Merge tag 'v5.10.168' of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux into ti-linux-5.10.y-cicd

This is the 5.10.168 stable release

* tag 'v5.10.168' of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux: (286 commits)
  Linux 5.10.168
  Fix page corruption caused by racy check in __free_pages
  arm64: dts: meson-axg: Make mmc host controller interrupts level-sensitive
  arm64: dts: meson-g12-common: Make mmc host controller interrupts level-sensitive
  arm64: dts: meson-gx: Make mmc host controller interrupts level-sensitive
  riscv: Fixup race condition on PG_dcache_clean in flush_icache_pte
  ceph: flush cap releases when the session is flushed
  usb: typec: altmodes/displayport: Fix probe pin assign check
  usb: core: add quirk for Alcor Link AK9563 smartcard reader
  btrfs: free device in btrfs_close_devices for a single device filesystem
  net: USB: Fix wrong-direction WARNING in plusb.c
  cifs: Fix use-after-free in rdata->read_into_pages()
  pinctrl: intel: Restore the pins that used to be in Direct IRQ mode
  spi: dw: Fix wrong FIFO level setting for long xfers
  pinctrl: single: fix potential NULL dereference
  pinctrl: aspeed: Fix confusing types in return value
  ALSA: pci: lx6464es: fix a debug loop
  selftests: forwarding: lib: quote the sysctl values
  rds: rds_rm_zerocopy_callback() use list_first_entry()
  net/mlx5: fw_tracer, Zero consumer index when reloading the tracer
  ...

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>

13 files changed, 265 insertions, 71 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 232c93357b90..9e5f1ebe67d7 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -570,6 +570,12 @@ static bool is_spilled_reg(const struct bpf_stack_state *stack)
 	return stack->slot_type[BPF_REG_SIZE - 1] == STACK_SPILL;
 }
 
+static void scrub_spilled_slot(u8 *stype)
+{
+	if (*stype != STACK_INVALID)
+		*stype = STACK_MISC;
+}
+
 static void print_verifier_state(struct bpf_verifier_env *env,
 				 const struct bpf_func_state *state)
 {
@@ -1876,8 +1882,6 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx,
 		 */
 		if (insn->src_reg != BPF_REG_FP)
 			return 0;
-		if (BPF_SIZE(insn->code) != BPF_DW)
-			return 0;
 
 		/* dreg = *(u64 *)[fp - off] was a fill from the stack.
 		 * that [fp - off] slot contains scalar that needs to be
@@ -1900,8 +1904,6 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx,
 		/* scalars can only be spilled into stack */
 		if (insn->dst_reg != BPF_REG_FP)
 			return 0;
-		if (BPF_SIZE(insn->code) != BPF_DW)
-			return 0;
 		spi = (-insn->off - 1) / BPF_REG_SIZE;
 		if (spi >= 64) {
 			verbose(env, "BUG spi %d\n", spi);
@@ -2272,16 +2274,33 @@ static bool __is_pointer_value(bool allow_ptr_leaks,
 	return reg->type != SCALAR_VALUE;
 }
 
+/* Copy src state preserving dst->parent and dst->live fields */
+static void copy_register_state(struct bpf_reg_state *dst, const struct bpf_reg_state *src)
+{
+	struct bpf_reg_state *parent = dst->parent;
+	enum bpf_reg_liveness live = dst->live;
+
+	*dst = *src;
+	dst->parent = parent;
+	dst->live = live;
+}
+
 static void save_register_state(struct bpf_func_state *state,
-				int spi, struct bpf_reg_state *reg)
+				int spi, struct bpf_reg_state *reg,
+				int size)
 {
 	int i;
 
-	state->stack[spi].spilled_ptr = *reg;
-	state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
+	copy_register_state(&state->stack[spi].spilled_ptr, reg);
+	if (size == BPF_REG_SIZE)
+		state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
+
+	for (i = BPF_REG_SIZE; i > BPF_REG_SIZE - size; i--)
+		state->stack[spi].slot_type[i - 1] = STACK_SPILL;
 
-	for (i = 0; i < BPF_REG_SIZE; i++)
-		state->stack[spi].slot_type[i] = STACK_SPILL;
+	/* size < 8 bytes spill */
+	for (; i; i--)
+		scrub_spilled_slot(&state->stack[spi].slot_type[i - 1]);
 }
 
 /* check_stack_{read,write}_fixed_off functions track spill/fill of registers,
@@ -2319,7 +2338,9 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 		bool sanitize = reg && is_spillable_regtype(reg->type);
 
 		for (i = 0; i < size; i++) {
-			if (state->stack[spi].slot_type[i] == STACK_INVALID) {
+			u8 type = state->stack[spi].slot_type[i];
+
+			if (type != STACK_MISC && type != STACK_ZERO) {
 				sanitize = true;
 				break;
 			}
@@ -2329,7 +2350,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 			env->insn_aux_data[insn_idx].sanitize_stack_spill = true;
 	}
 
-	if (reg && size == BPF_REG_SIZE && register_is_bounded(reg) &&
+	if (reg && !(off % BPF_REG_SIZE) && register_is_bounded(reg) &&
 	    !register_is_null(reg) && env->bpf_capable) {
 		if (dst_reg != BPF_REG_FP) {
 			/* The backtracking logic can only recognize explicit
@@ -2342,7 +2363,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 			if (err)
 				return err;
 		}
-		save_register_state(state, spi, reg);
+		save_register_state(state, spi, reg, size);
 	} else if (reg && is_spillable_regtype(reg->type)) {
 		/* register containing pointer is being spilled into stack */
 		if (size != BPF_REG_SIZE) {
@@ -2354,7 +2375,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 			verbose(env, "cannot spill pointers to stack into stack frame of the caller\n");
 			return -EINVAL;
 		}
-		save_register_state(state, spi, reg);
+		save_register_state(state, spi, reg, size);
 	} else {
 		u8 type = STACK_MISC;
 
@@ -2363,7 +2384,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 		/* Mark slots as STACK_MISC if they belonged to spilled ptr. */
 		if (is_spilled_reg(&state->stack[spi]))
 			for (i = 0; i < BPF_REG_SIZE; i++)
-				state->stack[spi].slot_type[i] = STACK_MISC;
+				scrub_spilled_slot(&state->stack[spi].slot_type[i]);
 
 		/* only mark the slot as written if all 8 bytes were written
 		 * otherwise read propagation may incorrectly stop too soon
@@ -2570,35 +2591,56 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 	struct bpf_func_state *state = vstate->frame[vstate->curframe];
 	int i, slot = -off - 1, spi = slot / BPF_REG_SIZE;
 	struct bpf_reg_state *reg;
-	u8 *stype;
+	u8 *stype, type;
 
 	stype = reg_state->stack[spi].slot_type;
 	reg = &reg_state->stack[spi].spilled_ptr;
 
 	if (is_spilled_reg(&reg_state->stack[spi])) {
-		if (size != BPF_REG_SIZE) {
+		u8 spill_size = 1;
+
+		for (i = BPF_REG_SIZE - 1; i > 0 && stype[i - 1] == STACK_SPILL; i--)
+			spill_size++;
+
+		if (size != BPF_REG_SIZE || spill_size != BPF_REG_SIZE) {
 			if (reg->type != SCALAR_VALUE) {
 				verbose_linfo(env, env->insn_idx, "; ");
 				verbose(env, "invalid size of register fill\n");
 				return -EACCES;
 			}
-			if (dst_regno >= 0) {
+
+			mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
+			if (dst_regno < 0)
+				return 0;
+
+			if (!(off % BPF_REG_SIZE) && size == spill_size) {
+				/* The earlier check_reg_arg() has decided the
+				 * subreg_def for this insn.  Save it first.
+				 */
+				s32 subreg_def = state->regs[dst_regno].subreg_def;
+
+				copy_register_state(&state->regs[dst_regno], reg);
+				state->regs[dst_regno].subreg_def = subreg_def;
+			} else {
+				for (i = 0; i < size; i++) {
+					type = stype[(slot - i) % BPF_REG_SIZE];
+					if (type == STACK_SPILL)
+						continue;
+					if (type == STACK_MISC)
+						continue;
+					verbose(env, "invalid read from stack off %d+%d size %d\n",
+						off, i, size);
+					return -EACCES;
+				}
 				mark_reg_unknown(env, state->regs, dst_regno);
-				state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
 			}
-			mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
+			state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
 			return 0;
 		}
-		for (i = 1; i < BPF_REG_SIZE; i++) {
-			if (stype[(slot - i) % BPF_REG_SIZE] != STACK_SPILL) {
-				verbose(env, "corrupted spill memory\n");
-				return -EACCES;
-			}
-		}
 
 		if (dst_regno >= 0) {
 			/* restore register state from stack */
-			state->regs[dst_regno] = *reg;
+			copy_register_state(&state->regs[dst_regno], reg);
 			/* mark reg as written since spilled pointer state likely
 			 * has its liveness marks cleared by is_state_visited()
 			 * which resets stack/reg liveness for state transitions
@@ -2617,8 +2659,6 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 		}
 		mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
 	} else {
-		u8 type;
-
 		for (i = 0; i < size; i++) {
 			type = stype[(slot - i) % BPF_REG_SIZE];
 			if (type == STACK_MISC)
@@ -4104,7 +4144,7 @@ static int check_stack_range_initialized(
 			if (clobber) {
 				__mark_reg_unknown(env, &state->stack[spi].spilled_ptr);
 				for (j = 0; j < BPF_REG_SIZE; j++)
-					state->stack[spi].slot_type[j] = STACK_MISC;
+					scrub_spilled_slot(&state->stack[spi].slot_type[j]);
 			}
 			goto mark;
 		}
@@ -5861,7 +5901,7 @@ do_sim:
 	 */
 	if (!ptr_is_dst_reg) {
 		tmp = *dst_reg;
-		*dst_reg = *ptr_reg;
+		copy_register_state(dst_reg, ptr_reg);
 	}
 	ret = sanitize_speculative_path(env, NULL, env->insn_idx + 1,
 					env->insn_idx);
@@ -7115,7 +7155,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 					 * to propagate min/max range.
 					 */
 					src_reg->id = ++env->id_gen;
-				*dst_reg = *src_reg;
+				copy_register_state(dst_reg, src_reg);
 				dst_reg->live |= REG_LIVE_WRITTEN;
 				dst_reg->subreg_def = DEF_NOT_SUBREG;
 			} else {
@@ -7126,7 +7166,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 						insn->src_reg);
 					return -EACCES;
 				} else if (src_reg->type == SCALAR_VALUE) {
-					*dst_reg = *src_reg;
+					copy_register_state(dst_reg, src_reg);
 					/* Make sure ID is cleared otherwise
 					 * dst_reg min/max could be incorrectly
 					 * propagated into src_reg by find_equal_scalars()
@@ -7946,7 +7986,7 @@ static void find_equal_scalars(struct bpf_verifier_state *vstate,
 
 	bpf_for_each_reg_in_vstate(vstate, state, reg, ({
 		if (reg->type == SCALAR_VALUE && reg->id == known_reg->id)
-			*reg = *known_reg;
+			copy_register_state(reg, known_reg);
 	}));
 }
 
diff --git a/kernel/exit.c b/kernel/exit.c
index 8989e1d1f79b..bacdaf980933 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -64,11 +64,58 @@
 #include <linux/rcuwait.h>
 #include <linux/compat.h>
 #include <linux/io_uring.h>
+#include <linux/sysfs.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/mmu_context.h>
 
+/*
+ * The default value should be high enough to not crash a system that randomly
+ * crashes its kernel from time to time, but low enough to at least not permit
+ * overflowing 32-bit refcounts or the ldsem writer count.
+ */
+static unsigned int oops_limit = 10000;
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table kern_exit_table[] = {
+	{
+		.procname       = "oops_limit",
+		.data           = &oops_limit,
+		.maxlen         = sizeof(oops_limit),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec,
+	},
+	{ }
+};
+
+static __init int kernel_exit_sysctls_init(void)
+{
+	register_sysctl_init("kernel", kern_exit_table);
+	return 0;
+}
+late_initcall(kernel_exit_sysctls_init);
+#endif
+
+static atomic_t oops_count = ATOMIC_INIT(0);
+
+#ifdef CONFIG_SYSFS
+static ssize_t oops_count_show(struct kobject *kobj, struct kobj_attribute *attr,
+			       char *page)
+{
+	return sysfs_emit(page, "%d\n", atomic_read(&oops_count));
+}
+
+static struct kobj_attribute oops_count_attr = __ATTR_RO(oops_count);
+
+static __init int kernel_exit_sysfs_init(void)
+{
+	sysfs_add_file_to_group(kernel_kobj, &oops_count_attr.attr, NULL);
+	return 0;
+}
+late_initcall(kernel_exit_sysfs_init);
+#endif
+
 static void __unhash_process(struct task_struct *p, bool group_dead)
 {
 	nr_threads--;
@@ -863,6 +910,31 @@ void __noreturn do_exit(long code)
 }
 EXPORT_SYMBOL_GPL(do_exit);
 
+void __noreturn make_task_dead(int signr)
+{
+	/*
+	 * Take the task off the cpu after something catastrophic has
+	 * happened.
+	 */
+	unsigned int limit;
+
+	/*
+	 * Every time the system oopses, if the oops happens while a reference
+	 * to an object was held, the reference leaks.
+	 * If the oops doesn't also leak memory, repeated oopsing can cause
+	 * reference counters to wrap around (if they're not using refcount_t).
+	 * This means that repeated oopsing can make unexploitable-looking bugs
+	 * exploitable through repeated oopsing.
+	 * To make sure this can't happen, place an upper bound on how often the
+	 * kernel may oops without panic().
+	 */
+	limit = READ_ONCE(oops_limit);
+	if (atomic_inc_return(&oops_count) >= limit && limit)
+		panic("Oopsed too often (kernel.oops_limit is %d)", limit);
+
+	do_exit(signr);
+}
+
 void complete_and_exit(struct completion *comp, long code)
 {
 	if (comp)
diff --git a/kernel/kcsan/kcsan-test.c b/kernel/kcsan/kcsan-test.c
index ebe7fd245104..8a8ccaf4f38f 100644
--- a/kernel/kcsan/kcsan-test.c
+++ b/kernel/kcsan/kcsan-test.c
@@ -149,7 +149,7 @@ static bool report_matches(const struct expect_report *r)
 	const bool is_assert = (r->access[0].type | r->access[1].type) & KCSAN_ACCESS_ASSERT;
 	bool ret = false;
 	unsigned long flags;
-	typeof(observed.lines) expect;
+	typeof(*observed.lines) *expect;
 	const char *end;
 	char *cur;
 	int i;
@@ -158,6 +158,10 @@ static bool report_matches(const struct expect_report *r)
 	if (!report_available())
 		return false;
 
+	expect = kmalloc(sizeof(observed.lines), GFP_KERNEL);
+	if (WARN_ON(!expect))
+		return false;
+
 	/* Generate expected report contents. */
 
 	/* Title */
@@ -241,6 +245,7 @@ static bool report_matches(const struct expect_report *r)
 		strstr(observed.lines[2], expect[1])));
 out:
 	spin_unlock_irqrestore(&observed.lock, flags);
+	kfree(expect);
 	return ret;
 }
 
diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
index d3bf87e6007c..069830f5a5d2 100644
--- a/kernel/kcsan/report.c
+++ b/kernel/kcsan/report.c
@@ -630,8 +630,8 @@ void kcsan_report(const volatile void *ptr, size_t size, int access_type,
 		bool reported = value_change != KCSAN_VALUE_CHANGE_FALSE &&
 				print_report(value_change, type, &ai, other_info);
 
-		if (reported && panic_on_warn)
-			panic("panic_on_warn set ...\n");
+		if (reported)
+			check_panic_on_warn("KCSAN");
 
 		release_report(&flags, other_info);
 	}
diff --git a/kernel/module.c b/kernel/module.c
index 6a0fd245c048..33d1dc6d4cd6 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3661,7 +3661,8 @@ static bool finished_loading(const char *name)
 	sched_annotate_sleep();
 	mutex_lock(&module_mutex);
 	mod = find_module_all(name, strlen(name), true);
-	ret = !mod || mod->state == MODULE_STATE_LIVE;
+	ret = !mod || mod->state == MODULE_STATE_LIVE
+		|| mod->state == MODULE_STATE_GOING;
 	mutex_unlock(&module_mutex);
 
 	return ret;
@@ -3827,20 +3828,35 @@ static int add_unformed_module(struct module *mod)
 
 	mod->state = MODULE_STATE_UNFORMED;
 
-again:
 	mutex_lock(&module_mutex);
 	old = find_module_all(mod->name, strlen(mod->name), true);
 	if (old != NULL) {
-		if (old->state != MODULE_STATE_LIVE) {
+		if (old->state == MODULE_STATE_COMING
+		    || old->state == MODULE_STATE_UNFORMED) {
 			/* Wait in case it fails to load. */
 			mutex_unlock(&module_mutex);
 			err = wait_event_interruptible(module_wq,
 					       finished_loading(mod->name));
 			if (err)
 				goto out_unlocked;
-			goto again;
+
+			/* The module might have gone in the meantime. */
+			mutex_lock(&module_mutex);
+			old = find_module_all(mod->name, strlen(mod->name),
+					      true);
 		}
-		err = -EEXIST;
+
+		/*
+		 * We are here only when the same module was being loaded. Do
+		 * not try to load it again right now. It prevents long delays
+		 * caused by serialized module load failures. It might happen
+		 * when more devices of the same type trigger load of
+		 * a particular module.
+		 */
+		if (old && old->state == MODULE_STATE_LIVE)
+			err = -EEXIST;
+		else
+			err = -EBUSY;
 		goto out;
 	}
 	mod_update_bounds(mod);
diff --git a/kernel/panic.c b/kernel/panic.c
index 332736a72a58..bc39e2b27d31 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -31,6 +31,7 @@
 #include <linux/bug.h>
 #include <linux/ratelimit.h>
 #include <linux/debugfs.h>
+#include <linux/sysfs.h>
 #include <asm/sections.h>
 
 #define PANIC_TIMER_STEP 100
@@ -41,7 +42,9 @@
  * Should we dump all CPUs backtraces in an oops event?
  * Defaults to 0, can be changed via sysctl.
  */
-unsigned int __read_mostly sysctl_oops_all_cpu_backtrace;
+static unsigned int __read_mostly sysctl_oops_all_cpu_backtrace;
+#else
+#define sysctl_oops_all_cpu_backtrace 0
 #endif /* CONFIG_SMP */
 
 int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
@@ -54,6 +57,7 @@ bool crash_kexec_post_notifiers;
 int panic_on_warn __read_mostly;
 unsigned long panic_on_taint;
 bool panic_on_taint_nousertaint = false;
+static unsigned int warn_limit __read_mostly;
 
 int panic_timeout = CONFIG_PANIC_TIMEOUT;
 EXPORT_SYMBOL_GPL(panic_timeout);
@@ -70,6 +74,56 @@ ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
 
 EXPORT_SYMBOL(panic_notifier_list);
 
+#ifdef CONFIG_SYSCTL
+static struct ctl_table kern_panic_table[] = {
+#ifdef CONFIG_SMP
+	{
+		.procname       = "oops_all_cpu_backtrace",
+		.data           = &sysctl_oops_all_cpu_backtrace,
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec_minmax,
+		.extra1         = SYSCTL_ZERO,
+		.extra2         = SYSCTL_ONE,
+	},
+#endif
+	{
+		.procname       = "warn_limit",
+		.data           = &warn_limit,
+		.maxlen         = sizeof(warn_limit),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec,
+	},
+	{ }
+};
+
+static __init int kernel_panic_sysctls_init(void)
+{
+	register_sysctl_init("kernel", kern_panic_table);
+	return 0;
+}
+late_initcall(kernel_panic_sysctls_init);
+#endif
+
+static atomic_t warn_count = ATOMIC_INIT(0);
+
+#ifdef CONFIG_SYSFS
+static ssize_t warn_count_show(struct kobject *kobj, struct kobj_attribute *attr,
+			       char *page)
+{
+	return sysfs_emit(page, "%d\n", atomic_read(&warn_count));
+}
+
+static struct kobj_attribute warn_count_attr = __ATTR_RO(warn_count);
+
+static __init int kernel_panic_sysfs_init(void)
+{
+	sysfs_add_file_to_group(kernel_kobj, &warn_count_attr.attr, NULL);
+	return 0;
+}
+late_initcall(kernel_panic_sysfs_init);
+#endif
+
 static long no_blink(int state)
 {
 	return 0;
@@ -166,6 +220,19 @@ static void panic_print_sys_info(void)
 		ftrace_dump(DUMP_ALL);
 }
 
+void check_panic_on_warn(const char *origin)
+{
+	unsigned int limit;
+
+	if (panic_on_warn)
+		panic("%s: panic_on_warn set ...\n", origin);
+
+	limit = READ_ONCE(warn_limit);
+	if (atomic_inc_return(&warn_count) >= limit && limit)
+		panic("%s: system warned too often (kernel.warn_limit is %d)",
+		      origin, limit);
+}
+
 /**
  *	panic - halt the system
  *	@fmt: The text string to print
@@ -183,6 +250,16 @@ void panic(const char *fmt, ...)
 	int old_cpu, this_cpu;
 	bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
 
+	if (panic_on_warn) {
+		/*
+		 * This thread may hit another WARN() in the panic path.
+		 * Resetting this prevents additional WARN() from panicking the
+		 * system on this thread.  Other threads are blocked by the
+		 * panic_mutex in panic().
+		 */
+		panic_on_warn = 0;
+	}
+
 	/*
 	 * Disable local interrupts. This will prevent panic_smp_self_stop
 	 * from deadlocking the first cpu that invokes the panic, since
@@ -594,16 +671,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
 	if (regs)
 		show_regs(regs);
 
-	if (panic_on_warn) {
-		/*
-		 * This thread may hit another WARN() in the panic path.
-		 * Resetting this prevents additional WARN() from panicking the
-		 * system on this thread.  Other threads are blocked by the
-		 * panic_mutex in panic().
-		 */
-		panic_on_warn = 0;
-		panic("panic_on_warn set ...\n");
-	}
+	check_panic_on_warn("kernel");
 
 	if (!regs)
 		dump_stack();
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index a875bc59804e..1303a2607f1f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4280,8 +4280,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
 		pr_err("Preemption disabled at:");
 		print_ip_sym(KERN_ERR, preempt_disable_ip);
 	}
-	if (panic_on_warn)
-		panic("scheduling while atomic\n");
+	check_panic_on_warn("scheduling while atomic");
 
 	dump_stack();
 	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 3eb527f8a269..d8b7b2846313 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2199,17 +2199,6 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= proc_dointvec,
 	},
 #endif
-#ifdef CONFIG_SMP
-	{
-		.procname	= "oops_all_cpu_backtrace",
-		.data		= &sysctl_oops_all_cpu_backtrace,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE,
-	},
-#endif /* CONFIG_SMP */
 	{
 		.procname	= "pid_max",
 		.data		= &pid_max,
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index a9e074769881..94e51d36fb49 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1055,6 +1055,7 @@ static void do_bpf_send_signal(struct irq_work *entry)
 
 	work = container_of(entry, struct send_signal_irq_work, irq_work);
 	group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
+	put_task_struct(work->task);
 }
 
 static int bpf_send_signal_common(u32 sig, enum pid_type type)
@@ -1072,6 +1073,9 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type)
 		return -EPERM;
 	if (unlikely(!nmi_uaccess_okay()))
 		return -EPERM;
+	/* Task should not be pid=1 to avoid kernel panic. */
+	if (unlikely(is_global_init(current)))
+		return -EPERM;
 
 	if (irqs_disabled()) {
 		/* Do an early check on signal validity. Otherwise,
@@ -1088,7 +1092,7 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type)
 		 * to the irq_work. The current task may change when queued
 		 * irq works get executed.
 		 */
-		work->task = current;
+		work->task = get_task_struct(current);
 		work->sig = sig;
 		work->type = type;
 		irq_work_queue(&work->irq_work);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c7c92b0eed04..8637eab2986e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8569,9 +8569,6 @@ buffer_percent_write(struct file *filp, const char __user *ubuf,
 	if (val > 100)
 		return -EINVAL;
 
-	if (!val)
-		val = 1;
-
 	tr->buffer_percent = val;
 
 	(*ppos)++;
@@ -9680,6 +9677,8 @@ void __init early_trace_init(void)
 			static_key_enable(&tracepoint_printk_key.key);
 	}
 	tracer_alloc_buffers();
+
+	init_events();
 }
 
 void __init trace_init(void)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8d67f7f44840..37f616bf5fa9 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1673,6 +1673,7 @@ extern void trace_event_enable_cmd_record(bool enable);
 extern void trace_event_enable_tgid_record(bool enable);
 
 extern int event_trace_init(void);
+extern int init_events(void);
 extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
 extern int event_trace_del_tracer(struct trace_array *tr);
 extern void __trace_early_add_events(struct trace_array *tr);
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 0ae3e4454ff2..ccc99cd23f3c 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1646,6 +1646,8 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
 		unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
 		hist_field->fn = hist_field_log2;
 		hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
+		if (!hist_field->operands[0])
+			goto free;
 		hist_field->size = hist_field->operands[0]->size;
 		hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL);
 		if (!hist_field->type)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 000e9dc224c6..b3ee8d9b6b62 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -1378,7 +1378,7 @@ static struct trace_event *events[] __initdata = {
 	NULL
 };
 
-__init static int init_events(void)
+__init int init_events(void)
 {
 	struct trace_event *event;
 	int i, ret;
@@ -1396,4 +1396,3 @@ __init static int init_events(void)
 
 	return 0;
 }
-early_initcall(init_events);