From 368211fb920a0b789c238942c6af0414539f79d6 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Thu, 5 Oct 2017 21:52:13 -0700 Subject: [PATCH] bpf: Append prog->aux->name in bpf_get_prog_name() This patch makes the bpf_prog's name available in kallsyms. The new format is bpf_prog_tag[_name]. Sample kallsyms from running selftests/bpf/test_progs: [root@arch-fb-vm1 ~]# egrep ' bpf_prog_[0-9a-fA-F]{16}' /proc/kallsyms ffffffffa0048000 t bpf_prog_dabf0207d1992486_test_obj_id ffffffffa0038000 t bpf_prog_a04f5eef06a7f555__123456789ABCDE ffffffffa0050000 t bpf_prog_a04f5eef06a7f555 Signed-off-by: Martin KaFai Lau Acked-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- kernel/bpf/core.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index c6be15ae83ee..248961af2421 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -309,12 +309,25 @@ bpf_get_prog_addr_region(const struct bpf_prog *prog, static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) { + const char *end = sym + KSYM_NAME_LEN; + BUILD_BUG_ON(sizeof("bpf_prog_") + - sizeof(prog->tag) * 2 + 1 > KSYM_NAME_LEN); + sizeof(prog->tag) * 2 + + /* name has been null terminated. + * We should need +1 for the '_' preceding + * the name. However, the null character + * is double counted between the name and the + * sizeof("bpf_prog_") above, so we omit + * the +1 here. + */ + sizeof(prog->aux->name) > KSYM_NAME_LEN); sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); - *sym = 0; + if (prog->aux->name[0]) + snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); + else + *sym = 0; } static __always_inline unsigned long -- 2.11.0