acrn-kernel/net/nfc
Duoming Zhou 4071bf121d NFC: netlink: fix sleep in atomic bug when firmware download timeout
There are sleep in atomic bug that could cause kernel panic during
firmware download process. The root cause is that nlmsg_new with
GFP_KERNEL parameter is called in fw_dnld_timeout which is a timer
handler. The call trace is shown below:

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:265
Call Trace:
kmem_cache_alloc_node
__alloc_skb
nfc_genl_fw_download_done
call_timer_fn
__run_timers.part.0
run_timer_softirq
__do_softirq
...

The nlmsg_new with GFP_KERNEL parameter may sleep during memory
allocation process, and the timer handler is run as the result of
a "software interrupt" that should not call any other function
that could sleep.

This patch changes allocation mode of netlink message from GFP_KERNEL
to GFP_ATOMIC in order to prevent sleep in atomic bug. The GFP_ATOMIC
flag makes memory allocation operation could be used in atomic context.

Fixes: 9674da8759 ("NFC: Add firmware upload netlink command")
Fixes: 9ea7187c53 ("NFC: netlink: Rename CMD_FW_UPLOAD to CMD_FW_DOWNLOAD")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220504055847.38026-1-duoming@zju.edu.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-05-05 10:18:15 +02:00
..
hci
nci
Kconfig
Makefile
af_nfc.c
core.c nfc: replace improper check device_is_registered() in netlink related functions 2022-05-01 13:26:05 +01:00
digital.h
digital_core.c
digital_dep.c
digital_technology.c
llcp.h
llcp_commands.c
llcp_core.c
llcp_sock.c
netlink.c NFC: netlink: fix sleep in atomic bug when firmware download timeout 2022-05-05 10:18:15 +02:00
nfc.h
rawsock.c