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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /tools/perf/examples/bpf
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'tools/perf/examples/bpf')
-rw-r--r--tools/perf/examples/bpf/5sec.c53
-rw-r--r--tools/perf/examples/bpf/augmented_raw_syscalls.c417
-rw-r--r--tools/perf/examples/bpf/empty.c12
-rw-r--r--tools/perf/examples/bpf/hello.c27
-rw-r--r--tools/perf/examples/bpf/sys_enter_openat.c33
5 files changed, 542 insertions, 0 deletions
diff --git a/tools/perf/examples/bpf/5sec.c b/tools/perf/examples/bpf/5sec.c
new file mode 100644
index 000000000..3bd7fc176
--- /dev/null
+++ b/tools/perf/examples/bpf/5sec.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ Description:
+
+ . Disable strace like syscall tracing (--no-syscalls), or try tracing
+ just some (-e *sleep).
+
+ . Attach a filter function to a kernel function, returning when it should
+ be considered, i.e. appear on the output.
+
+ . Run it system wide, so that any sleep of >= 5 seconds and < than 6
+ seconds gets caught.
+
+ . Ask for callgraphs using DWARF info, so that userspace can be unwound
+
+ . While this is running, run something like "sleep 5s".
+
+ . If we decide to add tv_nsec as well, then it becomes:
+
+ int probe(hrtimer_nanosleep, rqtp->tv_sec rqtp->tv_nsec)(void *ctx, int err, long sec, long nsec)
+
+ I.e. add where it comes from (rqtp->tv_nsec) and where it will be
+ accessible in the function body (nsec)
+
+ # perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c/call-graph=dwarf/
+ 0.000 perf_bpf_probe:func:(ffffffff9811b5f0) tv_sec=5
+ hrtimer_nanosleep ([kernel.kallsyms])
+ __x64_sys_nanosleep ([kernel.kallsyms])
+ do_syscall_64 ([kernel.kallsyms])
+ entry_SYSCALL_64 ([kernel.kallsyms])
+ __GI___nanosleep (/usr/lib64/libc-2.26.so)
+ rpl_nanosleep (/usr/bin/sleep)
+ xnanosleep (/usr/bin/sleep)
+ main (/usr/bin/sleep)
+ __libc_start_main (/usr/lib64/libc-2.26.so)
+ _start (/usr/bin/sleep)
+ ^C#
+
+ Copyright (C) 2018 Red Hat, Inc., Arnaldo Carvalho de Melo <acme@redhat.com>
+*/
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define NSEC_PER_SEC 1000000000L
+
+SEC("hrtimer_nanosleep=hrtimer_nanosleep rqtp")
+int hrtimer_nanosleep(void *ctx, int err, long long sec)
+{
+ return sec / NSEC_PER_SEC == 5ULL;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c
new file mode 100644
index 000000000..9a03189d3
--- /dev/null
+++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Augment the raw_syscalls tracepoints with the contents of the pointer arguments.
+ *
+ * Test it with:
+ *
+ * perf trace -e tools/perf/examples/bpf/augmented_raw_syscalls.c cat /etc/passwd > /dev/null
+ *
+ * This exactly matches what is marshalled into the raw_syscall:sys_enter
+ * payload expected by the 'perf trace' beautifiers.
+ *
+ * For now it just uses the existing tracepoint augmentation code in 'perf
+ * trace', in the next csets we'll hook up these with the sys_enter/sys_exit
+ * code that will combine entry/exit in a strace like way.
+ */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <linux/limits.h>
+
+// FIXME: These should come from system headers
+typedef char bool;
+typedef int pid_t;
+typedef long long int __s64;
+typedef __s64 time64_t;
+
+struct timespec64 {
+ time64_t tv_sec;
+ long int tv_nsec;
+};
+
+/* bpf-output associated map */
+struct __augmented_syscalls__ {
+ __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+ __type(key, int);
+ __type(value, __u32);
+ __uint(max_entries, __NR_CPUS__);
+} __augmented_syscalls__ SEC(".maps");
+
+/*
+ * What to augment at entry?
+ *
+ * Pointer arg payloads (filenames, etc) passed from userspace to the kernel
+ */
+struct syscalls_sys_enter {
+ __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+ __type(key, __u32);
+ __type(value, __u32);
+ __uint(max_entries, 512);
+} syscalls_sys_enter SEC(".maps");
+
+/*
+ * What to augment at exit?
+ *
+ * Pointer arg payloads returned from the kernel (struct stat, etc) to userspace.
+ */
+struct syscalls_sys_exit {
+ __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+ __type(key, __u32);
+ __type(value, __u32);
+ __uint(max_entries, 512);
+} syscalls_sys_exit SEC(".maps");
+
+struct syscall_enter_args {
+ unsigned long long common_tp_fields;
+ long syscall_nr;
+ unsigned long args[6];
+};
+
+struct syscall_exit_args {
+ unsigned long long common_tp_fields;
+ long syscall_nr;
+ long ret;
+};
+
+struct augmented_arg {
+ unsigned int size;
+ int err;
+ char value[PATH_MAX];
+};
+
+struct pids_filtered {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, pid_t);
+ __type(value, bool);
+ __uint(max_entries, 64);
+} pids_filtered SEC(".maps");
+
+/*
+ * Desired design of maximum size and alignment (see RFC2553)
+ */
+#define SS_MAXSIZE 128 /* Implementation specific max size */
+
+typedef unsigned short sa_family_t;
+
+/*
+ * FIXME: Should come from system headers
+ *
+ * The definition uses anonymous union and struct in order to control the
+ * default alignment.
+ */
+struct sockaddr_storage {
+ union {
+ struct {
+ sa_family_t ss_family; /* address family */
+ /* Following field(s) are implementation specific */
+ char __data[SS_MAXSIZE - sizeof(unsigned short)];
+ /* space to achieve desired size, */
+ /* _SS_MAXSIZE value minus size of ss_family */
+ };
+ void *__align; /* implementation specific desired alignment */
+ };
+};
+
+struct augmented_args_payload {
+ struct syscall_enter_args args;
+ union {
+ struct {
+ struct augmented_arg arg, arg2;
+ };
+ struct sockaddr_storage saddr;
+ char __data[sizeof(struct augmented_arg)];
+ };
+};
+
+// We need more tmp space than the BPF stack can give us
+struct augmented_args_tmp {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __type(key, int);
+ __type(value, struct augmented_args_payload);
+ __uint(max_entries, 1);
+} augmented_args_tmp SEC(".maps");
+
+static inline struct augmented_args_payload *augmented_args_payload(void)
+{
+ int key = 0;
+ return bpf_map_lookup_elem(&augmented_args_tmp, &key);
+}
+
+static inline int augmented__output(void *ctx, struct augmented_args_payload *args, int len)
+{
+ /* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */
+ return bpf_perf_event_output(ctx, &__augmented_syscalls__, BPF_F_CURRENT_CPU, args, len);
+}
+
+static inline
+unsigned int augmented_arg__read_str(struct augmented_arg *augmented_arg, const void *arg, unsigned int arg_len)
+{
+ unsigned int augmented_len = sizeof(*augmented_arg);
+ int string_len = bpf_probe_read_str(&augmented_arg->value, arg_len, arg);
+
+ augmented_arg->size = augmented_arg->err = 0;
+ /*
+ * probe_read_str may return < 0, e.g. -EFAULT
+ * So we leave that in the augmented_arg->size that userspace will
+ */
+ if (string_len > 0) {
+ augmented_len -= sizeof(augmented_arg->value) - string_len;
+ augmented_len &= sizeof(augmented_arg->value) - 1;
+ augmented_arg->size = string_len;
+ } else {
+ /*
+ * So that username notice the error while still being able
+ * to skip this augmented arg record
+ */
+ augmented_arg->err = string_len;
+ augmented_len = offsetof(struct augmented_arg, value);
+ }
+
+ return augmented_len;
+}
+
+SEC("!raw_syscalls:unaugmented")
+int syscall_unaugmented(struct syscall_enter_args *args)
+{
+ return 1;
+}
+
+/*
+ * These will be tail_called from SEC("raw_syscalls:sys_enter"), so will find in
+ * augmented_args_tmp what was read by that raw_syscalls:sys_enter and go
+ * on from there, reading the first syscall arg as a string, i.e. open's
+ * filename.
+ */
+SEC("!syscalls:sys_enter_connect")
+int sys_enter_connect(struct syscall_enter_args *args)
+{
+ struct augmented_args_payload *augmented_args = augmented_args_payload();
+ const void *sockaddr_arg = (const void *)args->args[1];
+ unsigned int socklen = args->args[2];
+ unsigned int len = sizeof(augmented_args->args);
+
+ if (augmented_args == NULL)
+ return 1; /* Failure: don't filter */
+
+ if (socklen > sizeof(augmented_args->saddr))
+ socklen = sizeof(augmented_args->saddr);
+
+ bpf_probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
+
+ return augmented__output(args, augmented_args, len + socklen);
+}
+
+SEC("!syscalls:sys_enter_sendto")
+int sys_enter_sendto(struct syscall_enter_args *args)
+{
+ struct augmented_args_payload *augmented_args = augmented_args_payload();
+ const void *sockaddr_arg = (const void *)args->args[4];
+ unsigned int socklen = args->args[5];
+ unsigned int len = sizeof(augmented_args->args);
+
+ if (augmented_args == NULL)
+ return 1; /* Failure: don't filter */
+
+ if (socklen > sizeof(augmented_args->saddr))
+ socklen = sizeof(augmented_args->saddr);
+
+ bpf_probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
+
+ return augmented__output(args, augmented_args, len + socklen);
+}
+
+SEC("!syscalls:sys_enter_open")
+int sys_enter_open(struct syscall_enter_args *args)
+{
+ struct augmented_args_payload *augmented_args = augmented_args_payload();
+ const void *filename_arg = (const void *)args->args[0];
+ unsigned int len = sizeof(augmented_args->args);
+
+ if (augmented_args == NULL)
+ return 1; /* Failure: don't filter */
+
+ len += augmented_arg__read_str(&augmented_args->arg, filename_arg, sizeof(augmented_args->arg.value));
+
+ return augmented__output(args, augmented_args, len);
+}
+
+SEC("!syscalls:sys_enter_openat")
+int sys_enter_openat(struct syscall_enter_args *args)
+{
+ struct augmented_args_payload *augmented_args = augmented_args_payload();
+ const void *filename_arg = (const void *)args->args[1];
+ unsigned int len = sizeof(augmented_args->args);
+
+ if (augmented_args == NULL)
+ return 1; /* Failure: don't filter */
+
+ len += augmented_arg__read_str(&augmented_args->arg, filename_arg, sizeof(augmented_args->arg.value));
+
+ return augmented__output(args, augmented_args, len);
+}
+
+SEC("!syscalls:sys_enter_rename")
+int sys_enter_rename(struct syscall_enter_args *args)
+{
+ struct augmented_args_payload *augmented_args = augmented_args_payload();
+ const void *oldpath_arg = (const void *)args->args[0],
+ *newpath_arg = (const void *)args->args[1];
+ unsigned int len = sizeof(augmented_args->args), oldpath_len;
+
+ if (augmented_args == NULL)
+ return 1; /* Failure: don't filter */
+
+ oldpath_len = augmented_arg__read_str(&augmented_args->arg, oldpath_arg, sizeof(augmented_args->arg.value));
+ len += oldpath_len + augmented_arg__read_str((void *)(&augmented_args->arg) + oldpath_len, newpath_arg, sizeof(augmented_args->arg.value));
+
+ return augmented__output(args, augmented_args, len);
+}
+
+SEC("!syscalls:sys_enter_renameat")
+int sys_enter_renameat(struct syscall_enter_args *args)
+{
+ struct augmented_args_payload *augmented_args = augmented_args_payload();
+ const void *oldpath_arg = (const void *)args->args[1],
+ *newpath_arg = (const void *)args->args[3];
+ unsigned int len = sizeof(augmented_args->args), oldpath_len;
+
+ if (augmented_args == NULL)
+ return 1; /* Failure: don't filter */
+
+ oldpath_len = augmented_arg__read_str(&augmented_args->arg, oldpath_arg, sizeof(augmented_args->arg.value));
+ len += oldpath_len + augmented_arg__read_str((void *)(&augmented_args->arg) + oldpath_len, newpath_arg, sizeof(augmented_args->arg.value));
+
+ return augmented__output(args, augmented_args, len);
+}
+
+#define PERF_ATTR_SIZE_VER0 64 /* sizeof first published struct */
+
+// we need just the start, get the size to then copy it
+struct perf_event_attr_size {
+ __u32 type;
+ /*
+ * Size of the attr structure, for fwd/bwd compat.
+ */
+ __u32 size;
+};
+
+SEC("!syscalls:sys_enter_perf_event_open")
+int sys_enter_perf_event_open(struct syscall_enter_args *args)
+{
+ struct augmented_args_payload *augmented_args = augmented_args_payload();
+ const struct perf_event_attr_size *attr = (const struct perf_event_attr_size *)args->args[0], *attr_read;
+ unsigned int len = sizeof(augmented_args->args);
+
+ if (augmented_args == NULL)
+ goto failure;
+
+ if (bpf_probe_read(&augmented_args->__data, sizeof(*attr), attr) < 0)
+ goto failure;
+
+ attr_read = (const struct perf_event_attr_size *)augmented_args->__data;
+
+ __u32 size = attr_read->size;
+
+ if (!size)
+ size = PERF_ATTR_SIZE_VER0;
+
+ if (size > sizeof(augmented_args->__data))
+ goto failure;
+
+ // Now that we read attr->size and tested it against the size limits, read it completely
+ if (bpf_probe_read(&augmented_args->__data, size, attr) < 0)
+ goto failure;
+
+ return augmented__output(args, augmented_args, len + size);
+failure:
+ return 1; /* Failure: don't filter */
+}
+
+SEC("!syscalls:sys_enter_clock_nanosleep")
+int sys_enter_clock_nanosleep(struct syscall_enter_args *args)
+{
+ struct augmented_args_payload *augmented_args = augmented_args_payload();
+ const void *rqtp_arg = (const void *)args->args[2];
+ unsigned int len = sizeof(augmented_args->args);
+ __u32 size = sizeof(struct timespec64);
+
+ if (augmented_args == NULL)
+ goto failure;
+
+ if (size > sizeof(augmented_args->__data))
+ goto failure;
+
+ bpf_probe_read(&augmented_args->__data, size, rqtp_arg);
+
+ return augmented__output(args, augmented_args, len + size);
+failure:
+ return 1; /* Failure: don't filter */
+}
+
+static pid_t getpid(void)
+{
+ return bpf_get_current_pid_tgid();
+}
+
+static bool pid_filter__has(struct pids_filtered *pids, pid_t pid)
+{
+ return bpf_map_lookup_elem(pids, &pid) != NULL;
+}
+
+SEC("raw_syscalls:sys_enter")
+int sys_enter(struct syscall_enter_args *args)
+{
+ struct augmented_args_payload *augmented_args;
+ /*
+ * We start len, the amount of data that will be in the perf ring
+ * buffer, if this is not filtered out by one of pid_filter__has(),
+ * syscall->enabled, etc, with the non-augmented raw syscall payload,
+ * i.e. sizeof(augmented_args->args).
+ *
+ * We'll add to this as we add augmented syscalls right after that
+ * initial, non-augmented raw_syscalls:sys_enter payload.
+ */
+ unsigned int len = sizeof(augmented_args->args);
+
+ if (pid_filter__has(&pids_filtered, getpid()))
+ return 0;
+
+ augmented_args = augmented_args_payload();
+ if (augmented_args == NULL)
+ return 1;
+
+ bpf_probe_read(&augmented_args->args, sizeof(augmented_args->args), args);
+
+ /*
+ * Jump to syscall specific augmenter, even if the default one,
+ * "!raw_syscalls:unaugmented" that will just return 1 to return the
+ * unaugmented tracepoint payload.
+ */
+ bpf_tail_call(args, &syscalls_sys_enter, augmented_args->args.syscall_nr);
+
+ // If not found on the PROG_ARRAY syscalls map, then we're filtering it:
+ return 0;
+}
+
+SEC("raw_syscalls:sys_exit")
+int sys_exit(struct syscall_exit_args *args)
+{
+ struct syscall_exit_args exit_args;
+
+ if (pid_filter__has(&pids_filtered, getpid()))
+ return 0;
+
+ bpf_probe_read(&exit_args, sizeof(exit_args), args);
+ /*
+ * Jump to syscall specific return augmenter, even if the default one,
+ * "!raw_syscalls:unaugmented" that will just return 1 to return the
+ * unaugmented tracepoint payload.
+ */
+ bpf_tail_call(args, &syscalls_sys_exit, exit_args.syscall_nr);
+ /*
+ * If not found on the PROG_ARRAY syscalls map, then we're filtering it:
+ */
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/perf/examples/bpf/empty.c b/tools/perf/examples/bpf/empty.c
new file mode 100644
index 000000000..3e296c0c5
--- /dev/null
+++ b/tools/perf/examples/bpf/empty.c
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct syscall_enter_args;
+
+SEC("raw_syscalls:sys_enter")
+int sys_enter(struct syscall_enter_args *args)
+{
+ return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/tools/perf/examples/bpf/hello.c b/tools/perf/examples/bpf/hello.c
new file mode 100644
index 000000000..e9080b0df
--- /dev/null
+++ b/tools/perf/examples/bpf/hello.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct __bpf_stdout__ {
+ __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+ __type(key, int);
+ __type(value, __u32);
+ __uint(max_entries, __NR_CPUS__);
+} __bpf_stdout__ SEC(".maps");
+
+#define puts(from) \
+ ({ const int __len = sizeof(from); \
+ char __from[sizeof(from)] = from; \
+ bpf_perf_event_output(args, &__bpf_stdout__, BPF_F_CURRENT_CPU, \
+ &__from, __len & (sizeof(from) - 1)); })
+
+struct syscall_enter_args;
+
+SEC("raw_syscalls:sys_enter")
+int sys_enter(struct syscall_enter_args *args)
+{
+ puts("Hello, world\n");
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/perf/examples/bpf/sys_enter_openat.c b/tools/perf/examples/bpf/sys_enter_openat.c
new file mode 100644
index 000000000..c4481c390
--- /dev/null
+++ b/tools/perf/examples/bpf/sys_enter_openat.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hook into 'openat' syscall entry tracepoint
+ *
+ * Test it with:
+ *
+ * perf trace -e tools/perf/examples/bpf/sys_enter_openat.c cat /etc/passwd > /dev/null
+ *
+ * It'll catch some openat syscalls related to the dynamic linked and
+ * the last one should be the one for '/etc/passwd'.
+ *
+ * The syscall_enter_openat_args can be used to get the syscall fields
+ * and use them for filtering calls, i.e. use in expressions for
+ * the return value.
+ */
+
+#include <bpf/bpf.h>
+
+struct syscall_enter_openat_args {
+ unsigned long long unused;
+ long syscall_nr;
+ long dfd;
+ char *filename_ptr;
+ long flags;
+ long mode;
+};
+
+int syscall_enter(openat)(struct syscall_enter_openat_args *args)
+{
+ return 1;
+}
+
+license(GPL);