Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted

Changes:

Make expedited grace periods expedite normal RCU callbacks

Miscellaneous fixes:
 * Improve diagnostic output with character task states.
 * Mark accesses to inform KCSAN of concurrency design.
 * Move from kmalloc() to kmalloc_obj().
 * Documentation updates.
 * Improve handling of RCU deferred quiescent states.
 * Clean up unused function arguments and structure fields.
 * Reduce show_rcu_gp_kthreads() stack space.

Tasks RCU updates:
 * Clean up after SRCU re-implementation of Tasks Trace RCU.
 * Mark accesses to inform KCSAN of concurrency design.
 * Add ->lazy_timer status to diagnostic output.
 * Remove an unnecessary memory barrier.
 * Fix a data race, courtesy of KCSAN.
 * Documentation updates.
 * Convert cond_resched_tasks_rcu_qs() from macro to static inline
   function.

SRCU updates:
 * Add Rust helpers for SRCU.
 * Avoid losing queued work at cleanup_srcu_struct() time.

Torture-test updates:
 * Preparation work for immediate RCU priority deboosting.
 * Test RCU readers from real interrupt handlers (as opposed to softirq).
 * Simplify code through use of cpumask_next_wrap().
 * Improve diagnostic output with character task states.
 * Add rcutorture.nwriters parameter to allow lightweight stall testing,
   and rcutorture.stall_only to make doing so easier.
 * Test an RCU Tasks Trace grace period implying an RCU grace period.
 * Make RCU Tasks Trace torturing track reader batches.
 * Fix a data race, courtesy of KCSAN.
 * Plug a shuffle_tmp_mask memory leak on kthread spawn failure.

1 files changed, 278 insertions, 0 deletions

diff --git a/net/6lowpan/debugfs.c b/net/6lowpan/debugfs.c
new file mode 100644
index 000000000..600b9563b
--- /dev/null
+++ b/net/6lowpan/debugfs.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Authors:
+ * (C) 2015 Pengutronix, Alexander Aring <aar@pengutronix.de>
+ * Copyright (c)  2015 Nordic Semiconductor. All Rights Reserved.
+ */
+
+#include <net/6lowpan.h>
+
+#include "6lowpan_i.h"
+
+#define LOWPAN_DEBUGFS_CTX_PFX_NUM_ARGS	8
+
+static struct dentry *lowpan_debugfs;
+
+static int lowpan_ctx_flag_active_set(void *data, u64 val)
+{
+	struct lowpan_iphc_ctx *ctx = data;
+
+	if (val != 0 && val != 1)
+		return -EINVAL;
+
+	if (val)
+		set_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE, &ctx->flags);
+	else
+		clear_bit(LOWPAN_IPHC_CTX_FLAG_ACTIVE, &ctx->flags);
+
+	return 0;
+}
+
+static int lowpan_ctx_flag_active_get(void *data, u64 *val)
+{
+	*val = lowpan_iphc_ctx_is_active(data);
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(lowpan_ctx_flag_active_fops,
+			 lowpan_ctx_flag_active_get,
+			 lowpan_ctx_flag_active_set, "%llu\n");
+
+static int lowpan_ctx_flag_c_set(void *data, u64 val)
+{
+	struct lowpan_iphc_ctx *ctx = data;
+
+	if (val != 0 && val != 1)
+		return -EINVAL;
+
+	if (val)
+		set_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
+	else
+		clear_bit(LOWPAN_IPHC_CTX_FLAG_COMPRESSION, &ctx->flags);
+
+	return 0;
+}
+
+static int lowpan_ctx_flag_c_get(void *data, u64 *val)
+{
+	*val = lowpan_iphc_ctx_is_compression(data);
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(lowpan_ctx_flag_c_fops, lowpan_ctx_flag_c_get,
+			 lowpan_ctx_flag_c_set, "%llu\n");
+
+static int lowpan_ctx_plen_set(void *data, u64 val)
+{
+	struct lowpan_iphc_ctx *ctx = data;
+	struct lowpan_iphc_ctx_table *t =
+		container_of(ctx, struct lowpan_iphc_ctx_table, table[ctx->id]);
+
+	if (val > 128)
+		return -EINVAL;
+
+	spin_lock_bh(&t->lock);
+	ctx->plen = val;
+	spin_unlock_bh(&t->lock);
+
+	return 0;
+}
+
+static int lowpan_ctx_plen_get(void *data, u64 *val)
+{
+	struct lowpan_iphc_ctx *ctx = data;
+	struct lowpan_iphc_ctx_table *t =
+		container_of(ctx, struct lowpan_iphc_ctx_table, table[ctx->id]);
+
+	spin_lock_bh(&t->lock);
+	*val = ctx->plen;
+	spin_unlock_bh(&t->lock);
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(lowpan_ctx_plen_fops, lowpan_ctx_plen_get,
+			 lowpan_ctx_plen_set, "%llu\n");
+
+static int lowpan_ctx_pfx_show(struct seq_file *file, void *offset)
+{
+	struct lowpan_iphc_ctx *ctx = file->private;
+	struct lowpan_iphc_ctx_table *t =
+		container_of(ctx, struct lowpan_iphc_ctx_table, table[ctx->id]);
+
+	spin_lock_bh(&t->lock);
+	seq_printf(file, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
+		   be16_to_cpu(ctx->pfx.s6_addr16[0]),
+		   be16_to_cpu(ctx->pfx.s6_addr16[1]),
+		   be16_to_cpu(ctx->pfx.s6_addr16[2]),
+		   be16_to_cpu(ctx->pfx.s6_addr16[3]),
+		   be16_to_cpu(ctx->pfx.s6_addr16[4]),
+		   be16_to_cpu(ctx->pfx.s6_addr16[5]),
+		   be16_to_cpu(ctx->pfx.s6_addr16[6]),
+		   be16_to_cpu(ctx->pfx.s6_addr16[7]));
+	spin_unlock_bh(&t->lock);
+
+	return 0;
+}
+
+static int lowpan_ctx_pfx_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, lowpan_ctx_pfx_show, inode->i_private);
+}
+
+static ssize_t lowpan_ctx_pfx_write(struct file *fp,
+				    const char __user *user_buf, size_t count,
+				    loff_t *ppos)
+{
+	char buf[128] = {};
+	struct seq_file *file = fp->private_data;
+	struct lowpan_iphc_ctx *ctx = file->private;
+	struct lowpan_iphc_ctx_table *t =
+		container_of(ctx, struct lowpan_iphc_ctx_table, table[ctx->id]);
+	int status = count, n, i;
+	unsigned int addr[8];
+
+	if (copy_from_user(&buf, user_buf, min_t(size_t, sizeof(buf) - 1,
+						 count))) {
+		status = -EFAULT;
+		goto out;
+	}
+
+	n = sscanf(buf, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x",
+		   &addr[0], &addr[1], &addr[2], &addr[3], &addr[4],
+		   &addr[5], &addr[6], &addr[7]);
+	if (n != LOWPAN_DEBUGFS_CTX_PFX_NUM_ARGS) {
+		status = -EINVAL;
+		goto out;
+	}
+
+	spin_lock_bh(&t->lock);
+	for (i = 0; i < 8; i++)
+		ctx->pfx.s6_addr16[i] = cpu_to_be16(addr[i] & 0xffff);
+	spin_unlock_bh(&t->lock);
+
+out:
+	return status;
+}
+
+static const struct file_operations lowpan_ctx_pfx_fops = {
+	.open		= lowpan_ctx_pfx_open,
+	.read		= seq_read,
+	.write		= lowpan_ctx_pfx_write,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void lowpan_dev_debugfs_ctx_init(struct net_device *dev,
+					struct dentry *ctx, u8 id)
+{
+	struct lowpan_dev *ldev = lowpan_dev(dev);
+	struct dentry *root;
+	char buf[32];
+
+	if (WARN_ON_ONCE(id >= LOWPAN_IPHC_CTX_TABLE_SIZE))
+		return;
+
+	sprintf(buf, "%d", id);
+
+	root = debugfs_create_dir(buf, ctx);
+
+	debugfs_create_file("active", 0644, root, &ldev->ctx.table[id],
+			    &lowpan_ctx_flag_active_fops);
+
+	debugfs_create_file("compression", 0644, root, &ldev->ctx.table[id],
+			    &lowpan_ctx_flag_c_fops);
+
+	debugfs_create_file("prefix", 0644, root, &ldev->ctx.table[id],
+			    &lowpan_ctx_pfx_fops);
+
+	debugfs_create_file("prefix_len", 0644, root, &ldev->ctx.table[id],
+			    &lowpan_ctx_plen_fops);
+}
+
+static int lowpan_context_show(struct seq_file *file, void *offset)
+{
+	struct lowpan_iphc_ctx_table *t = file->private;
+	int i;
+
+	seq_printf(file, "%3s|%-43s|%c\n", "cid", "prefix", 'C');
+	seq_puts(file, "-------------------------------------------------\n");
+
+	spin_lock_bh(&t->lock);
+	for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++) {
+		if (!lowpan_iphc_ctx_is_active(&t->table[i]))
+			continue;
+
+		seq_printf(file, "%3d|%39pI6c/%-3d|%d\n", t->table[i].id,
+			   &t->table[i].pfx, t->table[i].plen,
+			   lowpan_iphc_ctx_is_compression(&t->table[i]));
+	}
+	spin_unlock_bh(&t->lock);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(lowpan_context);
+
+static int lowpan_short_addr_get(void *data, u64 *val)
+{
+	struct wpan_dev *wdev = data;
+
+	rtnl_lock();
+	*val = le16_to_cpu(wdev->short_addr);
+	rtnl_unlock();
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(lowpan_short_addr_fops, lowpan_short_addr_get, NULL,
+			 "0x%04llx\n");
+
+static void lowpan_dev_debugfs_802154_init(const struct net_device *dev,
+					  struct lowpan_dev *ldev)
+{
+	struct dentry *root;
+
+	if (!lowpan_is_ll(dev, LOWPAN_LLTYPE_IEEE802154))
+		return;
+
+	root = debugfs_create_dir("ieee802154", ldev->iface_debugfs);
+
+	debugfs_create_file("short_addr", 0444, root,
+			    lowpan_802154_dev(dev)->wdev->ieee802154_ptr,
+			    &lowpan_short_addr_fops);
+}
+
+void lowpan_dev_debugfs_init(struct net_device *dev)
+{
+	struct lowpan_dev *ldev = lowpan_dev(dev);
+	struct dentry *contexts;
+	int i;
+
+	/* creating the root */
+	ldev->iface_debugfs = debugfs_create_dir(dev->name, lowpan_debugfs);
+
+	contexts = debugfs_create_dir("contexts", ldev->iface_debugfs);
+
+	debugfs_create_file("show", 0644, contexts, &lowpan_dev(dev)->ctx,
+			    &lowpan_context_fops);
+
+	for (i = 0; i < LOWPAN_IPHC_CTX_TABLE_SIZE; i++)
+		lowpan_dev_debugfs_ctx_init(dev, contexts, i);
+
+	lowpan_dev_debugfs_802154_init(dev, ldev);
+}
+
+void lowpan_dev_debugfs_exit(struct net_device *dev)
+{
+	debugfs_remove_recursive(lowpan_dev(dev)->iface_debugfs);
+}
+
+void __init lowpan_debugfs_init(void)
+{
+	lowpan_debugfs = debugfs_create_dir("6lowpan", NULL);
+}
+
+void lowpan_debugfs_exit(void)
+{
+	debugfs_remove_recursive(lowpan_debugfs);
+}