RE: [PATCH] Adds a new ioctl32 syscall for backwards compatibility layers
From: David Laight <hidden>
Date: 2021-01-17 18:33:37
Also in:
linux-api, linux-arm-kernel, linux-fsdevel, linux-s390, lkml
Possibly related (same subject, not in this thread)
- 2021-01-15 · Re: [PATCH] Adds a new ioctl32 syscall for backwards compatibility layers · Rich Felker <dalias@libc.org>
- 2021-01-15 · RE: [PATCH] Adds a new ioctl32 syscall for backwards compatibility layers · David Laight <hidden>
- 2021-01-15 · Re: [PATCH] Adds a new ioctl32 syscall for backwards compatibility layers · Arnd Bergmann <arnd@kernel.org>
- 2021-01-15 · RE: [PATCH] Adds a new ioctl32 syscall for backwards compatibility layers · David Laight <hidden>
- 2021-01-15 · [PATCH] Adds a new ioctl32 syscall for backwards compatibility layers · <hidden>
From: Christoph Hellwig
Sent: 16 January 2021 09:07
...
quoted
I personally would like to see in_compat_syscall() go away, but some other people (Hi, Christoph!) disagree, and usage seems to be increasing, not decreasing.I'm absolutely against it going away. in_compat_syscall helped to remove so much crap compared to the explicit compat syscalls.
The only other real option is to pass the 'syscall type' explicitly through all the layers into every piece of code that might need it. So passing it as a 'parameter' that is (probably) current->syscall_type does make sense. It might even make sense have separate bits for the required emulations. So you'd have separate bits for '32bit pointers' and '64bit items 32bit aligned' (etc). David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)