Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag
From: Al Viro <viro@zeniv.linux.org.uk>
Date: 2020-09-19 23:24:28
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io-uring, keyrings, linux-arch, linux-arm-kernel, linux-block, linux-fsdevel, linux-mips, linux-mm, linux-s390, linux-scsi, linux-security-module, lkml, netdev, sparclinux
On Sat, Sep 19, 2020 at 03:53:40PM -0700, Andy Lutomirski wrote:
quoted
It would not be a win - most of the syscalls don't give a damn about 32bit vs. 64bit...Any reasonable implementation would optimize it out for syscalls that don’t care. Or it could be explicit: DEFINE_MULTIARCH_SYSCALL(...)
1) what would that look like? 2) have you counted the syscalls that do and do not need that? 3) how many of those realistically *can* be unified with their compat counterparts? [hint: ioctl(2) cannot]