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-rw-r--r--samples/bpf/test_overhead_kprobe_kern.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/samples/bpf/test_overhead_kprobe_kern.c b/samples/bpf/test_overhead_kprobe_kern.c
new file mode 100644
index 000000000..f6d593e47
--- /dev/null
+++ b/samples/bpf/test_overhead_kprobe_kern.c
@@ -0,0 +1,48 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define _(P) \
+ ({ \
+ typeof(P) val = 0; \
+ bpf_probe_read_kernel(&val, sizeof(val), &(P)); \
+ val; \
+ })
+
+SEC("kprobe/__set_task_comm")
+int prog(struct pt_regs *ctx)
+{
+ struct signal_struct *signal;
+ struct task_struct *tsk;
+ char oldcomm[16] = {};
+ char newcomm[16] = {};
+ u16 oom_score_adj;
+ u32 pid;
+
+ tsk = (void *)PT_REGS_PARM1(ctx);
+
+ pid = _(tsk->pid);
+ bpf_probe_read_kernel(oldcomm, sizeof(oldcomm), &tsk->comm);
+ bpf_probe_read_kernel(newcomm, sizeof(newcomm),
+ (void *)PT_REGS_PARM2(ctx));
+ signal = _(tsk->signal);
+ oom_score_adj = _(signal->oom_score_adj);
+ return 0;
+}
+
+SEC("kprobe/urandom_read")
+int prog2(struct pt_regs *ctx)
+{
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;