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Alexei Starovoitov
f7e6bd33d1
Yonghong Song says: ==================== bpf: Support new insns from cpu v4 In previous discussion ([1]), it is agreed that we should introduce cpu version 4 (llvm flag -mcpu=v4) which contains some instructions which can simplify code, make code easier to understand, fix the existing problem, or simply for feature completeness. More specifically, the following new insns are proposed: . sign extended load . sign extended mov . bswap . signed div/mod . ja with 32-bit offset This patch set added kernel support for insns proposed in [1] except BPF_ST which already has full kernel support. Beside the above proposed insns, LLVM will generate BPF_ST insn as well under -mcpu=v4. The llvm patch ([2]) has been merged into llvm-project 'main' branch. The patchset implements interpreter, jit and verifier support for these new insns. For this patch set, I tested cpu v2/v3/v4 and the selftests are all passed. I also tested selftests introduced in this patch set with additional changes beside normal jit testing (bpf_jit_enable = 1 and bpf_jit_harden = 0) - bpf_jit_enable = 0 - bpf_jit_enable = 1 and bpf_jit_harden = 1 and both testing passed. [1] https://lore.kernel.org/bpf/4bfe98be-5333-1c7e-2f6d-42486c8ec039@meta.com/ [2] https://reviews.llvm.org/D144829 Changelogs: v4 -> v5: . for v4, patch 8/17 missed in mailing list and patchwork, so resend. . rebase on top of master v3 -> v4: . some minor asm syntax adjustment based on llvm change. . add clang version and target arch guard for new tests so they can still compile with old llvm compilers. . some changes to the bpf doc. v2 -> v3: . add missed disasm change from v2. . handle signed load of ctx fields properly. . fix some interpreter sdiv/smod error when bpf_jit_enable = 0. . fix some verifier range bounding errors. . add more C tests. RFCv1 -> v2: . add more verifier supports for signed extend load and mov insns. . rename some insn names to be more consistent with intel practice. . add cpuv4 test runner for test progs. . add more unit and C tests. . add documentation. ==================== Link: https://lore.kernel.org/r/20230728011143.3710005-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linux kernel
============
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be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
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the problems which may result by upgrading your kernel.