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From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andriin@fb.com>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"KP Singh" <kpsingh@chromium.org>, "Daniel Xu" <dxu@dxuuu.xyz>,
	"Steven Rostedt" <rostedt@goodmis.org>,
	"Jesper Brouer" <jbrouer@redhat.com>,
	"Toke Høiland-Jørgensen" <toke@redhat.com>,
	"Viktor Malik" <vmalik@redhat.com>
Subject: [RFC bpf-next 01/16] ftrace: Add check_direct_entry function
Date: Thu, 22 Oct 2020 10:21:23 +0200	[thread overview]
Message-ID: <20201022082138.2322434-2-jolsa@kernel.org> (raw)
In-Reply-To: <20201022082138.2322434-1-jolsa@kernel.org>

Move code that checks on valid direct ip into separate
check_direct_entry function. It will be used in following
patches, there's no functional change.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 kernel/trace/ftrace.c | 55 +++++++++++++++++++++++++------------------
 1 file changed, 32 insertions(+), 23 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8185f7240095..27e9210073d3 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5025,6 +5025,36 @@ struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
 	return NULL;
 }
 
+static int check_direct_ip(unsigned long ip)
+{
+	struct dyn_ftrace *rec;
+
+	/* See if there's a direct function at @ip already */
+	if (ftrace_find_rec_direct(ip))
+		return -EBUSY;
+
+	rec = lookup_rec(ip, ip);
+	if (!rec)
+		return -ENODEV;
+
+	/*
+	 * Check if the rec says it has a direct call but we didn't
+	 * find one earlier?
+	 */
+	if (WARN_ON(rec->flags & FTRACE_FL_DIRECT))
+		return -ENODEV;
+
+	/* Make sure the ip points to the exact record */
+	if (ip != rec->ip) {
+		ip = rec->ip;
+		/* Need to check this ip for a direct. */
+		if (ftrace_find_rec_direct(ip))
+			return -EBUSY;
+	}
+
+	return 0;
+}
+
 /**
  * register_ftrace_direct - Call a custom trampoline directly
  * @ip: The address of the nop at the beginning of a function
@@ -5047,35 +5077,14 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
 	struct ftrace_direct_func *direct;
 	struct ftrace_func_entry *entry;
 	struct ftrace_hash *free_hash = NULL;
-	struct dyn_ftrace *rec;
 	int ret = -EBUSY;
 
 	mutex_lock(&direct_mutex);
 
-	/* See if there's a direct function at @ip already */
-	if (ftrace_find_rec_direct(ip))
-		goto out_unlock;
-
-	ret = -ENODEV;
-	rec = lookup_rec(ip, ip);
-	if (!rec)
-		goto out_unlock;
-
-	/*
-	 * Check if the rec says it has a direct call but we didn't
-	 * find one earlier?
-	 */
-	if (WARN_ON(rec->flags & FTRACE_FL_DIRECT))
+	ret = check_direct_ip(ip);
+	if (ret)
 		goto out_unlock;
 
-	/* Make sure the ip points to the exact record */
-	if (ip != rec->ip) {
-		ip = rec->ip;
-		/* Need to check this ip for a direct. */
-		if (ftrace_find_rec_direct(ip))
-			goto out_unlock;
-	}
-
 	ret = -ENOMEM;
 	if (ftrace_hash_empty(direct_functions) ||
 	    direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
-- 
2.26.2


  reply	other threads:[~2020-10-22  8:21 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-22  8:21 [RFC bpf-next 00/16] bpf: Speed up trampoline attach Jiri Olsa
2020-10-22  8:21 ` Jiri Olsa [this message]
2020-10-22  8:21 ` [RFC bpf-next 02/16] ftrace: Add adjust_direct_size function Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 03/16] ftrace: Add get/put_direct_func function Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 04/16] ftrace: Add ftrace_set_filter_ips function Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 05/16] ftrace: Add register_ftrace_direct_ips function Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 06/16] ftrace: Add unregister_ftrace_direct_ips function Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 07/16] kallsyms: Use rb tree for kallsyms name search Jiri Olsa
2020-10-28 18:25   ` Jiri Olsa
2020-10-28 21:15     ` Alexei Starovoitov
2020-10-29  9:29       ` Jiri Olsa
2020-10-29 22:45         ` Andrii Nakryiko
2020-10-28 22:40     ` Andrii Nakryiko
2020-10-29  9:33       ` Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 08/16] bpf: Use delayed link free in bpf_link_put Jiri Olsa
2020-10-23 19:46   ` Andrii Nakryiko
2020-10-25 19:02     ` Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 09/16] bpf: Add BPF_TRAMPOLINE_BATCH_ATTACH support Jiri Olsa
2020-10-22 11:55   ` kernel test robot
2020-10-22 11:57   ` kernel test robot
2020-10-23 20:03   ` Andrii Nakryiko
2020-10-23 20:31     ` Steven Rostedt
2020-10-23 22:23       ` Andrii Nakryiko
2020-10-25 19:41         ` Jiri Olsa
2020-10-26 23:19           ` Andrii Nakryiko
2020-10-22  8:21 ` [RFC bpf-next 10/16] bpf: Add BPF_TRAMPOLINE_BATCH_DETACH support Jiri Olsa
2020-10-22 13:00   ` kernel test robot
2020-10-22 13:04   ` kernel test robot
2020-10-22  8:21 ` [RFC bpf-next 11/16] bpf: Sync uapi bpf.h to tools Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 12/16] bpf: Move synchronize_rcu_mult for batch processing (NOT TO BE MERGED) Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 13/16] libbpf: Add trampoline batch attach support Jiri Olsa
2020-10-23 20:09   ` Andrii Nakryiko
2020-10-25 19:11     ` Jiri Olsa
2020-10-26 23:15       ` Andrii Nakryiko
2020-10-27 19:03         ` Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 14/16] libbpf: Add trampoline batch detach support Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 15/16] selftests/bpf: Add trampoline batch test Jiri Olsa
2020-10-22  8:21 ` [RFC bpf-next 16/16] selftests/bpf: Add attach batch test (NOT TO BE MERGED) Jiri Olsa
2020-10-22 13:35 ` [RFC bpf-next 00/16] bpf: Speed up trampoline attach Steven Rostedt
2020-10-22 14:11   ` Jiri Olsa
2020-10-22 14:42     ` Steven Rostedt
2020-10-22 16:21       ` Steven Rostedt
2020-10-22 20:52         ` Steven Rostedt
2020-10-23  6:09           ` Jiri Olsa
2020-10-23 13:50             ` Steven Rostedt
2020-10-25 19:01               ` Jiri Olsa
2020-10-27  4:30       ` Alexei Starovoitov
2020-10-27 13:14         ` Steven Rostedt
2020-10-27 14:28         ` Jiri Olsa
2020-10-28 21:13           ` Alexei Starovoitov
2020-10-29 11:09             ` Jiri Olsa

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