Messages in this thread Patch in this message | | | From | Jim Cromie <> | Subject | [PATCH 19/25] dynamic_debug: add flags filtering to flags spec | Date | Mon, 25 Jul 2011 15:42:44 -0600 |
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Change definition of flags spec to [pmflta_]*[-+=][pmflta_]* The flags preceding the op are optional filter-flags; if provided, they add an additional constraint to call-site matching done by ddebug_change; call-sites which do not have all specified flags are skipped (additional flags are allowed).
This allows query/rules like "p+t" to turn on TID logging for all currently enabled call-sites, while leaving the others alone. This will also allow filtering on pending rules (with 'a' flag), which will support removal of pending rules.
Also allow 0 flags byte, so that active rules can be completely reset by writing "p=" or "p=_".
Patch factors flag-scanning into ddebug_parse_flag_settings(), and uses it for both filter-flags and new flags, and adds pr_err() where useful.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com> --- lib/dynamic_debug.c | 81 ++++++++++++++++++++++++++++++++------------------- 1 files changed, 51 insertions(+), 30 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 37f9748..275cf30 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -180,7 +180,8 @@ static bool query_matches_callsite(struct _ddebug *dp, * were matched. Called with ddebug_lock held. */ static int ddebug_change(const struct ddebug_query *query, - unsigned int flags, unsigned int mask) + unsigned int flags, unsigned int mask, + unsigned int filter) { int i; struct ddebug_table *dt; @@ -202,6 +203,9 @@ static int ddebug_change(const struct ddebug_query *query, if (!query_matches_callsite(dp, query)) continue; + if (filter && (dp->flags & filter) != filter) + continue; + nfound++; newflags = (dp->flags & mask) | flags; @@ -402,28 +406,9 @@ static int ddebug_parse_query(char *words[], int nwords, return 0; } -/* - * Parse `str' as a flags specification, format [-+=][p]+. - * Sets up *maskp and *flagsp to be used when changing the - * flags fields of matched _ddebug's. Returns 0 on success - * or <0 on error. - */ -static int ddebug_parse_flags(const char *str, unsigned int *flagsp, - unsigned int *maskp) +static int ddebug_parse_flag_settings(const char *str) { - unsigned flags = 0; - int op = '=', i; - - switch (*str) { - case '+': - case '-': - case '=': - op = *str++; - break; - default: - return -EINVAL; - } - pr_debug("op='%c'\n", op); + int i, flags = 0; for ( ; *str ; ++str) { for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) { @@ -432,12 +417,46 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, break; } } - if (i < 0) + if (i < 0 && *str) { + pr_err("unknown flag: %c\n", *str); return -EINVAL; + } } - if (flags == 0) + return flags; +} + +/* + * Parse `str' as a flags filter and specification, with format + * [ptlmfa]*[-+=][ptlmfa]+. Sets up *maskp, *flagsp and *filterp to + * be used when changing the flags fields of matched _ddebug's. + * Returns 0 on success or <0 on error. + */ +static int ddebug_parse_flags(const char *str, unsigned int *flagsp, + unsigned int *maskp, unsigned int *filterp) +{ + int flags, filter; + int op = '='; + char *s = strpbrk(str, "+-="); + + if (!s) { + pr_err("flags spec missing op, expecting [+-=]\n"); return -EINVAL; - pr_debug("flags=0x%x\n", flags); + } else { + op = *s; + *s++ = '\0'; + } + filter = ddebug_parse_flag_settings(str); + if (filter < 0) { + pr_err("flags_filter=0x%x\n", filter); + return -EINVAL; + } + *filterp = filter; + + flags = ddebug_parse_flag_settings(s); + if (flags < 0) { + pr_err("flags=0x%x\n", flags); + return -EINVAL; + } /* calculate final *flagsp, *maskp according to mask and op */ switch (op) { @@ -454,7 +473,9 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp, *flagsp = 0; break; } - pr_debug("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp); + pr_debug("filter=0x%x op='%c' flags=0x%x *flagsp=0x%x *maskp=0x%x\n", + filter, op, flags, *flagsp, *maskp); + return 0; } @@ -539,7 +560,7 @@ static int ddebug_save_pending(struct ddebug_query *query, static int ddebug_exec_query(char *query_string) { - unsigned int flags = 0, mask = 0; + unsigned int flags = 0, mask = 0, filter = 0; struct ddebug_query query; #define MAXWORDS 9 int nwords; @@ -551,12 +572,12 @@ static int ddebug_exec_query(char *query_string) return -EINVAL; if (ddebug_parse_query(words, nwords-1, &query)) return -EINVAL; - if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) + if (ddebug_parse_flags(words[nwords-1], &flags, &mask, &filter)) return -EINVAL; /* actually go and implement the change */ mutex_lock(&ddebug_lock); - nfound = ddebug_change(&query, flags, mask); + nfound = ddebug_change(&query, flags, mask, filter); qstr = show_ddebug_query(&query); pr_debug("nfound %d on %s\n", nfound, qstr); if (!nfound) { @@ -917,7 +938,7 @@ static void apply_pending_queries(struct ddebug_table *dt) char *qstr; list_for_each_entry_safe(pq, pqnext, &pending_queries, link) { - nfound = ddebug_change(&pq->query, pq->flags, pq->mask); + nfound = ddebug_change(&pq->query, pq->flags, pq->mask, 0); qstr = show_pending_query(pq); pr_debug("%s: %s\n", (nfound) ? "applied" : "no-match", qstr); kfree(qstr); -- 1.7.4.1
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