[PATCH v5 0/6] kernel.h: container_of() pointer checking

From: Ian Abbott
Date: Thu May 25 2017 - 08:05:38 EST


TL;DR: This series of patches splits BUILD_BUG related macros out of
"include/linux/bug.h" into new file "include/linux/build_bug.h" (patch
5), and changes the pointer type checking in the `container_of()` macro
to deal with pointers of array type better (patch 6). Patches 1 to 4
are prerequisites.

Patches 2, 3, 4, and 5 have been inserted since the previous version of
this patch series. Patch 6 here corresponds to v3 and v4's patch 2.

Patch 1 was a prerequisite in v3 of this series to avoid a lot of
warnings when <linux/bug.h> was included by <linux/kernel.h>. That is
no longer relevant for v5 of the series, but I left it in because it was
acked by a Arnd Bergmann and Michal Nazarewicz.

Patches 2, 3, and 4 are some checkpatch clean-ups on
"include/linux/bug.h" before splitting out the BUILD_BUG stuff in patch
5.

Patch 5 splits the BUILD_BUG related macros out of
"include/linux/bug.h" into new file "include/linux/build_bug.h" because
including <linux/bug.h> in "include/linux/kernel.h" would result in
build failures due to circular dependencies.

Patch 6 changes the pointer type checking by `container_of()` to avoid
some incompatible pointer warnings when the dereferenced pointer has
array type.

1) asm-generic/bug.h: declare struct pt_regs; before function prototype
2) linux/bug.h: correct formatting of block comment
3) linux/bug.h: correct "(foo*)" should be "(foo *)"
4) linux/bug.h: correct "space required before that '-'"
5) bug: split BUILD_BUG stuff out into <linux/build_bug.h>
6) kernel.h: handle pointers to arrays better in container_of()

include/asm-generic/bug.h | 1 +
include/linux/bug.h | 72 +---------------------------------------
include/linux/build_bug.h | 84 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/kernel.h | 9 +++--
4 files changed, 92 insertions(+), 74 deletions(-)