From f051f697955049c7cf10a635ab8149aa619243b2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 6 Apr 2020 15:55:06 +0200 Subject: x86/nmi: Protect NMI entry against instrumentation Mark all functions in the fragile code parts noinstr or force inlining so they can't be instrumented. Also make the hardware latency tracer invocation explicit outside of non-instrumentable section. Signed-off-by: Thomas Gleixner Reviewed-by: Alexandre Chartre Acked-by: Peter Zijlstra Acked-by: Andy Lutomirski Link: https://lkml.kernel.org/r/20200505135314.716186134@linutronix.de --- arch/x86/kernel/cpu/common.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'arch/x86/kernel/cpu') diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8be042df12c3..f4645f9ff9cb 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1709,21 +1709,19 @@ void syscall_init(void) DEFINE_PER_CPU(int, debug_stack_usage); DEFINE_PER_CPU(u32, debug_idt_ctr); -void debug_stack_set_zero(void) +noinstr void debug_stack_set_zero(void) { this_cpu_inc(debug_idt_ctr); load_current_idt(); } -NOKPROBE_SYMBOL(debug_stack_set_zero); -void debug_stack_reset(void) +noinstr void debug_stack_reset(void) { if (WARN_ON(!this_cpu_read(debug_idt_ctr))) return; if (this_cpu_dec_return(debug_idt_ctr) == 0) load_current_idt(); } -NOKPROBE_SYMBOL(debug_stack_reset); #else /* CONFIG_X86_64 */ -- cgit v1.2.3