ALSA: pcm: Remove VLA usage

A helper function used by snd_pcm_hw_refine() still keeps using VLA
for timestamps of hw constraint rules that are non-fixed size.

Let's replace the VLA with a simple kmalloc() array.

Reference: https://lkml.org/lkml/2018/3/7/621
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 77ba50ddcf9e346f799b2c099abfec5694921afb..756a9a3884a532455f93f5f06cca38dcd7866ad1 100644 (file)
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -323,7 +323,7 @@ static int constrain_params_by_rules(struct snd_pcm_substream *substream,
        struct snd_pcm_hw_constraints *constrs =
                                        &substream->runtime->hw_constraints;
        unsigned int k;
-       unsigned int rstamps[constrs->rules_num];
+       unsigned int *rstamps;
        unsigned int vstamps[SNDRV_PCM_HW_PARAM_LAST_INTERVAL + 1];
        unsigned int stamp;
        struct snd_pcm_hw_rule *r;
@@ -331,7 +331,7 @@ static int constrain_params_by_rules(struct snd_pcm_substream *substream,
        struct snd_mask old_mask;
        struct snd_interval old_interval;
        bool again;
-       int changed;
+       int changed, err = 0;
 
        /*
         * Each application of rule has own sequence number.
@@ -339,8 +339,9 @@ static int constrain_params_by_rules(struct snd_pcm_substream *substream,
         * Each member of 'rstamps' array represents the sequence number of
         * recent application of corresponding rule.
         */
-       for (k = 0; k < constrs->rules_num; k++)
-               rstamps[k] = 0;
+       rstamps = kcalloc(constrs->rules_num, sizeof(unsigned int), GFP_KERNEL);
+       if (!rstamps)
+               return -ENOMEM;
 
        /*
         * Each member of 'vstamps' array represents the sequence number of
@@ -398,8 +399,10 @@ retry:
                }
 
                changed = r->func(params, r);
-               if (changed < 0)
-                       return changed;
+               if (changed < 0) {
+                       err = changed;
+                       goto out;
+               }
 
                /*
                 * When the parameter is changed, notify it to the caller
@@ -430,7 +433,9 @@ retry:
        if (again)
                goto retry;
 
-       return 0;
+ out:
+       kfree(rstamps);
+       return err;
 }
 
 static int fixup_unreferenced_params(struct snd_pcm_substream *substream,