Hi folks, This is version two of the patches I previously posted as an RFC here: https://lore.kernel.org/lkml/20200110165636.28035-1-will@xxxxxxxxxx Changes since then include: * Adopted a less vomit-inducing series of macros for __unqual_scalar_typeof * Cast to 'const' in READ_ONCE() to prevent assignment to the resulting expression * Only warn once at build-time if GCC prior to 4.8 is detected... * ... and then raise the minimum GCC version to 4.8, with an error for older versions of the compiler * Remove some dead gcov code so that the resulting diffstat can distract from those less vomit-inducing macros I mentioned earlier on Failing the build for older compilers is always a contentious topic, so I've done that as a separate couple of patches on the end in case we end up dropping or reverting them. Cheers, Will Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx> Cc: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Peter Oberparleiter <oberpar@xxxxxxxxxxxxx> Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> --->8 Will Deacon (10): compiler/gcc: Emit build-time warning for GCC prior to version 4.8 netfilter: Avoid assigning 'const' pointer to non-const pointer fault_inject: Don't rely on "return value" from WRITE_ONCE() READ_ONCE: Simplify implementations of {READ,WRITE}_ONCE() READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses READ_ONCE: Drop pointer qualifiers when reading from scalar types locking/barriers: Use '__unqual_scalar_typeof' for load-acquire macros arm64: barrier: Use '__unqual_scalar_typeof' for acquire/release macros compiler/gcc: Raise minimum GCC version for kernel builds to 4.8 gcov: Remove old GCC 3.4 support Documentation/process/changes.rst | 2 +- arch/arm/crypto/Kconfig | 12 +- arch/arm64/include/asm/barrier.h | 16 +- crypto/Kconfig | 1 - drivers/xen/time.c | 2 +- include/asm-generic/barrier.h | 16 +- include/linux/compiler-gcc.h | 5 +- include/linux/compiler.h | 129 +++---- include/linux/compiler_types.h | 21 ++ init/Kconfig | 5 +- kernel/gcov/Kconfig | 24 -- kernel/gcov/Makefile | 3 +- kernel/gcov/gcc_3_4.c | 573 ------------------------------ lib/fault-inject.c | 4 +- net/netfilter/core.c | 2 +- net/xdp/xsk_queue.h | 2 +- scripts/Kconfig.include | 3 + scripts/gcc-plugins/Kconfig | 4 +- 18 files changed, 111 insertions(+), 713 deletions(-) delete mode 100644 kernel/gcov/gcc_3_4.c -- 2.25.0.341.g760bfbb309-goog
