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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
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        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
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        fengguang.wu@intel.com, jglisse@redhat.com,
        Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Subject: [PATCH v3 3/9] Uprobe: Move mmput() into free_map_info()
Date:   Tue, 17 Apr 2018 10:02:38 +0530
In-Reply-To: <20180417043244.7501-1-ravi.bangoria@linux.vnet.ibm.com>
References: <20180417043244.7501-1-ravi.bangoria@linux.vnet.ibm.com>
Message-Id: <20180417043244.7501-4-ravi.bangoria@linux.vnet.ibm.com>
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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.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