fs: dlm: avoid false-positive checker warning
This patch avoid the false-positive checker warning about writing 112
bytes into a 88 bytes field "e->request", see:
[ 54.891560] dlm: csmb1: dlm_recover_directory 23 out 2 messages
[ 54.990542] ------------[ cut here ]------------
[ 54.991012] memcpy: detected field-spanning write (size 112) of single field "&e->request" at fs/dlm/requestqueue.c:47 (size 88)
[ 54.992150] WARNING: CPU: 0 PID: 297 at fs/dlm/requestqueue.c:47 dlm_add_requestqueue+0x177/0x180
[ 54.993002] CPU: 0 PID: 297 Comm: kworker/u4:3 Not tainted 6.1.0-rc5-00008-ge01d50cbd6ee #248
[ 54.993878] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-1.fc36 04/01/2014
[ 54.994718] Workqueue: dlm_recv process_recv_sockets
[ 54.995230] RIP: 0010:dlm_add_requestqueue+0x177/0x180
[ 54.995731] Code: e7 01 0f 85 3b ff ff ff b9 58 00 00 00 48 c7 c2 c0 41 74 82 4c 89 ee 48 c7 c7 20 42 74 82 c6 05 8b 8d 30 02 01 e8 51 07 be 00 <0f> 0b e9 12 ff ff ff 66 90 0f 1f 44 00 00 41 57 48 8d 87 10 08 00
[ 54.997483] RSP: 0018:
ffffc90000b1fbe8 EFLAGS:
00010282
[ 54.997990] RAX:
0000000000000000 RBX:
ffff888024fc3d00 RCX:
0000000000000000
[ 54.998667] RDX:
0000000000000001 RSI:
ffffffff81155014 RDI:
fffff52000163f73
[ 54.999342] RBP:
ffff88800dbac000 R08:
0000000000000001 R09:
ffffc90000b1fa5f
[ 54.999997] R10:
fffff52000163f4b R11:
203a7970636d656d R12:
ffff88800cfb0018
[ 55.000673] R13:
0000000000000070 R14:
ffff888024fc3d18 R15:
0000000000000000
[ 55.001344] FS:
0000000000000000(0000) GS:
ffff88806d600000(0000) knlGS:
0000000000000000
[ 55.002078] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[ 55.002603] CR2:
00007f35d4f0b9a0 CR3:
0000000025495002 CR4:
0000000000770ef0
[ 55.003258] PKRU:
55555554
[ 55.003514] Call Trace:
[ 55.003756] <TASK>
[ 55.003953] dlm_receive_buffer+0x1c0/0x200
[ 55.004348] dlm_process_incoming_buffer+0x46d/0x780
[ 55.004786] ? kernel_recvmsg+0x8b/0xc0
[ 55.005150] receive_from_sock.isra.0+0x168/0x420
[ 55.005582] ? process_listen_recv_socket+0x10/0x10
[ 55.006018] ? finish_task_switch.isra.0+0xe0/0x400
[ 55.006469] ? __switch_to+0x2fe/0x6a0
[ 55.006808] ? read_word_at_a_time+0xe/0x20
[ 55.007197] ? strscpy+0x146/0x190
[ 55.007505] process_one_work+0x3d0/0x6b0
[ 55.007863] worker_thread+0x8d/0x620
[ 55.008209] ? __kthread_parkme+0xd8/0xf0
[ 55.008565] ? process_one_work+0x6b0/0x6b0
[ 55.008937] kthread+0x171/0x1a0
[ 55.009251] ? kthread_exit+0x60/0x60
[ 55.009582] ret_from_fork+0x1f/0x30
[ 55.009903] </TASK>
[ 55.010120] ---[ end trace
0000000000000000 ]---
[ 55.025783] dlm: csmb1: dlm_recover 5 generation 3 done: 201 ms
[ 55.026466] gfs2: fsid=smbcluster:csmb1.0: recover generation 3 done
It seems the checker is unable to detect the additional length bytes
which was allocated additionally for the flexible array in struct
dlm_message. To solve it we split the memcpy() into copy for the 88 bytes
struct and another memcpy() for the flexible array m_extra field.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>