Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

27 files changed, 336 insertions, 124 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 62f6bced3a3c..afca36f53c49 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -136,21 +136,29 @@ static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
 
 void *bpf_map_area_alloc(size_t size, int numa_node)
 {
-	/* We definitely need __GFP_NORETRY, so OOM killer doesn't
-	 * trigger under memory pressure as we really just want to
-	 * fail instead.
+	/* We really just want to fail instead of triggering OOM killer
+	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
+	 * which is used for lower order allocation requests.
+	 *
+	 * It has been observed that higher order allocation requests done by
+	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
+	 * to reclaim memory from the page cache, thus we set
+	 * __GFP_RETRY_MAYFAIL to avoid such situations.
 	 */
-	const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
+
+	const gfp_t flags = __GFP_NOWARN | __GFP_ZERO;
 	void *area;
 
 	if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
-		area = kmalloc_node(size, GFP_USER | flags, numa_node);
+		area = kmalloc_node(size, GFP_USER | __GFP_NORETRY | flags,
+				    numa_node);
 		if (area != NULL)
 			return area;
 	}
 
-	return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags,
-					   __builtin_return_address(0));
+	return __vmalloc_node_flags_caller(size, numa_node,
+					   GFP_KERNEL | __GFP_RETRY_MAYFAIL |
+					   flags, __builtin_return_address(0));
 }
 
 void bpf_map_area_free(void *area)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index dffeec3706ce..2fe89138309a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -352,6 +352,14 @@ static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
 		map_value_has_spin_lock(reg->map_ptr);
 }
 
+static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type)
+{
+	return type == PTR_TO_SOCKET ||
+		type == PTR_TO_SOCKET_OR_NULL ||
+		type == PTR_TO_TCP_SOCK ||
+		type == PTR_TO_TCP_SOCK_OR_NULL;
+}
+
 static bool arg_type_may_be_refcounted(enum bpf_arg_type type)
 {
 	return type == ARG_PTR_TO_SOCK_COMMON;
@@ -452,8 +460,9 @@ static void print_verifier_state(struct bpf_verifier_env *env,
 			if (t == PTR_TO_STACK)
 				verbose(env, ",call_%d", func(env, reg)->callsite);
 		} else {
-			verbose(env, "(id=%d ref_obj_id=%d", reg->id,
-				reg->ref_obj_id);
+			verbose(env, "(id=%d", reg->id);
+			if (reg_type_may_be_refcounted_or_null(t))
+				verbose(env, ",ref_obj_id=%d", reg->ref_obj_id);
 			if (t != SCALAR_VALUE)
 				verbose(env, ",off=%d", reg->off);
 			if (type_is_pkt_pointer(t))
@@ -3375,7 +3384,7 @@ do_sim:
 		*dst_reg = *ptr_reg;
 	}
 	ret = push_stack(env, env->insn_idx + 1, env->insn_idx, true);
-	if (!ptr_is_dst_reg)
+	if (!ptr_is_dst_reg && ret)
 		*dst_reg = tmp;
 	return !ret ? -EFAULT : 0;
 }
@@ -6072,15 +6081,17 @@ static int propagate_liveness(struct bpf_verifier_env *env,
 	}
 	/* Propagate read liveness of registers... */
 	BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG);
-	/* We don't need to worry about FP liveness because it's read-only */
-	for (i = 0; i < BPF_REG_FP; i++) {
-		if (vparent->frame[vparent->curframe]->regs[i].live & REG_LIVE_READ)
-			continue;
-		if (vstate->frame[vstate->curframe]->regs[i].live & REG_LIVE_READ) {
-			err = mark_reg_read(env, &vstate->frame[vstate->curframe]->regs[i],
-					    &vparent->frame[vstate->curframe]->regs[i]);
-			if (err)
-				return err;
+	for (frame = 0; frame <= vstate->curframe; frame++) {
+		/* We don't need to worry about FP liveness, it's read-only */
+		for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) {
+			if (vparent->frame[frame]->regs[i].live & REG_LIVE_READ)
+				continue;
+			if (vstate->frame[frame]->regs[i].live & REG_LIVE_READ) {
+				err = mark_reg_read(env, &vstate->frame[frame]->regs[i],
+						    &vparent->frame[frame]->regs[i]);
+				if (err)
+					return err;
+			}
 		}
 	}
 
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1032a16bd186..72d06e302e99 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7189,6 +7189,7 @@ static void perf_event_mmap_output(struct perf_event *event,
 	struct perf_output_handle handle;
 	struct perf_sample_data sample;
 	int size = mmap_event->event_id.header.size;
+	u32 type = mmap_event->event_id.header.type;
 	int ret;
 
 	if (!perf_event_mmap_match(event, data))
@@ -7232,6 +7233,7 @@ static void perf_event_mmap_output(struct perf_event *event,
 	perf_output_end(&handle);
 out:
 	mmap_event->event_id.header.size = size;
+	mmap_event->event_id.header.type = type;
 }
 
 static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
diff --git a/kernel/futex.c b/kernel/futex.c
index c3b73b0311bc..9e40cf7be606 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3436,6 +3436,10 @@ static int handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int p
 {
 	u32 uval, uninitialized_var(nval), mval;
 
+	/* Futex address must be 32bit aligned */
+	if ((((unsigned long)uaddr) % sizeof(*uaddr)) != 0)
+		return -1;
+
 retry:
 	if (get_user(uval, uaddr))
 		return -1;
diff --git a/kernel/irq/devres.c b/kernel/irq/devres.c
index 5d5378ea0afe..f808c6a97dcc 100644
--- a/kernel/irq/devres.c
+++ b/kernel/irq/devres.c
@@ -84,8 +84,6 @@ EXPORT_SYMBOL(devm_request_threaded_irq);
  *	@dev: device to request interrupt for
  *	@irq: Interrupt line to allocate
  *	@handler: Function to be called when the IRQ occurs
- *	@thread_fn: function to be called in a threaded interrupt context. NULL
- *		    for devices which handle everything in @handler
  *	@irqflags: Interrupt type flags
  *	@devname: An ascii name for the claiming device, dev_name(dev) if NULL
  *	@dev_id: A cookie passed back to the handler function
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 9ec34a2a6638..1401afa0d58a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -196,6 +196,7 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
 	case IRQ_SET_MASK_OK:
 	case IRQ_SET_MASK_OK_DONE:
 		cpumask_copy(desc->irq_common_data.affinity, mask);
+		/* fall through */
 	case IRQ_SET_MASK_OK_NOCOPY:
 		irq_validate_effective_affinity(data);
 		irq_set_thread_affinity(desc);
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 6b7654b8001f..02ca827b8fac 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -65,6 +65,7 @@ int console_printk[4] = {
 	CONSOLE_LOGLEVEL_MIN,		/* minimum_console_loglevel */
 	CONSOLE_LOGLEVEL_DEFAULT,	/* default_console_loglevel */
 };
+EXPORT_SYMBOL_GPL(console_printk);
 
 atomic_t ignore_console_lock_warning __read_mostly = ATOMIC_INIT(0);
 EXPORT_SYMBOL(ignore_console_lock_warning);
diff --git a/kernel/resource.c b/kernel/resource.c
index e81b17b53fa5..92190f62ebc5 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -382,7 +382,7 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,
 				 int (*func)(struct resource *, void *))
 {
 	struct resource res;
-	int ret = -1;
+	int ret = -EINVAL;
 
 	while (start < end &&
 	       !find_next_iomem_res(start, end, flags, desc, first_lvl, &res)) {
@@ -452,6 +452,9 @@ int walk_mem_res(u64 start, u64 end, void *arg,
  * This function calls the @func callback against all memory ranges of type
  * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY.
  * It is to be used only for System RAM.
+ *
+ * This will find System RAM ranges that are children of top-level resources
+ * in addition to top-level System RAM resources.
  */
 int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 			  void *arg, int (*func)(unsigned long, unsigned long, void *))
@@ -460,14 +463,14 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
 	unsigned long flags;
 	struct resource res;
 	unsigned long pfn, end_pfn;
-	int ret = -1;
+	int ret = -EINVAL;
 
 	start = (u64) start_pfn << PAGE_SHIFT;
 	end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1;
 	flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 	while (start < end &&
 	       !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
-				    true, &res)) {
+				    false, &res)) {
 		pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 		end_pfn = (res.end + 1) >> PAGE_SHIFT;
 		if (end_pfn > pfn)
@@ -1128,6 +1131,15 @@ struct resource * __request_region(struct resource *parent,
 		conflict = __request_resource(parent, res);
 		if (!conflict)
 			break;
+		/*
+		 * mm/hmm.c reserves physical addresses which then
+		 * become unavailable to other users.  Conflicts are
+		 * not expected.  Warn to aid debugging if encountered.
+		 */
+		if (conflict->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY) {
+			pr_warn("Unaddressable device %s %pR conflicts with %pR",
+				conflict->name, conflict, res);
+		}
 		if (conflict != parent) {
 			if (!(conflict->flags & IORESOURCE_BUSY)) {
 				parent = conflict;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ead464a0f2e5..4778c48a7fda 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6998,7 +6998,7 @@ static int __maybe_unused cpu_period_quota_parse(char *buf,
 {
 	char tok[21];	/* U64_MAX */
 
-	if (!sscanf(buf, "%s %llu", tok, periodp))
+	if (sscanf(buf, "%20s %llu", tok, periodp) < 1)
 		return -EINVAL;
 
 	*periodp *= NSEC_PER_USEC;
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 2efe629425be..5c41ea367422 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -48,10 +48,10 @@ struct sugov_cpu {
 
 	bool			iowait_boost_pending;
 	unsigned int		iowait_boost;
-	unsigned int		iowait_boost_max;
 	u64			last_update;
 
 	unsigned long		bw_dl;
+	unsigned long		min;
 	unsigned long		max;
 
 	/* The field below is for single-CPU policies only: */
@@ -303,8 +303,7 @@ static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time,
 	if (delta_ns <= TICK_NSEC)
 		return false;
 
-	sg_cpu->iowait_boost = set_iowait_boost
-		? sg_cpu->sg_policy->policy->min : 0;
+	sg_cpu->iowait_boost = set_iowait_boost ? sg_cpu->min : 0;
 	sg_cpu->iowait_boost_pending = set_iowait_boost;
 
 	return true;
@@ -344,14 +343,13 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time,
 
 	/* Double the boost at each request */
 	if (sg_cpu->iowait_boost) {
-		sg_cpu->iowait_boost <<= 1;
-		if (sg_cpu->iowait_boost > sg_cpu->iowait_boost_max)
-			sg_cpu->iowait_boost = sg_cpu->iowait_boost_max;
+		sg_cpu->iowait_boost =
+			min_t(unsigned int, sg_cpu->iowait_boost << 1, SCHED_CAPACITY_SCALE);
 		return;
 	}
 
 	/* First wakeup after IO: start with minimum boost */
-	sg_cpu->iowait_boost = sg_cpu->sg_policy->policy->min;
+	sg_cpu->iowait_boost = sg_cpu->min;
 }
 
 /**
@@ -373,47 +371,38 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time,
  * This mechanism is designed to boost high frequently IO waiting tasks, while
  * being more conservative on tasks which does sporadic IO operations.
  */
-static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time,
-			       unsigned long *util, unsigned long *max)
+static unsigned long sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time,
+					unsigned long util, unsigned long max)
 {
-	unsigned int boost_util, boost_max;
+	unsigned long boost;
 
 	/* No boost currently required */
 	if (!sg_cpu->iowait_boost)
-		return;
+		return util;
 
 	/* Reset boost if the CPU appears to have been idle enough */
 	if (sugov_iowait_reset(sg_cpu, time, false))
-		return;
+		return util;
 
-	/*
-	 * An IO waiting task has just woken up:
-	 * allow to further double the boost value
-	 */
-	if (sg_cpu->iowait_boost_pending) {
-		sg_cpu->iowait_boost_pending = false;
-	} else {
+	if (!sg_cpu->iowait_boost_pending) {
 		/*
-		 * Otherwise: reduce the boost value and disable it when we
-		 * reach the minimum.
+		 * No boost pending; reduce the boost value.
 		 */
 		sg_cpu->iowait_boost >>= 1;
-		if (sg_cpu->iowait_boost < sg_cpu->sg_policy->policy->min) {
+		if (sg_cpu->iowait_boost < sg_cpu->min) {
 			sg_cpu->iowait_boost = 0;
-			return;
+			return util;
 		}
 	}
 
+	sg_cpu->iowait_boost_pending = false;
+
 	/*
-	 * Apply the current boost value: a CPU is boosted only if its current
-	 * utilization is smaller then the current IO boost level.
+	 * @util is already in capacity scale; convert iowait_boost
+	 * into the same scale so we can compare.
 	 */
-	boost_util = sg_cpu->iowait_boost;
-	boost_max = sg_cpu->iowait_boost_max;
-	if (*util * boost_max < *max * boost_util) {
-		*util = boost_util;
-		*max = boost_max;
-	}
+	boost = (sg_cpu->iowait_boost * max) >> SCHED_CAPACITY_SHIFT;
+	return max(boost, util);
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
@@ -460,7 +449,7 @@ static void sugov_update_single(struct update_util_data *hook, u64 time,
 
 	util = sugov_get_util(sg_cpu);
 	max = sg_cpu->max;
-	sugov_iowait_apply(sg_cpu, time, &util, &max);
+	util = sugov_iowait_apply(sg_cpu, time, util, max);
 	next_f = get_next_freq(sg_policy, util, max);
 	/*
 	 * Do not reduce the frequency if the CPU has not been idle
@@ -500,7 +489,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
 
 		j_util = sugov_get_util(j_sg_cpu);
 		j_max = j_sg_cpu->max;
-		sugov_iowait_apply(j_sg_cpu, time, &j_util, &j_max);
+		j_util = sugov_iowait_apply(j_sg_cpu, time, j_util, j_max);
 
 		if (j_util * max > j_max * util) {
 			util = j_util;
@@ -837,7 +826,9 @@ static int sugov_start(struct cpufreq_policy *policy)
 		memset(sg_cpu, 0, sizeof(*sg_cpu));
 		sg_cpu->cpu			= cpu;
 		sg_cpu->sg_policy		= sg_policy;
-		sg_cpu->iowait_boost_max	= policy->cpuinfo.max_freq;
+		sg_cpu->min			=
+			(SCHED_CAPACITY_SCALE * policy->cpuinfo.min_freq) /
+			policy->cpuinfo.max_freq;
 	}
 
 	for_each_cpu(cpu, policy->cpus) {
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ea74d43924b2..fdab7eb6f351 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8060,6 +8060,18 @@ check_cpu_capacity(struct rq *rq, struct sched_domain *sd)
 }
 
 /*
+ * Check whether a rq has a misfit task and if it looks like we can actually
+ * help that task: we can migrate the task to a CPU of higher capacity, or
+ * the task's current CPU is heavily pressured.
+ */
+static inline int check_misfit_status(struct rq *rq, struct sched_domain *sd)
+{
+	return rq->misfit_task_load &&
+		(rq->cpu_capacity_orig < rq->rd->max_cpu_capacity ||
+		 check_cpu_capacity(rq, sd));
+}
+
+/*
  * Group imbalance indicates (and tries to solve) the problem where balancing
  * groups is inadequate due to ->cpus_allowed constraints.
  *
@@ -9586,35 +9598,21 @@ static void nohz_balancer_kick(struct rq *rq)
 	if (time_before(now, nohz.next_balance))
 		goto out;
 
-	if (rq->nr_running >= 2 || rq->misfit_task_load) {
+	if (rq->nr_running >= 2) {
 		flags = NOHZ_KICK_MASK;
 		goto out;
 	}
 
 	rcu_read_lock();
-	sds = rcu_dereference(per_cpu(sd_llc_shared, cpu));
-	if (sds) {
-		/*
-		 * If there is an imbalance between LLC domains (IOW we could
-		 * increase the overall cache use), we need some less-loaded LLC
-		 * domain to pull some load. Likewise, we may need to spread
-		 * load within the current LLC domain (e.g. packed SMT cores but
-		 * other CPUs are idle). We can't really know from here how busy
-		 * the others are - so just get a nohz balance going if it looks
-		 * like this LLC domain has tasks we could move.
-		 */
-		nr_busy = atomic_read(&sds->nr_busy_cpus);
-		if (nr_busy > 1) {
-			flags = NOHZ_KICK_MASK;
-			goto unlock;
-		}
-
-	}
 
 	sd = rcu_dereference(rq->sd);
 	if (sd) {
-		if ((rq->cfs.h_nr_running >= 1) &&
-		    check_cpu_capacity(rq, sd)) {
+		/*
+		 * If there's a CFS task and the current CPU has reduced
+		 * capacity; kick the ILB to see if there's a better CPU to run
+		 * on.
+		 */
+		if (rq->cfs.h_nr_running >= 1 && check_cpu_capacity(rq, sd)) {
 			flags = NOHZ_KICK_MASK;
 			goto unlock;
 		}
@@ -9622,6 +9620,11 @@ static void nohz_balancer_kick(struct rq *rq)
 
 	sd = rcu_dereference(per_cpu(sd_asym_packing, cpu));
 	if (sd) {
+		/*
+		 * When ASYM_PACKING; see if there's a more preferred CPU
+		 * currently idle; in which case, kick the ILB to move tasks
+		 * around.
+		 */
 		for_each_cpu_and(i, sched_domain_span(sd), nohz.idle_cpus_mask) {
 			if (sched_asym_prefer(i, cpu)) {
 				flags = NOHZ_KICK_MASK;
@@ -9629,6 +9632,45 @@ static void nohz_balancer_kick(struct rq *rq)
 			}
 		}
 	}
+
+	sd = rcu_dereference(per_cpu(sd_asym_cpucapacity, cpu));
+	if (sd) {
+		/*
+		 * When ASYM_CPUCAPACITY; see if there's a higher capacity CPU
+		 * to run the misfit task on.
+		 */
+		if (check_misfit_status(rq, sd)) {
+			flags = NOHZ_KICK_MASK;
+			goto unlock;
+		}
+
+		/*
+		 * For asymmetric systems, we do not want to nicely balance
+		 * cache use, instead we want to embrace asymmetry and only
+		 * ensure tasks have enough CPU capacity.
+		 *
+		 * Skip the LLC logic because it's not relevant in that case.
+		 */
+		goto unlock;
+	}
+
+	sds = rcu_dereference(per_cpu(sd_llc_shared, cpu));
+	if (sds) {
+		/*
+		 * If there is an imbalance between LLC domains (IOW we could
+		 * increase the overall cache use), we need some less-loaded LLC
+		 * domain to pull some load. Likewise, we may need to spread
+		 * load within the current LLC domain (e.g. packed SMT cores but
+		 * other CPUs are idle). We can't really know from here how busy
+		 * the others are - so just get a nohz balance going if it looks
+		 * like this LLC domain has tasks we could move.
+		 */
+		nr_busy = atomic_read(&sds->nr_busy_cpus);
+		if (nr_busy > 1) {
+			flags = NOHZ_KICK_MASK;
+			goto unlock;
+		}
+	}
 unlock:
 	rcu_read_unlock();
 out:
diff --git a/kernel/signal.c b/kernel/signal.c
index 5d53183e2705..b7953934aa99 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -19,7 +19,9 @@
 #include <linux/sched/task.h>
 #include <linux/sched/task_stack.h>
 #include <linux/sched/cputime.h>
+#include <linux/file.h>
 #include <linux/fs.h>
+#include <linux/proc_fs.h>
 #include <linux/tty.h>
 #include <linux/binfmts.h>
 #include <linux/coredump.h>
@@ -3487,6 +3489,16 @@ COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait_time32, compat_sigset_t __user *, uthese,
 #endif
 #endif
 
+static inline void prepare_kill_siginfo(int sig, struct kernel_siginfo *info)
+{
+	clear_siginfo(info);
+	info->si_signo = sig;
+	info->si_errno = 0;
+	info->si_code = SI_USER;
+	info->si_pid = task_tgid_vnr(current);
+	info->si_uid = from_kuid_munged(current_user_ns(), current_uid());
+}
+
 /**
  *  sys_kill - send a signal to a process
  *  @pid: the PID of the process
@@ -3496,16 +3508,125 @@ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig)
 {
 	struct kernel_siginfo info;
 
-	clear_siginfo(&info);
-	info.si_signo = sig;
-	info.si_errno = 0;
-	info.si_code = SI_USER;
-	info.si_pid = task_tgid_vnr(current);
-	info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
+	prepare_kill_siginfo(sig, &info);
 
 	return kill_something_info(sig, &info, pid);
 }
 
+#ifdef CONFIG_PROC_FS
+/*
+ * Verify that the signaler and signalee either are in the same pid namespace
+ * or that the signaler's pid namespace is an ancestor of the signalee's pid
+ * namespace.
+ */
+static bool access_pidfd_pidns(struct pid *pid)
+{
+	struct pid_namespace *active = task_active_pid_ns(current);
+	struct pid_namespace *p = ns_of_pid(pid);
+
+	for (;;) {
+		if (!p)
+			return false;
+		if (p == active)
+			break;
+		p = p->parent;
+	}
+
+	return true;
+}
+
+static int copy_siginfo_from_user_any(kernel_siginfo_t *kinfo, siginfo_t *info)
+{
+#ifdef CONFIG_COMPAT
+	/*
+	 * Avoid hooking up compat syscalls and instead handle necessary
+	 * conversions here. Note, this is a stop-gap measure and should not be
+	 * considered a generic solution.
+	 */
+	if (in_compat_syscall())
+		return copy_siginfo_from_user32(
+			kinfo, (struct compat_siginfo __user *)info);
+#endif
+	return copy_siginfo_from_user(kinfo, info);
+}
+
+/**
+ * sys_pidfd_send_signal - send a signal to a process through a task file
+ *                          descriptor
+ * @pidfd:  the file descriptor of the process
+ * @sig:    signal to be sent
+ * @info:   the signal info
+ * @flags:  future flags to be passed
+ *
+ * The syscall currently only signals via PIDTYPE_PID which covers
+ * kill(<positive-pid>, <signal>. It does not signal threads or process
+ * groups.
+ * In order to extend the syscall to threads and process groups the @flags
+ * argument should be used. In essence, the @flags argument will determine
+ * what is signaled and not the file descriptor itself. Put in other words,
+ * grouping is a property of the flags argument not a property of the file
+ * descriptor.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+SYSCALL_DEFINE4(pidfd_send_signal, int, pidfd, int, sig,
+		siginfo_t __user *, info, unsigned int, flags)
+{
+	int ret;
+	struct fd f;
+	struct pid *pid;
+	kernel_siginfo_t kinfo;
+
+	/* Enforce flags be set to 0 until we add an extension. */
+	if (flags)
+		return -EINVAL;
+
+	f = fdget_raw(pidfd);
+	if (!f.file)
+		return -EBADF;
+
+	/* Is this a pidfd? */
+	pid = tgid_pidfd_to_pid(f.file);
+	if (IS_ERR(pid)) {
+		ret = PTR_ERR(pid);
+		goto err;
+	}
+
+	ret = -EINVAL;
+	if (!access_pidfd_pidns(pid))
+		goto err;
+
+	if (info) {
+		ret = copy_siginfo_from_user_any(&kinfo, info);
+		if (unlikely(ret))
+			goto err;
+
+		ret = -EINVAL;
+		if (unlikely(sig != kinfo.si_signo))
+			goto err;
+
+		if ((task_pid(current) != pid) &&
+		    (kinfo.si_code >= 0 || kinfo.si_code == SI_TKILL)) {
+			/* Only allow sending arbitrary signals to yourself. */
+			ret = -EPERM;
+			if (kinfo.si_code != SI_USER)
+				goto err;
+
+			/* Turn this into a regular kill signal. */
+			prepare_kill_siginfo(sig, &kinfo);
+		}
+	} else {
+		prepare_kill_siginfo(sig, &kinfo);
+	}
+
+	ret = kill_pid_info(sig, &kinfo, pid);
+
+err:
+	fdput(f);
+	return ret;
+}
+#endif /* CONFIG_PROC_FS */
+
 static int
 do_send_specific(pid_t tgid, pid_t pid, int sig, struct kernel_siginfo *info)
 {
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 51d7c6794bf1..d21f4befaea4 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -168,6 +168,7 @@ COND_SYSCALL(syslog);
 /* kernel/sched/core.c */
 
 /* kernel/signal.c */
+COND_SYSCALL(pidfd_send_signal);
 
 /* kernel/sys.c */
 COND_SYSCALL(setregid);
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index dc1b6f1929f9..ac9c03dd6c7d 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -89,7 +89,7 @@ struct clocksource * __init __weak clocksource_default_clock(void)
 	return &clocksource_jiffies;
 }
 
-struct clocksource refined_jiffies;
+static struct clocksource refined_jiffies;
 
 int register_refined_jiffies(long cycles_per_second)
 {
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index fac0ddf8a8e2..e1c6d79fb4cc 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -723,6 +723,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
 #endif
 	case BLKTRACESTART:
 		start = 1;
+		/* fall through */
 	case BLKTRACESTOP:
 		ret = __blk_trace_startstop(q, start);
 		break;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fa79323331b2..26c8ca9bd06b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1992,7 +1992,7 @@ static void print_bug_type(void)
  * modifying the code. @failed should be one of either:
  * EFAULT - if the problem happens on reading the @ip address
  * EINVAL - if what is read at @ip is not what was expected
- * EPERM - if the problem happens on writting to the @ip address
+ * EPERM - if the problem happens on writing to the @ip address
  */
 void ftrace_bug(int failed, struct dyn_ftrace *rec)
 {
@@ -2391,7 +2391,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 		return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
 	}
 
-	return -1; /* unknow ftrace bug */
+	return -1; /* unknown ftrace bug */
 }
 
 void __weak ftrace_replace_code(int mod_flags)
@@ -3004,7 +3004,7 @@ ftrace_allocate_pages(unsigned long num_to_init)
 	int cnt;
 
 	if (!num_to_init)
-		return 0;
+		return NULL;
 
 	start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
 	if (!pg)
@@ -4755,7 +4755,7 @@ static int
 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
 		int reset, int enable)
 {
-	return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
+	return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable);
 }
 
 /**
@@ -5463,7 +5463,7 @@ void ftrace_create_filter_files(struct ftrace_ops *ops,
 
 /*
  * The name "destroy_filter_files" is really a misnomer. Although
- * in the future, it may actualy delete the files, but this is
+ * in the future, it may actually delete the files, but this is
  * really intended to make sure the ops passed in are disabled
  * and that when this function returns, the caller is free to
  * free the ops.
@@ -5786,7 +5786,7 @@ void ftrace_module_enable(struct module *mod)
 	/*
 	 * If the tracing is enabled, go ahead and enable the record.
 	 *
-	 * The reason not to enable the record immediatelly is the
+	 * The reason not to enable the record immediately is the
 	 * inherent check of ftrace_make_nop/ftrace_make_call for
 	 * correct previous instructions.  Making first the NOP
 	 * conversion puts the module to the correct state, thus
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 9a91479bbbfe..41b6f96e5366 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4191,6 +4191,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_consume);
  * ring_buffer_read_prepare - Prepare for a non consuming read of the buffer
  * @buffer: The ring buffer to read from
  * @cpu: The cpu buffer to iterate over
+ * @flags: gfp flags to use for memory allocation
  *
  * This performs the initial preparations necessary to iterate
  * through the buffer.  Memory is allocated, buffer recording
@@ -4208,7 +4209,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_consume);
  * This overall must be paired with ring_buffer_read_finish.
  */
 struct ring_buffer_iter *
-ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu)
+ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu, gfp_t flags)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_iter *iter;
@@ -4216,7 +4217,7 @@ ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu)
 	if (!cpumask_test_cpu(cpu, buffer->cpumask))
 		return NULL;
 
-	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+	iter = kmalloc(sizeof(*iter), flags);
 	if (!iter)
 		return NULL;
 
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 94ffc1c559d5..21153e64bf1c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4079,7 +4079,8 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
 		for_each_tracing_cpu(cpu) {
 			iter->buffer_iter[cpu] =
-				ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu);
+				ring_buffer_read_prepare(iter->trace_buffer->buffer,
+							 cpu, GFP_KERNEL);
 		}
 		ring_buffer_read_prepare_sync();
 		for_each_tracing_cpu(cpu) {
@@ -4089,7 +4090,8 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	} else {
 		cpu = iter->cpu_file;
 		iter->buffer_iter[cpu] =
-			ring_buffer_read_prepare(iter->trace_buffer->buffer, cpu);
+			ring_buffer_read_prepare(iter->trace_buffer->buffer,
+						 cpu, GFP_KERNEL);
 		ring_buffer_read_prepare_sync();
 		ring_buffer_read_start(iter->buffer_iter[cpu]);
 		tracing_iter_reset(iter, cpu);
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index dd1f43588d70..fa100ed3b4de 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -74,7 +74,7 @@ int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type)
 static int create_dyn_event(int argc, char **argv)
 {
 	struct dyn_event_operations *ops;
-	int ret;
+	int ret = -ENODEV;
 
 	if (argv[0][0] == '-' || argv[0][0] == '!')
 		return dyn_event_release(argc, argv, NULL);
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index ca46339f3009..795aa2038377 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3713,7 +3713,6 @@ static void track_data_destroy(struct hist_trigger_data *hist_data,
 	struct trace_event_file *file = hist_data->event_file;
 
 	destroy_hist_field(data->track_data.track_var, 0);
-	destroy_hist_field(data->track_data.var_ref, 0);
 
 	if (data->action == ACTION_SNAPSHOT) {
 		struct track_data *track_data;
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
index d953c163a079..810d78a8d14c 100644
--- a/kernel/trace/trace_kdb.c
+++ b/kernel/trace/trace_kdb.c
@@ -51,14 +51,16 @@ static void ftrace_dump_buf(int skip_lines, long cpu_file)
 	if (cpu_file == RING_BUFFER_ALL_CPUS) {
 		for_each_tracing_cpu(cpu) {
 			iter.buffer_iter[cpu] =
-			ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu);
+			ring_buffer_read_prepare(iter.trace_buffer->buffer,
+						 cpu, GFP_ATOMIC);
 			ring_buffer_read_start(iter.buffer_iter[cpu]);
 			tracing_iter_reset(&iter, cpu);
 		}
 	} else {
 		iter.cpu_file = cpu_file;
 		iter.buffer_iter[cpu_file] =
-			ring_buffer_read_prepare(iter.trace_buffer->buffer, cpu_file);
+			ring_buffer_read_prepare(iter.trace_buffer->buffer,
+						 cpu_file, GFP_ATOMIC);
 		ring_buffer_read_start(iter.buffer_iter[cpu_file]);
 		tracing_iter_reset(&iter, cpu_file);
 	}
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 99592c27465e..5d5129b05df7 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -35,7 +35,7 @@ static struct dyn_event_operations trace_kprobe_ops = {
 	.match = trace_kprobe_match,
 };
 
-/**
+/*
  * Kprobe event core functions
  */
 struct trace_kprobe {
@@ -221,7 +221,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 
 	tk->rp.maxactive = maxactive;
 
-	if (!event || !is_good_name(event)) {
+	if (!event || !group) {
 		ret = -EINVAL;
 		goto error;
 	}
@@ -231,11 +231,6 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
 	if (!tk->tp.call.name)
 		goto error;
 
-	if (!group || !is_good_name(group)) {
-		ret = -EINVAL;
-		goto error;
-	}
-
 	tk->tp.class.system = kstrdup(group, GFP_KERNEL);
 	if (!tk->tp.class.system)
 		goto error;
@@ -624,7 +619,11 @@ static int trace_kprobe_create(int argc, const char *argv[])
 	if (event)
 		event++;
 
-	if (is_return && isdigit(argv[0][1])) {
+	if (isdigit(argv[0][1])) {
+		if (!is_return) {
+			pr_info("Maxactive is not for kprobe");
+			return -EINVAL;
+		}
 		if (event)
 			len = event - &argv[0][1] - 1;
 		else
@@ -634,8 +633,8 @@ static int trace_kprobe_create(int argc, const char *argv[])
 		memcpy(buf, &argv[0][1], len);
 		buf[len] = '\0';
 		ret = kstrtouint(buf, 0, &maxactive);
-		if (ret) {
-			pr_info("Failed to parse maxactive.\n");
+		if (ret || !maxactive) {
+			pr_info("Invalid maxactive number\n");
 			return ret;
 		}
 		/* kretprobes instances are iterated over via a list. The
@@ -694,9 +693,9 @@ static int trace_kprobe_create(int argc, const char *argv[])
 	tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive,
 			       argc, is_return);
 	if (IS_ERR(tk)) {
-		pr_info("Failed to allocate trace_probe.(%d)\n",
-			(int)PTR_ERR(tk));
 		ret = PTR_ERR(tk);
+		/* This must return -ENOMEM otherwise there is a bug */
+		WARN_ON_ONCE(ret != -ENOMEM);
 		goto out;
 	}
 
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 89da34b326e3..8f8411e7835f 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -13,7 +13,7 @@
 
 #include "trace_probe.h"
 
-const char *reserved_field_names[] = {
+static const char *reserved_field_names[] = {
 	"common_type",
 	"common_flags",
 	"common_preempt_count",
@@ -159,6 +159,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
 				char *buf)
 {
 	const char *slash, *event = *pevent;
+	int len;
 
 	slash = strchr(event, '/');
 	if (slash) {
@@ -171,12 +172,25 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
 			return -E2BIG;
 		}
 		strlcpy(buf, event, slash - event + 1);
+		if (!is_good_name(buf)) {
+			pr_info("Group name must follow the same rules as C identifiers\n");
+			return -EINVAL;
+		}
 		*pgroup = buf;
 		*pevent = slash + 1;
+		event = *pevent;
 	}
-	if (strlen(event) == 0) {
+	len = strlen(event);
+	if (len == 0) {
 		pr_info("Event name is not specified\n");
 		return -EINVAL;
+	} else if (len > MAX_EVENT_NAME_LEN) {
+		pr_info("Event name is too long\n");
+		return -E2BIG;
+	}
+	if (!is_good_name(event)) {
+		pr_info("Event name must follow the same rules as C identifiers\n");
+		return -EINVAL;
 	}
 	return 0;
 }
@@ -548,6 +562,8 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, char *arg,
 
 	body = strchr(arg, '=');
 	if (body) {
+		if (body - arg > MAX_ARG_NAME_LEN || body == arg)
+			return -EINVAL;
 		parg->name = kmemdup_nul(arg, body - arg, GFP_KERNEL);
 		body++;
 	} else {
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 8a63f8bc01bc..2177c206de15 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -32,6 +32,7 @@
 #define MAX_TRACE_ARGS		128
 #define MAX_ARGSTR_LEN		63
 #define MAX_ARRAY_LEN		64
+#define MAX_ARG_NAME_LEN	32
 #define MAX_STRING_SIZE		PATH_MAX
 
 /* Reserved field names */
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 9bde07c06362..be78d99ee6bc 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -273,10 +273,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
 {
 	struct trace_uprobe *tu;
 
-	if (!event || !is_good_name(event))
-		return ERR_PTR(-EINVAL);
-
-	if (!group || !is_good_name(group))
+	if (!event || !group)
 		return ERR_PTR(-EINVAL);
 
 	tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
@@ -524,8 +521,9 @@ static int trace_uprobe_create(int argc, const char **argv)
 
 	tu = alloc_trace_uprobe(group, event, argc, is_return);
 	if (IS_ERR(tu)) {
-		pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
 		ret = PTR_ERR(tu);
+		/* This must return -ENOMEM otherwise there is a bug */
+		WARN_ON_ONCE(ret != -ENOMEM);
 		goto fail_address_parse;
 	}
 	tu->offset = offset;
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 8fbfda94a67b..403c9bd90413 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -42,9 +42,9 @@ int __read_mostly watchdog_user_enabled = 1;
 int __read_mostly nmi_watchdog_user_enabled = NMI_WATCHDOG_DEFAULT;
 int __read_mostly soft_watchdog_user_enabled = 1;
 int __read_mostly watchdog_thresh = 10;
-int __read_mostly nmi_watchdog_available;
+static int __read_mostly nmi_watchdog_available;
 
-struct cpumask watchdog_allowed_mask __read_mostly;
+static struct cpumask watchdog_allowed_mask __read_mostly;
 
 struct cpumask watchdog_cpumask __read_mostly;
 unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 4026d1871407..ddee541ea97a 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4266,7 +4266,7 @@ struct workqueue_struct *alloc_workqueue(const char *fmt,
 	INIT_LIST_HEAD(&wq->list);
 
 	if (alloc_and_link_pwqs(wq) < 0)
-		goto err_free_wq;
+		goto err_unreg_lockdep;
 
 	if (wq_online && init_rescuer(wq) < 0)
 		goto err_destroy;
@@ -4292,9 +4292,10 @@ struct workqueue_struct *alloc_workqueue(const char *fmt,
 
 	return wq;
 
-err_free_wq:
+err_unreg_lockdep:
 	wq_unregister_lockdep(wq);
 	wq_free_lockdep(wq);
+err_free_wq:
 	free_workqueue_attrs(wq->unbound_attrs);
 	kfree(wq);
 	return NULL;