pstore: Avoid recursive spinlocks in the oops_in_progress case

Like 8250 driver, when pstore is registered as a console,
to avoid recursive spinlocks when panic happening, change the
spin_lock_irqsave to spin_trylock_irqsave when oops_in_progress
is true.

Signed-off-by: liu chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 6c23eab7f76c..a40da07e93d6 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -164,7 +164,13 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c)
 
                 if (c > psinfo->bufsize)
                         c = psinfo->bufsize;
-                spin_lock_irqsave(&psinfo->buf_lock, flags);
+
+                if (oops_in_progress) {
+                        if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
+                                break;
+                } else {
+                        spin_lock_irqsave(&psinfo->buf_lock, flags);
+                }
                 memcpy(psinfo->buf, s, c);
                 psinfo->write(PSTORE_TYPE_CONSOLE, 0, NULL, 0, c, psinfo);
                 spin_unlock_irqrestore(&psinfo->buf_lock, flags);