samples: bpf: Replace symbol compare of trace_event

Previously, when this sample is added, commit 1c47910ef8013
("samples/bpf: add perf_event+bpf example"), a symbol 'sys_read' and
'sys_write' has been used without no prefixes. But currently there are
no exact symbols with these under kallsyms and this leads to failure.

This commit changes exact compare to substring compare to keep compatible
with exact symbol or prefixed symbol.

Fixes: 1c47910ef8013 ("samples/bpf: add perf_event+bpf example")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191205080114.19766-2-danieltimlee@gmail.com

diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c
index 16a16eadd509859c3640dac0507618d958c77b83..749a50f2f9f32cc608e290179d0ac543598b08b0 100644 (file)
--- a/samples/bpf/trace_event_user.c
+++ b/samples/bpf/trace_event_user.c
@@ -37,9 +37,9 @@ static void print_ksym(__u64 addr)
        }
 
        printf("%s;", sym->name);
-       if (!strcmp(sym->name, "sys_read"))
+       if (!strstr(sym->name, "sys_read"))
                sys_read_seen = true;
-       else if (!strcmp(sym->name, "sys_write"))
+       else if (!strstr(sym->name, "sys_write"))
                sys_write_seen = true;
 }