On Friday 08 January 2010 11:03:47 Christoph Hellwig wrote: > On Fri, Jan 08, 2010 at 10:50:23AM +0100, Christoph Hellwig wrote: > > Always return -EINVAL for the iBCS2 special case in SHMAT, and add a > > prototype to linux/syscalls.h ok, the changes look good. > Add a generic implementation of the ipc demultiplexer syscall. Except for > s390 and sparc64 all implementations of the sys_ipc are nearly identical. I think the s390 version is trivial to add as well, like SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second, unsigned long, third, void __user *, ptr) { if (call == SEMTIMEDOP) return sys_semtimedop(first, (struct sembuf __user *)ptr, (unsigned) second, (const struct timespec __user *)third); return sys_ipc(call & 0xffff, first, second, third, ptr, 0); } But while going over the code again, I noticed that you broke sign extension at least on powerpc and s390, possibly on all 64 bit machines: > +SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, int, second, > + unsigned long, third, void __user *, ptr, long, fifth) > +{ > + int version, ret; > + > + version = call >> 16; /* hack for backward compatibility */ > + call &= 0xffff; > + > + switch (call) { > + case SEMOP: > + return sys_semtimedop(first, (struct sembuf __user *)ptr, > + second, NULL); (unsigned)second, NULL > + case SEMTIMEDOP: > + return sys_semtimedop(first, (struct sembuf __user *)ptr, > + second, (unsigned)second, > + (const struct timespec __user *)fifth); > + > + case SEMGET: > + return sys_semget(first, second, third); (int)second, > + case SEMCTL: { > + union semun fourth; > + if (!ptr) > + return -EINVAL; > + if (get_user(fourth.__pad, (void __user * __user *) ptr)) > + return -EFAULT; > + return sys_semctl(first, second, third, fourth); return sys_semctl(first, (int)second, third, fourth); > + case MSGSND: > + return sys_msgsnd(first, (struct msgbuf __user *) ptr, > + second, third); (size_t)second, third); > + case MSGRCV: > + switch (version) { > + case 0: { > + struct ipc_kludge tmp; > + if (!ptr) > + return -EINVAL; > + > + if (copy_from_user(&tmp, > + (struct ipc_kludge __user *) ptr, > + sizeof(tmp))) > + return -EFAULT; > + return sys_msgrcv(first, tmp.msgp, second, return sys_msgrcv(first, tmp.msgp, (size_t)second, > + tmp.msgtyp, third); > + } > + default: > + return sys_msgrcv(first, > + (struct msgbuf __user *) ptr, > + second, fifth, third); (size_t)second, fifth, third); > + } > + case MSGGET: > + return sys_msgget((key_t) first, second); return sys_msgget((key_t) first, (int)second); > + case MSGCTL: > + return sys_msgctl(first, second, (struct msqid_ds __user *)ptr); return sys_msgctl(first, (int)second, (struct msqid_ds __user *)ptr); > + case SHMAT: > + switch (version) { > + default: { > + unsigned long raddr; > + ret = do_shmat(first, (char __user *)ptr, > + second, &raddr); (int)second, &raddr); > + if (ret) > + return ret; > + return put_user(raddr, (unsigned long __user *) third); > + } > + case 1: > + /* > + * This was the entry point for kernel-originating calls > + * from iBCS2 in 2.2 days. > + */ > + return -EINVAL; > + } > + case SHMDT: > + return sys_shmdt((char __user *)ptr); > + case SHMGET: > + return sys_shmget(first, second, third); (size_t)second, &raddr); > + case SHMCTL: > + return sys_shmctl(first, second, return sys_shmctl(first, (int)second, > + (struct shmid_ds __user *) ptr); > + default: > + return -ENOSYS; > + } > +} This is needed to make sure the upper half of the register is filled with zero-extended or sign-extended correctly and does not contain random garbage in the native 64 bit case. IIRC, x86_64 does not have this problem and mips64 may have the wrong code already. Alpha, parisc and ia64 don't have a native sys_ipc and the rest are 32 bit, so they don't care. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html