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, 206 insertions, 0 deletions

diff --git a/drivers/cxl/security.c b/drivers/cxl/security.c
new file mode 100644
index 000000000..ab793e857
--- /dev/null
+++ b/drivers/cxl/security.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2022 Intel Corporation. All rights reserved. */
+#include <linux/libnvdimm.h>
+#include <linux/unaligned.h>
+#include <linux/module.h>
+#include <linux/async.h>
+#include <linux/slab.h>
+#include <linux/memregion.h>
+#include "cxlmem.h"
+#include "cxl.h"
+
+static unsigned long cxl_pmem_get_security_flags(struct nvdimm *nvdimm,
+						 enum nvdimm_passphrase_type ptype)
+{
+	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
+	struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;
+	struct cxl_mailbox *cxl_mbox = &cxlmd->cxlds->cxl_mbox;
+	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
+	unsigned long security_flags = 0;
+	struct cxl_get_security_output {
+		__le32 flags;
+	} out;
+	struct cxl_mbox_cmd mbox_cmd;
+	u32 sec_out;
+	int rc;
+
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_GET_SECURITY_STATE,
+		.size_out = sizeof(out),
+		.payload_out = &out,
+	};
+
+	rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+	if (rc < 0)
+		return 0;
+
+	sec_out = le32_to_cpu(out.flags);
+	/* cache security state */
+	mds->security.state = sec_out;
+
+	if (ptype == NVDIMM_MASTER) {
+		if (sec_out & CXL_PMEM_SEC_STATE_MASTER_PASS_SET)
+			set_bit(NVDIMM_SECURITY_UNLOCKED, &security_flags);
+		else
+			set_bit(NVDIMM_SECURITY_DISABLED, &security_flags);
+		if (sec_out & CXL_PMEM_SEC_STATE_MASTER_PLIMIT)
+			set_bit(NVDIMM_SECURITY_FROZEN, &security_flags);
+		return security_flags;
+	}
+
+	if (sec_out & CXL_PMEM_SEC_STATE_USER_PASS_SET) {
+		if (sec_out & CXL_PMEM_SEC_STATE_FROZEN ||
+		    sec_out & CXL_PMEM_SEC_STATE_USER_PLIMIT)
+			set_bit(NVDIMM_SECURITY_FROZEN, &security_flags);
+
+		if (sec_out & CXL_PMEM_SEC_STATE_LOCKED)
+			set_bit(NVDIMM_SECURITY_LOCKED, &security_flags);
+		else
+			set_bit(NVDIMM_SECURITY_UNLOCKED, &security_flags);
+	} else {
+		set_bit(NVDIMM_SECURITY_DISABLED, &security_flags);
+	}
+
+	return security_flags;
+}
+
+static int cxl_pmem_security_change_key(struct nvdimm *nvdimm,
+					const struct nvdimm_key_data *old_data,
+					const struct nvdimm_key_data *new_data,
+					enum nvdimm_passphrase_type ptype)
+{
+	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
+	struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;
+	struct cxl_mailbox *cxl_mbox = &cxlmd->cxlds->cxl_mbox;
+	struct cxl_mbox_cmd mbox_cmd;
+	struct cxl_set_pass set_pass;
+
+	set_pass = (struct cxl_set_pass) {
+		.type = ptype == NVDIMM_MASTER ? CXL_PMEM_SEC_PASS_MASTER :
+						 CXL_PMEM_SEC_PASS_USER,
+	};
+	memcpy(set_pass.old_pass, old_data->data, NVDIMM_PASSPHRASE_LEN);
+	memcpy(set_pass.new_pass, new_data->data, NVDIMM_PASSPHRASE_LEN);
+
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_SET_PASSPHRASE,
+		.size_in = sizeof(set_pass),
+		.payload_in = &set_pass,
+	};
+
+	return cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+}
+
+static int __cxl_pmem_security_disable(struct nvdimm *nvdimm,
+				       const struct nvdimm_key_data *key_data,
+				       enum nvdimm_passphrase_type ptype)
+{
+	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
+	struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;
+	struct cxl_mailbox *cxl_mbox = &cxlmd->cxlds->cxl_mbox;
+	struct cxl_disable_pass dis_pass;
+	struct cxl_mbox_cmd mbox_cmd;
+
+	dis_pass = (struct cxl_disable_pass) {
+		.type = ptype == NVDIMM_MASTER ? CXL_PMEM_SEC_PASS_MASTER :
+						 CXL_PMEM_SEC_PASS_USER,
+	};
+	memcpy(dis_pass.pass, key_data->data, NVDIMM_PASSPHRASE_LEN);
+
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_DISABLE_PASSPHRASE,
+		.size_in = sizeof(dis_pass),
+		.payload_in = &dis_pass,
+	};
+
+	return cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+}
+
+static int cxl_pmem_security_disable(struct nvdimm *nvdimm,
+				     const struct nvdimm_key_data *key_data)
+{
+	return __cxl_pmem_security_disable(nvdimm, key_data, NVDIMM_USER);
+}
+
+static int cxl_pmem_security_disable_master(struct nvdimm *nvdimm,
+					    const struct nvdimm_key_data *key_data)
+{
+	return __cxl_pmem_security_disable(nvdimm, key_data, NVDIMM_MASTER);
+}
+
+static int cxl_pmem_security_freeze(struct nvdimm *nvdimm)
+{
+	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
+	struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;
+	struct cxl_mailbox *cxl_mbox = &cxlmd->cxlds->cxl_mbox;
+	struct cxl_mbox_cmd mbox_cmd = {
+		.opcode = CXL_MBOX_OP_FREEZE_SECURITY,
+	};
+
+	return cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+}
+
+static int cxl_pmem_security_unlock(struct nvdimm *nvdimm,
+				    const struct nvdimm_key_data *key_data)
+{
+	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
+	struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;
+	struct cxl_mailbox *cxl_mbox = &cxlmd->cxlds->cxl_mbox;
+	u8 pass[NVDIMM_PASSPHRASE_LEN];
+	struct cxl_mbox_cmd mbox_cmd;
+	int rc;
+
+	memcpy(pass, key_data->data, NVDIMM_PASSPHRASE_LEN);
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_UNLOCK,
+		.size_in = NVDIMM_PASSPHRASE_LEN,
+		.payload_in = pass,
+	};
+
+	rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+	if (rc < 0)
+		return rc;
+
+	return 0;
+}
+
+static int cxl_pmem_security_passphrase_erase(struct nvdimm *nvdimm,
+					      const struct nvdimm_key_data *key,
+					      enum nvdimm_passphrase_type ptype)
+{
+	struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
+	struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;
+	struct cxl_mailbox *cxl_mbox = &cxlmd->cxlds->cxl_mbox;
+	struct cxl_mbox_cmd mbox_cmd;
+	struct cxl_pass_erase erase;
+	int rc;
+
+	erase = (struct cxl_pass_erase) {
+		.type = ptype == NVDIMM_MASTER ? CXL_PMEM_SEC_PASS_MASTER :
+						 CXL_PMEM_SEC_PASS_USER,
+	};
+	memcpy(erase.pass, key->data, NVDIMM_PASSPHRASE_LEN);
+	mbox_cmd = (struct cxl_mbox_cmd) {
+		.opcode = CXL_MBOX_OP_PASSPHRASE_SECURE_ERASE,
+		.size_in = sizeof(erase),
+		.payload_in = &erase,
+	};
+
+	rc = cxl_internal_send_cmd(cxl_mbox, &mbox_cmd);
+	if (rc < 0)
+		return rc;
+
+	return 0;
+}
+
+static const struct nvdimm_security_ops __cxl_security_ops = {
+	.get_flags = cxl_pmem_get_security_flags,
+	.change_key = cxl_pmem_security_change_key,
+	.disable = cxl_pmem_security_disable,
+	.freeze = cxl_pmem_security_freeze,
+	.unlock = cxl_pmem_security_unlock,
+	.erase = cxl_pmem_security_passphrase_erase,
+	.disable_master = cxl_pmem_security_disable_master,
+};
+
+const struct nvdimm_security_ops *cxl_security_ops = &__cxl_security_ops;