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authorPeter Zijlstra <peterz@infradead.org>2020-02-24 22:25:03 +0100
committerThomas Gleixner <tglx@linutronix.de>2020-05-19 15:51:16 +0200
commitb0f51883f551b900a04a80f49fb0886caf7e9a12 (patch)
tree4de0c3f992cd9381608c90b847473322a32cfa21 /kernel/printk/printk_safe.c
parent8c4e93c362ff114def211d4629b120af86eb1275 (diff)
printk: Disallow instrumenting print_nmi_enter()
It happens early in nmi_enter(), no tracing, probing or other funnies allowed. Specifically as nmi_enter() will be used in do_debug(), which would cause recursive exceptions when kprobed. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Link: https://lkml.kernel.org/r/20200505134101.139720912@linutronix.de
Diffstat (limited to 'kernel/printk/printk_safe.c')
-rw-r--r--kernel/printk/printk_safe.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index e8791f206417..4242403316bb 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -10,6 +10,7 @@
#include <linux/cpumask.h>
#include <linux/irq_work.h>
#include <linux/printk.h>
+#include <linux/kprobes.h>
#include "internal.h"
@@ -293,12 +294,12 @@ static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args)
return printk_safe_log_store(s, fmt, args);
}
-void notrace printk_nmi_enter(void)
+void noinstr printk_nmi_enter(void)
{
this_cpu_add(printk_context, PRINTK_NMI_CONTEXT_OFFSET);
}
-void notrace printk_nmi_exit(void)
+void noinstr printk_nmi_exit(void)
{
this_cpu_sub(printk_context, PRINTK_NMI_CONTEXT_OFFSET);
}