Without this flag, log filters can only explicitly accept messages. Allowing denial makes it easier to filter certain subsystems. Unlike allow-ing filters, deny-ing filters are added to the beginning of the filter list. This should do the Right Thing most of the time, but it's less-universal than allowing filters to be inserted anywhere. If this becomes a problem, then perhaps log_filter_add* should take a filter number to insert before/after.
Signed-off-by: Sean Anderson seanga2@gmail.com Reviewed-by: Simon Glass sjg@chromium.org ---
(no changes since v1)
common/log.c | 12 ++++++++++-- include/log.h | 11 ++++++++++- 2 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/common/log.c b/common/log.c index a14b227231..6299c8b2d4 100644 --- a/common/log.c +++ b/common/log.c @@ -164,7 +164,11 @@ static bool log_passes_filters(struct log_device *ldev, struct log_rec *rec) if (filt->file_list && !log_has_file(filt->file_list, rec->file)) continue; - return true; + + if (filt->flags & LOGFF_DENY) + return false; + else + return true; }
return false; @@ -268,7 +272,11 @@ int log_add_filter_flags(const char *drv_name, enum log_category_t cat_list[], } } filt->filter_num = ldev->next_filter_num++; - list_add_tail(&filt->sibling_node, &ldev->filter_head); + /* Add deny filters to the beginning of the list */ + if (flags & LOGFF_DENY) + list_add(&filt->sibling_node, &ldev->filter_head); + else + list_add_tail(&filt->sibling_node, &ldev->filter_head);
return filt->filter_num;
diff --git a/include/log.h b/include/log.h index 4e59a2cf74..018180e788 100644 --- a/include/log.h +++ b/include/log.h @@ -359,13 +359,22 @@ enum { LOGF_MAX_CATEGORIES = 5, /* maximum categories per filter */ };
+/** + * enum log_filter_flags - Flags which modify a filter + */ enum log_filter_flags { - LOGFF_HAS_CAT = 1 << 0, /* Filter has a category list */ + /** @LOGFF_HAS_CAT: Filter has a category list */ + LOGFF_HAS_CAT = 1 << 0, + /** @LOGFF_DENY: Filter denies matching messages */ + LOGFF_DENY = 1 << 1, };
/** * struct log_filter - criterial to filter out log messages * + * If a message matches all criteria, then it is allowed. If LOGFF_DENY is set, + * then it is denied instead. + * * @filter_num: Sequence number of this filter. This is returned when adding a * new filter, and must be provided when removing a previously added * filter.