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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /samples/bpf/tracex6_kern.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | samples/bpf/tracex6_kern.c | 82 |
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; |