On Wed, Dec 2, 2020 at 4:20 PM Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote: > > ebiederm@xxxxxxxxxxxx (Eric W. Biederman) writes: > > > Oleg Nesterov recently asked[1] why is there an unshare_files in > > do_coredump. After digging through all of the callers of lookup_fd it > > turns out that it is > > arch/powerpc/platforms/cell/spufs/coredump.c:coredump_next_context > > that needs the unshare_files in do_coredump. > > > > Looking at the history[2] this code was also the only piece of coredump code > > that required the unshare_files when the unshare_files was added. > > > > Looking at that code it turns out that cell is also the only > > architecture that implements elf_coredump_extra_notes_size and > > elf_coredump_extra_notes_write. > > > > I looked at the gdb repo[3] support for cell has been removed[4] in binutils > > 2.34. Geoff Levand reports he is still getting questions on how to > > run modern kernels on the PS3, from people using 3rd party firmware so > > this code is not dead. According to Wikipedia the last PS3 shipped in > > Japan sometime in 2017. So it will probably be a little while before > > everyone's hardware dies. > > > > Add some comments briefly documenting the coredump code that exists > > only to support cell spufs to make it easier to understand the > > coredump code. Eventually the hardware will be dead, or their won't > > be userspace tools, or the coredump code will be refactored and it > > will be too difficult to update a dead architecture and these comments > > make it easy to tell where to pull to remove cell spufs support. > > > > [1] https://lkml.kernel.org/r/20201123175052.GA20279@xxxxxxxxxx > > [2] 179e037fc137 ("do_coredump(): make sure that descriptor table isn't shared") > > [3] git://sourceware.org/git/binutils-gdb.git > > [4] abf516c6931a ("Remove Cell Broadband Engine debugging support"). > > Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> > > --- > > > > Does this change look good to people? I think it captures this state of > > things and makes things clearer without breaking anything or removing > > functionality for anyone. > > I haven't heard anything except a general ack to the concept of > comments. So I am applying this. > Sorry I missed it when you originally sent it. Looks good ot me, Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
