dynamic_debug: add trim_prefix() to provide source-root relative paths
trim_prefix(path) skips past the absolute source path root, and
returns the pointer to the relative path from there. It is used to
shorten the displayed path in $DBGMT/dynamic_debug/control via
ddebug_proc_show(), and in ddebug_change() to allow relative filenames
to be used in applied queries. For example:
~# echo file kernel/freezer.c +p > $DBGMT/dynamic_debug/control
kernel/freezer.c:128 [freezer]cancel_freezing p " clean up: %s\012"
trim_prefix(path) insures common prefix before trimming it, so
out-of-tree module paths are shown as full absolute paths.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index d8773dc..a5508a1 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -69,6 +69,17 @@
return tail ? tail+1 : path;
}
+/* Return the path relative to source root */
+static inline const char *trim_prefix(const char *path)
+{
+ int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
+
+ if (strncmp(path, __FILE__, skip))
+ skip = 0; /* prefix mismatch, don't skip */
+
+ return path + skip;
+}
+
static struct { unsigned flag:8; char opt_char; } opt_array[] = {
{ _DPRINTK_FLAGS_PRINT, 'p' },
{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
@@ -125,7 +136,8 @@
/* match against the source filename */
if (query->filename &&
strcmp(query->filename, dp->filename) &&
- strcmp(query->filename, basename(dp->filename)))
+ strcmp(query->filename, basename(dp->filename)) &&
+ strcmp(query->filename, trim_prefix(dp->filename)))
continue;
/* match against the function */
@@ -154,7 +166,7 @@
dp->flags = newflags;
if (verbose)
pr_info("changed %s:%d [%s]%s =%s\n",
- dp->filename, dp->lineno,
+ trim_prefix(dp->filename), dp->lineno,
dt->mod_name, dp->function,
ddebug_describe_flags(dp, flagbuf,
sizeof(flagbuf)));
@@ -714,7 +726,7 @@
}
seq_printf(m, "%s:%u [%s]%s =%s \"",
- dp->filename, dp->lineno,
+ trim_prefix(dp->filename), dp->lineno,
iter->table->mod_name, dp->function,
ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
seq_escape(m, dp->format, "\t\r\n\"");