perf bpf examples: With no BPF events remove examples

The examples were used to give demonstrations of BPF events but such
functionality is now subsumed by using --filter with 'perf record' or
the direct use of BPF skeletons.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Fangrui Song <maskray@google.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Wang ShaoBo <bobo.shaobowang@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230810184853.2860737-4-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Makefile.perf

@@ -958,11 +958,6 @@ ifndef NO_JVMTI
 endif
 	$(call QUIET_INSTALL, libexec) \
 		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perfexec_instdir_SQ)'
-ifndef NO_LIBBPF
-	$(call QUIET_INSTALL, bpf-examples) \
-		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perf_examples_instdir_SQ)/bpf'; \
-		$(INSTALL) examples/bpf/*.c -m 644 -t '$(DESTDIR_SQ)$(perf_examples_instdir_SQ)/bpf'
-endif
 	$(call QUIET_INSTALL, perf-archive) \
 		$(INSTALL) $(OUTPUT)perf-archive -t '$(DESTDIR_SQ)$(perfexec_instdir_SQ)'
 	$(call QUIET_INSTALL, perf-iostat) \

tools/perf/examples/bpf/5sec.c

-// 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";

tools/perf/examples/bpf/empty.c

-// 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";

tools/perf/examples/bpf/hello.c

-// 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";

tools/perf/examples/bpf/sys_enter_openat.c

-// 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);