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authorJiri Kosina <jkosina@suse.cz>2020-09-01 14:19:48 +0200
committerJiri Kosina <jkosina@suse.cz>2020-09-01 14:19:48 +0200
commitead5d1f4d877e92c051e1a1ade623d0d30e71619 (patch)
treecb9db5698a546e7b96f7d5bef5ce544629dd37a2 /kernel/printk/printk_safe.c
parentf53fa968a7344970b8f8a5707c39cdcf17a6f367 (diff)
parentb51594df17d0ce80b9f9f35394a1f42d7ac94472 (diff)
Merge branch 'master' into for-next
Sync with Linus' branch in order to be able to apply fixups of more recent patches.
Diffstat (limited to 'kernel/printk/printk_safe.c')
-rw-r--r--kernel/printk/printk_safe.c27
1 files changed, 13 insertions, 14 deletions
diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index 08a8bf778990..e95d2a517244 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -6,10 +6,12 @@
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/debug_locks.h>
+#include <linux/kdb.h>
#include <linux/smp.h>
#include <linux/cpumask.h>
#include <linux/irq_work.h>
#include <linux/printk.h>
+#include <linux/kprobes.h>
#include "internal.h"
@@ -27,7 +29,6 @@
* There are situations when we want to make sure that all buffers
* were handled or when IRQs are blocked.
*/
-static int printk_safe_irq_ready __read_mostly;
#define SAFE_LOG_BUF_LEN ((1 << CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT) - \
sizeof(atomic_t) - \
@@ -51,7 +52,7 @@ static DEFINE_PER_CPU(struct printk_safe_seq_buf, nmi_print_seq);
/* Get flushed in a more safe context. */
static void queue_flush_work(struct printk_safe_seq_buf *s)
{
- if (printk_safe_irq_ready)
+ if (printk_percpu_data_ready())
irq_work_queue(&s->work);
}
@@ -294,14 +295,14 @@ 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_or(printk_context, PRINTK_NMI_CONTEXT_MASK);
+ this_cpu_add(printk_context, PRINTK_NMI_CONTEXT_OFFSET);
}
-void notrace printk_nmi_exit(void)
+void noinstr printk_nmi_exit(void)
{
- this_cpu_and(printk_context, ~PRINTK_NMI_CONTEXT_MASK);
+ this_cpu_sub(printk_context, PRINTK_NMI_CONTEXT_OFFSET);
}
/*
@@ -360,6 +361,12 @@ void __printk_safe_exit(void)
__printf(1, 0) int vprintk_func(const char *fmt, va_list args)
{
+#ifdef CONFIG_KGDB_KDB
+ /* Allow to pass printk() to kdb but avoid a recursion. */
+ if (unlikely(kdb_trap_printk && kdb_printf_cpu < 0))
+ return vkdb_printf(KDB_MSGSRC_PRINTK, fmt, args);
+#endif
+
/*
* Try to use the main logbuf even in NMI. But avoid calling console
* drivers that might have their own locks.
@@ -402,14 +409,6 @@ void __init printk_safe_init(void)
#endif
}
- /*
- * In the highly unlikely event that a NMI were to trigger at
- * this moment. Make sure IRQ work is set up before this
- * variable is set.
- */
- barrier();
- printk_safe_irq_ready = 1;
-
/* Flush pending messages that did not have scheduled IRQ works. */
printk_safe_flush();
}