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-rw-r--r--kernel/trace/trace.c63
-rw-r--r--kernel/trace/trace.h1
2 files changed, 58 insertions, 6 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 032bdedca5d9..73f8b79f1b0c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9004,8 +9004,8 @@ static int tracing_buffers_mmap(struct file *filp, struct vm_area_struct *vma)
struct trace_iterator *iter = &info->iter;
int ret = 0;
- /* A memmap'ed buffer is not supported for user space mmap */
- if (iter->tr->flags & TRACE_ARRAY_FL_MEMMAP)
+ /* A memmap'ed and backup buffers are not supported for user space mmap */
+ if (iter->tr->flags & (TRACE_ARRAY_FL_MEMMAP | TRACE_ARRAY_FL_VMALLOC))
return -ENODEV;
ret = get_snapshot_map(iter->tr);
@@ -10520,6 +10520,8 @@ static int __remove_instance(struct trace_array *tr)
reserve_mem_release_by_name(tr->range_name);
kfree(tr->range_name);
}
+ if (tr->flags & TRACE_ARRAY_FL_VMALLOC)
+ vfree((void *)tr->range_addr_start);
for (i = 0; i < tr->nr_topts; i++) {
kfree(tr->topts[i].topts);
@@ -11325,6 +11327,42 @@ __init static void do_allocate_snapshot(const char *name)
static inline void do_allocate_snapshot(const char *name) { }
#endif
+__init static int backup_instance_area(const char *backup,
+ unsigned long *addr, phys_addr_t *size)
+{
+ struct trace_array *backup_tr;
+ void *allocated_vaddr = NULL;
+
+ backup_tr = trace_array_get_by_name(backup, NULL);
+ if (!backup_tr) {
+ pr_warn("Tracing: Instance %s is not found.\n", backup);
+ return -ENOENT;
+ }
+
+ if (!(backup_tr->flags & TRACE_ARRAY_FL_BOOT)) {
+ pr_warn("Tracing: Instance %s is not boot mapped.\n", backup);
+ trace_array_put(backup_tr);
+ return -EINVAL;
+ }
+
+ *size = backup_tr->range_addr_size;
+
+ allocated_vaddr = vzalloc(*size);
+ if (!allocated_vaddr) {
+ pr_warn("Tracing: Failed to allocate memory for copying instance %s (size 0x%lx)\n",
+ backup, (unsigned long)*size);
+ trace_array_put(backup_tr);
+ return -ENOMEM;
+ }
+
+ memcpy(allocated_vaddr,
+ (void *)backup_tr->range_addr_start, (size_t)*size);
+ *addr = (unsigned long)allocated_vaddr;
+
+ trace_array_put(backup_tr);
+ return 0;
+}
+
__init static void enable_instances(void)
{
struct trace_array *tr;
@@ -11347,11 +11385,15 @@ __init static void enable_instances(void)
char *flag_delim;
char *addr_delim;
char *rname __free(kfree) = NULL;
+ char *backup;
tok = strsep(&curr_str, ",");
- flag_delim = strchr(tok, '^');
- addr_delim = strchr(tok, '@');
+ name = strsep(&tok, "=");
+ backup = tok;
+
+ flag_delim = strchr(name, '^');
+ addr_delim = strchr(name, '@');
if (addr_delim)
*addr_delim++ = '\0';
@@ -11359,7 +11401,10 @@ __init static void enable_instances(void)
if (flag_delim)
*flag_delim++ = '\0';
- name = tok;
+ if (backup) {
+ if (backup_instance_area(backup, &addr, &size) < 0)
+ continue;
+ }
if (flag_delim) {
char *flag;
@@ -11455,7 +11500,13 @@ __init static void enable_instances(void)
tr->ref++;
}
- if (start) {
+ /*
+ * Backup buffers can be freed but need vfree().
+ */
+ if (backup)
+ tr->flags |= TRACE_ARRAY_FL_VMALLOC;
+
+ if (start || backup) {
tr->flags |= TRACE_ARRAY_FL_BOOT | TRACE_ARRAY_FL_LAST_BOOT;
tr->range_name = no_free_ptr(rname);
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index a3aa225ed50a..666f9a2c189d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -454,6 +454,7 @@ enum {
TRACE_ARRAY_FL_LAST_BOOT = BIT(2),
TRACE_ARRAY_FL_MOD_INIT = BIT(3),
TRACE_ARRAY_FL_MEMMAP = BIT(4),
+ TRACE_ARRAY_FL_VMALLOC = BIT(5),
};
#ifdef CONFIG_MODULES