From:   Jiri Olsa <jolsa@redhat.com>
To:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>
Cc:     netdev@vger.kernel.org, bpf@vger.kernel.org,
        lkml <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Martin KaFai Lau <kafai@fb.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@chromium.org>,
        Ravi Bangoria <ravi.bangoria@amd.com>
Subject: [PATCH 4/8] libbpf: Add struct perf_event_open_args
Date:   Wed, 24 Nov 2021 09:41:15 +0100
Message-Id: <20211124084119.260239-5-jolsa@kernel.org>
In-Reply-To: <20211124084119.260239-1-jolsa@kernel.org>
References: <20211124084119.260239-1-jolsa@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Adding struct perf_event_open_args to hold arguments for
perf_event_open_probe, because there's already 6 arguments
and more will come in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/lib/bpf/libbpf.c | 42 ++++++++++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 10 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index b55c0fbfcc03..34219a0c39a7 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9625,11 +9625,20 @@ static int determine_uprobe_retprobe_bit(void)
 #define PERF_UPROBE_REF_CTR_OFFSET_BITS 32
 #define PERF_UPROBE_REF_CTR_OFFSET_SHIFT 32
 
-static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
-				 uint64_t offset, int pid, size_t ref_ctr_off)
+struct perf_event_open_args {
+	bool retprobe;
+	const char *name;
+	uint64_t offset;
+	int pid;
+	size_t ref_ctr_off;
+};
+
+static int perf_event_open_probe(bool uprobe, struct perf_event_open_args *args)
 {
+	size_t ref_ctr_off = args->ref_ctr_off;
 	struct perf_event_attr attr = {};
 	char errmsg[STRERR_BUFSIZE];
+	int pid = args->pid;
 	int type, pfd, err;
 
 	if (ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS))
@@ -9643,7 +9652,7 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
 			libbpf_strerror_r(type, errmsg, sizeof(errmsg)));
 		return type;
 	}
-	if (retprobe) {
+	if (args->retprobe) {
 		int bit = uprobe ? determine_uprobe_retprobe_bit()
 				 : determine_kprobe_retprobe_bit();
 
@@ -9658,8 +9667,8 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
 	attr.size = sizeof(attr);
 	attr.type = type;
 	attr.config |= (__u64)ref_ctr_off << PERF_UPROBE_REF_CTR_OFFSET_SHIFT;
-	attr.config1 = ptr_to_u64(name); /* kprobe_func or uprobe_path */
-	attr.config2 = offset;		 /* kprobe_addr or probe_offset */
+	attr.config1 = ptr_to_u64(args->name); /* kprobe_func or uprobe_path */
+	attr.config2 = args->offset;		 /* kprobe_addr or probe_offset */
 
 	/* pid filter is meaningful only for uprobes */
 	pfd = syscall(__NR_perf_event_open, &attr,
@@ -9791,9 +9800,15 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 
 	legacy = determine_kprobe_perf_type() < 0;
 	if (!legacy) {
-		pfd = perf_event_open_probe(false /* uprobe */, retprobe,
-					    func_name, offset,
-					    -1 /* pid */, 0 /* ref_ctr_off */);
+		struct perf_event_open_args args = {
+			.retprobe = retprobe,
+			.name = func_name,
+			.offset = offset,
+			.pid = -1,
+			.ref_ctr_off = 0,
+		};
+
+		pfd = perf_event_open_probe(false /* uprobe */, &args);
 	} else {
 		char probe_name[256];
 
@@ -9984,8 +9999,15 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 
 	legacy = determine_uprobe_perf_type() < 0;
 	if (!legacy) {
-		pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path,
-					    func_offset, pid, ref_ctr_off);
+		struct perf_event_open_args args = {
+			.retprobe = retprobe,
+			.name = binary_path,
+			.offset = func_offset,
+			.pid = pid,
+			.ref_ctr_off = ref_ctr_off,
+		};
+
+		pfd = perf_event_open_probe(true /* uprobe */, &args);
 	} else {
 		char probe_name[512];
 
-- 
2.33.1