On Sun, Dec 02, 2018 at 07:23:45PM +0100, Ruediger Meier wrote:
> From: Ruediger Meier <ruediger.meier@xxxxxxxxxxx>
>
> This reverts parts of commit eb06d5d4, which seems to be based on
> Linux kernel commit c7acec71. Unlike the original kernel patch we did
> not add that even stronger type checking by using macro BUILD_BUG_ON_MSG.
> So basically we removed a useful warning when compiling such
> broken code:
>
> struct st {
> int a;
> char b;
> };
> struct st t = { .a = 1, .b = 2 };
> struct st *x = container_of(&t.a, struct st, b);
> printf("%p %p\n", (void *)&t, (void *)x);
>
> Moreover we also introduced a new compiler warning for intel/icc:
> "arithmetic on pointer to void or function type"
>
> Let's just revert the update of container_of() because adding a
> kernel-like BUILD_BUG_ON_MSG would be too much noise and also
> problematic (see kernel commit c03567a8). Also note that the original
> problem addressed by the kernel commit seems to be only reproducible
> with gcc 4.9, not with any later gcc nor clang,icc. Moreover, currently
> we have no such use-case in the UL sources anyways.
Interesting, I do not see any issue with list_entry(() now ;-)
Applied, thanks!
Karel
--
Karel Zak <kzak@xxxxxxxxxx>
http://karelzak.blogspot.com
