site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Our disk kext is seeing a random kernel panic when simply calling writeBytes with an IOMemoryDescriptor. ... status = requestBuffer->prepare(); if ( status != kIOReturnSuccess ) { // Exit } requestBuffer->writeBytes( 0, buffer, bufferLength ); requestBuffer->complete(); ... The system where we are seeing this crash is using software RAID. The back trace shows IOMemoryDescripor::writeBytes (an address in AppleRAID) IOGeneralMemoryDescriptor::getPhysicalSegment IOGeneralMemoryDescriptor::dmaCommandOperation and then panic. The kext is simply copy data that was retrieved from the disk into the memory descriptor. The source buffer is from another memory descriptor. This descriptor was created using IOBufferMemoryDescriptor::inTaskWithPhysicalMask. The physical mask limits the memory to the 32b range. It seems like the AppleRAID driver is using a custom memory descriptor (which is reasonable and common) but is not handling some situation that we are presenting to it. Any ideas what we could be doing wrong here? Thanks, ...Duane -----BEGIN PGP SIGNATURE----- Version: PGP Desktop 9.10.0 (Build 500) Charset: US-ASCII wsBVAwUBSpbEz0rg9acQ4r2CAQj7rAgAhNGLR0tQAafylic7/CJu6H1J23ODHnlA moc7X8LNHM5jARLh1XqZU+arlt6oGahgvQAJM6v85NpNUVGTg07jG8kRNoXAz9pk hD99Yjl6IT4d5Hhse7HmU+u4teajrGqpQWJpom6hM01qx30WRw1ikR2/kTlHtHmm D4VvLxyxxP8RiigpS64GDbU8z1SYiCIVhjFhfLyKl/dhUM0H5ArO3AYjOlmvXKlP GcT+uqNsYWUrFqhH/XUU0Idwc4iEAbiJEL7o4WB5hsq/w/jyw1xZCm1O3vUMe6vy 82Eyd4OQe6+0Cr3pBOsoiAtYIbU2Mqc4oZZzUChaFc6uZWRfOQxZMQ== =erqH -----END PGP SIGNATURE----- _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... This email sent to site_archiver@lists.apple.com