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authorAndrii Nakryiko2019-12-13 17:47:09 -0800
committerAlexei Starovoitov2019-12-15 16:41:12 -0800
commit2ad97d473db57ab866f0756806bb94515f7f2551 (patch)
tree6823aff4884341d6aa088f33cc1504375a6d2504 /tools/bpf
parent166750bc1dd256b2184b22588fb9fe6d3fbb93ae (diff)
bpftool: Generate externs datasec in BPF skeleton
Add support for generation of mmap()-ed read-only view of libbpf-provided extern variables. As externs are not supposed to be provided by user code (that's what .data, .bss, and .rodata is for), don't mmap() it initially. Only after skeleton load is performed, map .extern contents as read-only memory. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191214014710.3449601-4-andriin@fb.com
Diffstat (limited to 'tools/bpf')
-rw-r--r--tools/bpf/bpftool/gen.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 7379dae35dca..a07c80429c7a 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -82,6 +82,8 @@ static const char *get_map_ident(const struct bpf_map *map)
return "rodata";
else if (str_has_suffix(name, ".bss"))
return "bss";
+ else if (str_has_suffix(name, ".extern"))
+ return "externs"; /* extern is a C keyword */
else
return NULL;
}
@@ -109,6 +111,8 @@ static int codegen_datasec_def(struct bpf_object *obj,
sec_ident = "bss";
else if (strcmp(sec_name, ".rodata") == 0)
sec_ident = "rodata";
+ else if (strcmp(sec_name, ".extern") == 0)
+ sec_ident = "externs"; /* extern is a C keyword */
else
return 0;