[PATCH 1/2] optee: fix tee out of memory failure seen during kexec reboot

From: Allen Pais <redacted>

On Wed, 17 Feb 2021 14:57:12 +0530, Allen Pais wrote:

-	/*
-	 * Ask OP-TEE to free all cached shared memory objects to decrease
-	 * reference counters and also avoid wild pointers in secure world
-	 * into the old shared memory range.
-	 */
-	optee_disable_shm_cache(optee);
+	if (shutdown) {
+		optee_disable_shm_cache(optee);
+	} else {
+		/*
+		 * Ask OP-TEE to free all cached shared memory
+		 * objects to decrease reference counters and
+		 * also avoid wild pointers in secure world
+		 * into the old shared memory range.
+		 */
+		optee_disable_shm_cache(optee);

 
Calling optee_disable_shm_cache() in both if and else. It could be
put in front of if().


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On Wed, 17 Feb 2021 14:57:12 +0530, Allen Pais wrote:

quoted

-	/*
-	 * Ask OP-TEE to free all cached shared memory objects to decrease
-	 * reference counters and also avoid wild pointers in secure world
-	 * into the old shared memory range.
-	 */
-	optee_disable_shm_cache(optee);
+	if (shutdown) {
+		optee_disable_shm_cache(optee);
+	} else {
+		/*
+		 * Ask OP-TEE to free all cached shared memory
+		 * objects to decrease reference counters and
+		 * also avoid wild pointers in secure world
+		 * into the old shared memory range.
+		 */
+		optee_disable_shm_cache(optee);

  
Calling optee_disable_shm_cache() in both if and else. It could be
put in front of if().

   Ideally, I could just use optee_remove for shutdown() too.
But it would not look good. Hence this approach.

- Allen

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On Mon, Feb 22, 2021 at 06:15:08PM +0530, Allen Pais wrote:

quoted

On Wed, 17 Feb 2021 14:57:12 +0530, Allen Pais wrote:

quoted

-	/*
-	 * Ask OP-TEE to free all cached shared memory objects to decrease
-	 * reference counters and also avoid wild pointers in secure world
-	 * into the old shared memory range.
-	 */
-	optee_disable_shm_cache(optee);
+	if (shutdown) {
+		optee_disable_shm_cache(optee);
+	} else {
+		/*
+		 * Ask OP-TEE to free all cached shared memory
+		 * objects to decrease reference counters and
+		 * also avoid wild pointers in secure world
+		 * into the old shared memory range.
+		 */
+		optee_disable_shm_cache(optee);

Calling optee_disable_shm_cache() in both if and else. It could be
put in front of if().

  Ideally, I could just use optee_remove for shutdown() too.
But it would not look good. Hence this approach.

What is the problem with using optee_remove() for shutdown()?

Cheers,
Jens

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quoted

quoted

quoted

-	/*
-	 * Ask OP-TEE to free all cached shared memory objects to decrease
-	 * reference counters and also avoid wild pointers in secure world
-	 * into the old shared memory range.
-	 */
-	optee_disable_shm_cache(optee);
+	if (shutdown) {
+		optee_disable_shm_cache(optee);
+	} else {
+		/*
+		 * Ask OP-TEE to free all cached shared memory
+		 * objects to decrease reference counters and
+		 * also avoid wild pointers in secure world
+		 * into the old shared memory range.
+		 */
+		optee_disable_shm_cache(optee);

Calling optee_disable_shm_cache() in both if and else. It could be
put in front of if().

   Ideally, I could just use optee_remove for shutdown() too.
But it would not look good. Hence this approach.

What is the problem with using optee_remove() for shutdown()?

  There is no problem, I just thought it would be more cleaner/readable
with this approach. If you'd like to keep it simple by just calling
optee_remove() for shutdown() too, I could quickly send out V2.

Thanks for the review.

- Allen

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On Tue, Feb 23, 2021 at 09:56:13PM +0530, Allen Pais wrote:

quoted

quoted

quoted

quoted

-	/*
-	 * Ask OP-TEE to free all cached shared memory objects to decrease
-	 * reference counters and also avoid wild pointers in secure world
-	 * into the old shared memory range.
-	 */
-	optee_disable_shm_cache(optee);
+	if (shutdown) {
+		optee_disable_shm_cache(optee);
+	} else {
+		/*
+		 * Ask OP-TEE to free all cached shared memory
+		 * objects to decrease reference counters and
+		 * also avoid wild pointers in secure world
+		 * into the old shared memory range.
+		 */
+		optee_disable_shm_cache(optee);

Calling optee_disable_shm_cache() in both if and else. It could be
put in front of if().

   Ideally, I could just use optee_remove for shutdown() too.
But it would not look good. Hence this approach.

What is the problem with using optee_remove() for shutdown()?

 There is no problem, I just thought it would be more cleaner/readable
with this approach. If you'd like to keep it simple by just calling
optee_remove() for shutdown() too, I could quickly send out V2.

In the patch you posted it looks like you'd like to call
only optee_disable_shm_cache() in the case of shutdown. Like:

static void optee_shutdown(struct platform_device *pdev)
{
        optee_disable_shm_cache(platform_get_drvdata(pdev));
}

and optee_remove() kept as it was before this patch.

Cheers,
Jens

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linux-arm-kernel@lists.infradead.org
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quoted

quoted

quoted

quoted

quoted

-	/*
-	 * Ask OP-TEE to free all cached shared memory objects to decrease
-	 * reference counters and also avoid wild pointers in secure world
-	 * into the old shared memory range.
-	 */
-	optee_disable_shm_cache(optee);
+	if (shutdown) {
+		optee_disable_shm_cache(optee);
+	} else {
+		/*
+		 * Ask OP-TEE to free all cached shared memory
+		 * objects to decrease reference counters and
+		 * also avoid wild pointers in secure world
+		 * into the old shared memory range.
+		 */
+		optee_disable_shm_cache(optee);

Calling optee_disable_shm_cache() in both if and else. It could be
put in front of if().

    Ideally, I could just use optee_remove for shutdown() too.
But it would not look good. Hence this approach.

What is the problem with using optee_remove() for shutdown()?

  There is no problem, I just thought it would be more cleaner/readable
with this approach. If you'd like to keep it simple by just calling
optee_remove() for shutdown() too, I could quickly send out V2.

In the patch you posted it looks like you'd like to call
only optee_disable_shm_cache() in the case of shutdown. Like:

static void optee_shutdown(struct platform_device *pdev)
{
         optee_disable_shm_cache(platform_get_drvdata(pdev));
}

and optee_remove() kept as it was before this patch.

  Sure, Will have it fixed and send out V2.

Thanks.

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