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, 155 insertions, 0 deletions

diff --git a/security/apparmor/secid.c b/security/apparmor/secid.c
new file mode 100644
index 000000000..28caf66b9
--- /dev/null
+++ b/security/apparmor/secid.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor security identifier (secid) manipulation fns
+ *
+ * Copyright 2009-2017 Canonical Ltd.
+ *
+ * AppArmor allocates a unique secid for every label used. If a label
+ * is replaced it receives the secid of the label it is replacing.
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/xarray.h>
+
+#include "include/cred.h"
+#include "include/lib.h"
+#include "include/secid.h"
+#include "include/label.h"
+#include "include/policy_ns.h"
+
+/*
+ * secids - do not pin labels with a refcount. They rely on the label
+ * properly updating/freeing them
+ */
+#define AA_FIRST_SECID 2
+
+static DEFINE_XARRAY_FLAGS(aa_secids, XA_FLAGS_LOCK_IRQ | XA_FLAGS_TRACK_FREE);
+
+int apparmor_display_secid_mode;
+
+/*
+ * TODO: allow policy to reserve a secid range?
+ * TODO: add secid pinning
+ * TODO: use secid_update in label replace
+ */
+
+/*
+ * see label for inverse aa_label_to_secid
+ */
+struct aa_label *aa_secid_to_label(u32 secid)
+{
+	return xa_load(&aa_secids, secid);
+}
+
+static int apparmor_label_to_secctx(struct aa_label *label,
+				    struct lsm_context *cp)
+{
+	/* TODO: cache secctx and ref count so we don't have to recreate */
+	int flags = FLAG_VIEW_SUBNS | FLAG_HIDDEN_UNCONFINED | FLAG_ABS_ROOT;
+	int len;
+
+	if (!label)
+		return -EINVAL;
+
+	if (apparmor_display_secid_mode)
+		flags |= FLAG_SHOW_MODE;
+
+	if (cp)
+		len = aa_label_asxprint(&cp->context, root_ns, label,
+					flags, GFP_ATOMIC);
+	else
+		len = aa_label_snxprint(NULL, 0, root_ns, label, flags);
+
+	if (len < 0)
+		return -ENOMEM;
+
+	if (cp) {
+		cp->len = len;
+		cp->id = LSM_ID_APPARMOR;
+	}
+
+	return len;
+}
+
+int apparmor_secid_to_secctx(u32 secid, struct lsm_context *cp)
+{
+	struct aa_label *label = aa_secid_to_label(secid);
+
+	return apparmor_label_to_secctx(label, cp);
+}
+
+int apparmor_lsmprop_to_secctx(struct lsm_prop *prop, struct lsm_context *cp)
+{
+	struct aa_label *label;
+
+	label = prop->apparmor.label;
+
+	return apparmor_label_to_secctx(label, cp);
+}
+
+int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
+{
+	struct aa_label *label;
+
+	label = aa_label_strn_parse(&root_ns->unconfined->label, secdata,
+				    seclen, GFP_KERNEL, false, false);
+	if (IS_ERR(label))
+		return PTR_ERR(label);
+	*secid = label->secid;
+
+	return 0;
+}
+
+void apparmor_release_secctx(struct lsm_context *cp)
+{
+	if (cp->id == LSM_ID_APPARMOR) {
+		kfree(cp->context);
+		cp->context = NULL;
+		cp->id = LSM_ID_UNDEF;
+	}
+}
+
+/**
+ * aa_alloc_secid - allocate a new secid for a profile
+ * @label: the label to allocate a secid for
+ * @gfp: memory allocation flags
+ *
+ * Returns: 0 with @label->secid initialized
+ *          <0 returns error with @label->secid set to AA_SECID_INVALID
+ */
+int aa_alloc_secid(struct aa_label *label, gfp_t gfp)
+{
+	unsigned long flags;
+	int ret;
+
+	xa_lock_irqsave(&aa_secids, flags);
+	ret = __xa_alloc(&aa_secids, &label->secid, label,
+			XA_LIMIT(AA_FIRST_SECID, INT_MAX), gfp);
+	xa_unlock_irqrestore(&aa_secids, flags);
+
+	if (ret < 0) {
+		label->secid = AA_SECID_INVALID;
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * aa_free_secid - free a secid
+ * @secid: secid to free
+ */
+void aa_free_secid(u32 secid)
+{
+	unsigned long flags;
+
+	xa_lock_irqsave(&aa_secids, flags);
+	__xa_erase(&aa_secids, secid);
+	xa_unlock_irqrestore(&aa_secids, flags);
+}