[PATCH v2 6/7] tools/bpf/bpftool/skeleton: replace bpf_probe_read_kernel with bpf_probe_read_kernel_str to get task comm

From: Yafang Shao
Date: Sat Nov 20 2021 - 06:28:25 EST


bpf_probe_read_kernel_str() will add a nul terminator to the dst, then
we don't care about if the dst size is big enough.

Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx>
Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>
Cc: Michal Miroslaw <mirq-linux@xxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
---
tools/bpf/bpftool/skeleton/pid_iter.bpf.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
index d9b420972934..f70702fcb224 100644
--- a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
+++ b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
@@ -71,8 +71,8 @@ int iter(struct bpf_iter__task_file *ctx)

e.pid = task->tgid;
e.id = get_obj_id(file->private_data, obj_type);
- bpf_probe_read_kernel(&e.comm, sizeof(e.comm),
- task->group_leader->comm);
+ bpf_probe_read_kernel_str(&e.comm, sizeof(e.comm),
+ task->group_leader->comm);
bpf_seq_write(ctx->meta->seq, &e, sizeof(e));

return 0;
--
2.17.1