diff --git a/docs/book/start/getting-data-to-user-space.md b/docs/book/start/getting-data-to-user-space.md
new file mode 100644
index 0000000..a1393fe
--- /dev/null
+++ b/docs/book/start/getting-data-to-user-space.md
@@ -0,0 +1,153 @@
+# Getting data to user-space
+
+In previous chapters we were logging packets with aya-log. But what if we want
+to send data about the packet data, or in general any kind of data, for the
+user-space program to use?
+
+This chapter is going to explain how to use perf buffers and define structures
+in the *-common* crate to send data from eBPF program to user-space, allowing
+user-space programs to access and use that data.
+
+!!! example "Source code"
+
+    Full code for the example in this chapter is available
+    [here](https://github.com/aya-rs/book/tree/main/examples/xdp-perfbuf-custom-data)
+
+## Sharing data
+
+To get data from kernel-space to user-space, we use an eBPF map. There are
+numerous types of maps to choose from, but in this example we'll be using a
+`PerfEventArray`.
+
+This time, instead of logging the information, we are going to write it into a
+struct and output it to user-space. The data structure that we'll need to send
+information to user-space will need to hold an IPv4 address and a port.
+
+```rust linenums="1" title="xdp-perfbuf-custom-data-common/src/lib.rs"
+--8<-- "examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-common/src/lib.rs"
+```
+
+1. We implement the `aya::Pod` trait for our struct since it is Plain Old Data
+as can be safely converted to a byte-slice and back.
+
+!!! tip "Alignment, padding and verifier errors"
+
+    At program load time, the eBPF verifier checks that all the memory used is
+    properly initialized. This can be a problem if - to ensure alignment - the
+    compiler inserts padding bytes between fields in your types.
+
+    **Example:**
+
+    ```rust
+    #[repr(C)]
+    struct SourceInfo {
+        source_port: u16,
+        source_ip: u32,
+    }
+
+    let source_port = ...;
+    let source_ip = ...;
+    let si = SourceInfo { source_port, source_ip };
+    ```
+
+    In the example above, the compiler will insert two extra bytes between the
+    struct fields `source_port` and `source_ip` to make sure that `source_ip` is
+    correctly aligned to a 4 bytes address (assuming `mem::align_of::<u32>() ==
+    4`).  Since padding bytes are typically not initialized by the compiler,
+    this will result in the infamous `invalid indirect read from stack` verifier
+    error.
+
+    To avoid the error, you can either manually ensure that all the fields in
+    your types are correctly aligned (e.g. by explicitly adding padding or by
+    making field types larger to enforce alignment) or use `#[repr(packed)]`.
+    Since the latter comes with its own foot-guns and can perform less
+    efficiently, explicitly adding padding or tweaking alignment is recommended.
+
+    **Solution ensuring alignment using larger types:**
+
+    ```rust
+    #[repr(C)]
+    struct SourceInfo {
+        source_port: u32,
+        source_ip: u32,
+    }
+
+    let source_port = ...;
+    let source_ip = ...;
+    let si = SourceInfo { source_port, source_ip };
+    ```
+
+    **Solution with explicit padding:**
+
+    ```rust
+    #[repr(C)]
+    struct SourceInfo {
+        source_port: u16,
+        padding: u16,
+        source_ip: u32,
+    }
+
+    let source_port = ...;
+    let source_ip = ...;
+    let si = SourceInfo { source_port, padding: 0, source_ip };
+    ```
+
+## Getting packet data from the context and into the map
+
+Our eBPF program code is going to be similar to the one in the previous chapters.
+It's going to get the information about source IP address and port from packet
+headers.
+
+The difference is that once we get the data from headers, instead of logging
+them, we create a `PacketLog` struct and output it to our `PerfEventArray`
+
+The resulting code looks like this:
+
+```rust linenums="1" title="xdp-perfbuf-custom-data-ebpf/src/main.rs"
+--8<-- "examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/src/main.rs"
+```
+
+1. Create our map.
+2. Output the event to the map.
+
+Don't forget to rebuild your eBPF program!
+
+## Reading data
+
+In order to read from the `AsyncPerfEventArray`, we have to call
+`AsyncPerfEventArray::open()` for each online CPU, then we have to poll the file
+descriptor for events. While this is do-able using `PerfEventArray` and `mio` or
+`epoll`, the code is much less easy to follow. Instead, we'll use `tokio`, which
+was added to our template for us.
+
+We'll need to add a dependency on `bytes` to `xdp-log/Cargo.toml` since
+this will make it easier to deal with the chunks of bytes yielded by the
+`AsyncPerfEventArray`.
+
+Here's the code:
+
+```rust linenums="1" title="xdp-perfbuf-custom-data/src/main.rs"
+--8<-- "examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data/src/main.rs"
+```
+
+1. Define our map.
+2. Call `open()` for each online CPU.
+3. Spawn a `tokio::task`.
+4. Create buffers.
+5. Read events in to buffers.
+6. Use `read_unaligned` to read the event data into a `PacketLog`.
+7. Log the packet data to the console.
+
+## Running the program
+
+As before, the interface can be overwritten by providing the interface name as a
+parameter, for example, `RUST_LOG=info cargo xtask run -- --iface wlp2s0`.
+
+```console
+$ RUST_LOG=info cargo xtask run
+[2023-01-25T08:57:41Z INFO  xdp_perfbuf_custom_data] SRC IP: 60.235.240.157, SRC_PORT: 443
+[2023-01-25T08:57:41Z INFO  xdp_perfbuf_custom_data] SRC IP: 98.21.76.76, SRC_PORT: 443
+[2023-01-25T08:57:41Z INFO  xdp_perfbuf_custom_data] SRC IP: 95.194.217.172, SRC_PORT: 443
+[2023-01-25T08:57:41Z INFO  xdp_perfbuf_custom_data] SRC IP: 95.194.217.172, SRC_PORT: 443
+[2023-01-25T08:57:41Z INFO  xdp_perfbuf_custom_data] SRC IP: 95.10.251.142, SRC_PORT: 443
+```
diff --git a/examples/xdp-perfbuf-custom-data/.cargo/config.toml b/examples/xdp-perfbuf-custom-data/.cargo/config.toml
new file mode 100644
index 0000000..f0ccbc9
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/.cargo/config.toml
@@ -0,0 +1,2 @@
+[alias]
+xtask = "run --package xtask --"
\ No newline at end of file
diff --git a/examples/xdp-perfbuf-custom-data/.gitignore b/examples/xdp-perfbuf-custom-data/.gitignore
new file mode 100644
index 0000000..54f741e
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/.gitignore
@@ -0,0 +1,13 @@
+### https://raw.github.com/github/gitignore/master/Rust.gitignore
+
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
diff --git a/examples/xdp-perfbuf-custom-data/.vim/coc-settings.json b/examples/xdp-perfbuf-custom-data/.vim/coc-settings.json
new file mode 100644
index 0000000..aad6f8f
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/.vim/coc-settings.json
@@ -0,0 +1,3 @@
+{
+  "rust-analyzer.linkedProjects": ["Cargo.toml", "xdp-perfbuf-custom-data-ebpf/Cargo.toml"]
+}
diff --git a/examples/xdp-perfbuf-custom-data/.vscode/settings.json b/examples/xdp-perfbuf-custom-data/.vscode/settings.json
new file mode 100644
index 0000000..aad6f8f
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+  "rust-analyzer.linkedProjects": ["Cargo.toml", "xdp-perfbuf-custom-data-ebpf/Cargo.toml"]
+}
diff --git a/examples/xdp-perfbuf-custom-data/Cargo.toml b/examples/xdp-perfbuf-custom-data/Cargo.toml
new file mode 100644
index 0000000..20148b4
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/Cargo.toml
@@ -0,0 +1,2 @@
+[workspace]
+members = ["xdp-perfbuf-custom-data", "xdp-perfbuf-custom-data-common", "xtask"]
diff --git a/examples/xdp-perfbuf-custom-data/README.md b/examples/xdp-perfbuf-custom-data/README.md
new file mode 100644
index 0000000..b1b556b
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/README.md
@@ -0,0 +1,28 @@
+# xdp-perfbuf-custom-data
+
+## Prerequisites
+
+1. Install a rust stable toolchain: `rustup install stable`
+1. Install a rust nightly toolchain: `rustup install nightly`
+1. Install bpf-linker: `cargo install bpf-linker`
+
+## Build eBPF
+
+```bash
+cargo xtask build-ebpf
+```
+
+To perform a release build you can use the `--release` flag.
+You may also change the target architecture with the `--target` flag
+
+## Build Userspace
+
+```bash
+cargo build
+```
+
+## Run
+
+```bash
+RUST_LOG=info cargo xtask run
+```
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-common/Cargo.toml b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-common/Cargo.toml
new file mode 100644
index 0000000..df8d5d5
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-common/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "xdp-perfbuf-custom-data-common"
+version = "0.1.0"
+edition = "2021"
+
+[features]
+default = []
+user = [ "aya" ]
+
+[dependencies]
+aya = { version = ">=0.11", optional=true }
+
+[lib]
+path = "src/lib.rs"
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-common/src/lib.rs b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-common/src/lib.rs
new file mode 100644
index 0000000..61f32c2
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-common/src/lib.rs
@@ -0,0 +1,11 @@
+#![no_std]
+
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub struct PacketLog {
+    pub ipv4_address: u32,
+    pub port: u32,
+}
+
+#[cfg(feature = "user")]
+unsafe impl aya::Pod for PacketLog {} // (1)
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/.cargo/config.toml b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/.cargo/config.toml
new file mode 100644
index 0000000..5d7e591
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/.cargo/config.toml
@@ -0,0 +1,6 @@
+[build]
+target-dir = "../target"
+target = "bpfel-unknown-none"
+
+[unstable]
+build-std = ["core"]
\ No newline at end of file
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/.vim/coc-settings.json b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/.vim/coc-settings.json
new file mode 100644
index 0000000..e2211a6
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/.vim/coc-settings.json
@@ -0,0 +1,4 @@
+{
+    "rust-analyzer.cargo.target": "bpfel-unknown-none",
+    "rust-analyzer.checkOnSave.allTargets": false
+}
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/.vscode/settings.json b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/.vscode/settings.json
new file mode 100644
index 0000000..e2211a6
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/.vscode/settings.json
@@ -0,0 +1,4 @@
+{
+    "rust-analyzer.cargo.target": "bpfel-unknown-none",
+    "rust-analyzer.checkOnSave.allTargets": false
+}
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/Cargo.toml b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/Cargo.toml
new file mode 100644
index 0000000..5273b28
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/Cargo.toml
@@ -0,0 +1,33 @@
+[package]
+name = "xdp-perfbuf-custom-data-ebpf"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+aya-bpf = { git = "https://github.com/aya-rs/aya", branch = "main" }
+aya-log-ebpf = { git = "https://github.com/aya-rs/aya", branch = "main" }
+xdp-perfbuf-custom-data-common = { path = "../xdp-perfbuf-custom-data-common" }
+network-types = "0.0.4"
+
+[[bin]]
+name = "xdp-perfbuf-custom-data"
+path = "src/main.rs"
+
+[profile.dev]
+opt-level = 3
+debug = false
+debug-assertions = false
+overflow-checks = false
+lto = true
+panic = "abort"
+incremental = false
+codegen-units = 1
+rpath = false
+
+[profile.release]
+lto = true
+panic = "abort"
+codegen-units = 1
+
+[workspace]
+members = []
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/rust-toolchain.toml b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/rust-toolchain.toml
new file mode 100644
index 0000000..4893202
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/rust-toolchain.toml
@@ -0,0 +1,5 @@
+[toolchain]
+channel="nightly-2023-01-10"
+# The source code of rustc, provided by the rust-src component, is needed for
+# building eBPF programs.
+components = [ "rustc", "rust-std", "cargo", "rust-docs", "rustfmt", "clippy", "rust-src" ]
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/src/main.rs b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/src/main.rs
new file mode 100644
index 0000000..d13340f
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data-ebpf/src/main.rs
@@ -0,0 +1,84 @@
+#![no_std]
+#![no_main]
+
+use core::mem;
+
+use aya_bpf::{
+    bindings::xdp_action,
+    macros::{map, xdp},
+    maps::PerfEventArray,
+    programs::XdpContext,
+};
+use network_types::{
+    eth::{EthHdr, EtherType},
+    ip::{IpProto, Ipv4Hdr},
+    tcp::TcpHdr,
+    udp::UdpHdr,
+};
+
+use xdp_perfbuf_custom_data_common::PacketLog;
+
+#[map(name = "EVENTS")] // (1)
+static mut EVENTS: PerfEventArray<PacketLog> =
+    PerfEventArray::<PacketLog>::with_max_entries(1024, 0);
+
+#[xdp(name = "xdp_perfbuf_custom_data")]
+pub fn xdp_perfbuf_custom_data(ctx: XdpContext) -> u32 {
+    match try_xdp_perfbuf_custom_data(ctx) {
+        Ok(ret) => ret,
+        Err(_) => xdp_action::XDP_ABORTED,
+    }
+}
+
+#[inline(always)]
+fn ptr_at<T>(ctx: &XdpContext, offset: usize) -> Result<*const T, ()> {
+    let start = ctx.data();
+    let end = ctx.data_end();
+    let len = mem::size_of::<T>();
+
+    if start + offset + len > end {
+        return Err(());
+    }
+
+    Ok((start + offset) as *const T)
+}
+
+fn try_xdp_perfbuf_custom_data(ctx: XdpContext) -> Result<u32, ()> {
+    let ethhdr: *const EthHdr = ptr_at(&ctx, 0)?;
+    match unsafe { (*ethhdr).ether_type } {
+        EtherType::Ipv4 => {}
+        _ => return Ok(xdp_action::XDP_PASS),
+    }
+
+    let ipv4hdr: *const Ipv4Hdr = ptr_at(&ctx, EthHdr::LEN)?;
+    let source_addr = unsafe { (*ipv4hdr).src_addr };
+
+    let source_port = match unsafe { (*ipv4hdr).proto } {
+        IpProto::Tcp => {
+            let tcphdr: *const TcpHdr =
+                ptr_at(&ctx, EthHdr::LEN + Ipv4Hdr::LEN)?;
+            u16::from_be(unsafe { (*tcphdr).source })
+        }
+        IpProto::Udp => {
+            let udphdr: *const UdpHdr =
+                ptr_at(&ctx, EthHdr::LEN + Ipv4Hdr::LEN)?;
+            u16::from_be(unsafe { (*udphdr).source })
+        }
+        _ => return Err(()),
+    };
+
+    let log_entry = PacketLog {
+        ipv4_address: source_addr,
+        port: source_port as u32,
+    };
+    unsafe {
+        EVENTS.output(&ctx, &log_entry, 0); // (2)
+    }
+
+    Ok(xdp_action::XDP_PASS)
+}
+
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    unsafe { core::hint::unreachable_unchecked() }
+}
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data/Cargo.toml b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data/Cargo.toml
new file mode 100644
index 0000000..a9e97d4
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "xdp-perfbuf-custom-data"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+aya = { version = ">=0.11", features=["async_tokio"] }
+aya-log = "0.1"
+xdp-perfbuf-custom-data-common = { path = "../xdp-perfbuf-custom-data-common", features=["user"] }
+anyhow = "1.0.42"
+clap = { version = "4.0", features = ["derive"] }
+env_logger = "0.10"
+log = "0.4"
+tokio = { version = "1.23", features = ["macros", "rt", "rt-multi-thread", "net", "signal"] }
+bytes = "1.3"
+
+[[bin]]
+name = "xdp-perfbuf-custom-data"
+path = "src/main.rs"
diff --git a/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data/src/main.rs b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data/src/main.rs
new file mode 100644
index 0000000..73d12c5
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xdp-perfbuf-custom-data/src/main.rs
@@ -0,0 +1,86 @@
+use std::net;
+
+use anyhow::Context;
+use aya::{
+    include_bytes_aligned,
+    maps::perf::AsyncPerfEventArray,
+    programs::{Xdp, XdpFlags},
+    util::online_cpus,
+    Bpf,
+};
+use bytes::BytesMut;
+use clap::Parser;
+use log::info;
+use tokio::{signal, task};
+
+use xdp_perfbuf_custom_data_common::PacketLog;
+
+#[derive(Debug, Parser)]
+struct Opt {
+    #[clap(short, long, default_value = "eth0")]
+    iface: String,
+}
+
+#[tokio::main]
+async fn main() -> Result<(), anyhow::Error> {
+    let opt = Opt::parse();
+
+    env_logger::init();
+
+    // This will include your eBPF object file as raw bytes at compile-time and load it at
+    // runtime. This approach is recommended for most real-world use cases. If you would
+    // like to specify the eBPF program at runtime rather than at compile-time, you can
+    // reach for `Bpf::load_file` instead.
+    #[cfg(debug_assertions)]
+    let mut bpf = Bpf::load(include_bytes_aligned!(
+        "../../target/bpfel-unknown-none/debug/xdp-perfbuf-custom-data"
+    ))?;
+    #[cfg(not(debug_assertions))]
+    let mut bpf = Bpf::load(include_bytes_aligned!(
+        "../../target/bpfel-unknown-none/release/xdp-perfbuf-custom-data"
+    ))?;
+    let program: &mut Xdp = bpf
+        .program_mut("xdp_perfbuf_custom_data")
+        .unwrap()
+        .try_into()?;
+    program.load()?;
+    program.attach(&opt.iface, XdpFlags::default())
+        .context("failed to attach the XDP program with default flags - try changing XdpFlags::default() to XdpFlags::SKB_MODE")?;
+
+    // (1)
+    let mut perf_array = AsyncPerfEventArray::try_from(bpf.map_mut("EVENTS")?)?;
+
+    let cpus = online_cpus()?;
+    for cpu_id in cpus {
+        // (2)
+        let mut buf = perf_array.open(cpu_id, None)?;
+
+        // (3)
+        task::spawn(async move {
+            // (4)
+            let mut buffers = (0..10)
+                .map(|_| BytesMut::with_capacity(1024))
+                .collect::<Vec<_>>();
+
+            loop {
+                // (5)
+                let events = buf.read_events(&mut buffers).await.unwrap();
+                for i in 0..events.read {
+                    let buf = &mut buffers[i];
+                    let ptr = buf.as_ptr() as *const PacketLog;
+                    // (6)
+                    let data = unsafe { ptr.read_unaligned() };
+                    let src_addr = net::Ipv4Addr::from(data.ipv4_address);
+                    // (7)
+                    info!("SRC IP: {}, SRC_PORT: {}", src_addr, data.port);
+                }
+            }
+        });
+    }
+
+    info!("Waiting for Ctrl-C...");
+    signal::ctrl_c().await?;
+    info!("Exiting...");
+
+    Ok(())
+}
diff --git a/examples/xdp-perfbuf-custom-data/xtask/Cargo.toml b/examples/xdp-perfbuf-custom-data/xtask/Cargo.toml
new file mode 100644
index 0000000..89080c9
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xtask/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "xtask"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+anyhow = "1"
+clap = { version = "4.0", features = ["derive"] }
diff --git a/examples/xdp-perfbuf-custom-data/xtask/src/build_ebpf.rs b/examples/xdp-perfbuf-custom-data/xtask/src/build_ebpf.rs
new file mode 100644
index 0000000..600dd79
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xtask/src/build_ebpf.rs
@@ -0,0 +1,68 @@
+use std::{path::PathBuf, process::Command};
+
+use clap::Parser;
+
+#[derive(Debug, Copy, Clone)]
+pub enum Architecture {
+    BpfEl,
+    BpfEb,
+}
+
+impl std::str::FromStr for Architecture {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(match s {
+            "bpfel-unknown-none" => Architecture::BpfEl,
+            "bpfeb-unknown-none" => Architecture::BpfEb,
+            _ => return Err("invalid target".to_owned()),
+        })
+    }
+}
+
+impl std::fmt::Display for Architecture {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(match self {
+            Architecture::BpfEl => "bpfel-unknown-none",
+            Architecture::BpfEb => "bpfeb-unknown-none",
+        })
+    }
+}
+
+#[derive(Debug, Parser)]
+pub struct Options {
+    /// Set the endianness of the BPF target
+    #[clap(default_value = "bpfel-unknown-none", long)]
+    pub target: Architecture,
+    /// Build the release target
+    #[clap(long)]
+    pub release: bool,
+}
+
+pub fn build_ebpf(opts: Options) -> Result<(), anyhow::Error> {
+    let dir = PathBuf::from("xdp-perfbuf-custom-data-ebpf");
+    let target = format!("--target={}", opts.target);
+    let mut args = vec![
+        "build",
+        "--verbose",
+        target.as_str(),
+        "-Z",
+        "build-std=core",
+    ];
+    if opts.release {
+        args.push("--release")
+    }
+
+    // Command::new creates a child process which inherits all env variables. This means env
+    // vars set by the cargo xtask command are also inherited. RUSTUP_TOOLCHAIN is removed
+    // so the rust-toolchain.toml file in the -ebpf folder is honored.
+
+    let status = Command::new("cargo")
+        .current_dir(dir)
+        .env_remove("RUSTUP_TOOLCHAIN")
+        .args(&args)
+        .status()
+        .expect("failed to build bpf program");
+    assert!(status.success());
+    Ok(())
+}
diff --git a/examples/xdp-perfbuf-custom-data/xtask/src/main.rs b/examples/xdp-perfbuf-custom-data/xtask/src/main.rs
new file mode 100644
index 0000000..c1c594e
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xtask/src/main.rs
@@ -0,0 +1,33 @@
+mod build_ebpf;
+mod run;
+
+use std::process::exit;
+
+use clap::Parser;
+
+#[derive(Debug, Parser)]
+pub struct Options {
+    #[clap(subcommand)]
+    command: Command,
+}
+
+#[derive(Debug, Parser)]
+enum Command {
+    BuildEbpf(build_ebpf::Options),
+    Run(run::Options),
+}
+
+fn main() {
+    let opts = Options::parse();
+
+    use Command::*;
+    let ret = match opts.command {
+        BuildEbpf(opts) => build_ebpf::build_ebpf(opts),
+        Run(opts) => run::run(opts),
+    };
+
+    if let Err(e) = ret {
+        eprintln!("{e:#}");
+        exit(1);
+    }
+}
diff --git a/examples/xdp-perfbuf-custom-data/xtask/src/run.rs b/examples/xdp-perfbuf-custom-data/xtask/src/run.rs
new file mode 100644
index 0000000..0cb103a
--- /dev/null
+++ b/examples/xdp-perfbuf-custom-data/xtask/src/run.rs
@@ -0,0 +1,67 @@
+use std::{os::unix::process::CommandExt, process::Command};
+
+use anyhow::Context as _;
+use clap::Parser;
+
+use crate::build_ebpf::{build_ebpf, Architecture, Options as BuildOptions};
+
+#[derive(Debug, Parser)]
+pub struct Options {
+    /// Set the endianness of the BPF target
+    #[clap(default_value = "bpfel-unknown-none", long)]
+    pub bpf_target: Architecture,
+    /// Build and run the release target
+    #[clap(long)]
+    pub release: bool,
+    /// The command used to wrap your application
+    #[clap(short, long, default_value = "sudo -E")]
+    pub runner: String,
+    /// Arguments to pass to your application
+    #[clap(name = "args", last = true)]
+    pub run_args: Vec<String>,
+}
+
+/// Build the project
+fn build(opts: &Options) -> Result<(), anyhow::Error> {
+    let mut args = vec!["build"];
+    if opts.release {
+        args.push("--release")
+    }
+    let status = Command::new("cargo")
+        .args(&args)
+        .status()
+        .expect("failed to build userspace");
+    assert!(status.success());
+    Ok(())
+}
+
+/// Build and run the project
+pub fn run(opts: Options) -> Result<(), anyhow::Error> {
+    // build our ebpf program followed by our application
+    build_ebpf(BuildOptions {
+        target: opts.bpf_target,
+        release: opts.release,
+    })
+    .context("Error while building eBPF program")?;
+    build(&opts).context("Error while building userspace application")?;
+
+    // profile we are building (release or debug)
+    let profile = if opts.release { "release" } else { "debug" };
+    let bin_path = format!("target/{profile}/xdp-perfbuf-custom-data");
+
+    // arguments to pass to the application
+    let mut run_args: Vec<_> = opts.run_args.iter().map(String::as_str).collect();
+
+    // configure args
+    let mut args: Vec<_> = opts.runner.trim().split_terminator(' ').collect();
+    args.push(bin_path.as_str());
+    args.append(&mut run_args);
+
+    // spawn the command
+    let err = Command::new(args.first().expect("No first argument"))
+        .args(args.iter().skip(1))
+        .exec();
+
+    // we shouldn't get here unless the command failed to spawn
+    Err(anyhow::Error::from(err).context(format!("Failed to run `{}`", args.join(" "))))
+}
diff --git a/mkdocs.yml b/mkdocs.yml
index d7a6ab3..549ab86 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -67,6 +67,7 @@ nav:
       - Hello XDP!: book/start/hello-xdp.md
       - Parsing packets: book/start/parsing-packets.md
       - Dropping Packets: book/start/dropping-packets.md
+      - Getting data to user-space: book/start/getting-data-to-user-space.md
     - Working With Aya:
       - book/aya/index.md
       - Program Lifecycle: book/aya/lifecycle.md