On 9/27/17 7:04 AM, Craig Gallek wrote:
From: Craig Gallek <kr...@google.com>
This extends struct bpf_map_def to include a flags field. Note that
this has the potential to break the validation logic in
bpf_object__validate_maps and bpf_object__init_maps as they use
sizeof(struct bpf_map_def) as a minimal allowable size of a map section.
Any bpf program compiled with a smaller struct bpf_map_def will fail this
check.
I don't believe this will be an issue in practice as both compile-time
definitions of struct bpf_map_def (in samples/bpf/bpf_load.h and
tools/testing/selftests/bpf/bpf_helpers.h) have always been larger
than this newly updated version in libbpf.h.
Signed-off-by: Craig Gallek <kr...@google.com>
---
tools/lib/bpf/libbpf.c | 2 +-
tools/lib/bpf/libbpf.h | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 35f6dfcdc565..6bea85f260a3 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -874,7 +874,7 @@ bpf_object__create_maps(struct bpf_object *obj)
def->key_size,
def->value_size,
def->max_entries,
- 0);
+ def->map_flags);
if (*pfd < 0) {
size_t j;
int err = *pfd;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 7959086eb9c9..6e20003109e0 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -207,6 +207,7 @@ struct bpf_map_def {
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
+ unsigned int map_flags;
};
yes it will break loading of pre-compiled .o
Instead of breaking, let's fix the loader to do it the way
samples/bpf/bpf_load.c does.
See commit 156450d9d964 ("samples/bpf: make bpf_load.c code compatible
with ELF maps section changes")
