Commit 3986f65d authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

kvm/emulate: Fix SETcc emulation for ENDBR 



Companion patch for commit fe83f5ea ("kvm/emulate: Fix SETcc
emulation function offsets with SLS"), now extending it to cover the
additional ENDBR instruction.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/YjMVpfe%2f9ldmWX8W@hirez.programming.kicks-ass.net
parent b9067cd8

arch/x86/kvm/emulate.c

+6 −4
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/stringify.h>

#include <asm/debugreg.h>

#include <asm/nospec-branch.h>

#include <asm/ibt.h>



#include "x86.h"

#include "tss.h"
@@ -434,15 +435,16 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop); 
/*

 * Depending on .config the SETcc functions look like:

 *

 * ENDBR       [4 bytes; CONFIG_X86_KERNEL_IBT]

 * SETcc %al   [3 bytes]

 * RET         [1 byte]

 * INT3        [1 byte; CONFIG_SLS]

 *

 * Which gives possible sizes 4 or 5.  When rounded up to the

 * next power-of-two alignment they become 4 or 8.

 * Which gives possible sizes 4, 5, 8 or 9.  When rounded up to the

 * next power-of-two alignment they become 4, 8 or 16 resp.

 */

#define SETCC_LENGTH	(4 + IS_ENABLED(CONFIG_SLS))

#define SETCC_ALIGN	(4 << IS_ENABLED(CONFIG_SLS))

#define SETCC_LENGTH	(ENDBR_INSN_SIZE + 4 + IS_ENABLED(CONFIG_SLS))

#define SETCC_ALIGN	(4 << IS_ENABLED(CONFIG_SLS) << HAS_KERNEL_IBT)

static_assert(SETCC_LENGTH <= SETCC_ALIGN);



#define FOP_SETCC(op) \