Commit fc220d6be3c7 ("virtio_console: refactor __send_to_port() buffer
ownership") added a .gfp argument to alloc_buf(), but forgot to convert
all allocation calls.

The result is that any GFP_ATOMIC calls, such as those from:

  hvc_console_print()
    put_chars()
      alloc_buf(.gfp = GFP_ATOMIC)

will trip the might_sleep_if() check when used from an atomic context.

Fixes: fc220d6be3c7 ("virtio_console: refactor __send_to_port() buffer
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 62eecfa61646..7f6cbe851d1e 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -426,7 +426,7 @@ static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size
 	 * Allocate buffer and the sg list. The sg list array is allocated
 	 * directly after the port_buffer struct.
 	 */
-	buf = kmalloc_flex(*buf, sg, pages);
+	buf = kmalloc_flex(*buf, sg, pages, gfp);
 	if (!buf)
 		goto fail;

On Fri, Aug 28, 2026 at 05:37:06PM +0200, Peter Zijlstra wrote:
> 
> Commit fc220d6be3c7 ("virtio_console: refactor __send_to_port() buffer
> ownership") added a .gfp argument to alloc_buf(), but forgot to convert
> all allocation calls.
> 
> The result is that any GFP_ATOMIC calls, such as those from:
> 
>   hvc_console_print()
>     put_chars()
>       alloc_buf(.gfp = GFP_ATOMIC)
> 
> will trip the might_sleep_if() check when used from an atomic context.
> 
> Fixes: fc220d6be3c7 ("virtio_console: refactor __send_to_port() buffer
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> 

Sorry for the delay, I took this earlier patch instead:
	https://lore.kernel.org/r/20260810-serial-v1-1-abbe51602c13@debian.org

On Fri, Aug 28, 2026 at 05:37:06PM +0200, Peter Zijlstra wrote:
> 
> Commit fc220d6be3c7 ("virtio_console: refactor __send_to_port() buffer
> ownership") added a .gfp argument to alloc_buf(), but forgot to convert
> all allocation calls.
> 
> The result is that any GFP_ATOMIC calls, such as those from:
> 
>   hvc_console_print()
>     put_chars()
>       alloc_buf(.gfp = GFP_ATOMIC)
> 
> will trip the might_sleep_if() check when used from an atomic context.
> 
> Fixes: fc220d6be3c7 ("virtio_console: refactor __send_to_port() buffer
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> 
> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> index 62eecfa61646..7f6cbe851d1e 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -426,7 +426,7 @@ static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size
>  	 * Allocate buffer and the sg list. The sg list array is allocated
>  	 * directly after the port_buffer struct.
>  	 */
> -	buf = kmalloc_flex(*buf, sg, pages);
> +	buf = kmalloc_flex(*buf, sg, pages, gfp);
>  	if (!buf)
>  		goto fail;
>  

Sorry about that, will grab it after -rc1 is out.

thanks,

greg k-h