APPLIED[Artful]: [PATCH] SAUCE: crypto: thunderx_zip: Fix fallout from CONFIG_VMAP_STACK

[Kleber Souza]

On 03/27/18 12:31, Paolo Pisati wrote:
> From: Jan Glauber <jglauber at cavium.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/1755073
> 
> Enabling virtual mapped kernel stacks breaks the thunderx_zip
> driver. On compression or decompression the executing CPU hangs
> in an endless loop. The reason for this is the usage of __pa()
> by the driver that does not work for an address that is
> not part of the 1:1 mapping.
> 
> The zip driver allocates a result struct on the stack and needs
> to tell the hardware the pysical address within this struct
> that is used to signal the completion of the request.
> With CONFIG_VMAP_STACK __pa() is no longer usable for a stack address.
> 
> As the hardware gets the wrong address it writes the result byte
> to an arbitrary address. The zip driver then waits forever for the
> completion byte to contain a non-zero value.
> 
> Allocating the result struct from 1:1 mapped memory resolves this
> bug.
> 
> Note that there are more outstanding issues with the used completion
> mechanism:
> - volatile is used for a bitfield
> - no barriers at all re used
> - the completion loop should have a retry counter and not run forever
> - polling for the result should use a delay
> - interrupts for completion and error notification should be used
> 
> Signed-off-by: Jan Glauber <jglauber at cavium.com>
> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>
> ---
>  drivers/crypto/cavium/zip/zip_crypto.c | 22 ++++++++++++++--------
>  1 file changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/crypto/cavium/zip/zip_crypto.c b/drivers/crypto/cavium/zip/zip_crypto.c
> index 8df4d26..2fc9b03 100644
> --- a/drivers/crypto/cavium/zip/zip_crypto.c
> +++ b/drivers/crypto/cavium/zip/zip_crypto.c
> @@ -124,7 +124,7 @@ int zip_compress(const u8 *src, unsigned int slen,
>  		 struct zip_kernel_ctx *zip_ctx)
>  {
>  	struct zip_operation  *zip_ops   = NULL;
> -	struct zip_state      zip_state;
> +	struct zip_state      *zip_state;
>  	struct zip_device     *zip = NULL;
>  	int ret;
>  
> @@ -135,20 +135,23 @@ int zip_compress(const u8 *src, unsigned int slen,
>  	if (!zip)
>  		return -ENODEV;
>  
> -	memset(&zip_state, 0, sizeof(struct zip_state));
> +	zip_state = kzalloc(sizeof(*zip_state), GFP_KERNEL);
> +	if (!zip_state)
> +		return -ENOMEM;
> +
>  	zip_ops = &zip_ctx->zip_comp;
>  
>  	zip_ops->input_len  = slen;
>  	zip_ops->output_len = *dlen;
>  	memcpy(zip_ops->input, src, slen);
>  
> -	ret = zip_deflate(zip_ops, &zip_state, zip);
> +	ret = zip_deflate(zip_ops, zip_state, zip);
>  
>  	if (!ret) {
>  		*dlen = zip_ops->output_len;
>  		memcpy(dst, zip_ops->output, *dlen);
>  	}
> -
> +	kfree(zip_state);
>  	return ret;
>  }
>  
> @@ -157,7 +160,7 @@ int zip_decompress(const u8 *src, unsigned int slen,
>  		   struct zip_kernel_ctx *zip_ctx)
>  {
>  	struct zip_operation  *zip_ops   = NULL;
> -	struct zip_state      zip_state;
> +	struct zip_state      *zip_state;
>  	struct zip_device     *zip = NULL;
>  	int ret;
>  
> @@ -168,7 +171,10 @@ int zip_decompress(const u8 *src, unsigned int slen,
>  	if (!zip)
>  		return -ENODEV;
>  
> -	memset(&zip_state, 0, sizeof(struct zip_state));
> +	zip_state = kzalloc(sizeof(*zip_state), GFP_KERNEL);
> +	if (!zip_state)
> +		return -ENOMEM;
> +
>  	zip_ops = &zip_ctx->zip_decomp;
>  	memcpy(zip_ops->input, src, slen);
>  
> @@ -179,13 +185,13 @@ int zip_decompress(const u8 *src, unsigned int slen,
>  	zip_ops->input_len  = slen;
>  	zip_ops->output_len = *dlen;
>  
> -	ret = zip_inflate(zip_ops, &zip_state, zip);
> +	ret = zip_inflate(zip_ops, zip_state, zip);
>  
>  	if (!ret) {
>  		*dlen = zip_ops->output_len;
>  		memcpy(dst, zip_ops->output, *dlen);
>  	}
> -
> +	kfree(zip_state);
>  	return ret;
>  }
>  
> 

Applied to artful/master-next branch.

Thanks,
Kleber