[PATCH v12 07/40] dyndbg: factor ddebug_match_desc out from ddebug_change
flat view
WARM3d
REVIEWED: 1 (1M)
From: Jim Cromie via B4 Relay <devnull+jim.cromie.gmail.com@kernel.org>
Date: 2026-10-13 02:36:38
Also in:
b4-sent, dri-devel, linux-arch, linux-doc, linux-kbuild, linux-kselftest, linux-pm, lkml
Subsystem:
dynamic debug, library code, the rest · Maintainers:
Jason Baron, Jim Cromie, Andrew Morton, Linus Torvalds
Revision v12 of 3 in this series; 1 review trailer.
Revisions (3)
- v10 [diff vs current]
- v11 [diff vs current]
- v12 current
From: Jim Cromie <jim.cromie@gmail.com> ddebug_change() is a big (~100 lines) function with a nested for loop. The outer loop walks the per-module ddebug_tables list, and does module stuff: it filters on a query's "module FOO*" and "class BAR", failures here skip the entire inner loop. The inner loop (60 lines) scans a module's descriptors. It starts with a long block of filters on function, line, format, and the validated "BAR" class (or the legacy/_DPRINTK_CLASS_DFLT). These filters "continue" past pr_debugs that don't match the query criteria, before it falls through the code below that counts matches, then adjusts the flags and static-keys. This is unnecessarily hard to think about. So move the per-descriptor filter-block into a boolean function: ddebug_match_desc(desc), and change each "continue" to "return false". This puts a clear interface in place, so any future changes are either inside, outside, or across this interface. also fix checkpatch complaints about spaces and braces. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com> --- v11: . move doc comment block down to precede ddebug_change(). Sashiko review complaint (patch 7): "Does this placement separate the block comment from its intended target? The comment describes a function that returns the number of matching callsites and takes ddebug_lock, which accurately describes ddebug_change(). However, by inserting ddebug_match_desc() immediately after this comment, does it leave ddebug_change() undocumented and make the comment falsely apply to ddebug_match_desc()..." v5: check for null format in callsite. shouldnt happen, but pr_debug() isnt illegal v7: elevate null format to pr_err adding filename, function, lineno. --- lib/dynamic_debug.c | 91 ++++++++++++++++++++++++++++++++--------------------- 1 file changed, 55 insertions(+), 36 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 49334d1aa4b3..8682c23b5fe7 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c@@ -166,6 +166,60 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons } #define __outvar /* filled by callee */ +static bool ddebug_match_desc(const struct ddebug_query *query, + struct _ddebug *dp, + int valid_class) +{ + /* match site against query-class */ + if (dp->class_id != valid_class) + return false; + + if (!dp->format) { + pr_err_ratelimited("ddebug: NULL format string at %s:%s:%u\n", + dp->filename ? dp->filename : "?", + dp->function ? dp->function : "?", + dp->lineno); + return false; + } + + /* match against the source filename */ + if (query->filename && + !match_wildcard(query->filename, dp->filename) && + !match_wildcard(query->filename, + kbasename(dp->filename)) && + !match_wildcard(query->filename, + trim_prefix(dp->filename))) + return false; + + /* match against the function */ + if (query->function && + !match_wildcard(query->function, dp->function)) + return false; + + /* match against the format */ + if (query->format) { + if (*query->format == '^') { + char *p; + /* anchored search. match must be at beginning */ + p = strstr(dp->format, query->format + 1); + if (p != dp->format) + return false; + } else if (!strstr(dp->format, query->format)) { + return false; + } + } + + /* match against the line number range */ + if (query->first_lineno && + dp->lineno < query->first_lineno) + return false; + if (query->last_lineno && + dp->lineno > query->last_lineno) + return false; + + return true; +} + /* * Search the tables for _ddebug's which match the given `query' and * apply the `flags' and `mask' to them. Returns number of matching
@@ -204,42 +258,7 @@ static int ddebug_change(const struct ddebug_query *query, for (i = 0; i < dt->num_ddebugs; i++) { struct _ddebug *dp = &dt->ddebugs[i]; - /* match site against query-class */ - if (dp->class_id != valid_class) - continue; - - /* match against the source filename */ - if (query->filename && - !match_wildcard(query->filename, dp->filename) && - !match_wildcard(query->filename, - kbasename(dp->filename)) && - !match_wildcard(query->filename, - trim_prefix(dp->filename))) - continue; - - /* match against the function */ - if (query->function && - !match_wildcard(query->function, dp->function)) - continue; - - /* match against the format */ - if (query->format) { - if (*query->format == '^') { - char *p; - /* anchored search. match must be at beginning */ - p = strstr(dp->format, query->format+1); - if (p != dp->format) - continue; - } else if (!strstr(dp->format, query->format)) - continue; - } - - /* match against the line number range */ - if (query->first_lineno && - dp->lineno < query->first_lineno) - continue; - if (query->last_lineno && - dp->lineno > query->last_lineno) + if (!ddebug_match_desc(query, dp, valid_class)) continue; nfound++;
--
2.56.0