Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 18bc9b5..e676a99 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
@@ -21,19 +22,21 @@
#include <linux/ratelimit.h>
#include <linux/slab.h>
#include <linux/export.h>
+#include <linux/atomic.h>
#include <linux/sched/clock.h>
#if defined(CONFIG_EDAC)
#include <linux/edac.h>
#endif
-#include <linux/atomic.h>
+#include <asm/cpu_entry_area.h>
#include <asm/traps.h>
#include <asm/mach_traps.h>
#include <asm/nmi.h>
#include <asm/x86_init.h>
#include <asm/reboot.h>
#include <asm/cache.h>
+#include <asm/nospec-branch.h>
#define CREATE_TRACE_POINTS
#include <trace/events/nmi.h>
@@ -487,11 +490,31 @@
* switch back to the original IDT.
*/
static DEFINE_PER_CPU(int, update_debug_stack);
+
+static bool notrace is_debug_stack(unsigned long addr)
+{
+ struct cea_exception_stacks *cs = __this_cpu_read(cea_exception_stacks);
+ unsigned long top = CEA_ESTACK_TOP(cs, DB);
+ unsigned long bot = CEA_ESTACK_BOT(cs, DB1);
+
+ if (__this_cpu_read(debug_stack_usage))
+ return true;
+ /*
+ * Note, this covers the guard page between DB and DB1 as well to
+ * avoid two checks. But by all means @addr can never point into
+ * the guard page.
+ */
+ return addr >= bot && addr < top;
+}
+NOKPROBE_SYMBOL(is_debug_stack);
#endif
dotraplinkage notrace void
do_nmi(struct pt_regs *regs, long error_code)
{
+ if (IS_ENABLED(CONFIG_SMP) && cpu_is_offline(smp_processor_id()))
+ return;
+
if (this_cpu_read(nmi_state) != NMI_NOT_RUNNING) {
this_cpu_write(nmi_state, NMI_LATCHED);
return;
@@ -533,6 +556,9 @@
write_cr2(this_cpu_read(nmi_cr2));
if (this_cpu_dec_return(nmi_state))
goto nmi_restart;
+
+ if (user_mode(regs))
+ mds_user_clear_cpu_buffers();
}
NOKPROBE_SYMBOL(do_nmi);