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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/tracex2_kern.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/bpf/tracex2_kern.c')
-rw-r--r-- | samples/bpf/tracex2_kern.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/samples/bpf/tracex2_kern.c b/samples/bpf/tracex2_kern.c new file mode 100644 index 000000000..5bc696bac --- /dev/null +++ b/samples/bpf/tracex2_kern.c @@ -0,0 +1,102 @@ +/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com + * + * 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/skbuff.h> +#include <linux/netdevice.h> +#include <linux/version.h> +#include <uapi/linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include "trace_common.h" + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __type(key, long); + __type(value, long); + __uint(max_entries, 1024); +} my_map SEC(".maps"); + +/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe + * example will no longer be meaningful + */ +SEC("kprobe/kfree_skb") +int bpf_prog2(struct pt_regs *ctx) +{ + long loc = 0; + long init_val = 1; + long *value; + + /* read ip of kfree_skb caller. + * non-portable version of __builtin_return_address(0) + */ + BPF_KPROBE_READ_RET_IP(loc, ctx); + + value = bpf_map_lookup_elem(&my_map, &loc); + if (value) + *value += 1; + else + bpf_map_update_elem(&my_map, &loc, &init_val, BPF_ANY); + return 0; +} + +static unsigned int log2(unsigned int v) +{ + unsigned int r; + unsigned int shift; + + r = (v > 0xFFFF) << 4; v >>= r; + shift = (v > 0xFF) << 3; v >>= shift; r |= shift; + shift = (v > 0xF) << 2; v >>= shift; r |= shift; + shift = (v > 0x3) << 1; v >>= shift; r |= shift; + r |= (v >> 1); + return r; +} + +static unsigned int log2l(unsigned long v) +{ + unsigned int hi = v >> 32; + if (hi) + return log2(hi) + 32; + else + return log2(v); +} + +struct hist_key { + char comm[16]; + u64 pid_tgid; + u64 uid_gid; + u64 index; +}; + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_HASH); + __uint(key_size, sizeof(struct hist_key)); + __uint(value_size, sizeof(long)); + __uint(max_entries, 1024); +} my_hist_map SEC(".maps"); + +SEC("kprobe/" SYSCALL(sys_write)) +int bpf_prog3(struct pt_regs *ctx) +{ + long write_size = PT_REGS_PARM3(ctx); + long init_val = 1; + long *value; + struct hist_key key; + + key.index = log2l(write_size); + key.pid_tgid = bpf_get_current_pid_tgid(); + key.uid_gid = bpf_get_current_uid_gid(); + bpf_get_current_comm(&key.comm, sizeof(key.comm)); + + value = bpf_map_lookup_elem(&my_hist_map, &key); + if (value) + __sync_fetch_and_add(value, 1); + else + bpf_map_update_elem(&my_hist_map, &key, &init_val, BPF_ANY); + return 0; +} +char _license[] SEC("license") = "GPL"; +u32 _version SEC("version") = LINUX_VERSION_CODE; |