Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 208 insertions, 0 deletions

diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c
new file mode 100644
index 0000000000..776cae20af
--- /dev/null
+++ b/fs/pstore/ftrace.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2012  Google, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/irqflags.h>
+#include <linux/percpu.h>
+#include <linux/smp.h>
+#include <linux/atomic.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/ftrace.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/err.h>
+#include <linux/cache.h>
+#include <linux/slab.h>
+#include <asm/barrier.h>
+#include "internal.h"
+
+/* This doesn't need to be atomic: speed is chosen over correctness here. */
+static u64 pstore_ftrace_stamp;
+
+static void notrace pstore_ftrace_call(unsigned long ip,
+				       unsigned long parent_ip,
+				       struct ftrace_ops *op,
+				       struct ftrace_regs *fregs)
+{
+	int bit;
+	unsigned long flags;
+	struct pstore_ftrace_record rec = {};
+	struct pstore_record record = {
+		.type = PSTORE_TYPE_FTRACE,
+		.buf = (char *)&rec,
+		.size = sizeof(rec),
+		.psi = psinfo,
+	};
+
+	if (unlikely(oops_in_progress))
+		return;
+
+	bit = ftrace_test_recursion_trylock(ip, parent_ip);
+	if (bit < 0)
+		return;
+
+	local_irq_save(flags);
+
+	rec.ip = ip;
+	rec.parent_ip = parent_ip;
+	pstore_ftrace_write_timestamp(&rec, pstore_ftrace_stamp++);
+	pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id());
+	psinfo->write(&record);
+
+	local_irq_restore(flags);
+	ftrace_test_recursion_unlock(bit);
+}
+
+static struct ftrace_ops pstore_ftrace_ops __read_mostly = {
+	.func	= pstore_ftrace_call,
+};
+
+static DEFINE_MUTEX(pstore_ftrace_lock);
+static bool pstore_ftrace_enabled;
+
+static int pstore_set_ftrace_enabled(bool on)
+{
+	ssize_t ret;
+
+	if (on == pstore_ftrace_enabled)
+		return 0;
+
+	if (on) {
+		ftrace_ops_set_global_filter(&pstore_ftrace_ops);
+		ret = register_ftrace_function(&pstore_ftrace_ops);
+	} else {
+		ret = unregister_ftrace_function(&pstore_ftrace_ops);
+	}
+
+	if (ret) {
+		pr_err("%s: unable to %sregister ftrace ops: %zd\n",
+		       __func__, on ? "" : "un", ret);
+	} else {
+		pstore_ftrace_enabled = on;
+	}
+
+	return ret;
+}
+
+static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf,
+					size_t count, loff_t *ppos)
+{
+	u8 on;
+	ssize_t ret;
+
+	ret = kstrtou8_from_user(buf, count, 2, &on);
+	if (ret)
+		return ret;
+
+	mutex_lock(&pstore_ftrace_lock);
+	ret = pstore_set_ftrace_enabled(on);
+	mutex_unlock(&pstore_ftrace_lock);
+
+	if (ret == 0)
+		ret = count;
+
+	return ret;
+}
+
+static ssize_t pstore_ftrace_knob_read(struct file *f, char __user *buf,
+				       size_t count, loff_t *ppos)
+{
+	char val[] = { '0' + pstore_ftrace_enabled, '\n' };
+
+	return simple_read_from_buffer(buf, count, ppos, val, sizeof(val));
+}
+
+static const struct file_operations pstore_knob_fops = {
+	.open	= simple_open,
+	.read	= pstore_ftrace_knob_read,
+	.write	= pstore_ftrace_knob_write,
+};
+
+static struct dentry *pstore_ftrace_dir;
+
+static bool record_ftrace;
+module_param(record_ftrace, bool, 0400);
+MODULE_PARM_DESC(record_ftrace,
+		 "enable ftrace recording immediately (default: off)");
+
+void pstore_register_ftrace(void)
+{
+	if (!psinfo->write)
+		return;
+
+	pstore_ftrace_dir = debugfs_create_dir("pstore", NULL);
+
+	pstore_set_ftrace_enabled(record_ftrace);
+
+	debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir, NULL,
+			    &pstore_knob_fops);
+}
+
+void pstore_unregister_ftrace(void)
+{
+	mutex_lock(&pstore_ftrace_lock);
+	if (pstore_ftrace_enabled) {
+		unregister_ftrace_function(&pstore_ftrace_ops);
+		pstore_ftrace_enabled = false;
+	}
+	mutex_unlock(&pstore_ftrace_lock);
+
+	debugfs_remove_recursive(pstore_ftrace_dir);
+}
+
+ssize_t pstore_ftrace_combine_log(char **dest_log, size_t *dest_log_size,
+				  const char *src_log, size_t src_log_size)
+{
+	size_t dest_size, src_size, total, dest_off, src_off;
+	size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
+	void *merged_buf;
+	struct pstore_ftrace_record *drec, *srec, *mrec;
+	size_t record_size = sizeof(struct pstore_ftrace_record);
+
+	dest_off = *dest_log_size % record_size;
+	dest_size = *dest_log_size - dest_off;
+
+	src_off = src_log_size % record_size;
+	src_size = src_log_size - src_off;
+
+	total = dest_size + src_size;
+	merged_buf = kmalloc(total, GFP_KERNEL);
+	if (!merged_buf)
+		return -ENOMEM;
+
+	drec = (struct pstore_ftrace_record *)(*dest_log + dest_off);
+	srec = (struct pstore_ftrace_record *)(src_log + src_off);
+	mrec = (struct pstore_ftrace_record *)(merged_buf);
+
+	while (dest_size > 0 && src_size > 0) {
+		if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
+		    pstore_ftrace_read_timestamp(&srec[src_idx])) {
+			mrec[merged_idx++] = drec[dest_idx++];
+			dest_size -= record_size;
+		} else {
+			mrec[merged_idx++] = srec[src_idx++];
+			src_size -= record_size;
+		}
+	}
+
+	while (dest_size > 0) {
+		mrec[merged_idx++] = drec[dest_idx++];
+		dest_size -= record_size;
+	}
+
+	while (src_size > 0) {
+		mrec[merged_idx++] = srec[src_idx++];
+		src_size -= record_size;
+	}
+
+	kfree(*dest_log);
+	*dest_log = merged_buf;
+	*dest_log_size = total;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pstore_ftrace_combine_log);