On Mon, 25 Sept 2023 at 15:04, Christian Brauner <brauner@xxxxxxxxxx> wrote: > > On Mon, Sep 25, 2023 at 02:57:31PM +0200, Arnd Bergmann wrote: > > On Wed, Sep 13, 2023, at 17:22, Miklos Szeredi wrote: > > > > > asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, > > > struct statfs64 __user *buf); > > > +asmlinkage long sys_statmnt(u64 mnt_id, u64 mask, > > > + struct statmnt __user *buf, size_t bufsize, > > > + unsigned int flags); > > > > This definition is problematic on 32-bit architectures for two > > reasons: > > > > - 64-bit register arguments are passed in pairs of registers > > on two architectures, so anything passing those needs to > > have a separate entry point for compat syscalls on 64-bit > > architectures. I would suggest also using the same one on > > 32-bit ones, so you don't rely on the compiler splitting > > up the long arguments into pairs. > > > > - There is a limit of six argument registers for system call > > entry points, but with two pairs and three single registers > > you end up with seven of them. > > > > The listmnt syscall in patch 3 also has the first problem, > > but not the second. > > Both fields could also just be moved into the struct itself just like we > did for clone3() and others. Let's not mix in and out args, please. How about passing u64 *? Thanks, Miklos
