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author | Tyler Hicks <tyhicks@canonical.com> | 2012-06-11 10:21:34 -0700 |
---|---|---|
committer | Tyler Hicks <tyhicks@canonical.com> | 2012-07-03 16:34:10 -0700 |
commit | 60d65f1f07a7d81d3eb3b91fc13fca80f2fdbb12 (patch) | |
tree | f1551f13ab37a33d1ce9c4e1377823cea7256556 | |
parent | 9fe79d7600497ed8a95c3981cbe5b73ab98222f0 (diff) | |
download | linux-3.10-60d65f1f07a7d81d3eb3b91fc13fca80f2fdbb12.tar.gz linux-3.10-60d65f1f07a7d81d3eb3b91fc13fca80f2fdbb12.tar.bz2 linux-3.10-60d65f1f07a7d81d3eb3b91fc13fca80f2fdbb12.zip |
eCryptfs: Fix lockdep warning in miscdev operations
Don't grab the daemon mutex while holding the message context mutex.
Addresses this lockdep warning:
ecryptfsd/2141 is trying to acquire lock:
(&ecryptfs_msg_ctx_arr[i].mux){+.+.+.}, at: [<ffffffffa029c213>] ecryptfs_miscdev_read+0x143/0x470 [ecryptfs]
but task is already holding lock:
(&(*daemon)->mux){+.+...}, at: [<ffffffffa029c2ec>] ecryptfs_miscdev_read+0x21c/0x470 [ecryptfs]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&(*daemon)->mux){+.+...}:
[<ffffffff810a3b8d>] lock_acquire+0x9d/0x220
[<ffffffff8151c6da>] __mutex_lock_common+0x5a/0x4b0
[<ffffffff8151cc64>] mutex_lock_nested+0x44/0x50
[<ffffffffa029c5d7>] ecryptfs_send_miscdev+0x97/0x120 [ecryptfs]
[<ffffffffa029b744>] ecryptfs_send_message+0x134/0x1e0 [ecryptfs]
[<ffffffffa029a24e>] ecryptfs_generate_key_packet_set+0x2fe/0xa80 [ecryptfs]
[<ffffffffa02960f8>] ecryptfs_write_metadata+0x108/0x250 [ecryptfs]
[<ffffffffa0290f80>] ecryptfs_create+0x130/0x250 [ecryptfs]
[<ffffffff811963a4>] vfs_create+0xb4/0x120
[<ffffffff81197865>] do_last+0x8c5/0xa10
[<ffffffff811998f9>] path_openat+0xd9/0x460
[<ffffffff81199da2>] do_filp_open+0x42/0xa0
[<ffffffff81187998>] do_sys_open+0xf8/0x1d0
[<ffffffff81187a91>] sys_open+0x21/0x30
[<ffffffff81527d69>] system_call_fastpath+0x16/0x1b
-> #0 (&ecryptfs_msg_ctx_arr[i].mux){+.+.+.}:
[<ffffffff810a3418>] __lock_acquire+0x1bf8/0x1c50
[<ffffffff810a3b8d>] lock_acquire+0x9d/0x220
[<ffffffff8151c6da>] __mutex_lock_common+0x5a/0x4b0
[<ffffffff8151cc64>] mutex_lock_nested+0x44/0x50
[<ffffffffa029c213>] ecryptfs_miscdev_read+0x143/0x470 [ecryptfs]
[<ffffffff811887d3>] vfs_read+0xb3/0x180
[<ffffffff811888ed>] sys_read+0x4d/0x90
[<ffffffff81527d69>] system_call_fastpath+0x16/0x1b
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
-rw-r--r-- | fs/ecryptfs/miscdev.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c index 3a06f4043df..3c632ec412e 100644 --- a/fs/ecryptfs/miscdev.c +++ b/fs/ecryptfs/miscdev.c @@ -191,31 +191,32 @@ int ecryptfs_send_miscdev(char *data, size_t data_size, struct ecryptfs_msg_ctx *msg_ctx, u8 msg_type, u16 msg_flags, struct ecryptfs_daemon *daemon) { - int rc = 0; + struct ecryptfs_message *msg; - mutex_lock(&msg_ctx->mux); - msg_ctx->msg = kmalloc((sizeof(*msg_ctx->msg) + data_size), - GFP_KERNEL); - if (!msg_ctx->msg) { - rc = -ENOMEM; + msg = kmalloc((sizeof(*msg) + data_size), GFP_KERNEL); + if (!msg) { printk(KERN_ERR "%s: Out of memory whilst attempting " "to kmalloc(%zd, GFP_KERNEL)\n", __func__, - (sizeof(*msg_ctx->msg) + data_size)); - goto out_unlock; + (sizeof(*msg) + data_size)); + return -ENOMEM; } + + mutex_lock(&msg_ctx->mux); + msg_ctx->msg = msg; msg_ctx->msg->index = msg_ctx->index; msg_ctx->msg->data_len = data_size; msg_ctx->type = msg_type; memcpy(msg_ctx->msg->data, data, data_size); msg_ctx->msg_size = (sizeof(*msg_ctx->msg) + data_size); - mutex_lock(&daemon->mux); list_add_tail(&msg_ctx->daemon_out_list, &daemon->msg_ctx_out_queue); + mutex_unlock(&msg_ctx->mux); + + mutex_lock(&daemon->mux); daemon->num_queued_msg_ctx++; wake_up_interruptible(&daemon->wait); mutex_unlock(&daemon->mux); -out_unlock: - mutex_unlock(&msg_ctx->mux); - return rc; + + return 0; } /* |