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

Groups > linux.kernel > #1286100

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

Show all headers | View raw

On Oct 31, 2015 8:25 AM, "Stas Sergeev" <stsp@list.ru> wrote:
>
> 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?

There's a bunch of ongoing work about FS and GS.  I want to wait and see.
--
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 | Find similar | Unroll thread

Thread

Re: [PATCH v2 1/4] x86/signal/64: Add a comment about sigcontext->fs  and gs Andy Lutomirski <luto@amacapital.net> - 2015-12-08 00:30 +0100

csiph-web