From: Michael Jeanson <mjeanson@efficios.com>
Date: Mon, 18 Mar 2019 20:20:36 +0000 (-0400)
Subject: Fix: atomic_long_add_unless() returns a boolean
X-Git-Tag: v2.11.0-rc5~19
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=5ad19305fc87a9928e787d888ab95b954ba80a9e;p=lttng-modules.git

Fix: atomic_long_add_unless() returns a boolean

Because of a documentation error in older kernels, it was assumed that
atomic_long_add_unless would return the old value, but the
implementation actually returns a boolean.

Also add missing error code int 'ret' and compare against the right type
max value.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/lttng-abi.c b/lttng-abi.c
index 0534472a..ca943791 100644
--- a/lttng-abi.c
+++ b/lttng-abi.c
@@ -419,8 +419,8 @@ int lttng_abi_create_channel(struct file *session_file,
 		transport_name = "<unknown>";
 		break;
 	}
-	if (atomic_long_add_unless(&session_file->f_count,
-		1, INT_MAX) == INT_MAX) {
+	if (!atomic_long_add_unless(&session_file->f_count, 1, LONG_MAX)) {
+		ret = -EOVERFLOW;
 		goto refcount_error;
 	}
 	/*
@@ -1072,8 +1072,7 @@ int lttng_abi_create_event(struct file *channel_file,
 		goto file_error;
 	}
 	/* The event holds a reference on the channel */
-	if (atomic_long_add_unless(&channel_file->f_count,
-		1, INT_MAX) == INT_MAX) {
+	if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
 		ret = -EOVERFLOW;
 		goto refcount_error;
 	}
diff --git a/lttng-events.c b/lttng-events.c
index 742bec4d..0d62f9fb 100644
--- a/lttng-events.c
+++ b/lttng-events.c
@@ -1141,8 +1141,8 @@ int lttng_session_list_tracker_pids(struct lttng_session *session)
 		ret = PTR_ERR(tracker_pids_list_file);
 		goto file_error;
 	}
-	if (atomic_long_add_unless(&session->file->f_count,
-		1, INT_MAX) == INT_MAX) {
+	if (!atomic_long_add_unless(&session->file->f_count, 1, LONG_MAX)) {
+		ret = -EOVERFLOW;
 		goto refcount_error;
 	}
 	ret = lttng_tracker_pids_list_fops.open(NULL, tracker_pids_list_file);