[Crash-utility] [PATCH] Add eBPF program name to "bpf -p|-P" options output

[HAGIO KAZUHITO(萩尾 一仁)]

"bpftool prog list" command displays eBPF program name if available.
Also, the crash "bpf -m|-M" options display eBPF map name.  But the
"bpf -p|-P" options don't display its name.  It would be useful in
finding the program which we want to see.

Signed-off-by: Kazuhito Hagio <k-hagio-ab at nec.com>
---
 bpf.c     | 12 ++++++++++++
 defs.h    |  1 +
 help.c    |  3 ++-
 symbols.c |  2 ++
 4 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/bpf.c b/bpf.c
index 39ced88..cb6b0ed 100644
--- a/bpf.c
+++ b/bpf.c
@@ -194,6 +194,7 @@ bpf_init(struct bpf_info *bpf)
 		MEMBER_OFFSET_INIT(bpf_prog_pages, "bpf_prog", "pages");
 		MEMBER_OFFSET_INIT(bpf_prog_aux_load_time, "bpf_prog_aux", "load_time");
 		MEMBER_OFFSET_INIT(bpf_prog_aux_user, "bpf_prog_aux", "user");
+		MEMBER_OFFSET_INIT(bpf_prog_aux_name, "bpf_prog_aux", "name");
 		MEMBER_OFFSET_INIT(bpf_map_key_size, "bpf_map", "key_size");
 		MEMBER_OFFSET_INIT(bpf_map_value_size, "bpf_map", "value_size");
 		MEMBER_OFFSET_INIT(bpf_map_max_entries, "bpf_map", "max_entries");
@@ -452,6 +453,17 @@ do_bpf(ulong flags, ulong prog_id, ulong map_id, int radix)
 			bpf_prog_gpl_compatible(buf1, (ulong)bpf->proglist[i].value);
 			fprintf(fp, "     GPL_COMPATIBLE: %s", buf1);
 
+			fprintf(fp, "  NAME: ");
+			if (VALID_MEMBER(bpf_prog_aux_name)) {
+				BCOPY(&bpf->bpf_prog_aux_buf[OFFSET(bpf_prog_aux_name)], buf1, 16);
+				buf1[16] = NULLCHAR;
+				if (strlen(buf1))
+					fprintf(fp, "\"%s\"", buf1);
+				else
+					fprintf(fp, "(unused)");
+			} else
+				fprintf(fp, "(unknown)");
+
 			fprintf(fp, "  UID: ");
 			if (VALID_MEMBER(bpf_prog_aux_user) && VALID_MEMBER(user_struct_uid)) {
 				user = ULONG(bpf->bpf_prog_aux_buf + OFFSET(bpf_prog_aux_user));
diff --git a/defs.h b/defs.h
index fbd19b0..e852ddf 100644
--- a/defs.h
+++ b/defs.h
@@ -2078,6 +2078,7 @@ struct offset_table {                    /* stash of commonly-used offsets */
 	long bpf_map_memory;
 	long bpf_map_memory_pages;
 	long bpf_map_memory_user;
+	long bpf_prog_aux_name;
 };
 
 struct size_table {         /* stash of commonly-used sizes */
diff --git a/help.c b/help.c
index 5c313af..eda5ce9 100644
--- a/help.c
+++ b/help.c
@@ -2412,7 +2412,8 @@ char *help_bpf[] = {
 "    -p ID  displays the basic information specific to the program ID, plus the",
 "           size in bytes of its translated bytecode, the size in bytes of its",
 "           jited code, the number of bytes locked into memory, the time that",
-"           the program was loaded, whether it is GPL compatible, and its UID.",
+"           the program was loaded, whether it is GPL compatible, its name",
+"           string, and its UID.",
 "    -P     same as -p, but displays the basic and extra data for all programs.",
 "    -m ID  displays the basic information specific to the map ID, plus the", 
 "           size in bytes of its key and value, the maximum number of key-value",
diff --git a/symbols.c b/symbols.c
index f1f659b..9c3032d 100644
--- a/symbols.c
+++ b/symbols.c
@@ -10494,6 +10494,8 @@ dump_offset_table(char *spec, ulong makestruct)
 		OFFSET(bpf_prog_aux_load_time));
 	fprintf(fp, "             bpf_prog_aux_user: %ld\n",
 		OFFSET(bpf_prog_aux_user));
+	fprintf(fp, "             bpf_prog_aux_name: %ld\n",
+		OFFSET(bpf_prog_aux_name));
 	fprintf(fp, "               user_struct_uid: %ld\n",
 		OFFSET(user_struct_uid));
 
-- 
2.24.1