samples/bpf: load_bpf.c make callback fixup more flexible

Do this change before others start to use this callback.
Change map_perf_test_user.c which seems to be the only user.

This patch extends capabilities of commit 9fd63d05f3e8 ("bpf:
Allow bpf sample programs (*_user.c) to change bpf_map_def").

Give fixup callback access to struct bpf_map_data, instead of
only stuct bpf_map_def.  This add flexibility to allow userspace
to reassign the map file descriptor.  This is very useful when
wanting to share maps between several bpf programs.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 2 deletions

diff --git a/samples/bpf/bpf_load.h b/samples/bpf/bpf_load.h
index 05822f83173a..4d4fd4678a64 100644
--- a/samples/bpf/bpf_load.h
+++ b/samples/bpf/bpf_load.h
@@ -15,8 +15,14 @@ struct bpf_map_def {
 	unsigned int inner_map_idx;
 };
 
-typedef void (*fixup_map_cb)(struct bpf_map_def *map, const char *map_name,
-			     int idx);
+struct bpf_map_data {
+	int fd;
+	char *name;
+	size_t elf_offset;
+	struct bpf_map_def def;
+};
+
+typedef void (*fixup_map_cb)(struct bpf_map_data *map, int idx);
 
 extern int map_fd[MAX_MAPS];
 extern int prog_fd[MAX_PROGS];