On Thu, Dec 30, 2010 at 3:00 PM, Joseph S. Myers <jos...@codesourcery.com> wrote: > On Thu, 30 Dec 2010, H. Peter Anvin wrote: > >> On 12/30/2010 02:21 PM, Robert Millan wrote: >> > 2010/12/30 Richard Guenther <richard.guent...@gmail.com>: >> >> Would be nice if LFS would be mandatory on the new ABI, thus >> >> off_t being 64bits. >> > >> > Please do also consider time_t. >> > >> >> Changing the kernel-facing time_t might completely wreck the reuse of >> the i386 kernel ABI; I'm not sure. > > Before changing time_t for a new ILP32 ABI, you probably want to work out > what is required - on both the libc and kernel sides - to change it for > existing 32-bit ABIs (whether providing a new ABI variant like > _FILE_OFFSET_BITS does, or changing it unconditionally and using symbol > versioning for compatibility with old binaries built for 32-bit time_t). > Having done that you then have whatever new syscalls may be needed to work > with 64-bit time_t on IA32, and can make the new ILP32 ABI not use the old > 32-bit time_t syscalls if desired. > > Of course making LFS (or 64-bit time_t) mandatory doesn't help with those > interfaces that hardcode types such as "int" or "long" - you'll still have > code that uses fseek rather than fseeko, for example. If you follow the > GNU principles of avoiding arbitrary (or at least inappropriate) limits, > there are quite a lot of libc interfaces that can be problematic in > extreme cases (large files, strings over 2GB (e.g. regoff_t - glibc bug > 5945 - which is probably one of the easier cases), etc.). It would be > good to fix these things, both on the GNU principles and for general > robustness (there are probably various security holes related to these > issues - integer overflow issues are always tricky to avoid in C, but bad > choice of types in APIs certainly doesn't help), but it's quite tricky > (lots of core ISO C interfaces are involved) and really needs to be kept > separate from the introduction of new ABIs at the level of x86_64 ILP32. >
I am checking in ILP32 binutils so that people can play with it. -- H.J.
