From 217e0250cccb9e54d457991446cd3fab413085e1 Mon Sep 17 00:00:00 2001 From: Volodymyr Babchuk Date: Wed, 29 Nov 2017 14:48:37 +0200 Subject: tee: use reference counting for tee_context We need to ensure that tee_context is present until last shared buffer will be freed. Signed-off-by: Volodymyr Babchuk Signed-off-by: Jens Wiklander --- drivers/tee/tee_core.c | 40 +++++++++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 9 deletions(-) (limited to 'drivers/tee/tee_core.c') diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 295910f5cdd0..3d49ac2e3c84 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -54,6 +54,7 @@ static int tee_open(struct inode *inode, struct file *filp) goto err; } + kref_init(&ctx->refcount); ctx->teedev = teedev; INIT_LIST_HEAD(&ctx->list_shm); filp->private_data = ctx; @@ -68,19 +69,40 @@ err: return rc; } -static int tee_release(struct inode *inode, struct file *filp) +void teedev_ctx_get(struct tee_context *ctx) { - struct tee_context *ctx = filp->private_data; - struct tee_device *teedev = ctx->teedev; - struct tee_shm *shm; + if (ctx->releasing) + return; + + kref_get(&ctx->refcount); +} +static void teedev_ctx_release(struct kref *ref) +{ + struct tee_context *ctx = container_of(ref, struct tee_context, + refcount); + ctx->releasing = true; ctx->teedev->desc->ops->release(ctx); - mutex_lock(&ctx->teedev->mutex); - list_for_each_entry(shm, &ctx->list_shm, link) - shm->ctx = NULL; - mutex_unlock(&ctx->teedev->mutex); kfree(ctx); - tee_device_put(teedev); +} + +void teedev_ctx_put(struct tee_context *ctx) +{ + if (ctx->releasing) + return; + + kref_put(&ctx->refcount, teedev_ctx_release); +} + +static void teedev_close_context(struct tee_context *ctx) +{ + tee_device_put(ctx->teedev); + teedev_ctx_put(ctx); +} + +static int tee_release(struct inode *inode, struct file *filp) +{ + teedev_close_context(filp->private_data); return 0; } -- cgit v1.2.3