From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/kernel/printk/printk_safe.c | 34 +++++++++++++++-------------------
1 files changed, 15 insertions(+), 19 deletions(-)
diff --git a/kernel/kernel/printk/printk_safe.c b/kernel/kernel/printk/printk_safe.c
index 0dbc060..2e9e3ed 100644
--- a/kernel/kernel/printk/printk_safe.c
+++ b/kernel/kernel/printk/printk_safe.c
@@ -1,27 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* printk_safe.c - Safe printk for printk-deadlock-prone contexts
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#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"
@@ -32,7 +22,7 @@
* is later flushed into the main ring buffer via IRQ work.
*
* The alternative implementation is chosen transparently
- * by examinig current printk() context mask stored in @printk_context
+ * by examining current printk() context mask stored in @printk_context
* per-CPU variable.
*
* The implementation allows to flush the strings also from another CPU.
@@ -313,14 +303,14 @@
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);
}
/*
@@ -379,6 +369,12 @@
__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.
@@ -387,7 +383,7 @@
raw_spin_trylock(&logbuf_lock)) {
int len;
- len = vprintk_store(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args);
+ len = vprintk_store(0, LOGLEVEL_DEFAULT, NULL, fmt, args);
raw_spin_unlock(&logbuf_lock);
defer_console_output();
return len;
--
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