CVS commit: src/sys/opencrypto

["Kengo NAKAHARA" <knakahara%netbsd.org@localhost>]

Module Name:    src
Committed By:   knakahara
Date:           Fri Apr  7 12:15:51 UTC 2017

Modified Files:
        src/sys/opencrypto: cryptodev.c cryptodev.h

Log Message:
fix race among crypto_done(), cryptoret(), and {cryptodev_op(), cryptodev_key()}.

crypto_op() waited to be set CRYPTO_F_DONE with crp->crp_cv.
However, there is context switch chances between being set CRYPTO_F_DONE in
crypto_done() and done cv_signal(crp->crp_cv) in cryptodev_cb(), that is,
cryptodev_op() thread can run to cv_destroy(crp->crp_cv) before cryptoret()
thread is waken up. As a result, cryptodev_cb() can call invalid(destroyed)
cv_signal(crp->crp_cv).

Furthermore, below two implementations cause other races.
    - waiting CRYPTO_F_DONE with crp->crp_cv
    - context witch chances between set CRYPTO_F_DONE and cv_signal(crp->crp_cv)

So, use other flag(CRYPTO_F_DQRETQ) for cryptodev_op() and cryptodev_key(),
and then call cv_signal(crp->crp_cv) immediately after set CRYPTO_F_DQRETQ.

Tested concurrent over 20 processes with software and hardware drivers.


To generate a diff of this commit:
cvs rdiff -u -r1.86 -r1.87 src/sys/opencrypto/cryptodev.c
cvs rdiff -u -r1.29 -r1.30 src/sys/opencrypto/cryptodev.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.