[PATCH 1/2] s390: export memory encryption helper functions

[PATCH 1/2] s390: export memory encryption helper functions

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

The set_memory_encrypted/set_memory_decrypted functions are exported
on x86 and arm64 but not on s390, which leads to a new build failure
because they are now used in a loadable module:

ERROR: modpost: "set_memory_encrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
ERROR: modpost: "set_memory_decrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!

Export these the same way we do on the other architectures.

Fixes: fd55edff8a0a ("dma-buf: heaps: system: Turn the heap into a module")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/s390/mm/init.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index f07168a0d3dd..d589c5e4d388 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -124,6 +124,7 @@ int set_memory_encrypted(unsigned long vaddr, int numpages)
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(set_memory_encrypted);
 
 int set_memory_decrypted(unsigned long vaddr, int numpages)
 {
@@ -135,6 +136,7 @@ int set_memory_decrypted(unsigned long vaddr, int numpages)
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(set_memory_decrypted);
 
 /* are we a protected virtualization guest? */
 bool force_dma_unencrypted(struct device *dev)
-- 
2.39.5

[PATCH 2/2] powerpc: export memory encryption helper functions

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

The set_memory_encrypted/set_memory_decrypted functions are exported
on x86 and arm64 but not on powerpc, which leads to a new build failure
because they are now used in a loadable module:

ERROR: modpost: "set_memory_encrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
ERROR: modpost: "set_memory_decrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!

Export these the same way we do on the other architectures.

Fixes: fd55edff8a0a ("dma-buf: heaps: system: Turn the heap into a module")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/powerpc/platforms/pseries/svm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c
index 384c9dc1899a..ab8f8c722741 100644
--- a/arch/powerpc/platforms/pseries/svm.c
+++ b/arch/powerpc/platforms/pseries/svm.c
@@ -6,6 +6,7 @@
  * Author: Anshuman Khandual <khandual@linux.vnet.ibm.com>
  */
 
+#include <linux/export.h>
 #include <linux/mm.h>
 #include <linux/memblock.h>
 #include <linux/mem_encrypt.h>
@@ -50,6 +51,7 @@ int set_memory_encrypted(unsigned long addr, int numpages)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(set_memory_encrypted);
 
 int set_memory_decrypted(unsigned long addr, int numpages)
 {
@@ -63,6 +65,7 @@ int set_memory_decrypted(unsigned long addr, int numpages)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(set_memory_decrypted);
 
 /* There's one dispatch log per CPU. */
 #define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)
-- 
2.39.5

Re: [PATCH 2/2] powerpc: export memory encryption helper functions

[Christophe Leroy (CS GROUP)]

Hi Arnd,

Le 26/05/2026 à 12:20, Arnd Bergmann a écrit :
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The set_memory_encrypted/set_memory_decrypted functions are exported
> on x86 and arm64 but not on powerpc, which leads to a new build failure
> because they are now used in a loadable module:
> 
> ERROR: modpost: "set_memory_encrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> ERROR: modpost: "set_memory_decrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> 
> Export these the same way we do on the other architectures.

The same fix was rejected already, see 
https://lore.kernel.org/all/ahPqbfH54R3JJyaV@infradead.org/

Christophe

> 
> Fixes: fd55edff8a0a ("dma-buf: heaps: system: Turn the heap into a module")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   arch/powerpc/platforms/pseries/svm.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c
> index 384c9dc1899a..ab8f8c722741 100644
> --- a/arch/powerpc/platforms/pseries/svm.c
> +++ b/arch/powerpc/platforms/pseries/svm.c
> @@ -6,6 +6,7 @@
>    * Author: Anshuman Khandual <khandual@linux.vnet.ibm.com>
>    */
>   
> +#include <linux/export.h>
>   #include <linux/mm.h>
>   #include <linux/memblock.h>
>   #include <linux/mem_encrypt.h>
> @@ -50,6 +51,7 @@ int set_memory_encrypted(unsigned long addr, int numpages)
>   
>   	return 0;
>   }
> +EXPORT_SYMBOL_GPL(set_memory_encrypted);
>   
>   int set_memory_decrypted(unsigned long addr, int numpages)
>   {
> @@ -63,6 +65,7 @@ int set_memory_decrypted(unsigned long addr, int numpages)
>   
>   	return 0;
>   }
> +EXPORT_SYMBOL_GPL(set_memory_decrypted);
>   
>   /* There's one dispatch log per CPU. */
>   #define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)

Re: [PATCH 1/2] s390: export memory encryption helper functions

[Claudio Imbrenda]

On Tue, 26 May 2026 12:20:37 +0200
Arnd Bergmann <arnd@kernel.org> wrote:

> From: Arnd Bergmann <arnd@arndb.de>
> 
> The set_memory_encrypted/set_memory_decrypted functions are exported
> on x86 and arm64 but not on s390, which leads to a new build failure
> because they are now used in a loadable module:
> 
> ERROR: modpost: "set_memory_encrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> ERROR: modpost: "set_memory_decrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> 
> Export these the same way we do on the other architectures.
> 
> Fixes: fd55edff8a0a ("dma-buf: heaps: system: Turn the heap into a module")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

> ---
>  arch/s390/mm/init.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index f07168a0d3dd..d589c5e4d388 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -124,6 +124,7 @@ int set_memory_encrypted(unsigned long vaddr, int numpages)
>  	}
>  	return 0;
>  }
> +EXPORT_SYMBOL_GPL(set_memory_encrypted);
>  
>  int set_memory_decrypted(unsigned long vaddr, int numpages)
>  {
> @@ -135,6 +136,7 @@ int set_memory_decrypted(unsigned long vaddr, int numpages)
>  	}
>  	return 0;
>  }
> +EXPORT_SYMBOL_GPL(set_memory_decrypted);
>  
>  /* are we a protected virtualization guest? */
>  bool force_dma_unencrypted(struct device *dev)

Re: [PATCH 1/2] s390: export memory encryption helper functions

[Uwe Kleine-König]

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Hello,

On Tue, May 26, 2026 at 12:20:37PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The set_memory_encrypted/set_memory_decrypted functions are exported
> on x86 and arm64 but not on s390, which leads to a new build failure
> because they are now used in a loadable module:
> 
> ERROR: modpost: "set_memory_encrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> ERROR: modpost: "set_memory_decrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> 
> Export these the same way we do on the other architectures.
> 
> Fixes: fd55edff8a0a ("dma-buf: heaps: system: Turn the heap into a module")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

That problem still exists as of next-20260608. Even though there is
resistance to this approach, can we please apply this patch to fix the
build failure given that we're already at -rc7? This doesn't have to stop efforts to get rid of that
export for all archs.

Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>

Best regards
Uwe

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Re: [PATCH 1/2] s390: export memory encryption helper functions

[Christian Borntraeger]

Am 26.05.26 um 12:20 schrieb Arnd Bergmann:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The set_memory_encrypted/set_memory_decrypted functions are exported
> on x86 and arm64 but not on s390, which leads to a new build failure
> because they are now used in a loadable module:
> 
> ERROR: modpost: "set_memory_encrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> ERROR: modpost: "set_memory_decrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> 
> Export these the same way we do on the other architectures.
> 
> Fixes: fd55edff8a0a ("dma-buf: heaps: system: Turn the heap into a module")

This commit id was from an next tree? Seems to be no longer valid.

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>

@Alexander/vasily/Heiko, can you maybe queue that via the s390 fixes tree?> ---
>   arch/s390/mm/init.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index f07168a0d3dd..d589c5e4d388 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -124,6 +124,7 @@ int set_memory_encrypted(unsigned long vaddr, int numpages)
>   	}
>   	return 0;
>   }
> +EXPORT_SYMBOL_GPL(set_memory_encrypted);
>   
>   int set_memory_decrypted(unsigned long vaddr, int numpages)
>   {
> @@ -135,6 +136,7 @@ int set_memory_decrypted(unsigned long vaddr, int numpages)
>   	}
>   	return 0;
>   }
> +EXPORT_SYMBOL_GPL(set_memory_decrypted);
>   
>   /* are we a protected virtualization guest? */
>   bool force_dma_unencrypted(struct device *dev)

Re: [PATCH 1/2] s390: export memory encryption helper functions

[Heiko Carstens]

On Tue, Jun 09, 2026 at 02:38:45PM +0200, Christian Borntraeger wrote:
> Am 26.05.26 um 12:20 schrieb Arnd Bergmann:
> > From: Arnd Bergmann <arnd@arndb.de>
> > 
> > The set_memory_encrypted/set_memory_decrypted functions are exported
> > on x86 and arm64 but not on s390, which leads to a new build failure
> > because they are now used in a loadable module:
> > 
> > ERROR: modpost: "set_memory_encrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> > ERROR: modpost: "set_memory_decrypted" [drivers/dma-buf/heaps/system_heap.ko] undefined!
> > 
> > Export these the same way we do on the other architectures.
> > 
> > Fixes: fd55edff8a0a ("dma-buf: heaps: system: Turn the heap into a module")
> 
> This commit id was from an next tree? Seems to be no longer valid.
> 
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
> 
> @Alexander/vasily/Heiko, can you maybe queue that via the s390 fixes tree?

There is a lot of discussion ongoing for the similar powerpc
patch. Waiting for the end result.

https://lore.kernel.org/all/20260522225853.878411-1-tjmercier@google.com/