[PATCH 3/6] alloc_tag: add size-based filtering to ioctl

[Abhishek Bapat]

Extend the allocinfo filtering mechanism to allow users to filter tags
based on the total number of bytes allocated [min_size, max_size]. The
size range is inclusive.

Filtering by size involves retrieving allocinfo per-CPU counters, which
is an expensive operation. Hence, the performance of size-based
filtering will be worse than other filters.

Signed-off-by: Abhishek Bapat <abhishekbapat@xxxxxxxxxx>
---
 include/uapi/linux/alloc_tag.h |  8 +++++++-
 lib/alloc_tag.c                | 15 +++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/alloc_tag.h b/include/uapi/linux/alloc_tag.h
index 0cc9db5298c6..229068efd24c 100644
--- a/include/uapi/linux/alloc_tag.h
+++ b/include/uapi/linux/alloc_tag.h
@@ -20,6 +20,8 @@ struct allocinfo_tag {
 	char function[ALLOCINFO_STR_SIZE];
 	char filename[ALLOCINFO_STR_SIZE];
 	__u64 lineno;
+	__u64 min_size;
+	__u64 max_size;
 };
 
 struct allocinfo_counter {
@@ -39,13 +41,17 @@ enum {
 	ALLOCINFO_FILTER_FUNCTION,
 	ALLOCINFO_FILTER_FILENAME,
 	ALLOCINFO_FILTER_LINENO,
-	__ALLOCINFO_FILTER_LAST = ALLOCINFO_FILTER_LINENO
+	ALLOCINFO_FILTER_MIN_SIZE,
+	ALLOCINFO_FILTER_MAX_SIZE,
+	__ALLOCINFO_FILTER_LAST = ALLOCINFO_FILTER_MAX_SIZE
 };
 
 #define ALLOCINFO_FILTER_MASK_MODNAME		(1 << ALLOCINFO_FILTER_MODNAME)
 #define ALLOCINFO_FILTER_MASK_FUNCTION		(1 << ALLOCINFO_FILTER_FUNCTION)
 #define ALLOCINFO_FILTER_MASK_FILENAME		(1 << ALLOCINFO_FILTER_FILENAME)
 #define ALLOCINFO_FILTER_MASK_LINENO		(1 << ALLOCINFO_FILTER_LINENO)
+#define ALLOCINFO_FILTER_MASK_MIN_SIZE		(1 << ALLOCINFO_FILTER_MIN_SIZE)
+#define ALLOCINFO_FILTER_MASK_MAX_SIZE		(1 << ALLOCINFO_FILTER_MAX_SIZE)
 
 #define ALLOCINFO_FILTER_MASKS \
 	((1 << (__ALLOCINFO_FILTER_LAST + 1)) - 1)
diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
index 7ff936e15e97..98a27c302928 100644
--- a/lib/alloc_tag.c
+++ b/lib/alloc_tag.c
@@ -195,6 +195,9 @@ static int allocinfo_ioctl_get_content_id(struct seq_file *m, void __user *arg)
 
 static bool matches_filter(struct codetag *ct, struct allocinfo_filter *filter)
 {
+	struct alloc_tag *tag;
+	struct alloc_tag_counters counters;
+
 	if (!ct || !filter || !filter->mask)
 		return true;
 
@@ -214,6 +217,18 @@ static bool matches_filter(struct codetag *ct, struct allocinfo_filter *filter)
 	    ct->lineno != filter->fields.lineno)
 		return false;
 
+	if ((filter->mask & ALLOCINFO_FILTER_MASK_MIN_SIZE) ||
+	    (filter->mask & ALLOCINFO_FILTER_MASK_MAX_SIZE)) {
+		tag = ct_to_alloc_tag(ct);
+		counters = alloc_tag_read(tag);
+		if ((filter->mask & ALLOCINFO_FILTER_MASK_MIN_SIZE) &&
+		    counters.bytes < filter->fields.min_size)
+			return false;
+		if ((filter->mask & ALLOCINFO_FILTER_MASK_MAX_SIZE) &&
+		    counters.bytes > filter->fields.max_size)
+			return false;
+	}
+
 	return true;
 }
 
-- 
2.54.0.545.g6539524ca2-goog