On Sun, Sep 20, 2020 at 5:15 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > On Fri, Sep 18, 2020 at 02:45:25PM +0200, Christoph Hellwig wrote: > > Add a flag to force processing a syscall as a compat syscall. This is > > required so that in_compat_syscall() works for I/O submitted by io_uring > > helper threads on behalf of compat syscalls. > > Al doesn't like this much, but my suggestion is to introduce two new > opcodes -- IORING_OP_READV32 and IORING_OP_WRITEV32. The compat code > can translate IORING_OP_READV to IORING_OP_READV32 and then the core > code can know what that user pointer is pointing to. How is that different from the current approach of storing the ABI as a flag in ctx->compat? Arnd