x86/spec_ctrl: Add missing IBRS_DISABLE

.. which was missing when the system call is done before
the IBRS.

Orabug: 27365403

Reported-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Signed-off-by: Kirtikar Kashyap <kirtikar.kashyap@oracle.com>

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 507bf55f518c4e7e85abf30f3d9292bdcdc68dc0..b0b13f6ed83275804088b2204009e95a60921b3d 100644 (file)
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -307,6 +307,7 @@ system_call_fastpath:
        CFI_REGISTER    rip,rcx
        movq    EFLAGS(%rsp),%r11
        /*CFI_REGISTER  rflags,r11*/
+       DISABLE_IBRS
        RESTORE_C_REGS_EXCEPT_RCX_R11
        /*
         * This opens a window where we have a user CR3, but are