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 <[email protected]>
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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
