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kvm/emulate: Fix SETcc emulation for ENDBR

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Companion patch for commit fe83f5eae432 ("kvm/emulate: Fix SETcc
emulation function offsets with SLS"), now extending it to cover the
additional ENDBR instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/YjMVpfe%2f9ldmWX8W@hirez.programming.kicks-ass.net
This commit is contained in:
Peter Zijlstra 2022-03-21 10:13:12 +01:00
parent b9067cd80f
commit 3986f65d4f
1 changed files with 6 additions and 4 deletions
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10
arch/x86/kvm/emulate.c
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@ -24,6 +24,7 @@
#include <linux/stringify.h> #include <linux/stringify.h>
#include <asm/debugreg.h> #include <asm/debugreg.h>
#include <asm/nospec-branch.h> #include <asm/nospec-branch.h>
#include <asm/ibt.h>
#include "x86.h" #include "x86.h"
#include "tss.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: * Depending on .config the SETcc functions look like:
* *
* ENDBR [4 bytes; CONFIG_X86_KERNEL_IBT]
* SETcc %al [3 bytes] * SETcc %al [3 bytes]
* RET [1 byte] * RET [1 byte]
* INT3 [1 byte; CONFIG_SLS] * INT3 [1 byte; CONFIG_SLS]
* *
* Which gives possible sizes 4 or 5. When rounded up to the * Which gives possible sizes 4, 5, 8 or 9. When rounded up to the
* next power-of-two alignment they become 4 or 8. * next power-of-two alignment they become 4, 8 or 16 resp.
*/ */
#define SETCC_LENGTH (4 + IS_ENABLED(CONFIG_SLS)) #define SETCC_LENGTH (ENDBR_INSN_SIZE + 4 + IS_ENABLED(CONFIG_SLS))
#define SETCC_ALIGN (4 << IS_ENABLED(CONFIG_SLS)) #define SETCC_ALIGN (4 << IS_ENABLED(CONFIG_SLS) << HAS_KERNEL_IBT)
static_assert(SETCC_LENGTH <= SETCC_ALIGN); static_assert(SETCC_LENGTH <= SETCC_ALIGN);
#define FOP_SETCC(op) \ #define FOP_SETCC(op) \