[PATCH 05/25] dynamic_debug: trim source-path prefix from dynamic_debug/control

[Jim Cromie <jim.cromie@gmail.com>]

Check for a common source-path prefix, and skip past it, to print a
path thats relative to kernel source's root-dir.  For in-tree modules,
this makes the control file easier to read without a wide screen.

For example:
  kernel/freezer.c:128 [freezer]cancel_freezing - "  clean up: %s\012"

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 887940d..76f80dc 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -646,6 +646,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 	struct ddebug_iter *iter = m->private;
 	struct _ddebug *dp = p;
 	char flagsbuf[8];
+	int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
 
 	pr_debug("called m=%p p=%p\n", m, p);
 
@@ -655,8 +656,11 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 		return 0;
 	}
 
+	if (strncmp(dp->filename, __FILE__, skip))
+		skip = 0; /* prefix mismatch, don't skip */
+
 	seq_printf(m, "%s:%u [%s]%s %s \"",
-		   dp->filename, dp->lineno,
+		   dp->filename + skip, dp->lineno,
 		   iter->table->mod_name, dp->function,
 		   ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
 	seq_escape(m, dp->format, "\t\r\n\"");
-- 
1.7.4.1