Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
To:     mhiramat@kernel.org, oleg@redhat.com, peterz@infradead.org,
        srikar@linux.vnet.ibm.com, rostedt@goodmis.org
Cc:     acme@kernel.org, ananth@linux.vnet.ibm.com,
        akpm@linux-foundation.org, alexander.shishkin@linux.intel.com,
        alexis.berlemont@gmail.com, corbet@lwn.net,
        dan.j.williams@intel.com, jolsa@redhat.com, kan.liang@intel.com,
        kjlx@templeofstupid.com, kstewart@linuxfoundation.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, milian.wolff@kdab.com, mingo@redhat.com,
        namhyung@kernel.org, naveen.n.rao@linux.vnet.ibm.com,
        pc@us.ibm.com, tglx@linutronix.de, yao.jin@linux.intel.com,
        fengguang.wu@intel.com, jglisse@redhat.com,
        Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Subject: [PATCH v2 3/9] Uprobe: Move mmput() into free_map_info()
Date:   Wed,  4 Apr 2018 14:01:04 +0530
In-Reply-To: <20180404083110.18647-1-ravi.bangoria@linux.vnet.ibm.com>
References: <20180404083110.18647-1-ravi.bangoria@linux.vnet.ibm.com>
Message-Id: <20180404083110.18647-4-ravi.bangoria@linux.vnet.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Oleg Nesterov <oleg@redhat.com>

build_map_info() has a side effect like one need to perform
mmput() when done with the mm. Add mmput() in free_map_info()
so that user does not have to call it explicitly.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
---
 kernel/events/uprobes.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 535fd39..1d439c7 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -704,6 +704,7 @@ struct map_info {
 static inline struct map_info *free_map_info(struct map_info *info)
 {
 	struct map_info *next = info->next;
+	mmput(info->mm);
 	kfree(info);
 	return next;
 }
@@ -773,8 +774,11 @@ static inline struct map_info *free_map_info(struct map_info *info)
 
 	goto again;
  out:
-	while (prev)
-		prev = free_map_info(prev);
+	while (prev) {
+		info = prev;
+		prev = prev->next;
+		kfree(info);
+	}
 	return curr;
 }
 
@@ -824,7 +828,6 @@ static inline struct map_info *free_map_info(struct map_info *info)
  unlock:
 		up_write(&mm->mmap_sem);
  free:
-		mmput(mm);
 		info = free_map_info(info);
 	}
  out:
-- 
1.8.3.1