From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Wed, 21 Nov 2018 14:17:31 +0100 Subject: [PATCH v2 0/2] bpf: permit JIT allocations to be served outside the module region Message-ID: <20181121131733.14910-1-ard.biesheuvel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On arm64, modules are allocated from a 128 MB window which is close to the core kernel, so that relative direct branches are guaranteed to be in range (except in some KASLR configurations). Also, module_alloc() is in charge of allocating KASAN shadow memory when running with KASAN enabled. This means that the way BPF reuses module_alloc()/module_memfree() is undesirable on arm64 (and potentially other architectures as well), and so this series refactors BPF's use of those functions to permit architectures to change this behavior. Patch #1 breaks out the module_alloc() and module_memfree() calls into __weak functions so they can be overridden. Patch #4 implements the new alloc/free overrides for arm64 Changes since v1: - Drop misguided attempt to 'fix' and refactor the free path. Instead, just add another __weak wrapper for the invocation of module_memfree() Cc: Daniel Borkmann Cc: Alexei Starovoitov Cc: Rick Edgecombe Cc: Eric Dumazet Cc: Jann Horn Cc: Kees Cook Cc: Jessica Yu Cc: Arnd Bergmann Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: "David S. Miller" Cc: linux-arm-kernel at lists.infradead.org Cc: linux-kernel at vger.kernel.org Cc: netdev at vger.kernel.org Ard Biesheuvel (2): bpf: add __weak hook for allocating executable memory arm64/bpf: don't allocate BPF JIT programs in module memory arch/arm64/net/bpf_jit_comp.c | 10 ++++++++++ kernel/bpf/core.c | 14 ++++++++++++-- 2 files changed, 22 insertions(+), 2 deletions(-) -- 2.17.1