On 02/15/2018 07:06 PM, Kamil Konieczny wrote: > > > On 15.02.2018 18:06, Marek Vasut wrote: >> On 02/15/2018 06:00 PM, Kamil Konieczny wrote: >>> >>> >>> On 15.02.2018 17:27, Marek Vasut wrote: >>>> On 02/15/2018 04:41 PM, Herbert Xu wrote: >>>>> On Thu, Jan 18, 2018 at 07:33:59PM +0100, Kamil Konieczny wrote: >>>>>> First four patches add empty hash export and import functions to each driver, >>>>>> with the same behaviour as in crypto framework. The last one drops them from >>>>>> crypto framework. Last one for ahash.c depends on all previous. >>>>>> >>>>>> Changes in v3: >>>>>> added change for bfin_crc.c >>>>>> make this a patchset, instead of unreleated patches >>>>>> make commit message more descriptive >>>>>> >>>>>> Kamil Konieczny (5): >>>>>> crypto: mxs-dcp: Add empty hash export and import >>>>>> crypto: n2_core: Add empty hash export and import >>>>>> crypto: ux500/hash: Add empty export and import >>>>>> crypto: bfin_crc: Add empty hash export and import >>>>>> crypto: ahash.c: Require export/import in ahash >>>>>> >>>>>> crypto/ahash.c | 18 ++---------------- >>>>>> drivers/crypto/bfin_crc.c | 12 ++++++++++++ >>>>>> drivers/crypto/mxs-dcp.c | 14 ++++++++++++++ >>>>>> drivers/crypto/n2_core.c | 12 ++++++++++++ >>>>>> drivers/crypto/ux500/hash/hash_core.c | 18 ++++++++++++++++++ >>>>>> 5 files changed, 58 insertions(+), 16 deletions(-) >>>>> >>>>> All applied. Thanks. >>>> >>>> This makes no sense, cfr my comment on 5/5 >>>> >>>> Seems like if the driver doesn't implement those, the core can easily >>>> detect that and perform the necessary action. Moving the checks out of >>>> core seems like the wrong thing to do, rather you should enhance the >>>> checks in core if they're insufficient in my opinion. >>> >>> The bug can only be in driver which will not implement those two functions, >>> but we already had all drivers with those due to patches 1..4 >>> All other drivers do have them. >> >> The core can very well check if these functions are not populated and >> return ENOSYS >> >>> Additionally, with crypto we want minimize code and run as fast as possible. >> >> So you remove all NULL pointer checks ? Esp. in security-sensitive code? >> What is the impact of this non-critical path code on performance? >> >> Come on ... >> > > Why you want checks for something that not exist ? > > Those without them will not work and will do Oops in crypto testmgr, > so such drivers should not be used nor accepted in drivers/crypto > > Ask yourself why crypto do not check for NULL in ahash digest or other > required ahash functions. Are you suggesting that the kernel code should NOT perform NULL pointer checks ? Are you suggesting each driver should implement every single callback available and if it is not implemented, return -ENOSYS ? This looks like a MASSIVE code duplication. >>> Moving checks out of core will impose on driver author need for implement >>> those functions, or declare them empty, but in case of empty ones >>> crypto will not work properly with such driver. >> >> You can very well impose that in the core, except you don't duplicate >> the code. > > Now size of crypto core is reduced. You implemented the same code thrice, it surely is not reduced. -- Best regards, Marek Vasut
