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From: Jiri Olsa <jolsa@redhat.com>
To: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andriin@fb.com>
Subject: [PATCH 7/8] ftrace: Add multi direct modify interface
Date: Tue, 31 Aug 2021 11:50:16 +0200	[thread overview]
Message-ID: <20210831095017.412311-8-jolsa@kernel.org> (raw)
In-Reply-To: <20210831095017.412311-1-jolsa@kernel.org>

Adding interface to modify registered direct function
for ftrace_ops. Adding following function:

   modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)

The function changes the currently registered direct
function for all attached functions.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 include/linux/ftrace.h |  6 ++++++
 kernel/trace/ftrace.c  | 43 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index e40b5201c16e..f3ba6366f7af 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -318,6 +318,8 @@ int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
 unsigned long ftrace_find_rec_direct(unsigned long ip);
 int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
 int unregister_ftrace_direct_multi(struct ftrace_ops *ops);
+int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
+
 #else
 struct ftrace_ops;
 # define ftrace_direct_func_count 0
@@ -357,6 +359,10 @@ static inline int unregister_ftrace_direct_multi(struct ftrace_ops *ops)
 {
 	return -ENODEV;
 }
+static inline int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+	return -ENODEV;
+}
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
 
 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7243769493c9..59940a6a907c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5518,6 +5518,49 @@ int unregister_ftrace_direct_multi(struct ftrace_ops *ops)
 	return err;
 }
 EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi);
+
+int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+	struct ftrace_hash *hash = ops->func_hash->filter_hash;
+	struct ftrace_func_entry *entry, *iter;
+	int i, size;
+	int err;
+
+	if (check_direct_multi(ops))
+		return -EINVAL;
+	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+		return -EINVAL;
+
+	mutex_lock(&direct_mutex);
+	mutex_lock(&ftrace_lock);
+
+	/*
+	 * Shutdown the ops, change 'direct' pointer for each
+	 * ops entry in direct_functions hash and startup the
+	 * ops back again.
+	 */
+	err = ftrace_shutdown(ops, 0);
+	if (err)
+		goto out_unlock;
+
+	size = 1 << hash->size_bits;
+	for (i = 0; i < size; i++) {
+		hlist_for_each_entry(iter, &hash->buckets[i], hlist) {
+			entry = __ftrace_lookup_ip(direct_functions, iter->ip);
+			if (!entry)
+				continue;
+			entry->direct = addr;
+		}
+	}
+
+	err = ftrace_startup(ops, 0);
+
+ out_unlock:
+	mutex_unlock(&ftrace_lock);
+	mutex_unlock(&direct_mutex);
+	return err;
+}
+EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi);
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
 
 /**
-- 
2.31.1


  parent reply	other threads:[~2021-08-31  9:51 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-31  9:50 [PATCH 0/8] x86/ftrace: Add direct batch interface Jiri Olsa
2021-08-31  9:50 ` [PATCH 1/8] x86/ftrace: Remove extra orig rax move Jiri Olsa
2021-08-31  9:50 ` [PATCH 2/8] x86/ftrace: Remove fault protection code in prepare_ftrace_return Jiri Olsa
2021-08-31  9:50 ` [PATCH 3/8] x86/ftrace: Make function graph use ftrace directly Jiri Olsa
2021-08-31  9:50 ` [PATCH 4/8] tracing: Add trampoline/graph selftest Jiri Olsa
2021-08-31  9:50 ` [PATCH 5/8] ftrace: Add ftrace_add_rec_direct function Jiri Olsa
2021-08-31  9:50 ` [PATCH 6/8] ftrace: Add multi direct register/unregister interface Jiri Olsa
2021-09-14 21:35   ` Steven Rostedt
2021-09-16 19:45     ` Jiri Olsa
2021-08-31  9:50 ` Jiri Olsa [this message]
2021-09-14 21:41   ` [PATCH 7/8] ftrace: Add multi direct modify interface Steven Rostedt
2021-09-15 21:47     ` Steven Rostedt
2021-09-16 19:49       ` Jiri Olsa
2021-09-16 20:41         ` Steven Rostedt
2021-08-31  9:50 ` [PATCH 8/8] ftrace/samples: Add multi direct interface test module Jiri Olsa
2021-09-01 15:23 ` [PATCH 0/8] x86/ftrace: Add direct batch interface Alexei Starovoitov
2021-09-01 19:06   ` Jiri Olsa
2021-09-02 14:54     ` Steven Rostedt
2021-10-08  9:13 [PATCHv2 " Jiri Olsa
2021-10-08  9:13 ` [PATCH 7/8] ftrace: Add multi direct modify interface Jiri Olsa
2021-10-14 20:28   ` Steven Rostedt
2021-10-15 12:05     ` Jiri Olsa
2021-10-15 14:05       ` Steven Rostedt
2021-10-16 11:39         ` Jiri Olsa
2021-10-19  2:10           ` Steven Rostedt
2021-10-19 13:19             ` Jiri Olsa
2021-10-19 13:26               ` Jiri Olsa
2021-10-19 13:32                 ` Steven Rostedt
2021-10-19 14:03                   ` Jiri Olsa
2021-10-19 14:44                     ` Steven Rostedt
2021-10-19 14:47                       ` Jiri Olsa

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