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, 127 insertions, 0 deletions

diff --git a/drivers/ras/ras.c b/drivers/ras/ras.c
new file mode 100644
index 000000000..03df3db62
--- /dev/null
+++ b/drivers/ras/ras.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2014 Intel Corporation
+ *
+ * Authors:
+ *	Chen, Gong <gong.chen@linux.intel.com>
+ */
+
+#include <linux/init.h>
+#include <linux/ras.h>
+#include <linux/uuid.h>
+
+#if IS_ENABLED(CONFIG_AMD_ATL)
+/*
+ * Once set, this function pointer should never be unset.
+ *
+ * The library module will set this pointer if it successfully loads. The module
+ * should not be unloaded except for testing and debug purposes.
+ */
+static unsigned long (*amd_atl_umc_na_to_spa)(struct atl_err *err);
+
+void amd_atl_register_decoder(unsigned long (*f)(struct atl_err *))
+{
+	amd_atl_umc_na_to_spa = f;
+}
+EXPORT_SYMBOL_GPL(amd_atl_register_decoder);
+
+void amd_atl_unregister_decoder(void)
+{
+	amd_atl_umc_na_to_spa = NULL;
+}
+EXPORT_SYMBOL_GPL(amd_atl_unregister_decoder);
+
+unsigned long amd_convert_umc_mca_addr_to_sys_addr(struct atl_err *err)
+{
+	if (!amd_atl_umc_na_to_spa)
+		return -EINVAL;
+
+	return amd_atl_umc_na_to_spa(err);
+}
+EXPORT_SYMBOL_GPL(amd_convert_umc_mca_addr_to_sys_addr);
+#endif /* CONFIG_AMD_ATL */
+
+#define CREATE_TRACE_POINTS
+#define TRACE_INCLUDE_PATH ../../include/ras
+#include <ras/ras_event.h>
+
+void log_non_standard_event(const guid_t *sec_type, const guid_t *fru_id,
+			    const char *fru_text, const u8 sev, const u8 *err,
+			    const u32 len)
+{
+	trace_non_standard_event(sec_type, fru_id, fru_text, sev, err, len);
+}
+EXPORT_SYMBOL_GPL(log_non_standard_event);
+
+void log_arm_hw_error(struct cper_sec_proc_arm *err, const u8 sev)
+{
+	struct cper_arm_err_info *err_info;
+	struct cper_arm_ctx_info *ctx_info;
+	u8 *ven_err_data;
+	u32 ctx_len = 0;
+	int n, sz, cpu;
+	s32 vsei_len;
+	u32 pei_len;
+	u8 *pei_err, *ctx_err;
+
+	pei_len = sizeof(struct cper_arm_err_info) * err->err_info_num;
+	pei_err = (u8 *)(err + 1);
+
+	err_info = (struct cper_arm_err_info *)(err + 1);
+	ctx_info = (struct cper_arm_ctx_info *)(err_info + err->err_info_num);
+	ctx_err = (u8 *)ctx_info;
+
+	for (n = 0; n < err->context_info_num; n++) {
+		sz = sizeof(struct cper_arm_ctx_info);
+
+		if (sz + (long)ctx_info - (long)err >= err->section_length)
+			sz += ctx_info->size;
+
+		ctx_info = (struct cper_arm_ctx_info *)((long)ctx_info + sz);
+		ctx_len += sz;
+	}
+
+	vsei_len = err->section_length - (sizeof(struct cper_sec_proc_arm) + pei_len + ctx_len);
+	if (vsei_len < 0) {
+		pr_warn(FW_BUG "section length: %d\n", err->section_length);
+		pr_warn(FW_BUG "section length is too small\n");
+		pr_warn(FW_BUG "firmware-generated error record is incorrect\n");
+		vsei_len = 0;
+	}
+	ven_err_data = (u8 *)ctx_info;
+
+	cpu = GET_LOGICAL_INDEX(err->mpidr);
+	if (cpu < 0)
+		cpu = -1;
+
+	trace_arm_event(err, pei_err, pei_len, ctx_err, ctx_len,
+			ven_err_data, (u32)vsei_len, sev, cpu);
+}
+
+static int __init ras_init(void)
+{
+	int rc = 0;
+
+	ras_debugfs_init();
+	rc = ras_add_daemon_trace();
+
+	return rc;
+}
+subsys_initcall(ras_init);
+
+#if defined(CONFIG_ACPI_EXTLOG) || defined(CONFIG_ACPI_EXTLOG_MODULE)
+EXPORT_TRACEPOINT_SYMBOL_GPL(extlog_mem_event);
+#endif
+EXPORT_TRACEPOINT_SYMBOL_GPL(mc_event);
+EXPORT_TRACEPOINT_SYMBOL_GPL(non_standard_event);
+EXPORT_TRACEPOINT_SYMBOL_GPL(arm_event);
+
+static int __init parse_ras_param(char *str)
+{
+#ifdef CONFIG_RAS_CEC
+	parse_cec_param(str);
+#endif
+
+	return 1;
+}
+__setup("ras", parse_ras_param);