diff options
| author |   Peter Zijlstra <peterz@infradead.org> | 2020-02-24 22:25:03 +0100 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2020-05-19 15:51:16 +0200 |
| commit | b0f51883f551b900a04a80f49fb0886caf7e9a12 (patch) | |
| tree | 4de0c3f992cd9381608c90b847473322a32cfa21 /kernel/printk | |
| parent | printk: Prepare for nested printk_nmi_enter() (diff) | |
| download | wireguard-linux-b0f51883f551b900a04a80f49fb0886caf7e9a12.tar.xz wireguard-linux-b0f51883f551b900a04a80f49fb0886caf7e9a12.zip | |
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')
| -rw-r--r-- | kernel/printk/printk_safe.c | 5 |
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); } |