From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Alexei Starovoitov <ast@kernel.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
Jann Horn <jannh@google.com>, Kees Cook <keescook@chromium.org>,
Jessica Yu <jeyu@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
"David S. Miller" <davem@davemloft.net>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH v2 0/2] bpf: permit JIT allocations to be served outside the module region
Date: Wed, 21 Nov 2018 14:17:31 +0100 [thread overview]
Message-ID: <20181121131733.14910-1-ard.biesheuvel@linaro.org> (raw)
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 <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@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
next reply other threads:[~2018-11-21 13:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-21 13:17 Ard Biesheuvel [this message]
2018-11-21 13:17 ` [PATCH v2 1/2] bpf: add __weak hook for allocating executable memory Ard Biesheuvel
2018-11-22 20:01 ` kbuild test robot
2018-11-22 21:08 ` Ard Biesheuvel
2018-11-21 13:17 ` [PATCH v2 2/2] arm64/bpf: don't allocate BPF JIT programs in module memory Ard Biesheuvel
2018-11-21 23:20 ` Daniel Borkmann
2018-11-22 8:02 ` Ard Biesheuvel
2018-11-22 22:49 ` Daniel Borkmann
2018-11-24 2:57 ` kbuild test robot
2018-11-21 19:48 ` [PATCH v2 0/2] bpf: permit JIT allocations to be served outside the module region Edgecombe, Rick P
2018-11-21 20:36 ` Ard Biesheuvel
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