Hi folks, (trimmed CC list since v4 since this is largely just a rebase)
This is version five of the READ_ONCE() codegen improvement series that I've previously posted here: RFC: https://lore.kernel.org/lkml/[email protected] v2: https://lore.kernel.org/lkml/[email protected] v3: https://lore.kernel.org/lkml/[email protected] v4: https://lore.kernel.org/lkml/[email protected] The main change since v4 is that this is now based on top of the KCSAN changes queued in -tip (locking/kcsan) and therefore contains the patches necessary to avoid breaking sparc32 as well as some cleanups to consolidate {READ,WRITE}_ONCE() and data_race(). Other changes include: * Treat 'char' as distinct from 'signed char' and 'unsigned char' for __builtin_types_compatible_p() * Add a compile-time assertion that the argument to READ_ONCE_NOCHECK() points at something the same size as 'unsigned long' I'm happy for all of this to go via -tip, or I can take it via arm64. Please let me know. Cheers, Will Cc: Marco Elver <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> --->8 Will Deacon (18): sparc32: mm: Fix argument checking in __srmmu_get_nocache() sparc32: mm: Restructure sparc32 MMU page-table layout sparc32: mm: Change pgtable_t type to pte_t * instead of struct page * sparc32: mm: Reduce allocation size for PMD and PTE tables compiler/gcc: Raise minimum GCC version for kernel builds to 4.8 netfilter: Avoid assigning 'const' pointer to non-const pointer net: tls: Avoid assigning 'const' pointer to non-const pointer fault_inject: Don't rely on "return value" from WRITE_ONCE() arm64: csum: Disable KASAN for do_csum() 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 gcov: Remove old GCC 3.4 support kcsan: Rework data_race() so that it can be used by READ_ONCE() READ_ONCE: Use data_race() to avoid KCSAN instrumentation linux/compiler.h: Remove redundant '#else' Documentation/process/changes.rst | 2 +- arch/arm/crypto/Kconfig | 12 +- arch/arm64/include/asm/barrier.h | 16 +- arch/arm64/lib/csum.c | 20 +- arch/sparc/include/asm/page_32.h | 12 +- arch/sparc/include/asm/pgalloc_32.h | 11 +- arch/sparc/include/asm/pgtable_32.h | 40 +- arch/sparc/include/asm/pgtsrmmu.h | 36 +- arch/sparc/include/asm/viking.h | 5 +- arch/sparc/kernel/head_32.S | 8 +- arch/sparc/mm/hypersparc.S | 3 +- arch/sparc/mm/srmmu.c | 95 ++--- arch/sparc/mm/viking.S | 5 +- crypto/Kconfig | 1 - drivers/xen/time.c | 2 +- include/asm-generic/barrier.h | 16 +- include/linux/compiler-gcc.h | 5 +- include/linux/compiler.h | 207 +++++----- include/linux/compiler_types.h | 26 ++ init/Kconfig | 1 - 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/tls/tls_main.c | 2 +- scripts/gcc-plugins/Kconfig | 2 +- 27 files changed, 257 insertions(+), 876 deletions(-) delete mode 100644 kernel/gcov/gcc_3_4.c -- 2.26.2.645.ge9eca65c58-goog
