diff mbox series

[v2,04/11] io/channel-websock: Replace strlen(const_str) by sizeof(const_str) - 1

Message ID 20220819153931.3147384-5-peter.maydell@linaro.org
State Superseded
Headers show
Series misc: Remove variable-length arrays on the stack | expand

Commit Message

Peter Maydell Aug. 19, 2022, 3:39 p.m. UTC 
From: Philippe Mathieu-Daudé <philmd@redhat.com>

The combined_key[... QIO_CHANNEL_WEBSOCK_GUID_LEN ...] array in
qio_channel_websock_handshake_send_res_ok() expands to a call
to strlen(QIO_CHANNEL_WEBSOCK_GUID), and the compiler doesn't
realize the string is const, so consider combined_key[] being
a variable-length array.

To remove the variable-length array, we provide it a hint to
the compiler by using sizeof() - 1 instead of strlen().

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 io/channel-websock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Richard Henderson Oct. 24, 2022, 11:13 p.m. UTC | #1 
On 8/20/22 01:39, Peter Maydell wrote:
> From: Philippe Mathieu-Daudé<philmd@redhat.com>
> 
> The combined_key[... QIO_CHANNEL_WEBSOCK_GUID_LEN ...] array in
> qio_channel_websock_handshake_send_res_ok() expands to a call
> to strlen(QIO_CHANNEL_WEBSOCK_GUID), and the compiler doesn't
> realize the string is const, so consider combined_key[] being
> a variable-length array.
> 
> To remove the variable-length array, we provide it a hint to
> the compiler by using sizeof() - 1 instead of strlen().
> 
> Signed-off-by: Philippe Mathieu-Daudé<philmd@redhat.com>
> Reviewed-by: Daniel P. Berrangé<berrange@redhat.com>
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   io/channel-websock.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~
diff mbox series

Patch

diff --git a/io/channel-websock.c b/io/channel-websock.c
index 9619906ac36..fb4932ade70 100644
--- a/io/channel-websock.c
+++ b/io/channel-websock.c
@@ -32,7 +32,7 @@ 
 
 #define QIO_CHANNEL_WEBSOCK_CLIENT_KEY_LEN 24
 #define QIO_CHANNEL_WEBSOCK_GUID "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
-#define QIO_CHANNEL_WEBSOCK_GUID_LEN strlen(QIO_CHANNEL_WEBSOCK_GUID)
+#define QIO_CHANNEL_WEBSOCK_GUID_LEN (sizeof(QIO_CHANNEL_WEBSOCK_GUID) - 1)
 
 #define QIO_CHANNEL_WEBSOCK_HEADER_PROTOCOL "sec-websocket-protocol"
 #define QIO_CHANNEL_WEBSOCK_HEADER_VERSION "sec-websocket-version"