diff options
| author | Breno Leitao <leitao@debian.org> | 2023-03-08 11:07:45 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-22 13:33:43 +0100 |
| commit | 9180aa4622a720b433e842b4d3aa34d73eec577a (patch) | |
| tree | a0a095d4c7159626d97af37e6c80440ce7e7d6ee /drivers/vdpa | |
| parent | 6f93f5d6d7affa57860d285f8ec719a7a83ae14f (diff) | |
| download | linux-9180aa4622a720b433e842b4d3aa34d73eec577a.tar.gz linux-9180aa4622a720b433e842b4d3aa34d73eec577a.tar.bz2 linux-9180aa4622a720b433e842b4d3aa34d73eec577a.zip | |
tcp: tcp_make_synack() can be called from process context
[ Upstream commit bced3f7db95ff2e6ca29dc4d1c9751ab5e736a09 ]
tcp_rtx_synack() now could be called in process context as explained in
0a375c822497 ("tcp: tcp_rtx_synack() can be called from process
context").
tcp_rtx_synack() might call tcp_make_synack(), which will touch per-CPU
variables with preemption enabled. This causes the following BUG:
BUG: using __this_cpu_add() in preemptible [00000000] code: ThriftIO1/5464
caller is tcp_make_synack+0x841/0xac0
Call Trace:
<TASK>
dump_stack_lvl+0x10d/0x1a0
check_preemption_disabled+0x104/0x110
tcp_make_synack+0x841/0xac0
tcp_v6_send_synack+0x5c/0x450
tcp_rtx_synack+0xeb/0x1f0
inet_rtx_syn_ack+0x34/0x60
tcp_check_req+0x3af/0x9e0
tcp_rcv_state_process+0x59b/0x2030
tcp_v6_do_rcv+0x5f5/0x700
release_sock+0x3a/0xf0
tcp_sendmsg+0x33/0x40
____sys_sendmsg+0x2f2/0x490
__sys_sendmsg+0x184/0x230
do_syscall_64+0x3d/0x90
Avoid calling __TCP_INC_STATS() with will touch per-cpu variables. Use
TCP_INC_STATS() which is safe to be called from context switch.
Fixes: 8336886f786f ("tcp: TCP Fast Open Server - support TFO listeners")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230308190745.780221-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/vdpa')
0 files changed, 0 insertions, 0 deletions