On 15 June 2011 15:32, Richard Henderson <[email protected]> wrote: > On 06/15/2011 01:35 AM, Alexander Graf wrote: >>> - abi_ulong arg5 = 0, arg6 = 0, arg7 = 0, arg8 = 0; >>> + abi_ulong arg5 = 0, arg6 = 0; >>> >>> nb_args = mips_syscall_args[syscall_num]; >>> sp_reg = env->active_tc.gpr[29]; >>> switch (nb_args) { >>> /* these arguments are taken from the stack */ >>> /* FIXME - what to do if get_user() fails? */ >>> - case 8: get_user_ual(arg8, sp_reg + 28); >>> - case 7: get_user_ual(arg7, sp_reg + 24); >>> + case 8: /* get_user_ual(arg8, sp_reg + 28); */ >>> + case 7: /* get_user_ual(arg7, sp_reg + 24); */ >> >> I'd prefer to see these and the respective variable definitions #if >> 0'd with a comment, stating that they're currently unused. > > I'd prefer not to see if 0 code. Better, I think, to mark the > variables as __attribute__((unused)) with that same comment.
Ideally what we ought to be doing here is actually plumbing arg7 and arg8 through to do_syscall(). Two syscalls in the table, sys_fadvise64_64 and sys_sync_file_range, take 7 arguments (and we can deduce that they're misimplemented in do_syscall() for 32 bit MIPS targets, probably by not gluing together two 32 bit arguments into a 64 bit value to pass to the libc function); arg8 is needed in order to be able to invoke these 7 argument syscalls via sys_syscall. (sys_syscall's entry in the mips_syscall_args[] array says it takes zero arguments, which I think is just broken.) Actually fixing the 7-argument syscalls is a bit out of scope, but I think widening do_syscall() to take 8 arguments is straightforward enough. (Incidentally this whole code looks a bit 32 bit specific, do we support 64 bit mips targets in linux-user mode ?) -- PMM -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
