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>

1 files changed, 12 insertions, 7 deletions

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 77ba50ddcf9e..756a9a3884a5 100644
--- 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,