diff options
| author | Dave Thaler | 2024-05-17 08:34:45 -0700 |
|---|---|---|
| committer | Alexei Starovoitov | 2024-05-25 10:37:49 -0700 |
| commit | 4652072e7b9d643edc9ebb04e3e2c021461b7af0 (patch) | |
| tree | 19ee76f42e4dd42c51b0fed02ab269c0d4053c60 /Documentation/bpf | |
| parent | 2c1713a8f1c94033a6e00aae4693ab03e8a3b9f1 (diff) | |
bpf, docs: Move sentence about returning R0 to abi.rst
As discussed at LSF/MM/BPF, the sentence about using R0 for returning
values from calls is part of the calling convention and belongs in
abi.rst. Any further additions or clarifications to this text are left
for future patches on abi.rst. The current patch is simply to unblock
progression of instruction-set.rst to a standard.
In contrast, the restriction of register numbers to the range 0-10
is untouched, left in the instruction-set.rst definition of the
src_reg and dst_reg fields.
Signed-off-by: Dave Thaler <dthaler1968@googlemail.com>
Link: https://lore.kernel.org/r/20240517153445.3914-1-dthaler1968@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'Documentation/bpf')
| -rw-r--r-- | Documentation/bpf/standardization/abi.rst | 3 | ||||
| -rw-r--r-- | Documentation/bpf/standardization/instruction-set.rst | 3 |
2 files changed, 3 insertions, 3 deletions
diff --git a/Documentation/bpf/standardization/abi.rst b/Documentation/bpf/standardization/abi.rst index 0c2e10eeb89a..41514137cb7b 100644 --- a/Documentation/bpf/standardization/abi.rst +++ b/Documentation/bpf/standardization/abi.rst @@ -23,3 +23,6 @@ The BPF calling convention is defined as: R0 - R5 are scratch registers and BPF programs needs to spill/fill them if necessary across calls. + +The BPF program needs to store the return value into register R0 before doing an +``EXIT``. diff --git a/Documentation/bpf/standardization/instruction-set.rst b/Documentation/bpf/standardization/instruction-set.rst index 00c93eb42613..e2f6c0a4a559 100644 --- a/Documentation/bpf/standardization/instruction-set.rst +++ b/Documentation/bpf/standardization/instruction-set.rst @@ -476,9 +476,6 @@ the jump instruction. Thus 'PC += 1' skips execution of the next instruction if it's a basic instruction or results in undefined behavior if the next instruction is a 128-bit wide instruction. -The BPF program needs to store the return value into register R0 before doing an -``EXIT``. - Example: ``{JSGE, X, JMP32}`` means:: |