Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1260012

Re: [PATCH v2 1/4] x86/signal/64: Add a comment about sigcontext->fs and gs

Show all headers | View raw

26.10.2015 04:25, Andy Lutomirski пишет:
> These fields have a strange history.  This tries to document it.
>
> This borrows from 9a036b93a344 ("x86/signal/64: Remove 'fs' and 'gs'
> from sigcontext"), which was reverted by ed596cde9425 ("Revert x86
> sigcontext cleanups").
>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
Now the strategy about SS is to always save it to the sigcontext.
This is good because the syscall can clobber it, so the app had
to be very careful in the past trying to save it by hands.
How about saving also fs and gs? (without restoring yet)
If you do, you'll save dosemu a headache of doing any "pre-syscall"
work. Pre-syscall work is very nasty.
I haven't checked if the syscall clobber also these or only SS,
but perhaps saving them by the kernel won't hurt?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH v2 0/4] x86: sigcontext fixes, again Andy Lutomirski <luto@kernel.org> - 2015-10-26 02:30 +0100
  [PATCH v2 2/4] x86/signal/64: Fix SS if needed when delivering a 64-bit signal Andy Lutomirski <luto@kernel.org> - 2015-10-26 02:30 +0100
  [PATCH v2 1/4] x86/signal/64: Add a comment about sigcontext->fs and gs Andy Lutomirski <luto@kernel.org> - 2015-10-26 02:30 +0100
    Re: [PATCH v2 1/4] x86/signal/64: Add a comment about sigcontext->fs  and gs Stas Sergeev <stsp@list.ru> - 2015-10-31 16:30 +0100
  [PATCH v2 3/4] x86/signal/64: Re-add support for SS in the 64-bit signal context Andy Lutomirski <luto@kernel.org> - 2015-10-26 02:30 +0100
    Re: [PATCH v2 3/4] x86/signal/64: Re-add support for SS in the 64-bit  signal context Stas Sergeev <stsp@list.ru> - 2015-10-31 16:20 +0100
  [PATCH v2 4/4] selftests/x86: Add tests for UC_SIGCONTEXT_SS and UC_STRICT_RESTORE_SS Andy Lutomirski <luto@kernel.org> - 2015-10-26 02:30 +0100
  Re: [PATCH v2 0/4] x86: sigcontext fixes, again Stas Sergeev <stsp@list.ru> - 2015-10-26 12:50 +0100
    Re: [PATCH v2 0/4] x86: sigcontext fixes, again Andy Lutomirski <luto@amacapital.net> - 2015-10-27 02:00 +0100
      Re: [PATCH v2 0/4] x86: sigcontext fixes, again Linus Torvalds <torvalds@linux-foundation.org> - 2015-10-27 23:40 +0100
        Re: [PATCH v2 0/4] x86: sigcontext fixes, again Toshi Kani <toshi.kani@hpe.com> - 2015-10-28 01:10 +0100
          Re: [PATCH v2 0/4] x86: sigcontext fixes, again Stas Sergeev <stsp@list.ru> - 2015-10-28 11:00 +0100
            Re: [PATCH v2 0/4] x86: sigcontext fixes, again Toshi Kani <toshi.kani@hpe.com> - 2015-10-28 17:40 +0100
              Re: [PATCH v2 0/4] x86: sigcontext fixes, again Toshi Kani <toshi.kani@hpe.com> - 2015-10-28 20:30 +0100
                Re: [PATCH v2 0/4] x86: sigcontext fixes, again Toshi Kani <toshi.kani@hpe.com> - 2015-10-29 00:00 +0100
                Re: [PATCH v2 0/4] x86: sigcontext fixes, again Stas Sergeev <stsp@list.ru> - 2015-10-31 13:50 +0100
                Re: [PATCH v2 0/4] x86: sigcontext fixes, again Toshi Kani <toshi.kani@hpe.com> - 2015-11-02 18:10 +0100
      Re: [PATCH v2 0/4] x86: sigcontext fixes, again Andy Lutomirski <luto@amacapital.net> - 2015-10-31 01:00 +0100

csiph-web