On Fri, Sep 13, 2024 at 5:14 AM Justin Stitt [off-list ref] wrote:

Hi,

On Wed, Aug 28, 2024 at 11:03:17AM GMT, Yafang Shao wrote:

quoted

Let's explicitly ensure the destination string is NUL-terminated. This way,
it won't be affected by changes to the source string.

Signed-off-by: Yafang Shao <redacted>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
---
 tools/bpf/bpftool/pids.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/bpf/bpftool/pids.c b/tools/bpf/bpftool/pids.c
index 9b898571b49e..23f488cf1740 100644
--- a/tools/bpf/bpftool/pids.c
+++ b/tools/bpf/bpftool/pids.c

@@ -54,6 +54,7 @@ static void add_ref(struct hashmap *map, struct pid_iter_entry *e)
              ref = &refs->refs[refs->ref_cnt];
              ref->pid = e->pid;
              memcpy(ref->comm, e->comm, sizeof(ref->comm));
+             ref->comm[sizeof(ref->comm) - 1] = '\0';

...

quoted

              refs->ref_cnt++;

              return;

@@ -77,6 +78,7 @@ static void add_ref(struct hashmap *map, struct pid_iter_entry *e)
      ref = &refs->refs[0];
      ref->pid = e->pid;
      memcpy(ref->comm, e->comm, sizeof(ref->comm));
+     ref->comm[sizeof(ref->comm) - 1] = '\0';

Excuse my ignorance, do we not have a strscpy() equivalent usable in bpf
code?

To my knowledge, there is no direct equivalent of the standard
strcpy() function available in bpftool or libbpf code.

-- 
Regards
Yafang