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, 490 insertions, 0 deletions

diff --git a/security/ipe/policy_fs.c b/security/ipe/policy_fs.c
new file mode 100644
index 000000000..9d92d8a14
--- /dev/null
+++ b/security/ipe/policy_fs.c
@@ -0,0 +1,490 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/types.h>
+#include <linux/dcache.h>
+#include <linux/security.h>
+
+#include "ipe.h"
+#include "policy.h"
+#include "eval.h"
+#include "fs.h"
+#include "audit.h"
+
+#define MAX_VERSION_SIZE ARRAY_SIZE("65535.65535.65535")
+
+/**
+ * struct ipefs_file - defines a file in securityfs.
+ *
+ * @name: file name inside the policy subdirectory
+ * @access: file permissions
+ * @fops: &file_operations specific to this file
+ */
+struct ipefs_file {
+	const char *name;
+	umode_t access;
+	const struct file_operations *fops;
+};
+
+/**
+ * read_pkcs7() - Read handler for "ipe/policies/$name/pkcs7".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the pkcs7 blob representing the policy
+ * on success. If the policy is unsigned (like the boot policy), this
+ * will return -ENOENT.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted or is unsigned
+ */
+static ssize_t read_pkcs7(struct file *f, char __user *data,
+			  size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	int rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	if (!p->pkcs7) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rc = simple_read_from_buffer(data, len, offset, p->pkcs7, p->pkcs7len);
+
+out:
+	inode_unlock_shared(root);
+
+	return rc;
+}
+
+/**
+ * read_policy() - Read handler for "ipe/policies/$name/policy".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the plain-text version of the policy
+ * on success.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t read_policy(struct file *f, char __user *data,
+			   size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	int rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rc = simple_read_from_buffer(data, len, offset, p->text, p->textlen);
+
+out:
+	inode_unlock_shared(root);
+
+	return rc;
+}
+
+/**
+ * read_name() - Read handler for "ipe/policies/$name/name".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the policy_name attribute on success.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t read_name(struct file *f, char __user *data,
+			 size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	int rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rc = simple_read_from_buffer(data, len, offset, p->parsed->name,
+				     strlen(p->parsed->name));
+
+out:
+	inode_unlock_shared(root);
+
+	return rc;
+}
+
+/**
+ * read_version() - Read handler for "ipe/policies/$name/version".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the version string on success.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t read_version(struct file *f, char __user *data,
+			    size_t len, loff_t *offset)
+{
+	char buffer[MAX_VERSION_SIZE] = { 0 };
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	size_t strsize = 0;
+	ssize_t rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	strsize = scnprintf(buffer, ARRAY_SIZE(buffer), "%hu.%hu.%hu",
+			    p->parsed->version.major, p->parsed->version.minor,
+			    p->parsed->version.rev);
+
+	rc = simple_read_from_buffer(data, len, offset, buffer, strsize);
+
+out:
+	inode_unlock_shared(root);
+
+	return rc;
+}
+
+/**
+ * setactive() - Write handler for "ipe/policies/$name/active".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-EPERM			- Insufficient permission
+ * * %-EINVAL			- Invalid input
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t setactive(struct file *f, const char __user *data,
+			 size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	bool value = false;
+	int rc = 0;
+
+	if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN))
+		return -EPERM;
+
+	rc = kstrtobool_from_user(data, len, &value);
+	if (rc)
+		return rc;
+
+	if (!value)
+		return -EINVAL;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+	inode_lock(root);
+
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		rc = -ENOENT;
+		goto out;
+	}
+
+	rc = ipe_set_active_pol(p);
+
+out:
+	inode_unlock(root);
+	return (rc < 0) ? rc : len;
+}
+
+/**
+ * getactive() - Read handler for "ipe/policies/$name/active".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * @data will be populated with the 1 or 0 depending on if the
+ * corresponding policy is active.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t getactive(struct file *f, char __user *data,
+			 size_t len, loff_t *offset)
+{
+	const struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	const char *str;
+	int rc = 0;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+
+	inode_lock_shared(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		inode_unlock_shared(root);
+		return -ENOENT;
+	}
+	inode_unlock_shared(root);
+
+	str = (p == rcu_access_pointer(ipe_active_policy)) ? "1" : "0";
+	rc = simple_read_from_buffer(data, len, offset, str, 1);
+
+	return rc;
+}
+
+/**
+ * update_policy() - Write handler for "ipe/policies/$name/update".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * On success this updates the policy represented by $name,
+ * in-place.
+ *
+ * Return:
+ * * Length of buffer written		- Success
+ * * %-EPERM				- Insufficient permission
+ * * %-ENOMEM				- Out of memory (OOM)
+ * * %-ENOENT				- Policy was deleted while updating
+ * * %-EINVAL				- Policy name mismatch
+ * * %-ESTALE				- Policy version too old
+ */
+static ssize_t update_policy(struct file *f, const char __user *data,
+			     size_t len, loff_t *offset)
+{
+	struct inode *root = NULL;
+	char *copy = NULL;
+	int rc = 0;
+
+	if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN)) {
+		rc = -EPERM;
+		goto out;
+	}
+
+	copy = memdup_user(data, len);
+	if (IS_ERR(copy)) {
+		rc = PTR_ERR(copy);
+		copy = NULL;
+		goto out;
+	}
+
+	root = d_inode(f->f_path.dentry->d_parent);
+	inode_lock(root);
+	rc = ipe_update_policy(root, NULL, 0, copy, len);
+	inode_unlock(root);
+
+out:
+	kfree(copy);
+	if (rc) {
+		ipe_audit_policy_load(ERR_PTR(rc));
+		return rc;
+	}
+
+	return len;
+}
+
+/**
+ * delete_policy() - write handler for  "ipe/policies/$name/delete".
+ * @f: Supplies a file structure representing the securityfs node.
+ * @data: Supplies a buffer passed to the write syscall.
+ * @len: Supplies the length of @data.
+ * @offset: unused.
+ *
+ * On success this deletes the policy represented by $name.
+ *
+ * Return:
+ * * Length of buffer written	- Success
+ * * %-EPERM			- Insufficient permission/deleting active policy
+ * * %-EINVAL			- Invalid input
+ * * %-ENOENT			- Policy initializing/deleted
+ */
+static ssize_t delete_policy(struct file *f, const char __user *data,
+			     size_t len, loff_t *offset)
+{
+	struct ipe_policy *ap = NULL;
+	struct ipe_policy *p = NULL;
+	struct inode *root = NULL;
+	bool value = false;
+	int rc = 0;
+
+	if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN))
+		return -EPERM;
+
+	rc = kstrtobool_from_user(data, len, &value);
+	if (rc)
+		return rc;
+
+	if (!value)
+		return -EINVAL;
+
+	root = d_inode(f->f_path.dentry->d_parent);
+	inode_lock(root);
+	p = (struct ipe_policy *)root->i_private;
+	if (!p) {
+		inode_unlock(root);
+		return -ENOENT;
+	}
+
+	mutex_lock(&ipe_policy_lock);
+	ap = rcu_dereference_protected(ipe_active_policy,
+				       lockdep_is_held(&ipe_policy_lock));
+	if (p == ap) {
+		mutex_unlock(&ipe_policy_lock);
+		inode_unlock(root);
+		return -EPERM;
+	}
+	mutex_unlock(&ipe_policy_lock);
+
+	root->i_private = NULL;
+	inode_unlock(root);
+
+	synchronize_rcu();
+	ipe_free_policy(p);
+
+	return len;
+}
+
+static const struct file_operations content_fops = {
+	.read = read_policy,
+};
+
+static const struct file_operations pkcs7_fops = {
+	.read = read_pkcs7,
+};
+
+static const struct file_operations name_fops = {
+	.read = read_name,
+};
+
+static const struct file_operations ver_fops = {
+	.read = read_version,
+};
+
+static const struct file_operations active_fops = {
+	.write = setactive,
+	.read = getactive,
+};
+
+static const struct file_operations update_fops = {
+	.write = update_policy,
+};
+
+static const struct file_operations delete_fops = {
+	.write = delete_policy,
+};
+
+/*
+ * policy_subdir - files under a policy subdirectory
+ */
+static const struct ipefs_file policy_subdir[] = {
+	{ "pkcs7", 0444, &pkcs7_fops },
+	{ "policy", 0444, &content_fops },
+	{ "name", 0444, &name_fops },
+	{ "version", 0444, &ver_fops },
+	{ "active", 0600, &active_fops },
+	{ "update", 0200, &update_fops },
+	{ "delete", 0200, &delete_fops },
+};
+
+/**
+ * ipe_del_policyfs_node() - Delete a securityfs entry for @p.
+ * @p: Supplies a pointer to the policy to delete a securityfs entry for.
+ */
+void ipe_del_policyfs_node(struct ipe_policy *p)
+{
+	securityfs_remove(p->policyfs);
+	p->policyfs = NULL;
+}
+
+/**
+ * ipe_new_policyfs_node() - Create a securityfs entry for @p.
+ * @p: Supplies a pointer to the policy to create a securityfs entry for.
+ *
+ * Return: %0 on success. If an error occurs, the function will return
+ * the -errno.
+ */
+int ipe_new_policyfs_node(struct ipe_policy *p)
+{
+	const struct ipefs_file *f = NULL;
+	struct dentry *policyfs = NULL;
+	struct inode *root = NULL;
+	struct dentry *d = NULL;
+	size_t i = 0;
+	int rc = 0;
+
+	if (p->policyfs)
+		return 0;
+
+	policyfs = securityfs_create_dir(p->parsed->name, policy_root);
+	if (IS_ERR(policyfs))
+		return PTR_ERR(policyfs);
+
+	root = d_inode(policyfs);
+
+	for (i = 0; i < ARRAY_SIZE(policy_subdir); ++i) {
+		f = &policy_subdir[i];
+
+		d = securityfs_create_file(f->name, f->access, policyfs,
+					   NULL, f->fops);
+		if (IS_ERR(d)) {
+			rc = PTR_ERR(d);
+			goto err;
+		}
+	}
+
+	inode_lock(root);
+	p->policyfs = policyfs;
+	root->i_private = p;
+	inode_unlock(root);
+
+	return 0;
+err:
+	securityfs_remove(policyfs);
+	return rc;
+}