This is a followup to [0]: [PATCH] bpf: don't rely on GCC __attribute__((optimize)) to disable GCSE[0] Changes since v1: - only use -fno-gcse when CONFIG_BPF_JIT_ALWAYS_ON=y and CONFIG_CC_IS_GCC=y (but ignore CONFIG_RETPOLINE since we want to avoid GCSE in all cases) - to avoid potential impact of disabling GCSE on other code, put the interpreter in a separate file (patch #2) Note that patch #1 is intended for backporting, as function scope GCC optimization attributes are really quite broken. I don't have a strong opinion on whether the interpreter code should be split off or not, but it looks like it can be done fairly painlessly, so it is probably a good idea to do it anyway. [0] https://lore.kernel.org/bpf/20201027205723.12514-1-ardb@xxxxxxxxxx/ Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Cc: Arvind Sankar <nivedita@xxxxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Ard Biesheuvel (2): bpf: don't rely on GCC __attribute__((optimize)) to disable GCSE bpf: move interpreter into separate source file include/linux/compiler-gcc.h | 2 - include/linux/compiler_types.h | 4 - include/linux/filter.h | 1 + kernel/bpf/Makefile | 7 +- kernel/bpf/core.c | 567 ------------------ kernel/bpf/interp.c | 601 ++++++++++++++++++++ 6 files changed, 607 insertions(+), 575 deletions(-) create mode 100644 kernel/bpf/interp.c -- 2.17.1
