From d03712dc63f85d6ff4c6ccbab09f998cda796ad0 Mon Sep 17 00:00:00 2001
From: Ali Javidi Ghasr <71215076+AliJavidiCS@users.noreply.github.com>
Date: Sat, 16 Dec 2023 15:43:58 +0330
Subject: [PATCH]  Fix extracting pid form bpf_get_current_pid_tgid()

Based on Issue #35,
pid must be extracted from the return value by using an and operation with 0xFFFFFFFF.

Signed-off-by: Ali Javidi Ghasr <71215076+AliJavidiCS@users.noreply.github.com>
---
 chapter4/hello-ring-buffer-config.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/chapter4/hello-ring-buffer-config.py b/chapter4/hello-ring-buffer-config.py
index 869837f..1dc6548 100755
--- a/chapter4/hello-ring-buffer-config.py
+++ b/chapter4/hello-ring-buffer-config.py
@@ -24,7 +24,7 @@
    char message[12] = "Hello World";
    struct user_msg_t *p;
 
-   data.pid = bpf_get_current_pid_tgid() >> 32;
+   data.pid = bpf_get_current_pid_tgid() & 0xFFFFFFFF;
    data.uid = bpf_get_current_uid_gid() & 0xFFFFFFFF;
 
    bpf_get_current_comm(&data.command, sizeof(data.command));