The buffer is used by virtio console driver as DMA buffer. Since v4.9
(if VMAP_STACK is enabled) we shouldn't use the stack for DMA.
Signed-off-by: Jan Dakinevich <jan.dakinevich@xxxxxxxxx>
---
drivers/tty/hvc/hvc_console.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index 9b5c0fb..1ce6aaf 100644
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c
@@ -143,10 +143,15 @@ static struct hvc_struct *hvc_get_by_index(int index)
static void hvc_console_print(struct console *co, const char *b,
unsigned count)
{
- char c[N_OUTBUF] __ALIGNED__;
unsigned i = 0, n = 0;
int r, donecr = 0, index = co->index;
+ /*
+ * Access to the buffer is serialized by console_sem in caller code from
+ * kernel/printk/printk.c
+ */
+ static char c[N_OUTBUF] __ALIGNED__;
+
/* Console access attempt outside of acceptable console range. */
if (index >= MAX_NR_HVC_CONSOLES)
return;
--
1.9.1
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