From: Samium Gromoff _deepfire@feelingofgreen.ru
From: Juho Snellman jsnell@iki.fi
Samium Gromoff _deepfire@feelingofgreen.ru writes:
Good day,
While debugging mysterious ioctl() failures in lh-usb on SBCL, I have discovered that using CFFI:WITH-POINTER-TO-VECTOR-DATA doesn't guarantee that the vector is in a writable region.
I thought we'd never write protect specialized raw arrays (either they are in the nursery, or they're tenured into an unboxed region which never get wpd). And passing generic arrays to ffi doesn't feel right. What's the use case?
Array element type is (unsigned-byte 8), use case is shovelling data in/out a USB device using bulk transfers via ioctl().
A missing detail: while the vector is created in a live core all /seems/ to be well[1]. But when it comes from a dumped core, it gets a chance (there doesn't appears to be a determinism there) of being in a write-protected region.
regards, Samium Gromoff -- 1. It might be just that I didn't have enough statistics, as I'm working mainly with cores of my own dumping. Eh, hehe.
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