Jakub Kicinski 79ffe6087e net/tls: add a TX lock ... TLS TX needs to release and re-acquire the socket lock if send buffer fills up. TLS SW TX path currently depends on only allowing one thread to enter the function by the abuse of sk_write_pending. If another writer is already waiting for memory no new ones are allowed in. This has two problems: - writers don't wake other threads up when they leave the kernel; meaning that this scheme works for single extra thread (second application thread or delayed work) because memory becoming available will send a wake up request, but as Mallesham and Pooja report with larger number of threads it leads to threads being put to sleep indefinitely; - the delayed work does not get _scheduled_ but it may _run_ when other writers are present leading to crashes as writers don't expect state to change under their feet (same records get pushed and freed multiple times); it's hard to reliably bail from the work, however, because the mere presence of a writer does not guarantee that the writer will push pending records before exiting. Ensuring wakeups always happen will make the code basically open code a mutex. Just use a mutex. The TLS HW TX path does not have any locking (not even the sk_write_pending hack), yet it uses a per-socket sg_tx_data array to push records. Fixes: a42055e8d2 ("net/tls: Add support for async encryption of records for performance") Reported-by: Mallesham Jatharakonda <mallesh537@gmail.com> Reported-by: Pooja Trivedi <poojatrivedi@gmail.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2019-11-06 17:33:32 -08:00
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Kconfig
Makefile
tls_device_fallback.c
tls_device.c	net/tls: add a TX lock	2019-11-06 17:33:32 -08:00
tls_main.c	net/tls: add a TX lock	2019-11-06 17:33:32 -08:00
tls_sw.c	net/tls: add a TX lock	2019-11-06 17:33:32 -08:00