU has cgroup events.
-		 *
-		 * ctx->nr_cgroups reports the number of cgroup
-		 * events for a context.
-		 */
-		if (cpuctx->ctx.nr_cgroups > 0) {
-			perf_ctx_lock(cpuctx, cpuctx->task_ctx);
-			perf_pmu_disable(cpuctx->ctx.pmu);
+		perf_ctx_lock(cpuctx, cpuctx->task_ctx);
+		perf_pmu_disable(cpuctx->ctx.pmu);
 
-			if (mode & PERF_CGROUP_SWOUT) {
-				cpu_ctx_sched_out(cpuctx, EVENT_ALL);
-				/*
-				 * must not be done before ctxswout due
-				 * to event_filter_match() in event_sched_out()
-				 */
-				cpuctx->cgrp = NULL;
-			}
+		if (mode & PERF_CGROUP_SWOUT) {
+			cpu_ctx_sched_out(cpuctx, EVENT_ALL);
+			/*
+			 * must not be done before ctxswout due
+			 * to event_filter_match() in event_sched_out()
+			 */
+			cpuctx->cgrp = NULL;
+		}
 
-			if (mode & PERF_CGROUP_SWIN) {
-				WARN_ON_ONCE(cpuctx->cgrp);
-				/*
-				 * set cgrp before ctxsw in to allow
-				 * event_filter_match() to not have to pass
-				 * task around
-				 * we pass the cpuctx->ctx to perf_cgroup_from_task()
-				 * because cgorup events are only per-cpu
-				 */
-				cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx);
-				cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
-			}
-			perf_pmu_enable(cpuctx->ctx.pmu);
-			perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
+		if (mode & PERF_CGROUP_SWIN) {
+			WARN_ON_ONCE(cpuctx->cgrp);
+			/*
+			 * set cgrp before ctxsw in to allow
+			 * event_filter_match() to not have to pass
+			 * task around
+			 * we pass the cpuctx->ctx to perf_cgroup_from_task()
+			 * because cgorup events are only per-cpu
+			 */
+			cpuctx->cgrp = perf_cgroup_from_task(task,
+							     &cpuctx->ctx);
+			cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
 		}
+		perf_pmu_enable(cpuctx->ctx.pmu);
+		perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
 	}
 
 	local_irq_restore(flags);
@@ -889,6 +878,7 @@ list_update_cgroup_event(struct perf_event *event,
 			 struct perf_event_context *ctx, bool add)
 {
 	struct perf_cpu_context *cpuctx;
+	struct list_head *cpuctx_entry;
 
 	if (!is_cgroup_event(event))
 		return;
@@ -902,15 +892,16 @@ list_update_cgroup_event(struct perf_event *event,
 	 * this will always be called from the right CPU.
 	 */
 	cpuctx = __get_cpu_context(ctx);
-
-	/*
-	 * cpuctx->cgrp is NULL until a cgroup event is sched in or
-	 * ctx->nr_cgroup == 0 .
-	 */
-	if (add && perf_cgroup_from_task(current, ctx) == event->cgrp)
-		cpuctx->cgrp = event->cgrp;
-	else if (!add)
+	cpuctx_entry = &cpuctx->cgrp_cpuctx_entry;
+	/* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/
+	if (add) {
+		list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list));
+		if (perf_cgroup_from_task(current, ctx) == event->cgrp)
+			cpuctx->cgrp = event->cgrp;
+	} else {
+		list_del(cpuctx_entry);
 		cpuctx->cgrp = NULL;
+	}
 }
 
 #else /* !CONFIG_CGROUP_PERF */
@@ -1453,6 +1444,20 @@ static void update_group_times(struct perf_event *leader)
 		update_event_times(event);
 }
 
+static enum event_type_t get_event_type(struct perf_event *event)
+{
+	struct perf_event_context *ctx = event->ctx;
+	enum event_type_t event_type;
+
+	lockdep_assert_held(&ctx->lock);
+
+	event_type = event->attr.pinned ? EVENT_PINNED : EVENT_FLEXIBLE;
+	if (!ctx->task)
+		event_type |= EVENT_CPU;
+
+	return event_type;
+}
+
 static struct list_head *
 ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
 {
@@ -2226,7 +2231,8 @@ ctx_sched_in(struct perf_event_context *ctx,
 	     struct task_struct *task);
 
 static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
-			       struct perf_event_context *ctx)
+			       struct perf_event_context *ctx,
+			       enum event_type_t event_type)
 {
 	if (!cpuctx->task_ctx)
 		return;
@@ -2234,7 +2240,7 @@ static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
 	if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
 		return;
 
-	ctx_sched_out(ctx, cpuctx, EVENT_ALL);
+	ctx_sched_out(ctx, cpuctx, event_type);
 }
 
 static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
@@ -2249,13 +2255,51 @@ static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
 		ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
 }
 
+/*
+ * We want to maintain the following priority of scheduling:
+ *  - CPU pinned (EVENT_CPU | EVENT_PINNED)
+ *  - task pinned (EVENT_PINNED)
+ *  - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
+ *  - task flexible (EVENT_FLEXIBLE).
+ *
+ * In order to avoid unscheduling and scheduling back in everything every
+ * time an event is added, only do it for the groups of equal priority and
+ * below.
+ *
+ * This can be called after a batch operation on task events, in which case
+ * event_type is a bit mask of the types of events involved. For CPU events,
+ * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
+ */
 static void ctx_resched(struct perf_cpu_context *cpuctx,
-			struct perf_event_context *task_ctx)
+			struct perf_event_context *task_ctx,
+			enum event_type_t event_type)
 {
+	enum event_type_t ctx_event_type = event_type & EVENT_ALL;
+	bool cpu_event = !!(event_type & EVENT_CPU);
+
+	/*
+	 * If pinned groups are involved, flexible groups also need to be
+	 * scheduled out.
+	 */
+	if (event_type & EVENT_PINNED)
+		event_type |= EVENT_FLEXIBLE;
+
 	perf_pmu_disable(cpuctx->ctx.pmu);
 	if (task_ctx)
-		task_ctx_sched_out(cpuctx, task_ctx);
-	cpu_ctx_sched_out(cpuctx, EVENT_ALL);
+		task_ctx_sched_out(cpuctx, task_ctx, event_type);
+
+	/*
+	 * Decide which cpu ctx groups to schedule out based on the types
+	 * of events that caused rescheduling:
+	 *  - EVENT_CPU: schedule out corresponding groups;
+	 *  - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
+	 *  - otherwise, do nothing more.
+	 */
+	if (cpu_event)
+		cpu_ctx_sched_out(cpuctx, ctx_event_type);
+	else if (ctx_event_type & EVENT_PINNED)
+		cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
+
 	perf_event_sched_in(cpuctx, task_ctx, current);
 	perf_pmu_enable(cpuctx->ctx.pmu);
 }
@@ -2302,7 +2346,7 @@ static int  __perf_install_in_context(void *info)
 	if (reprogram) {
 		ctx_sched_out(ctx, cpuctx, EVENT_TIME);
 		add_event_to_ctx(event, ctx);
-		ctx_resched(cpuctx, task_ctx);
+		ctx_resched(cpuctx, task_ctx, get_event_type(event));
 	} else {
 		add_event_to_ctx(event, ctx);
 	}
@@ -2469,7 +2513,7 @@ static void __perf_event_enable(struct perf_event *event,
 	if (ctx->task)
 		WARN_ON_ONCE(task_ctx != ctx);
 
-	ctx_resched(cpuctx, task_ctx);
+	ctx_resched(cpuctx, task_ctx, get_event_type(event));
 }
 
 /*
@@ -2896,7 +2940,7 @@ unlock:
 
 	if (do_switch) {
 		raw_spin_lock(&ctx->lock);
-		task_ctx_sched_out(cpuctx, ctx);
+		task_ctx_sched_out(cpuctx, ctx, EVENT_ALL);
 		raw_spin_unlock(&ctx->lock);
 	}
 }
@@ -2943,7 +2987,7 @@ static void perf_pmu_sched_task(struct task_struct *prev,
 		return;
 
 	list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) {
-		pmu = cpuctx->unique_pmu; /* software PMUs will not have sched_task */
+		pmu = cpuctx->ctx.pmu; /* software PMUs will not have sched_task */
 
 		if (WARN_ON_ONCE(!pmu->sched_task))
 			continue;
@@ -3133,8 +3177,12 @@ static void perf_event_context_sched_in(struct perf_event_context *ctx,
 	 * We want to keep the following priority order:
 	 * cpu pinned (that don't need to move), task pinned,
 	 * cpu flexible, task flexible.
+	 *
+	 * However, if task's ctx is not carrying any pinned
+	 * events, no need to flip the cpuctx's events around.
 	 */
-	cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
+	if (!list_empty(&ctx->pinned_groups))
+		cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
 	perf_event_sched_in(cpuctx, ctx, task);
 	perf_pmu_enable(ctx->pmu);
 	perf_ctx_unlock(cpuctx, ctx);
@@ -3449,6 +3497,7 @@ static int event_enable_on_exec(struct perf_event *event,
 static void perf_event_enable_on_exec(int ctxn)
 {
 	struct perf_event_context *ctx, *clone_ctx = NULL;
+	enum event_type_t event_type = 0;
 	struct perf_cpu_context *cpuctx;
 	struct perf_event *event;
 	unsigned long flags;
@@ -3462,15 +3511,17 @@ static void perf_event_enable_on_exec(int ctxn)
 	cpuctx = __get_cpu_context(ctx);
 	perf_ctx_lock(cpuctx, ctx);
 	ctx_sched_out(ctx, cpuctx, EVENT_TIME);
-	list_for_each_entry(event, &ctx->event_list, event_entry)
+	list_for_each_entry(event, &ctx->event_list, event_entry) {
 		enabled |= event_enable_on_exec(event, ctx);
+		event_type |= get_event_type(event);
+	}
 
 	/*
 	 * Unclone and reschedule this context if we enabled any event.
 	 */
 	if (enabled) {
 		clone_ctx = unclone_ctx(ctx);
-		ctx_resched(cpuctx, ctx);
+		ctx_resched(cpuctx, ctx, event_type);
 	}
 	perf_ctx_unlock(cpuctx, ctx);
 
@@ -8044,6 +8095,9 @@ static void perf_event_addr_filters_apply(struct perf_event *event)
 	if (task == TASK_TOMBSTONE)
 		return;
 
+	if (!ifh->nr_file_filters)
+		return;
+
 	mm = get_task_mm(event->ctx->task);
 	if (!mm)
 		goto restart;
@@ -8214,6 +8268,7 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
 		 * attribute.
 		 */
 		if (state == IF_STATE_END) {
+			ret = -EINVAL;
 			if (kernel && event->attr.exclude_kernel)
 				goto fail;
 
@@ -8221,6 +8276,18 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
 				if (!filename)
 					goto fail;
 
+				/*
+				 * For now, we only support file-based filters
+				 * in per-task events; doing so for CPU-wide
+				 * events requires additional context switching
+				 * trickery, since same object code will be
+				 * mapped at different virtual addresses in
+				 * different processes.
+				 */
+				ret = -EOPNOTSUPP;
+				if (!event->ctx->task)
+					goto fail_free_name;
+
 				/* look up the path and grab its inode */
 				ret = kern_path(filename, LOOKUP_FOLLOW, &path);
 				if (ret)
@@ -8236,6 +8303,8 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
 				    !S_ISREG(filter->inode->i_mode))
 					/* free_filters_list() will iput() */
 					goto fail;
+
+				event->addr_filters.nr_file_filters++;
 			}
 
 			/* ready to consume more filters */
@@ -8275,24 +8344,13 @@ perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
 	if (WARN_ON_ONCE(event->parent))
 		return -EINVAL;
 
-	/*
-	 * For now, we only support filtering in per-task events; doing so
-	 * for CPU-wide events requires additional context switching trickery,
-	 * since same object code will be mapped at different virtual
-	 * addresses in different processes.
-	 */
-	if (!event->ctx->task)
-		return -EOPNOTSUPP;
-
 	ret = perf_event_parse_addr_filter(event, filter_str, &filters);
 	if (ret)
-		return ret;
+		goto fail_clear_files;
 
 	ret = event->pmu->addr_filters_validate(&filters);
-	if (ret) {
-		free_filters_list(&filters);
-		return ret;
-	}
+	if (ret)
+		goto fail_free_filters;
 
 	/* remove existing filters, if any */
 	perf_addr_filters_splice(event, &filters);
@@ -8301,6 +8359,14 @@ perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
 	perf_event_for_each_child(event, perf_event_addr_filters_apply);
 
 	return ret;
+
+fail_free_filters:
+	free_filters_list(&filters);
+
+fail_clear_files:
+	event->addr_filters.nr_file_filters = 0;
+
+	return ret;
 }
 
 static int perf_event_set_filter(struct perf_event *event, void __user *arg)
@@ -8652,37 +8718,10 @@ static struct perf_cpu_context __percpu *find_pmu_context(int ctxn)
 	return NULL;
 }
 
-static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu)
-{
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		struct perf_cpu_context *cpuctx;
-
-		cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
-
-		if (cpuctx->unique_pmu == old_pmu)
-			cpuctx->unique_pmu = pmu;
-	}
-}
-
 static void free_pmu_context(struct pmu *pmu)
 {
-	struct pmu *i;
-
 	mutex_lock(&pmus_lock);
-	/*
-	 * Like a real lame refcount.
-	 */
-	list_for_each_entry(i, &pmus, entry) {
-		if (i->pmu_cpu_context == pmu->pmu_cpu_context) {
-			update_pmu_context(i, pmu);
-			goto out;
-		}
-	}
-
 	free_percpu(pmu->pmu_cpu_context);
-out:
 	mutex_unlock(&pmus_lock);
 }
 
@@ -8886,8 +8925,6 @@ skip_type:
 		cpuctx->ctx.pmu = pmu;
 
 		__perf_mux_hrtimer_init(cpuctx, cpu);
-
-		cpuctx->unique_pmu = pmu;
 	}
 
 got_cpu_context:
@@ -9005,6 +9042,14 @@ static struct pmu *perf_init_event(struct perf_event *event)
 
 	idx = srcu_read_lock(&pmus_srcu);
 
+	/* Try parent's PMU first: */
+	if (event->parent && event->parent->pmu) {
+		pmu = event->parent->pmu;
+		ret = perf_try_init_event(pmu, event);
+		if (!ret)
+			goto unlock;
+	}
+
 	rcu_read_lock();
 	pmu = idr_find(&pmu_idr, event->attr.type);
 	rcu_read_unlock();
@@ -10265,7 +10310,7 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
 	 * in.
 	 */
 	raw_spin_lock_irq(&child_ctx->lock);
-	task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx);
+	task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx, EVENT_ALL);
 
 	/*
 	 * Now that the context is inactive, destroy the task <-> ctx relation
@@ -10714,6 +10759,9 @@ static void __init perf_event_init_all_cpus(void)
 		INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu));
 		raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu));
 
+#ifdef CONFIG_CGROUP_PERF
+		INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list, cpu));
+#endif
 		INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu));
 	}
 }
diff --git a/kernel/extable.c b/kernel/extable.c
index e3beec4a2339..e1359474baa5 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -20,6 +20,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/init.h>
+#include <linux/kprobes.h>
 
 #include <asm/sections.h>
 #include <linux/uaccess.h>
@@ -104,6 +105,8 @@ int __kernel_text_address(unsigned long addr)
 		return 1;
 	if (is_ftrace_trampoline(addr))
 		return 1;
+	if (is_kprobe_optinsn_slot(addr) || is_kprobe_insn_slot(addr))
+		return 1;
 	/*
 	 * There might be init symbols in saved stacktraces.
 	 * Give those symbols a chance to be printed in
@@ -123,7 +126,11 @@ int kernel_text_address(unsigned long addr)
 		return 1;
 	if (is_module_text_address(addr))
 		return 1;
-	return is_ftrace_trampoline(addr);
+	if (is_ftrace_trampoline(addr))
+		return 1;
+	if (is_kprobe_optinsn_slot(addr) || is_kprobe_insn_slot(addr))
+		return 1;
+	return 0;
 }
 
 /*
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 43460104f119..ebb4dadca66b 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -149,9 +149,11 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c)
 	struct kprobe_insn_page *kip;
 	kprobe_opcode_t *slot = NULL;
 
+	/* Since the slot array is not protected by rcu, we need a mutex */
 	mutex_lock(&c->mutex);
  retry:
-	list_for_each_entry(kip, &c->pages, list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(kip, &c->pages, list) {
 		if (kip->nused < slots_per_page(c)) {
 			int i;
 			for (i = 0; i < slots_per_page(c); i++) {
@@ -159,6 +161,7 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c)
 					kip->slot_used[i] = SLOT_USED;
 					kip->nused++;
 					slot = kip->insns + (i * c->insn_size);
+					rcu_read_unlock();
 					goto out;
 				}
 			}
@@ -167,6 +170,7 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c)
 			WARN_ON(1);
 		}
 	}
+	rcu_read_unlock();
 
 	/* If there are any garbage slots, collect it and try again. */
 	if (c->nr_garbage && collect_garbage_slots(c) == 0)
@@ -193,7 +197,7 @@ kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c)
 	kip->nused = 1;
 	kip->ngarbage = 0;
 	kip->cache = c;
-	list_add(&kip->list, &c->pages);
+	list_add_rcu(&kip->list, &c->pages);
 	slot = kip->insns;
 out:
 	mutex_unlock(&c->mutex);
@@ -213,7 +217,8 @@ static int collect_one_slot(struct kprobe_insn_page *kip, int idx)
 		 * next time somebody inserts a probe.
 		 */
 		if (!list_is_singular(&kip->list)) {
-			list_del(&kip->list);
+			list_del_rcu(&kip->list);
+			synchronize_rcu();
 			kip->cache->free(kip->insns);
 			kfree(kip);
 		}
@@ -235,8 +240,7 @@ static int collect_garbage_slots(struct kprobe_insn_cache *c)
 			continue;
 		kip->ngarbage = 0;	/* we will collect all garbages */
 		for (i = 0; i < slots_per_page(c); i++) {
-			if (kip->slot_used[i] == SLOT_DIRTY &&
-			    collect_one_slot(kip, i))
+			if (kip->slot_used[i] == SLOT_DIRTY && collect_one_slot(kip, i))
 				break;
 		}
 	}
@@ -248,29 +252,60 @@ void __free_insn_slot(struct kprobe_insn_cache *c,
 		      kprobe_opcode_t *slot, int dirty)
 {
 	struct kprobe_insn_page *kip;
+	long idx;
 
 	mutex_lock(&c->mutex);
-	list_for_each_entry(kip, &c->pages, list) {
-		long idx = ((long)slot - (long)kip->insns) /
-				(c->insn_size * sizeof(kprobe_opcode_t));
-		if (idx >= 0 && idx < slots_per_page(c)) {
-			WARN_ON(kip->slot_used[idx] != SLOT_USED);
-			if (dirty) {
-				kip->slot_used[idx] = SLOT_DIRTY;
-				kip->ngarbage++;
-				if (++c->nr_garbage > slots_per_page(c))
-					collect_garbage_slots(c);
-			} else
-				collect_one_slot(kip, idx);
+	rcu_read_lock();
+	list_for_each_entry_rcu(kip, &c->pages, list) {
+		idx = ((long)slot - (long)kip->insns) /
+			(c->insn_size * sizeof(kprobe_opcode_t));
+		if (idx >= 0 && idx < slots_per_page(c))
 			goto out;
-		}
 	}
-	/* Could not free this slot. */
+	/* Could not find this slot. */
 	WARN_ON(1);
+	kip = NULL;
 out:
+	rcu_read_unlock();
+	/* Mark and sweep: this may sleep */
+	if (kip) {
+		/* Check double free */
+		WARN_ON(kip->slot_used[idx] != SLOT_USED);
+		if (dirty) {
+			kip->slot_used[idx] = SLOT_DIRTY;
+			kip->ngarbage++;
+			if (++c->nr_garbage > slots_per_page(c))
+				collect_garbage_slots(c);
+		} else {
+			collect_one_slot(kip, idx);
+		}
+	}
 	mutex_unlock(&c->mutex);
 }
 
+/*
+ * Check given address is on the page of kprobe instruction slots.
+ * This will be used for checking whether the address on a stack
+ * is on a text area or not.
+ */
+bool __is_insn_slot_addr(struct kprobe_insn_cache *c, unsigned long addr)
+{
+	struct kprobe_insn_page *kip;
+	bool ret = false;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(kip, &c->pages, list) {
+		if (addr >= (unsigned long)kip->insns &&
+		    addr < (unsigned long)kip->insns + PAGE_SIZE) {
+			ret = true;
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
 #ifdef CONFIG_OPTPROBES
 /* For optimized_kprobe buffer */
 struct kprobe_insn_cache kprobe_optinsn_slots = {