From 2bf16bddd7ec09ec8d5cde6aac274c8c8a9fc603 Mon Sep 17 00:00:00 2001 From: Pawan Gupta Date: Tue, 12 Mar 2024 15:40:44 -0700 Subject: [PATCH] x86/entry_32: Add VERW just before userspace transition commit a0e2dab44d22b913b4c228c8b52b2a104434b0b3 upstream. As done for entry_64, add support for executing VERW late in exit to user path for 32-bit mode. Signed-off-by: Pawan Gupta Signed-off-by: Dave Hansen Link: https://lore.kernel.org/all/20240213-delay-verw-v8-3-a6216d83edb7%40linux.intel.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/entry/entry_32.S | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 10b7c62a3..97d422f31 100755 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -949,6 +949,7 @@ SYM_FUNC_START(entry_SYSENTER_32) BUG_IF_WRONG_CR3 no_user_check=1 popfl popl %eax + CLEAR_CPU_BUFFERS /* * Return back to the vDSO, which will pop ecx and edx. @@ -1021,6 +1022,7 @@ restore_all_switch_stack: /* Restore user state */ RESTORE_REGS pop=4 # skip orig_eax/error_code + CLEAR_CPU_BUFFERS .Lirq_return: /* * ARCH_HAS_MEMBARRIER_SYNC_CORE rely on IRET core serialization @@ -1219,6 +1221,7 @@ SYM_CODE_START(asm_exc_nmi) /* Not on SYSENTER stack. */ call exc_nmi + CLEAR_CPU_BUFFERS jmp .Lnmi_return .Lnmi_from_sysenter_stack: