At exit_intr, we GET_THREAD_INFO(%rcx) and then jump to retint_kernel if saved CS was from kernel. But code at retint_kernel doesn't need %rcx.
Move GET_THREAD_INFO(%rcx) down, after CS check and branch. While at it, remove "has a correct top of stack" comment. After recent changes which eliminated FIXUP_TOP_OF_STACK, we always have correct pt_regs layout. Signed-off-by: Denys Vlasenko <[email protected]> CC: Linus Torvalds <[email protected]> CC: Steven Rostedt <[email protected]> CC: Ingo Molnar <[email protected]> CC: Borislav Petkov <[email protected]> CC: "H. Peter Anvin" <[email protected]> CC: Andy Lutomirski <[email protected]> CC: Oleg Nesterov <[email protected]> CC: Frederic Weisbecker <[email protected]> CC: Alexei Starovoitov <[email protected]> CC: Will Drewry <[email protected]> CC: Kees Cook <[email protected]> CC: [email protected] CC: [email protected] --- arch/x86/kernel/entry_64.S | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 290ecb3..16bf357 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -654,13 +654,12 @@ ret_from_intr: CFI_ADJUST_CFA_OFFSET RBP exit_intr: - GET_THREAD_INFO(%rcx) testl $3,CS(%rsp) je retint_kernel - /* Interrupt came from user space */ + + GET_THREAD_INFO(%rcx) /* - * Has a correct top of stack. * %rcx: thread info. Interrupts off. */ retint_with_reschedule: -- 1.8.1.4 -- 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/
