ALSA: drivers: Mark some variables as __ro_after_init

Some variables in the 'ALSA/drivers' are initialized only during the
init phase in the '__init' functions and never changed. So, mark them
as __ro_after_init to reduce the attack surface.

Signed-off-by: Len Bao <len.bao@gmx.us>
Link: https://patch.msgid.link/20260524165249.48941-1-len.bao@gmx.us
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/drivers/mpu401/mpu401.c b/sound/drivers/mpu401/mpu401.c
index d3f9424088d4f825216843293a6a69a0bf6654e8..b615a310c79ae0b63c09aea2b197e38760131c9a 100644 (file)
--- a/sound/drivers/mpu401/mpu401.c
+++ b/sound/drivers/mpu401/mpu401.c
@@ -46,7 +46,7 @@ module_param_array(uart_enter, bool, NULL, 0444);
 MODULE_PARM_DESC(uart_enter, "Issue UART_ENTER command at open.");
 
 static struct platform_device *platform_devices[SNDRV_CARDS];
-static int pnp_registered;
+static int pnp_registered __ro_after_init;
 static unsigned int snd_mpu401_devices;
 
 static int snd_mpu401_create(struct device *devptr, int dev,

diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c
index 7f93557b51eca292b09f021a45d6c64da7602de0..5d5281e4deb7c15206f3bf55d705d2b4c2c59500 100644 (file)
--- a/sound/drivers/pcmtest.c
+++ b/sound/drivers/pcmtest.c
@@ -113,7 +113,7 @@ struct pcmtst_buf_iter {
        struct timer_list timer_instance;
 };
 
-static struct snd_pcm_hardware snd_pcmtst_hw = {
+static struct snd_pcm_hardware snd_pcmtst_hw __ro_after_init = {
        .info = (SNDRV_PCM_INFO_INTERLEAVED |
                 SNDRV_PCM_INFO_BLOCK_TRANSFER |
                 SNDRV_PCM_INFO_NONINTERLEAVED |
@@ -137,7 +137,7 @@ struct pattern_buf {
        u32 len;
 };
 
-static int buf_allocated;
+static int buf_allocated __ro_after_init;
 static struct pattern_buf patt_bufs[MAX_CHANNELS_NUM];
 
 static inline void inc_buf_pos(struct pcmtst_buf_iter *v_iter, size_t by, size_t bytes)