RE: [PATCH 1/2] crypto: inside-secure - fix uninitialized-variable warning

[Pascal Van Leeuwen]

> -----Original Message-----
> From: Arnd Bergmann <arnd@xxxxxxxx>
> Sent: Friday, September 6, 2019 5:22 PM
> To: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>;
> Antoine Tenart <antoine.tenart@xxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>; Pascal Van Leeuwen <pvanleeuwen@xxxxxxxxxxxxxx>; Ard
> Biesheuvel <ard.biesheuvel@xxxxxxxxxx>; Kees Cook <keescook@xxxxxxxxxxxx>; linux-
> crypto@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH 1/2] crypto: inside-secure - fix uninitialized-variable warning
> 
> The addition of PCI support introduced multiple randconfig issues.
> 
> - When PCI is disabled, some external functions are undeclared:
> drivers/crypto/inside-secure/safexcel.c:944:9: error: implicit declaration of function
> 'pci_irq_vector' [-Werror,-Wimplicit-function-declaration]
> 
> - Also, in the same configuration, there is an uninitialized variable:
> drivers/crypto/inside-secure/safexcel.c:940:6: error: variable 'irq' is used
> uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
> 
> - Finally, the driver fails to completely if both PCI and OF
>   are disabled.
> 
> Take care of all of the above by adding more checks for CONFIG_PCI
> and CONFIG_OF.
> 
> Fixes: 625f269a5a7a ("crypto: inside-secure - add support for PCI based FPGA development
> board")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  drivers/crypto/Kconfig                  | 2 +-
>  drivers/crypto/inside-secure/safexcel.c | 8 ++++++++
>  2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
> index 3c4361947f8d..048bc4b393ac 100644
> --- a/drivers/crypto/Kconfig
> +++ b/drivers/crypto/Kconfig
> @@ -719,7 +719,7 @@ source "drivers/crypto/stm32/Kconfig"
> 
>  config CRYPTO_DEV_SAFEXCEL
>  	tristate "Inside Secure's SafeXcel cryptographic engine driver"
> -	depends on OF || PCI || COMPILE_TEST
> +	depends on OF || PCI
>

This seems like it just ignores the problem by not allowing compile testing
anymore? Somehow that does not feel right ...

>  	select CRYPTO_LIB_AES
>  	select CRYPTO_AUTHENC
>  	select CRYPTO_BLKCIPHER
> diff --git a/drivers/crypto/inside-secure/safexcel.c b/drivers/crypto/inside-
> secure/safexcel.c
> index e12a2a3a5422..9c0bce77de14 100644
> --- a/drivers/crypto/inside-secure/safexcel.c
> +++ b/drivers/crypto/inside-secure/safexcel.c
> @@ -938,6 +938,7 @@ static int safexcel_request_ring_irq(void *pdev, int irqid,
>  	struct device *dev;
> 
>  	if (IS_ENABLED(CONFIG_PCI) && is_pci_dev) {
> +#ifdef CONFIG_PCI
>

The whole point was NOT to use regular #ifdefs such that the code can
be compile tested without needing to switch configurations.
There is already a different solution in the works involving some empty
inline stubs for those pci routines, please see an earlier mail by Herbert
titled "PCI: Add stub pci_irq_vector and others". 

>  		struct pci_dev *pci_pdev = pdev;
> 
>  		dev = &pci_pdev->dev;
> @@ -947,6 +948,7 @@ static int safexcel_request_ring_irq(void *pdev, int irqid,
>  				irqid, irq);
>  			return irq;
>  		}
> +#endif
>  	} else if (IS_ENABLED(CONFIG_OF)) {
>  		struct platform_device *plf_pdev = pdev;
>  		char irq_name[6] = {0}; /* "ringX\0" */
> @@ -960,6 +962,8 @@ static int safexcel_request_ring_irq(void *pdev, int irqid,
>  				irq_name, irq);
>  			return irq;
>  		}
> +	} else {
> +		return -ENXIO;
>  	}
> 
>  	ret = devm_request_threaded_irq(dev, irq, handler,
> @@ -1138,6 +1142,7 @@ static int safexcel_probe_generic(void *pdev,
>  	safexcel_configure(priv);
> 
>  	if (IS_ENABLED(CONFIG_PCI) && priv->version == EIP197_DEVBRD) {
> +#ifdef CONFIG_PCI
>  		/*
>  		 * Request MSI vectors for global + 1 per ring -
>  		 * or just 1 for older dev images
> @@ -1152,6 +1157,7 @@ static int safexcel_probe_generic(void *pdev,
>  			dev_err(dev, "Failed to allocate PCI MSI interrupts\n");
>  			return ret;
>  		}
> +#endif
>  	}
> 
>  	/* Register the ring IRQ handlers and configure the rings */
> @@ -1503,7 +1509,9 @@ static struct pci_driver safexcel_pci_driver = {
> 
>  static int __init safexcel_init(void)
>  {
> +#ifdef CONFIG_PCI
>  	int rc;
> +#endif
>
I'm working on a fix for this part already, seems to involve a bit
more than just removing the int declaration ...

> 
>  #if IS_ENABLED(CONFIG_OF)
>  		/* Register platform driver */
> --
> 2.20.0

Regards,
Pascal van Leeuwen
Silicon IP Architect, Multi-Protocol Engines @ Verimatrix
www.insidesecure.com