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libbpf: Replace '.' with '_' in legacy kprobe event name

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'.' 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>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com
This commit is contained in:
Menglong Dong 2023-01-13 17:34:27 +08:00 committed by Andrii Nakryiko
parent 878625e1c7
commit 2fa0745365
1 changed files with 7 additions and 0 deletions
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7
tools/lib/bpf/libbpf.c
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@ -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;
snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx_%d", getpid(), kfunc_name, offset,
__sync_fetch_and_add(&index, 1));
/* sanitize binary_path in the probe name */
for (i = 0; buf[i]; i++) {
if (!isalnum(buf[i]))
buf[i] = '_';
}
}
static int add_kprobe_event_legacy(const char *probe_name, bool retprobe,