Messages in this thread | | | Date | Fri, 19 Nov 2021 10:26:19 -0800 | From | Kees Cook <> | Subject | Re: [PATCH] skbuff: Switch structure bounds to struct_group() |
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On Thu, Nov 18, 2021 at 11:13:55PM -0800, Jakub Kicinski wrote: > On Thu, 18 Nov 2021 10:36:15 -0800 Kees Cook wrote: > > In preparation for FORTIFY_SOURCE performing compile-time and run-time > > field bounds checking for memcpy(), memmove(), and memset(), avoid > > intentionally writing across neighboring fields. > > > > Replace the existing empty member position markers "headers_start" and > > "headers_end" with a struct_group(). This will allow memcpy() and sizeof() > > to more easily reason about sizes, and improve readability. > > > > "pahole" shows no size nor member offset changes to struct sk_buff. > > "objdump -d" shows no object code changes (outside of WARNs affected by > > source line number changes). > > This adds ~27k of these warnings to W=1 gcc builds: > > include/linux/skbuff.h:851:1: warning: directive in macro's argument list
Hrm, I can't reproduce this, using several GCC versions and net-next. What compiler version[1] and base commit[2] were used here?
-Kees
[1] https://github.com/kuba-moo/nipa/pull/10 [2] https://github.com/kuba-moo/nipa/pull/11
-- Kees Cook
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