[PATCH 0/1] get_nr_restart_syscall() should return __NR_ia32_restart_syscall if __USER32_CS

[Oleg Nesterov]

Hello,

get_nr_restart_syscall() is still buggy, TS_I386_REGS_POKED can't
really help and should probably die.

The fix just adds the __USER32_CS check, but perhaps we can avoid
these "fundamentally broken" checks altogether?

Is __NR_ia32_restart_syscall/__NR_restart_syscall the part of ABI?
OK, we probaly can't remove them, at least right now. But what if
we simply add the new syscall number,

        #define __NR_new_restart_syscall        383
        #define __NR_ia32_new_restart_syscall   383

so that it doesn't depends on bitness and we can just do

        static inline unsigned long get_nr_restart_syscall(const struct pt_regs 
*regs)
        {
                BUILD_BUG_ON(__NR_ia32_new_restart_syscall != 
__NR_new_restart_syscall);
        #ifdef CONFIG_X86_X32_ABI
                return __NR_new_restart_syscall | (regs->orig_ax & 
__X32_SYSCALL_BIT);
        #else
                return __NR_new_restart_syscall;
        #endif
        }

?

Oleg.