Commit 01c97c73 authored by Juergen Gross's avatar Juergen Gross Committed by Borislav Petkov
Browse files

x86/mtrr: Add comment for set_mtrr_state() serialization 



Add a comment about set_mtrr_state() needing serialization.

  [ bp: Touchups. ]

Suggested-by: default avatarBorislav Petkov <bp@alien8.de>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220820092533.29420-2-jgross@suse.com
parent 1d30800c

arch/x86/kernel/cpu/mtrr/generic.c

+4 −1
Original line number Diff line number Diff line
@@ -684,7 +684,10 @@ static u32 deftype_lo, deftype_hi; 
/**

 * set_mtrr_state - Set the MTRR state for this CPU.

 *

 * NOTE: The CPU must already be in a safe state for MTRR changes.

 * NOTE: The CPU must already be in a safe state for MTRR changes, including

 *       measures that only a single CPU can be active in set_mtrr_state() in

 *       order to not be subject to races for usage of deftype_lo. This is

 *       accomplished by taking set_atomicity_lock.

 * RETURNS: 0 if no changes made, else a mask indicating what was changed.

 */

static unsigned long set_mtrr_state(void)