2021-09-27 12:18:43

by Arnd Bergmann

Subject: [PATCH] crypto: ccree - avoid out-of-range warnings from clang

From: Arnd Bergmann <[email protected]>

clang points out inconsistencies in the FIELD_PREP() invocation in
this driver that result from the 'mask' being a 32-bit value:

drivers/crypto/ccree/cc_driver.c:117:18: error: result of comparison of constant 18446744073709551615 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
cache_params |= FIELD_PREP(mask, val);
^~~~~~~~~~~~~~~~~~~~~
include/linux/bitfield.h:94:3: note: expanded from macro 'FIELD_PREP'
__BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/bitfield.h:52:28: note: expanded from macro '__BF_FIELD_CHECK'
BUILD_BUG_ON_MSG((_mask) > (typeof(_reg))~0ull, \
~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This does not happen in other places that just pass a constant here.

Work around the warnings by widening the type of the temporary variable.

Fixes: 05c2a705917b ("crypto: ccree - rework cache parameters handling")
Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/crypto/ccree/cc_driver.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/ccree/cc_driver.c b/drivers/crypto/ccree/cc_driver.c
index e599ac6dc162..790fa9058a36 100644
--- a/drivers/crypto/ccree/cc_driver.c
+++ b/drivers/crypto/ccree/cc_driver.c
@@ -103,7 +103,8 @@ MODULE_DEVICE_TABLE(of, arm_ccree_dev_of_match);
static void init_cc_cache_params(struct cc_drvdata *drvdata)
{
struct device *dev = drvdata_to_dev(drvdata);
- u32 cache_params, ace_const, val, mask;
+ u32 cache_params, ace_const, val;
+ u64 mask;

/* compute CC_AXIM_CACHE_PARAMS */
cache_params = cc_ioread(drvdata, CC_REG(AXIM_CACHE_PARAMS));
--
2.29.2

2021-09-28 14:02:39

by Gilad Ben-Yossef

Subject: Re: [PATCH] crypto: ccree - avoid out-of-range warnings from clang

Hi,

Thank you Arnd.

On Mon, Sep 27, 2021 at 3:18 PM Arnd Bergmann <[email protected]> wrote:
>
> From: Arnd Bergmann <[email protected]>
>
> clang points out inconsistencies in the FIELD_PREP() invocation in
> this driver that result from the 'mask' being a 32-bit value:
>
> drivers/crypto/ccree/cc_driver.c:117:18: error: result of comparison of constant 18446744073709551615 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
> cache_params |= FIELD_PREP(mask, val);
> ^~~~~~~~~~~~~~~~~~~~~
> include/linux/bitfield.h:94:3: note: expanded from macro 'FIELD_PREP'
> __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/bitfield.h:52:28: note: expanded from macro '__BF_FIELD_CHECK'
> BUILD_BUG_ON_MSG((_mask) > (typeof(_reg))~0ull, \
> ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> This does not happen in other places that just pass a constant here.
>
> Work around the warnings by widening the type of the temporary variable.
>
> Fixes: 05c2a705917b ("crypto: ccree - rework cache parameters handling")
> Signed-off-by: Arnd Bergmann <[email protected]>

Acked-by: Gilad ben-Yossef <[email protected]>

Gilad



--
Gilad Ben-Yossef
Chief Coffee Drinker

values of β will give rise to dom!

2021-10-08 12:26:34

by Herbert Xu

Subject: Re: [PATCH] crypto: ccree - avoid out-of-range warnings from clang

On Mon, Sep 27, 2021 at 02:18:03PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <[email protected]>
>
> clang points out inconsistencies in the FIELD_PREP() invocation in
> this driver that result from the 'mask' being a 32-bit value:
>
> drivers/crypto/ccree/cc_driver.c:117:18: error: result of comparison of constant 18446744073709551615 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
> cache_params |= FIELD_PREP(mask, val);
> ^~~~~~~~~~~~~~~~~~~~~
> include/linux/bitfield.h:94:3: note: expanded from macro 'FIELD_PREP'
> __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> include/linux/bitfield.h:52:28: note: expanded from macro '__BF_FIELD_CHECK'
> BUILD_BUG_ON_MSG((_mask) > (typeof(_reg))~0ull, \
> ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> This does not happen in other places that just pass a constant here.
>
> Work around the warnings by widening the type of the temporary variable.
>
> Fixes: 05c2a705917b ("crypto: ccree - rework cache parameters handling")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> drivers/crypto/ccree/cc_driver.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt