Messages in this thread | | | From | Andy Lutomirski <> | Date | Mon, 7 Dec 2015 15:23:01 -0800 | Subject | Re: [PATCH v2 1/4] x86/signal/64: Add a comment about sigcontext->fs and gs |
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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.
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