On 10/27, dthaler1968@xxxxxxxxxxxxxx wrote:
From: Dave Thaler <dthaler@xxxxxxxxxxxxx>
Add note about type convention
Signed-off-by: Dave Thaler <dthaler@xxxxxxxxxxxxx>
For the series:
Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Carry-on from my shift last week.
---
Documentation/bpf/instruction-set.rst | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/Documentation/bpf/instruction-set.rst
b/Documentation/bpf/instruction-set.rst
index 5d798437d..bed6d33fc 100644
--- a/Documentation/bpf/instruction-set.rst
+++ b/Documentation/bpf/instruction-set.rst
@@ -7,6 +7,11 @@ eBPF Instruction Set Specification, v1.0
This document specifies version 1.0 of the eBPF instruction set.
+Documentation conventions
+=========================
+
+For brevity, this document uses the type notion "u64", "u32", etc.
+to mean an unsigned integer whose width is the specified number of bits.
Registers and calling convention
================================
@@ -116,6 +121,8 @@ BPF_END 0xd0 byte swap operations (see `Byte swap
instructions`_ below)
dst_reg = (u32) dst_reg + (u32) src_reg;
+where '(u32)' indicates truncation to 32 bits.
+
``BPF_ADD | BPF_X | BPF_ALU64`` means::
dst_reg = dst_reg + src_reg
--
2.33.4
