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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /samples/bpf/tracex6_kern.c
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/bpf/tracex6_kern.c')
-rw-r--r--samples/bpf/tracex6_kern.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/samples/bpf/tracex6_kern.c b/samples/bpf/tracex6_kern.c
new file mode 100644
index 000000000..fd602c277
--- /dev/null
+++ b/samples/bpf/tracex6_kern.c
@@ -0,0 +1,82 @@
+#include <linux/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+ __uint(key_size, sizeof(int));
+ __uint(value_size, sizeof(u32));
+ __uint(max_entries, 64);
+} counters SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, int);
+ __type(value, u64);
+ __uint(max_entries, 64);
+} values SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, int);
+ __type(value, struct bpf_perf_event_value);
+ __uint(max_entries, 64);
+} values2 SEC(".maps");
+
+SEC("kprobe/htab_map_get_next_key")
+int bpf_prog1(struct pt_regs *ctx)
+{
+ u32 key = bpf_get_smp_processor_id();
+ u64 count, *val;
+ s64 error;
+
+ count = bpf_perf_event_read(&counters, key);
+ error = (s64)count;
+ if (error <= -2 && error >= -22)
+ return 0;
+
+ val = bpf_map_lookup_elem(&values, &key);
+ if (val)
+ *val = count;
+ else
+ bpf_map_update_elem(&values, &key, &count, BPF_NOEXIST);
+
+ return 0;
+}
+
+/*
+ * Since *_map_lookup_elem can't be expected to trigger bpf programs
+ * due to potential deadlocks (bpf_disable_instrumentation), this bpf
+ * program will be attached to bpf_map_copy_value (which is called
+ * from map_lookup_elem) and will only filter the hashtable type.
+ */
+SEC("kprobe/bpf_map_copy_value")
+int BPF_KPROBE(bpf_prog2, struct bpf_map *map)
+{
+ u32 key = bpf_get_smp_processor_id();
+ struct bpf_perf_event_value *val, buf;
+ enum bpf_map_type type;
+ int error;
+
+ type = BPF_CORE_READ(map, map_type);
+ if (type != BPF_MAP_TYPE_HASH)
+ return 0;
+
+ error = bpf_perf_event_read_value(&counters, key, &buf, sizeof(buf));
+ if (error)
+ return 0;
+
+ val = bpf_map_lookup_elem(&values2, &key);
+ if (val)
+ *val = buf;
+ else
+ bpf_map_update_elem(&values2, &key, &buf, BPF_NOEXIST);
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;