diff options
Diffstat (limited to 'arch/x86/kernel/nmi.c')
| -rw-r--r-- | arch/x86/kernel/nmi.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 18bc9b51ac9b..4df7705022b9 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> @@ -487,6 +490,23 @@ static DEFINE_PER_CPU(unsigned long, nmi_cr2); * 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 @@ -533,6 +553,9 @@ nmi_restart: 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); |