diff options
Diffstat (limited to 'Documentation/bpf')
| -rw-r--r-- | Documentation/bpf/bpf_devel_QA.rst | 7 | ||||
| -rw-r--r-- | Documentation/bpf/standardization/instruction-set.rst | 6 |
2 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst index 0acb4c9b8d90..45bc5c5cd793 100644 --- a/Documentation/bpf/bpf_devel_QA.rst +++ b/Documentation/bpf/bpf_devel_QA.rst @@ -611,9 +611,10 @@ Q: I have added a new BPF instruction to the kernel, how can I integrate it into LLVM? A: LLVM has a ``-mcpu`` selector for the BPF back end in order to allow -the selection of BPF instruction set extensions. By default the -``generic`` processor target is used, which is the base instruction set -(v1) of BPF. +the selection of BPF instruction set extensions. Before llvm version 20, +the ``generic`` processor target is used, which is the base instruction +set (v1) of BPF. Since llvm 20, the default processor target has changed +to instruction set v3. LLVM has an option to select ``-mcpu=probe`` where it will probe the host kernel for supported BPF instruction set extensions and selects the diff --git a/Documentation/bpf/standardization/instruction-set.rst b/Documentation/bpf/standardization/instruction-set.rst index fbe975585236..39c74611752b 100644 --- a/Documentation/bpf/standardization/instruction-set.rst +++ b/Documentation/bpf/standardization/instruction-set.rst @@ -350,9 +350,9 @@ Underflow and overflow are allowed during arithmetic operations, meaning the 64-bit or 32-bit value will wrap. If BPF program execution would result in division by zero, the destination register is instead set to zero. Otherwise, for ``ALU64``, if execution would result in ``LLONG_MIN`` -dividing -1, the desination register is instead set to ``LLONG_MIN``. For -``ALU``, if execution would result in ``INT_MIN`` dividing -1, the -desination register is instead set to ``INT_MIN``. +divided by -1, the destination register is instead set to ``LLONG_MIN``. For +``ALU``, if execution would result in ``INT_MIN`` divided by -1, the +destination register is instead set to ``INT_MIN``. If execution would result in modulo by zero, for ``ALU64`` the value of the destination register is unchanged whereas for ``ALU`` the upper |