On Saturday 18 April 2015 21:24:19 Arnd Bergmann wrote: > Given Catalin's comments from yesterday, I think we can just fix the > definitions of 'struct stat64' for asm-generic to make it have the same > layout as the 64-bit version of 'struct stat', and use that for aarch64-ilp32. > > Similarly for the four sysvipc headers, we can have a modified version of > the asm-generic ones in arch/arm64/uapi/asm, which will use the same layout > for ilp32 and lp64 without having to set __kernel_ulong_t to 64-bit.
To pick up that earlier thread, I now have a prototype implementation for converting all 32-bit architectures to use 64-bit time_t. For 'struct stat', I ended up introducing a new structure on arm32 that matches the layout of arm64 (and I did the same for all other 32-bit architectures that have a 64-bit counterpart). This means we can share the same system calls between arm64-lp64, arm64-ilp32 and arm32 with 64-bit time_t and arm64-aarch32 emulation for 32-bit time_t, while using the existing compat handling for the original 'struct stat' emulation in both arm32 and arm64-aarch32. However, for ipc, the situation is different: I found a way to use extra padding fields in semid64_ds/shmid64_ds/msqid64_ds, so the ipc system calls will still use normal 32-bit data structures on arm32 and arm64-aarch64, but you cannot use them arm64-ilp32, and will have to #ifdef the three header files there to choose between the two implementations. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/