[PATCH 14/16] dyndbg: prefer declarative init in caller, to memset in callee

[PATCH 14/16] dyndbg: prefer declarative init in caller, to memset in callee

[Jim Cromie]

drop memset in ddebug_parse_query, instead initialize the stack
variable in the caller.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index c6273fabe52c..4369afeb52f0 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -358,7 +358,6 @@ static int ddebug_parse_query(char *words[], int nwords,
 		pr_err("expecting pairs of match-spec <value>\n");
 		return -EINVAL;
 	}
-	memset(query, 0, sizeof(*query));
 
 	if (modname)
 		/* support $modname.dyndbg=<multiple queries> */
@@ -479,7 +478,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
 {
 	struct flagsettings mods = {};
 	struct flagsettings filter = {};
-	struct ddebug_query query;
+	struct ddebug_query query = {};
 #define MAXWORDS 9
 	int nwords, nfound;
 	char *words[MAXWORDS];
-- 
2.21.0

[PATCH 00/16] dynamic_debug: cleanups, 2 features

[Jim Cromie]

Patchset starts with 7 "cleanups";
- it changes section name from vague "__verbose" to "__dyndbg"
- cleaner docs, drop obsolete comment & useless debug prints, refine
  verbosity, fix a BUG_ON, ram reporting miscounts.

It adds a few query parsing conveniences;
accept combined file:line & file:func forms

  file inode.c:100-200		# file & line-range
  file inode.c:start_*		# file & function

Then it expands flags:

Adds 'u' user flag, allowing user to compose an arbitrary set of
callsites by marking them with 'u', without altering current
print-modifying flags.

Adds 'PFMLTU' flags, which negate their lower-case counterparts.

Extends flags-spec with filter-flags, which select callsites for
modification based upon their current flags.  This lets user activate
the set of callsites marked with 'u' in a batch.

  echo 'u+p' > control

This was previously submitted before events overtook.
 v1: https://lkml.org/lkml/2019/10/29/989
 v2: https://lkml.org/lkml/2019/11/27/547

Jim Cromie (16):
cleanups:
  dyndbg-docs: eschew file /full/path query in docs
  dyndbg: drop obsolete comment on ddebug_proc_open
  dyndbg: refine debug verbosity
  dyndbg: rename __verbose section to __dyndbg
  dyndbg: fix overcounting of ram used by dyndbg
  dyndbg: fix a BUG_ON in ddebug_describe_flags
  dyndbg: make ddebug_tables list LIFO for add/remove_module
new features:
-parsing conveniences
  dyndbg: refactor parse_linerange out of ddebug_parse_query
  dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100'
-flags extensions
--internal rework
  dyndbg: refactor ddebug_read_flags out of ddebug_parse_flags
  dyndbg: combine flags & mask into a struct, use that
  dyndbg: add filter parameter to ddebug_parse_flags
  dyndbg: extend ddebug_parse_flags to accept optional filter-flags
  dyndbg: prefer declarative init in caller, to memset in callee
--expose the features
  dyndbg: add user-flag, negating-flags, and filtering on flags
  dyndbg: allow negating flag-chars in modflags

 .../admin-guide/dynamic-debug-howto.rst       |  75 +++--
 include/asm-generic/vmlinux.lds.h             |   6 +-
 include/linux/dynamic_debug.h                 |   5 +-
 kernel/module.c                               |   2 +-
 lib/dynamic_debug.c                           | 282 ++++++++++--------
 5 files changed, 225 insertions(+), 145 deletions(-)

-- 
2.26.2

[PATCH 14/16] dyndbg: prefer declarative init in caller, to memset in callee

[Jim Cromie]

drop memset in ddebug_parse_query, instead initialize the stack
variable in the caller; let the compiler decide how to do it.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 90061833ef3f..f0c0c31e91ea 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -372,7 +372,6 @@ static int ddebug_parse_query(char *words[], int nwords,
 		pr_err("expecting pairs of match-spec <value>\n");
 		return -EINVAL;
 	}
-	memset(query, 0, sizeof(*query));
 
 	if (modname)
 		/* support $modname.dyndbg=<multiple queries> */
@@ -493,7 +492,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
 {
 	struct flagsettings mods = {};
 	struct flagsettings filter = {};
-	struct ddebug_query query;
+	struct ddebug_query query = {};
 #define MAXWORDS 9
 	int nwords, nfound;
 	char *words[MAXWORDS];
-- 
2.26.2