Zitat von Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>:
On Thu, May 17, 2018 at 07:03:30PM +0200, Guido Kiener wrote:+/* + * usbtmc_message->flags: + */ +#define USBTMC_FLAG_ASYNC 0x0001 +#define USBTMC_FLAG_APPEND 0x0002 +#define USBTMC_FLAG_IGNORE_TRAILER 0x0004 + +struct usbtmc_message { + void __user *message; /* pointer to header and data */ + __u64 transfer_size; /* size of bytes to transfer */ + __u64 transferred; /* size of received/written bytes */ + __u32 flags; /* bit 0: 0 = synchronous; 1 = asynchronous */ +} __attribute__ ((packed));Very odd structure. Your userspace pointer is going to be totally out of alignment on 32bit systems running on a 64bit kernel. Why have a separate pointer at all? Why not just put the mesage at the end of this structure directly with something like: __u8 message[0]; ?
Oh yes, I should know that from another project. Indead we did not test it with 32 bit applications on 64 platforms. When we use your proposal then we just can use #define USBTMC_IOCTL_WRITE _IO(USBTMC_IOC_NR, 13)?
Much easier and you don't have to mess with the whole compatible ioctl thunking layer (which I think you ignored here, which means you all didn't test it...) thanks, greg k-h
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