[PATCH] Fix for "bpf -m|-M" options to appropriately display MEMLOCK and UID

[Lianbo Jiang <lijiang@xxxxxxxxxx>]

Kernel commit <80ee81e0403c> ("bpf: Eliminate rlimit-based memory
accounting infra for bpf maps") removed the struct bpf_map_memory
member from struct bpf_map. Without the patch, "bpf -m|-M" options
will print the following errors:

crash> bpf -m 1
 ID      BPF_MAP          BPF_MAP_TYPE     MAP_FLAGS
 1   ffff96ba41804400        ARRAY          00000000
     KEY_SIZE: 4  VALUE_SIZE: 8  MAX_ENTRIES: 64  MEMLOCK: (unknown)
     							    ^^^^^^^
     NAME: "dist"  UID: (unknown)
                         ^^^^^^^

Signed-off-by: Lianbo Jiang <lijiang@xxxxxxxxxx>
---
 bpf.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 64 insertions(+), 3 deletions(-)

diff --git a/bpf.c b/bpf.c
index cb6b0ed385f9..d45e9ab9311b 100644
--- a/bpf.c
+++ b/bpf.c
@@ -15,6 +15,7 @@
  */
 
 #include "defs.h"
+#include <stdbool.h>
 
 struct bpf_info {
 	ulong status;
@@ -63,6 +64,66 @@ static int do_old_idr(int, ulong, struct list_pair *);
 #define PROG_VERBOSE  (0x40)
 #define MAP_VERBOSE   (0x80)
 
+static bool map_is_per_cpu(ulong type)
+{
+	/*
+	 * See the definition of bpf_map_type:
+	 * include/uapi/linux/bpf.h
+	 */
+	#define BPF_MAP_TYPE_PERCPU_HASH (5UL)
+	#define BPF_MAP_TYPE_PERCPU_ARRAY (6UL)
+	#define BPF_MAP_TYPE_LRU_PERCPU_HASH (10UL)
+	#define BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE (21UL)
+
+	return type == BPF_MAP_TYPE_PERCPU_HASH ||
+	       type == BPF_MAP_TYPE_PERCPU_ARRAY ||
+	       type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
+	       type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE;
+}
+
+static bool map_is_fd_map(ulong type)
+{
+	/*
+	 * See the definition of bpf_map_type:
+	 * include/uapi/linux/bpf.h
+	 */
+	#define BPF_MAP_TYPE_PROG_ARRAY (3UL)
+	#define BPF_MAP_TYPE_PERF_EVENT_ARRAY (4UL)
+	#define BPF_MAP_TYPE_CGROUP_ARRAY (8UL)
+	#define BPF_MAP_TYPE_ARRAY_OF_MAPS (12UL)
+	#define BPF_MAP_TYPE_HASH_OF_MAPS (13UL)
+
+	return type == BPF_MAP_TYPE_PROG_ARRAY ||
+	       type == BPF_MAP_TYPE_PERF_EVENT_ARRAY ||
+	       type == BPF_MAP_TYPE_CGROUP_ARRAY ||
+	       type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
+	       type == BPF_MAP_TYPE_HASH_OF_MAPS;
+
+}
+
+static ulong bpf_map_memory_size(ulong map_type, ulong vsize, ulong ksize, ulong esize)
+{
+	ulong memsize,valsize;
+	int cpus = 0;
+
+	valsize = vsize;
+
+	if (map_is_fd_map(map_type))
+		valsize = sizeof(ulong);
+
+	if (map_is_per_cpu(map_type)) {
+		cpus = get_cpus_possible();
+		if (!cpus)
+			error(WARNING, "cpu_possible_map does not exist, pissible cpus: %d\n", cpus);
+
+		valsize = roundup(vsize, 8) * cpus;
+	}
+
+	memsize = roundup((ksize + valsize), 8);
+
+	return roundup((esize * memsize), PAGESIZE());
+}
+
 void
 cmd_bpf(void)
 {
@@ -332,7 +393,7 @@ do_bpf(ulong flags, ulong prog_id, ulong map_id, int radix)
 {
 	struct bpf_info *bpf;
 	int i, c, found, entries, type;
-	uint uid, map_pages, key_size, value_size, max_entries;
+	uint uid, map_pages, key_size = 0, value_size = 0, max_entries = 0;
 	ulong bpf_prog_aux, bpf_func, end_func, addr, insnsi, user;
 	ulong do_progs, do_maps;
 	ulonglong load_time;
@@ -603,7 +664,7 @@ do_map_only:
 				map_pages = UINT(bpf->bpf_map_buf + OFFSET(bpf_map_pages));
 				fprintf(fp, "%d\n", map_pages * PAGESIZE());
 			} else
-				fprintf(fp, "(unknown)\n");
+				fprintf(fp, "%ld\n", bpf_map_memory_size(type, value_size, key_size, max_entries));
 
 			fprintf(fp, "     NAME: ");
 			if (VALID_MEMBER(bpf_map_name)) {
@@ -632,7 +693,7 @@ do_map_only:
 				else
 					fprintf(fp, "(unknown)\n");
 			} else
-				fprintf(fp, "(unknown)\n");
+				fprintf(fp, "(unused)\n");
 		}
 
 		if (flags & DUMP_STRUCT) {
-- 
2.20.1

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