Re: [PATCH 5.10 104/299] crypto: stm32/hash - Fix PM reference leak on stm32-hash.c

From: Pavel Machek
Date: Mon May 10 2021 - 08:51:17 EST


Hi!

> pm_runtime_get_sync will increment pm usage counter even it failed.
> Forgetting to putting operation will result in reference leak here.
> Fix it by replacing it with pm_runtime_resume_and_get to keep usage
> counter balanced.

I believe we need to enforce "patches need to be tested" rule at least
against robots.

Code was correct in 3/4 instances, this introduces bugs. Yes, last one
needs fixing.

Best regards,
Pavel

> +++ b/drivers/crypto/stm32/stm32-hash.c
> @@ -812,7 +812,7 @@ static void stm32_hash_finish_req(struct ahash_request *req, int err)
> static int stm32_hash_hw_init(struct stm32_hash_dev *hdev,
> struct stm32_hash_request_ctx *rctx)
> {
> - pm_runtime_get_sync(hdev->dev);
> + pm_runtime_resume_and_get(hdev->dev);
>
> if (!(HASH_FLAGS_INIT & hdev->flags)) {
> stm32_hash_write(hdev, HASH_CR, HASH_CR_INIT);
> @@ -961,7 +961,7 @@ static int stm32_hash_export(struct ahash_request *req, void *out)
> u32 *preg;
> unsigned int i;
>
> - pm_runtime_get_sync(hdev->dev);
> + pm_runtime_resume_and_get(hdev->dev);
>
> while ((stm32_hash_read(hdev, HASH_SR) & HASH_SR_BUSY))
> cpu_relax();
> @@ -999,7 +999,7 @@ static int stm32_hash_import(struct ahash_request *req, const void *in)
>
> preg = rctx->hw_context;
>
> - pm_runtime_get_sync(hdev->dev);
> + pm_runtime_resume_and_get(hdev->dev);
>
> stm32_hash_write(hdev, HASH_IMR, *preg++);
> stm32_hash_write(hdev, HASH_STR, *preg++);

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