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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-12 12:13:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-12 12:13:36 -0700
commit5c2fb57af0f42550eb718a3b0b445c81ec923895 (patch)
treebf0493dc247f07554a66302b653f6a7f7bdc0da4
parent923ea1631e942f8af179ca418e0cc1915025e4c2 (diff)
parent2a9e5ded9543436620a7fbc9329ddcc32bf97bc7 (diff)
downloadlwn-5c2fb57af0f42550eb718a3b0b445c81ec923895.tar.gz
lwn-5c2fb57af0f42550eb718a3b0b445c81ec923895.zip
Merge tag 'printk-for-5.8-kdb-nmi' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk fix from Petr Mladek: "One more printk change for 5.8: make sure that messages printed from KDB context are redirected to KDB console handlers. It did not work when KDB interrupted NMI or printk_safe contexts. Arm people started hitting this problem more often recently. I forgot to add the fix into the previous pull request by mistake" * tag 'printk-for-5.8-kdb-nmi' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk/kdb: Redirect printk messages into kdb in any context
-rw-r--r--kernel/printk/printk.c14
-rw-r--r--kernel/printk/printk_safe.c7
2 files changed, 8 insertions, 13 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 3132d6f860a8..8c14835be46c 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -35,7 +35,6 @@
#include <linux/memblock.h>
#include <linux/syscalls.h>
#include <linux/crash_core.h>
-#include <linux/kdb.h>
#include <linux/ratelimit.h>
#include <linux/kmsg_dump.h>
#include <linux/syslog.h>
@@ -2047,18 +2046,7 @@ EXPORT_SYMBOL(vprintk);
int vprintk_default(const char *fmt, va_list args)
{
- int r;
-
-#ifdef CONFIG_KGDB_KDB
- /* Allow to pass printk() to kdb but avoid a recursion. */
- if (unlikely(kdb_trap_printk && kdb_printf_cpu < 0)) {
- r = vkdb_printf(KDB_MSGSRC_PRINTK, fmt, args);
- return r;
- }
-#endif
- r = vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args);
-
- return r;
+ return vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args);
}
EXPORT_SYMBOL_GPL(vprintk_default);
diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index 4242403316bb..50aeae770434 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -6,6 +6,7 @@
#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>
@@ -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.