[tip: x86/core] x86/ibt,paravirt: Sprinkle ENDBR

["tip-bot2 for Peter Zijlstra" <tip-bot2@linutronix.de>]

The following commit has been merged into the x86/core branch of tip:

Commit-ID:     c3b037917c6a4cbb09ab2d6ccf19f02335ad1847
Gitweb:        https://git.kernel.org/tip/c3b037917c6a4cbb09ab2d6ccf19f02335ad1847
Author:        Peter Zijlstra <peterz@infradead.org>
AuthorDate:    Tue, 08 Mar 2022 16:30:26 +01:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Tue, 15 Mar 2022 10:32:36 +01:00

x86/ibt,paravirt: Sprinkle ENDBR

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154318.051635891@infradead.org
---
 arch/x86/include/asm/paravirt.h           | 1 +
 arch/x86/include/asm/qspinlock_paravirt.h | 3 +++
 arch/x86/kernel/kvm.c                     | 3 ++-
 arch/x86/kernel/paravirt.c                | 2 ++
 4 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 0d76502..964442b 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -666,6 +666,7 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu);
 	    ".globl " PV_THUNK_NAME(func) ";"				\
 	    ".type " PV_THUNK_NAME(func) ", @function;"			\
 	    PV_THUNK_NAME(func) ":"					\
+	    ASM_ENDBR							\
 	    FRAME_BEGIN							\
 	    PV_SAVE_ALL_CALLER_REGS					\
 	    "call " #func ";"						\
diff --git a/arch/x86/include/asm/qspinlock_paravirt.h b/arch/x86/include/asm/qspinlock_paravirt.h
index 1474cf9..892fd8c 100644
--- a/arch/x86/include/asm/qspinlock_paravirt.h
+++ b/arch/x86/include/asm/qspinlock_paravirt.h
@@ -2,6 +2,8 @@
 #ifndef __ASM_QSPINLOCK_PARAVIRT_H
 #define __ASM_QSPINLOCK_PARAVIRT_H
 
+#include <asm/ibt.h>
+
 /*
  * For x86-64, PV_CALLEE_SAVE_REGS_THUNK() saves and restores 8 64-bit
  * registers. For i386, however, only 1 32-bit register needs to be saved
@@ -39,6 +41,7 @@ asm    (".pushsection .text;"
 	".type " PV_UNLOCK ", @function;"
 	".align 4,0x90;"
 	PV_UNLOCK ": "
+	ASM_ENDBR
 	FRAME_BEGIN
 	"push  %rdx;"
 	"mov   $0x1,%eax;"
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index d77481e..79e0b8d 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -1029,10 +1029,11 @@ asm(
 ".global __raw_callee_save___kvm_vcpu_is_preempted;"
 ".type __raw_callee_save___kvm_vcpu_is_preempted, @function;"
 "__raw_callee_save___kvm_vcpu_is_preempted:"
+ASM_ENDBR
 "movq	__per_cpu_offset(,%rdi,8), %rax;"
 "cmpb	$0, " __stringify(KVM_STEAL_TIME_preempted) "+steal_time(%rax);"
 "setne	%al;"
-"ret;"
+ASM_RET
 ".size __raw_callee_save___kvm_vcpu_is_preempted, .-__raw_callee_save___kvm_vcpu_is_preempted;"
 ".popsection");
 
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 6ecbbb0..7ca2d46 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -41,6 +41,7 @@ extern void _paravirt_nop(void);
 asm (".pushsection .entry.text, \"ax\"\n"
      ".global _paravirt_nop\n"
      "_paravirt_nop:\n\t"
+     ASM_ENDBR
      ASM_RET
      ".size _paravirt_nop, . - _paravirt_nop\n\t"
      ".type _paravirt_nop, @function\n\t"
@@ -50,6 +51,7 @@ asm (".pushsection .entry.text, \"ax\"\n"
 asm (".pushsection .entry.text, \"ax\"\n"
      ".global paravirt_ret0\n"
      "paravirt_ret0:\n\t"
+     ASM_ENDBR
      "xor %" _ASM_AX ", %" _ASM_AX ";\n\t"
      ASM_RET
      ".size paravirt_ret0, . - paravirt_ret0\n\t"