Handle pointers to kernel strings nicer

Some trace events point to strings within the kernel, and print them
with '%s'. Since the stored value is just a pointer, unless we
export those strings we can't print them out. Instead of trying to print
out garbage (a string pointer), print out the value instead.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/parse-events.c b/parse-events.c
index ff44523..af50bc1 100644
--- a/parse-events.c
+++ b/parse-events.c
@@ -2255,6 +2255,7 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
 {
         struct print_flag_sym *flag;
         unsigned long long val, fval;
+        unsigned long addr;
         char *str;
         int print;
         int len;
@@ -2274,7 +2275,19 @@ static void print_str_arg(struct trace_seq *s, void *data, int size,
                 }
                 /* Zero sized fields, mean the rest of the data */
                 len = arg->field.field->size ? : size;
-                str = malloc_or_die(size + 1);
+
+                /*
+                 * Some events pass in pointers. If this is not an array
+                 * and the size is the same as long_size, assume that it
+                 * is a pointer.
+                 */
+                if (!(arg->field.field->flags & FIELD_IS_ARRAY) &&
+                    len == long_size) {
+                        addr = *(unsigned long *)(data + arg->field.field->offset);
+                        trace_seq_printf(s, "%lx", addr);
+                        break;
+                }
+                str = malloc_or_die(len + 1);
                 memcpy(str, data + arg->field.field->offset, len);
                 str[len] = 0;
                 trace_seq_puts(s, str);