Commit 2b678319 authored by Jim Cromie's avatar Jim Cromie Committed by Greg Kroah-Hartman
Browse files

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: default avatarJim Cromie <jim.cromie@gmail.com>
Signed-off-by: default avatarJason Baron <jbaron@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 7281491c

Documentation/dynamic-debug-howto.txt

+4 −3
Original line number Diff line number Diff line
@@ -144,11 +144,12 @@ func 
    func svc_tcp_accept



file

    The given string is compared against either the full

    pathname or the basename of the source file of each

    callsite.  Examples:

    The given string is compared against either the full pathname, the

    src-root relative pathname, or the basename of the source file of

    each callsite.  Examples:



    file svcsock.c

    file kernel/freezer.c

    file /usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svcsock.c



module

lib/dynamic_debug.c

+15 −3
Original line number Diff line number Diff line
@@ -69,6 +69,17 @@ static inline const char *basename(const char *path) 
	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 @@ static void ddebug_change(const struct ddebug_query *query, 
			/* 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 @@ static void ddebug_change(const struct ddebug_query *query, 
			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 @@ static int ddebug_proc_show(struct seq_file *m, void *p) 
	}



	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\"");

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