On Wed, Sep 23, 2020 at 04:32:51PM +0200, Christoph Hellwig wrote: > On Wed, Sep 23, 2020 at 03:25:49PM +0100, Al Viro wrote: > > On Wed, Sep 23, 2020 at 08:05:43AM +0200, Christoph Hellwig wrote: > > > COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, > > > - const struct compat_iovec __user *,vec, > > > + const struct iovec __user *, vec, > > > > Um... Will it even compile? > > > > > #ifdef __ARCH_WANT_COMPAT_SYS_PREADV64 > > > COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd, > > > - const struct compat_iovec __user *,vec, > > > + const struct iovec __user *, vec, > > > > Ditto. Look into include/linux/compat.h and you'll see > > > > asmlinkage long compat_sys_preadv64(unsigned long fd, > > const struct compat_iovec __user *vec, > > unsigned long vlen, loff_t pos); > > > > How does that manage to avoid the compiler screaming bloody > > murder? > > That's a very good question. But it does not just compile but actually > works. Probably because all the syscall wrappers mean that we don't > actually generate the normal names. I just tried this: > > --- a/include/linux/syscalls.h > +++ b/include/linux/syscalls.h > @@ -468,7 +468,7 @@ asmlinkage long sys_lseek(unsigned int fd, off_t offset, > asmlinkage long sys_read(unsigned int fd, char __user *buf, size_t count); > asmlinkage long sys_write(unsigned int fd, const char __user *buf, > size_t count); > -asmlinkage long sys_readv(unsigned long fd, > +asmlinkage long sys_readv(void *fd, > > for fun, and the compiler doesn't care either.. Try to build it for sparc or ppc...
