From: Len Bao <len.bao@gmx.us>
Date: Sun, 24 May 2026 16:29:13 +0000 (+0000)
Subject: ALSA: core: Mark some variables as __ro_after_init
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=055cda1d47960c32e04dcb5d163e4fda7175632e;p=thirdparty%2Flinux.git

ALSA: core: Mark some variables as __ro_after_init

Some variables in the 'ALSA/core' 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/20260524162914.47764-1-len.bao@gmx.us
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/sound/core/hrtimer.c b/sound/core/hrtimer.c
index 9fcd1c03dc5b..92c585f8eeb1 100644
--- a/sound/core/hrtimer.c
+++ b/sound/core/hrtimer.c
@@ -20,7 +20,7 @@ MODULE_LICENSE("GPL");
 MODULE_ALIAS("snd-timer-" __stringify(SNDRV_TIMER_GLOBAL_HRTIMER));
 
 #define NANO_SEC	1000000000UL	/* 10^9 in sec */
-static unsigned int resolution;
+static unsigned int resolution __ro_after_init;
 
 struct snd_hrtimer {
 	struct snd_timer *timer;
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 746eaf93e1a5..9826d9a0be6d 100644
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -32,8 +32,8 @@
 
 #define OSS_ALSAEMULVER		_SIOR ('M', 249, int)
 
-static int dsp_map[SNDRV_CARDS];
-static int adsp_map[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = 1};
+static int dsp_map[SNDRV_CARDS] __ro_after_init;
+static int adsp_map[SNDRV_CARDS] __ro_after_init = {[0 ... (SNDRV_CARDS-1)] = 1};
 static bool nonblock_open = 1;
 
 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index 3b1034a44938..4dfd9d53e6d3 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -28,8 +28,8 @@ MODULE_DESCRIPTION("Midlevel RawMidi code for ALSA.");
 MODULE_LICENSE("GPL");
 
 #ifdef CONFIG_SND_OSSEMUL
-static int midi_map[SNDRV_CARDS];
-static int amidi_map[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS-1)] = 1};
+static int midi_map[SNDRV_CARDS] __ro_after_init;
+static int amidi_map[SNDRV_CARDS] __ro_after_init = {[0 ... (SNDRV_CARDS-1)] = 1};
 module_param_array(midi_map, int, NULL, 0444);
 MODULE_PARM_DESC(midi_map, "Raw MIDI device number assigned to 1st OSS device.");
 module_param_array(amidi_map, int, NULL, 0444);
diff --git a/sound/core/seq/oss/seq_oss_init.c b/sound/core/seq/oss/seq_oss_init.c
index d3e6a8a8d823..1aece46c8b06 100644
--- a/sound/core/seq/oss/seq_oss_init.c
+++ b/sound/core/seq/oss/seq_oss_init.c
@@ -27,8 +27,8 @@ static int maxqlen = SNDRV_SEQ_OSS_MAX_QLEN;
 module_param(maxqlen, int, 0444);
 MODULE_PARM_DESC(maxqlen, "maximum queue length");
 
-static int system_client = -1; /* ALSA sequencer client number */
-static int system_port = -1;
+static int system_client __ro_after_init = -1; /* ALSA sequencer client number */
+static int system_port __ro_after_init = -1;
 
 static int num_clients;
 static struct seq_oss_devinfo *client_table[SNDRV_SEQ_OSS_MAX_CLIENTS];
diff --git a/sound/core/seq/seq_dummy.c b/sound/core/seq/seq_dummy.c
index af45f328ae99..3fe0853aace3 100644
--- a/sound/core/seq/seq_dummy.c
+++ b/sound/core/seq/seq_dummy.c
@@ -71,7 +71,7 @@ struct snd_seq_dummy_port {
 	int connect;
 };
 
-static int my_client = -1;
+static int my_client __ro_after_init = -1;
 
 /*
  * event input callback - just redirect events to subscribers