On 20 December 2012 20:56, Laurent Vivier <laur...@vivier.eu> wrote: > This allows to pass the device name.
> +static void target_to_host_string (void *dst, const void *src) > +{ > +#if HOST_LONG_BITS == 32 && TARGET_ABI_BITS == 32 > + if (*(uint32_t*)src == 0) { > + *(uint32_t*)dst = 0; > + return; > + } > + *(uint32_t *)dst = (uint32_t)g2h(tswap32(*(uint32_t *)src)); > +#elif HOST_LONG_BITS == 64 && TARGET_ABI_BITS == 32 > + if (*(uint32_t*)src == 0) { > + *(uint64_t*)dst = 0; > + return; > + } > + *(uint64_t *)dst = (uint64_t)g2h(tswap32(*(uint32_t *)src)); > +#elif HOST_LONG_BITS == 64 && TARGET_ABI_BITS == 64 > + if (*(uint64_t*)src == 0) { > + *(uint64_t*)dst = 0; > + return; > + } > + *(uint64_t *)dst = (uint64_t)g2h(tswap64(*(uint64_t *)src)); > +#elif HOST_LONG_BITS == 32 && TARGET_ABI_BITS == 64 > + if (*(uint64_t*)src == 0) { > + *(uint32_t*)dst = 0; > + return; > + } > + *(uint32_t *)dst = (uint32_t)g2h(tswap64(*(uint64_t *)src)); > +#endif > +} > + > +static void host_to_target_string (void *dst, const void *src) > +{ > +#if HOST_LONG_BITS == 32 && TARGET_ABI_BITS == 32 > + if (*(uint32_t*)src == 0) { > + *(uint32_t*)dst = 0; > + return; > + } > + *(uint32_t *)dst = tswap32(h2g(*(uint32_t *)src)); > +#elif HOST_LONG_BITS == 64 && TARGET_ABI_BITS == 32 > + if (*(uint64_t*)src == 0) { > + *(uint32_t*)dst = 0; > + return; > + } > + *(uint32_t *)dst = tswap32(h2g(*(uint64_t *)src)); > +#elif HOST_LONG_BITS == 64 && TARGET_ABI_BITS == 64 > + if (*(uint64_t*)src == 0) { > + *(uint64_t*)dst = 0; > + return; > + } > + *(uint64_t *)dst = tswap64(h2g(*(uint64_t *)src)); > +#elif HOST_LONG_BITS == 32 && TARGET_ABI_BITS == 64 > + if (*(uint32_t*)src == 0) { > + *(uint64_t*)dst = 0; > + return; > + } > + *(uint64_t *)dst = tswap64(h2g(*(uint32_t *)src)); > +#endif > +} > + > +static const StructEntry struct_string_def = { > + .convert = { host_to_target_string, target_to_host_string }, > + .size = { sizeof(target_long), sizeof(long) }, > + .align = { __alignof__(target_long), __alignof__(long) }, > +}; This is the wrong approach, I'm afraid. Among other problems, you don't have anywhere to catch the case of being passed a bad pointer (should fail EFAULT). In general, the thunk_convert routines aren't designed to handle converting pointed-to data and your patch is abusing MK_STRUCT (which is for embedded structs, not pointed-to anything). Unless you feel like doing the redesign of the thunk conversion code, the right way to handle oddball ioctl parameters is to write a do_ioctl_fn for them (compare SIOCGIFCONF, for example). The kernel sources: http://lxr.linux.no/#linux+v3.7.1/net/socket.c#L3175 show that it always copies a fixed 15 bytes, incidentally. -- PMM