tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Augment the raw_syscalls tracepoints with the contents of the pointer arguments.
  *
  * This exactly matches what is marshalled into the raw_syscall:sys_enter
  * payload expected by the 'perf trace' beautifiers.
  */

 #include "vmlinux.h"
 #include <bpf/bpf_helpers.h>
 #include <linux/limits.h>

 /**
  * is_power_of_2() - check if a value is a power of two
  * @n: the value to check
  *
  * Determine whether some value is a power of two, where zero is *not*
  * considered a power of two.  Return: true if @n is a power of 2, otherwise
  * false.
  */
 #define is_power_of_2(n) (n != 0 && ((n & (n - 1)) == 0))

 #define MAX_CPUS  4096

 /* bpf-output associated map */
 struct __augmented_syscalls__ {
 	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
 	__type(key, int);
 	__type(value, __u32);
 	__uint(max_entries, MAX_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_user_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;
 		_Static_assert(is_power_of_2(sizeof(augmented_arg->value)), "sizeof(augmented_arg->value) needs to be a power of two");
 		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("tp/raw_syscalls/sys_enter")
 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("tp/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 */

 	_Static_assert(is_power_of_2(sizeof(augmented_args->saddr)), "sizeof(augmented_args->saddr) needs to be a power of two");
 	socklen &= sizeof(augmented_args->saddr) - 1;

 	bpf_probe_read_user(&augmented_args->saddr, socklen, sockaddr_arg);

 	return augmented__output(args, augmented_args, len + socklen);
 }

 SEC("tp/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 */

 	socklen &= sizeof(augmented_args->saddr) - 1;

 	bpf_probe_read_user(&augmented_args->saddr, socklen, sockaddr_arg);

 	return augmented__output(args, augmented_args, len + socklen);
 }

 SEC("tp/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("tp/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("tp/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("tp/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("tp/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_user(&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_user(&augmented_args->__data, size, attr) < 0)
 		goto failure;

 	return augmented__output(args, augmented_args, len + size);
 failure:
 	return 1; /* Failure: don't filter */
 }

 SEC("tp/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_user(&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("tp/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.
 	 */

 	if (pid_filter__has(&pids_filtered, getpid()))
 		return 0;

 	augmented_args = augmented_args_payload();
 	if (augmented_args == NULL)
 		return 1;

 	bpf_probe_read_kernel(&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("tp/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_kernel(&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";
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Augment the raw_syscalls tracepoints with the contents of the pointer arguments.
	*
	* This exactly matches what is marshalled into the raw_syscall:sys_enter
	* payload expected by the 'perf trace' beautifiers.
	*/

	#include "vmlinux.h"
	#include <bpf/bpf_helpers.h>
	#include <linux/limits.h>

	/**
	* is_power_of_2() - check if a value is a power of two
	* @n: the value to check
	*
	* Determine whether some value is a power of two, where zero is not
	* considered a power of two. Return: true if @n is a power of 2, otherwise
	* false.
	*/
	#define is_power_of_2(n) (n != 0 && ((n & (n - 1)) == 0))

	#define MAX_CPUS 4096

	/* bpf-output associated map */
	struct __augmented_syscalls__ {
	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
	__type(key, int);
	__type(value, __u32);
	__uint(max_entries, MAX_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_user_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;
	_Static_assert(is_power_of_2(sizeof(augmented_arg->value)), "sizeof(augmented_arg->value) needs to be a power of two");
	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("tp/raw_syscalls/sys_enter")
	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("tp/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 */

	_Static_assert(is_power_of_2(sizeof(augmented_args->saddr)), "sizeof(augmented_args->saddr) needs to be a power of two");
	socklen &= sizeof(augmented_args->saddr) - 1;

	bpf_probe_read_user(&augmented_args->saddr, socklen, sockaddr_arg);

	return augmented__output(args, augmented_args, len + socklen);
	}

	SEC("tp/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 */

	socklen &= sizeof(augmented_args->saddr) - 1;

	bpf_probe_read_user(&augmented_args->saddr, socklen, sockaddr_arg);

	return augmented__output(args, augmented_args, len + socklen);
	}

	SEC("tp/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("tp/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("tp/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("tp/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("tp/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_user(&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_user(&augmented_args->__data, size, attr) < 0)
	goto failure;

	return augmented__output(args, augmented_args, len + size);
	failure:
	return 1; /* Failure: don't filter */
	}

	SEC("tp/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_user(&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("tp/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.
	*/

	if (pid_filter__has(&pids_filtered, getpid()))
	return 0;

	augmented_args = augmented_args_payload();
	if (augmented_args == NULL)
	return 1;

	bpf_probe_read_kernel(&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("tp/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_kernel(&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";