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authorMartin KaFai Lau <kafai@fb.com>2017-10-05 21:52:13 -0700
committerDavid S. Miller <davem@davemloft.net>2017-10-07 23:29:39 +0100
commit368211fb920a0b789c238942c6af0414539f79d6 (patch)
treec2bccb6962e725d691b9529445f5436e385b3bf7 /kernel/bpf/core.c
parent067cae47771c864604969fd902efe10916e0d79c (diff)
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 <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/bpf/core.c')
-rw-r--r--kernel/bpf/core.c17
1 files 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