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-rw-r--r--fs/pstore/ftrace.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c
index bfbfc2698070..5c0450701293 100644
--- a/fs/pstore/ftrace.c
+++ b/fs/pstore/ftrace.c
@@ -16,6 +16,7 @@
#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/cache.h>
+#include <linux/slab.h>
#include <asm/barrier.h>
#include "internal.h"
@@ -132,3 +133,56 @@ void pstore_unregister_ftrace(void)
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);