[PATCH 05/39] x86/entry/32: Unshare NMI return path

From: Joerg Roedel
Date: Wed Jul 18 2018 - 05:41:29 EST


From: Joerg Roedel <jroedel@xxxxxxx>

NMI will no longer use most of the shared return path,
because NMI needs special handling when the CR3 switches for
PTI are added. This patch prepares for that.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
arch/x86/entry/entry_32.S | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index ef7d653..4364131 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1017,7 +1017,7 @@ ENTRY(nmi)

/* Not on SYSENTER stack. */
call do_nmi
- jmp .Lrestore_all_notrace
+ jmp .Lnmi_return

.Lnmi_from_sysenter_stack:
/*
@@ -1028,7 +1028,11 @@ ENTRY(nmi)
movl PER_CPU_VAR(cpu_current_top_of_stack), %esp
call do_nmi
movl %ebx, %esp
- jmp .Lrestore_all_notrace
+
+.Lnmi_return:
+ CHECK_AND_APPLY_ESPFIX
+ RESTORE_REGS 4
+ jmp .Lirq_return

#ifdef CONFIG_X86_ESPFIX32
.Lnmi_espfix_stack:
--
2.7.4