Messages in this thread | | | Date | Fri, 7 Sep 2018 10:00:41 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 2/3] x86/entry/64: Use the TSS sp2 slot for SYSCALL/SYSRET scratch space |
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On Mon, Sep 03, 2018 at 03:59:43PM -0700, Andy Lutomirski wrote: > In the non-trampoline SYSCALL64 path, we use a percpu variable to > temporarily store the user RSP value. Instead of a separate > variable, use the otherwise unused sp2 slot in the TSS. This will > improve cache locality, as the sp1 slot is already used in the same > code to find the kernel stack. It will also simplify a future > change to make the non-trampoline path work in PTI mode. > > Signed-off-by: Andy Lutomirski <luto@kernel.org> > --- > arch/x86/entry/entry_64.S | 16 +++++++++------- > arch/x86/include/asm/processor.h | 6 ++++++ > arch/x86/kernel/asm-offsets.c | 3 ++- > arch/x86/kernel/process_64.c | 2 -- > arch/x86/xen/xen-asm_64.S | 8 +++++--- > 5 files changed, 22 insertions(+), 13 deletions(-)
Reviewed-by: Borislav Petkov <bp@suse.de>
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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