Re: [RFC PATCH 0/3] Introduce kernel small arrays (KSA)
> On Oct 4, 2017, at 7:22 PM, Ben Hutchings> wrote: > > On Tue, 2017-09-19 at 12:30 +0400, Ilya Matveychikov wrote: >> Hi guys, >> >> Please review the approach of using small fixed-sized arrays to improve >> parsing of values like get_options() does. >> >> This comes to me after fixing an overflow in get_options(). See the thread >> for details: https://lkml.org/lkml/2017/5/22/581 >> >> If the approach is OK I’ll suggest to replace all of get_options() calls >> to ksa_parse_ints() and remove get_options() at all. > > You didn't cc the patches to me, and I can't find patch 3/3 at all. Thanks for you answer. I posted them on list, except the last one as what I wanted is to get the feedback first. I CC’d you as you found a problem with my patch for get_options() before (read out of bounds). > > don't think the KSA() macro should be casting its argument. Where the > cast is necessary, it ought to be explicit in the caller. KSA(x) it’s just a simple way to cast from custom-defined small array to generic one. Do you think that it’s better to use explicit casting: ksa_parse_foo(..., (struct ksmall_array *)_custom_ksa) Instead of: ksa_parse_foo(..., KSA(_custom_ksa)) Not sure... > > Similarly I think the BUILD_BUG_ON() in ksa_build_check() doesn't belong > there, but in whichever caller of ksa_parse_ints() requires struct > ksmall_array to have the same layout as a simple array of unsigned int. Not sure that I understand your point. The purpose of ksa_build_check() as I wrote it is to to do compile-time check for sizeof(struct ksmall_array) to fit sizeof(unsigned int). Note that ksmall_array{} is the header for any possible “small” array build by using the KSA_DECLARE() macro.
Re: [RFC PATCH 0/3] Introduce kernel small arrays (KSA)
> On Oct 4, 2017, at 7:22 PM, Ben Hutchings > wrote: > > On Tue, 2017-09-19 at 12:30 +0400, Ilya Matveychikov wrote: >> Hi guys, >> >> Please review the approach of using small fixed-sized arrays to improve >> parsing of values like get_options() does. >> >> This comes to me after fixing an overflow in get_options(). See the thread >> for details: https://lkml.org/lkml/2017/5/22/581 >> >> If the approach is OK I’ll suggest to replace all of get_options() calls >> to ksa_parse_ints() and remove get_options() at all. > > You didn't cc the patches to me, and I can't find patch 3/3 at all. Thanks for you answer. I posted them on list, except the last one as what I wanted is to get the feedback first. I CC’d you as you found a problem with my patch for get_options() before (read out of bounds). > > don't think the KSA() macro should be casting its argument. Where the > cast is necessary, it ought to be explicit in the caller. KSA(x) it’s just a simple way to cast from custom-defined small array to generic one. Do you think that it’s better to use explicit casting: ksa_parse_foo(..., (struct ksmall_array *)_custom_ksa) Instead of: ksa_parse_foo(..., KSA(_custom_ksa)) Not sure... > > Similarly I think the BUILD_BUG_ON() in ksa_build_check() doesn't belong > there, but in whichever caller of ksa_parse_ints() requires struct > ksmall_array to have the same layout as a simple array of unsigned int. Not sure that I understand your point. The purpose of ksa_build_check() as I wrote it is to to do compile-time check for sizeof(struct ksmall_array) to fit sizeof(unsigned int). Note that ksmall_array{} is the header for any possible “small” array build by using the KSA_DECLARE() macro.
Re: [RFC PATCH 0/3] Introduce kernel small arrays (KSA)
On Tue, 2017-09-19 at 12:30 +0400, Ilya Matveychikov wrote: > Hi guys, > > Please review the approach of using small fixed-sized arrays to improve > parsing of values like get_options() does. > > This comes to me after fixing an overflow in get_options(). See the thread > for details: https://lkml.org/lkml/2017/5/22/581 > > If the approach is OK I’ll suggest to replace all of get_options() calls > to ksa_parse_ints() and remove get_options() at all. You didn't cc the patches to me, and I can't find patch 3/3 at all. I don't think the KSA() macro should be casting its argument. Where the cast is necessary, it ought to be explicit in the caller. Similarly I think the BUILD_BUG_ON() in ksa_build_check() doesn't belong there, but in whichever caller of ksa_parse_ints() requires struct ksmall_array to have the same layout as a simple array of unsigned int. Ben. -- Ben Hutchings Software Developer, Codethink Ltd.
Re: [RFC PATCH 0/3] Introduce kernel small arrays (KSA)
On Tue, 2017-09-19 at 12:30 +0400, Ilya Matveychikov wrote: > Hi guys, > > Please review the approach of using small fixed-sized arrays to improve > parsing of values like get_options() does. > > This comes to me after fixing an overflow in get_options(). See the thread > for details: https://lkml.org/lkml/2017/5/22/581 > > If the approach is OK I’ll suggest to replace all of get_options() calls > to ksa_parse_ints() and remove get_options() at all. You didn't cc the patches to me, and I can't find patch 3/3 at all. I don't think the KSA() macro should be casting its argument. Where the cast is necessary, it ought to be explicit in the caller. Similarly I think the BUILD_BUG_ON() in ksa_build_check() doesn't belong there, but in whichever caller of ksa_parse_ints() requires struct ksmall_array to have the same layout as a simple array of unsigned int. Ben. -- Ben Hutchings Software Developer, Codethink Ltd.
[RFC PATCH 0/3] Introduce kernel small arrays (KSA)
Hi guys, Please review the approach of using small fixed-sized arrays to improve parsing of values like get_options() does. This comes to me after fixing an overflow in get_options(). See the thread for details: https://lkml.org/lkml/2017/5/22/581 If the approach is OK I’ll suggest to replace all of get_options() calls to ksa_parse_ints() and remove get_options() at all. Thank you.
[RFC PATCH 0/3] Introduce kernel small arrays (KSA)
Hi guys, Please review the approach of using small fixed-sized arrays to improve parsing of values like get_options() does. This comes to me after fixing an overflow in get_options(). See the thread for details: https://lkml.org/lkml/2017/5/22/581 If the approach is OK I’ll suggest to replace all of get_options() calls to ksa_parse_ints() and remove get_options() at all. Thank you.