Re: [alsa-devel] [PATCH] pcm_native: Remove VLA usage
On Wed, Mar 28, 2018 at 3:11 PM, Kyle Spiers kyle@spiers.me wrote:
As part of the effort to remove VLAs from the kernel[1], this changes the allocation of the rstamps array from being on the stack to being kcalloc()ed. This also allows for the removal of the explicit zeroing loop.
[1] https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Kyle Spiers kyle@spiers.me
sound/core/pcm_native.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 77ba50d..57240b8 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;
@@ -339,8 +339,8 @@ 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(*rstamps), GFP_KERNEL); /* * Each member of 'vstamps' array represents the sequence number of
@@ -399,6 +399,7 @@ static int constrain_params_by_rules(struct snd_pcm_substream *substream,
changed = r->func(params, r); if (changed < 0)
kfree(rstamps); return changed;
Whoops, this needs { } s:
if (changed < 0) { kfree(rstamps); return changed; }
Otherwise, looks good! Once that's fixed:
Reviewed-by: Kees Cook keescook@chromium.org
-Kees
/*
@@ -430,6 +431,7 @@ static int constrain_params_by_rules(struct snd_pcm_substream *substream, if (again) goto retry;
kfree(rstamps); return 0;
}
-- 2.7.4
participants (1)
-
Kees Cook