[PATCH v2 bpf-next 0/2] arm64/bpf: remove 128MB limit for BPF JIT programs

From: Alan Maguire <alan.maguire@oracle.com>
To: ardb@kernel.org, catalin.marinas@arm.com, will@kernel.org,
	daniel@iogearbox.net, ast@kernel.org
Cc: zlim.lnx@gmail.com, andrii@kernel.org, kafai@fb.com,
	songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com,
	kpsingh@kernel.org, andreyknvl@gmail.com,
	vincenzo.frascino@arm.com, mark.rutland@arm.com,
	samitolvanen@google.com, joey.gouly@arm.com, maz@kernel.org,
	daizhiyuan@phytium.com.cn, jthierry@redhat.com,
	tiantao6@hisilicon.com, pcc@google.com,
	akpm@linux-foundation.org, rppt@kernel.org,
	Jisheng.Zhang@synaptics.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org, Alan Maguire <alan.maguire@oracle.com>
Subject: [PATCH v2 bpf-next 0/2] arm64/bpf: remove 128MB limit for BPF JIT programs
Date: Fri,  5 Nov 2021 16:50:44 +0000	[thread overview]
Message-ID: <1636131046-5982-1-git-send-email-alan.maguire@oracle.com> (raw)

There is a 128MB limit on BPF JIT program allocations; this is
to ensure BPF programs are in branching range of each other.
Patch 1 in this series removes this restriction.  To verify
exception handling still works, a test case to validate
exception handling in BPF programs is added in patch 2.

There was previous discussion around this topic [1], in particular
would be good to get feedback from Daniel if this approach makes
sense.

[1] https://lore.kernel.org/all/20181121131733.14910-1-ard.biesheuvel@linaro.org/

Changes since v1:

 - respin picked up changes in arm64 exception handling changes
   which removed need for special BPF exception handling in patch 1
 - made selftest use task creation/task_struct field instead to
   minimize BPF selftests parallel runs, moved from CHECK()s
   to ASSERT_*()s (Andrii, patch 2)

Alan Maguire (1):
  selftests/bpf: add exception handling selftests for tp_bpf program

Russell King (1):
  arm64/bpf: remove 128MB limit for BPF JIT programs

 arch/arm64/include/asm/extable.h                   |  9 -----
 arch/arm64/include/asm/memory.h                    |  5 +--
 arch/arm64/kernel/traps.c                          |  2 +-
 arch/arm64/mm/ptdump.c                             |  2 -
 arch/arm64/net/bpf_jit_comp.c                      |  7 +---
 tools/testing/selftests/bpf/prog_tests/exhandler.c | 43 ++++++++++++++++++++++
 tools/testing/selftests/bpf/progs/exhandler_kern.c | 43 ++++++++++++++++++++++
 7 files changed, 90 insertions(+), 21 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/exhandler.c
 create mode 100644 tools/testing/selftests/bpf/progs/exhandler_kern.c

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1.8.3.1