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Subject[PATCH] libbpf: replace '.' with '_' in legacy kprobe event name
Date
From: Menglong Dong <imagedong@tencent.com>

'.' is not allowed in the event name of kprobe. Therefore, we will get a
EINVAL if the kernel function name has a '.' in legacy kprobe attach
case, such as 'icmp_reply.constprop.0'.

In order to adapt this case, we need to replace the '.' with other char
in gen_kprobe_legacy_event_name(). And I use '_' for this propose.

Signed-off-by: Menglong Dong <imagedong@tencent.com>
---
tools/lib/bpf/libbpf.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index fdfb1ca34ced..5d6f6675c2f2 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9994,9 +9994,16 @@ static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz,
const char *kfunc_name, size_t offset)
{
static int index = 0;
+ int i = 0;

snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx_%d", getpid(), kfunc_name, offset,
__sync_fetch_and_add(&index, 1));
+
+ while (buf[i] != '\0') {
+ if (buf[i] == '.')
+ buf[i] = '_';
+ i++;
+ }
}

static int add_kprobe_event_legacy(const char *probe_name, bool retprobe,
--
2.39.0
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