Date: Wed, 12 Apr 2017 16:07:03 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 218597] [CRYPTODEV] spurious wakeup and synchronisation problem Message-ID: <bug-218597-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D218597 Bug ID: 218597 Summary: [CRYPTODEV] spurious wakeup and synchronisation problem Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: alexandre.martins@stormshield.eu Created attachment 181725 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D181725&action= =3Dedit proposed patch I using a dual core ARMADA 38X platform that contains a CESA module to accelerate cryptography operations. I have some crashes when using the cryptodev through OpenSSL. The crash only happen when the following conditions are met: - Multi-core system is used - Hardware acceleration is used - Hardware acceleration perform an interruption to signal the operations completion That are the scenario, first: - A process ask a cryptographic operation - The crypto operation is send to the CESA - msleep is called, but the process seems to be migrated on another CPU, a= nd msleep return immediately (spurious wakeup) (I puted a KASSERT that check if the CRYPTO_F_DONE is present and it ris= e) - The operation looks like complete and memory is freed - The CESA performs the cryptographic operation on the freed memory that m= ay cause corruption in some other parts of the kernel. Second: - The call to crypto_dispatch is done, but the scheduler prempt the process before the lock on ces->lock is done - The CESA perform the operation and crypto_done is called by the ithread - The flag CRYPTO_F_DONE is put and scheduler preempt the ithread - The user process continue, take the lock and check the flag, that is present, and doesn't call msleep. - It free the memory, and return to the userland - The ithread is resumed and calls the callbacks that crash by accessing t= he freed memory. I attach my proposed patch to fix that issue --=20 You are receiving this mail because: You are the assignee for the bug.=
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