Re: [PATCH 2/3] serial: Move LF -> CRLF replacement from serial console to kdb

[Daniel Thompson <daniel@riscstar.com>]

On Tue, Dec 10, 2024 at 05:34:47AM -0800, Amal Raj T wrote:
> From: Amal Raj T <amalrajt@meta.com>
>
> The current implementation of `poll_put_char` in the serial console driver
> performs LF -> CRLF replacement, which can corrupt binary data. Since kdb
> is the only user of `poll_put_char`, this patch moves the LF -> CRLF
> replacement logic to kdb.

This description only explains why it is safe to change
uart_poll_put_char() but...



> Link: https://lore.kernel.org/linux-debuggers/Zy093jVKPs9gSVx2@telecaster/
>
> Signed-off-by: Amal Raj T <amalrajt@meta.com>
> ---
>  drivers/tty/serial/serial_core.c | 4 ----
>  kernel/debug/kdb/kdb_io.c        | 2 ++
>  2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 74fa02b23772..ed18492b7f8f 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -2142,8 +2142,6 @@ void uart_console_write(struct uart_port *port, const char *s,
>  	unsigned int i;
>
>  	for (i = 0; i < count; i++, s++) {
> -		if (*s == '\n')
> -			putchar(port, '\r');
>  		putchar(port, *s);
>  	}
>  }

... kgdb isn't the only user of uart_console_write() though, right?


Daniel.