[PATCH 06/15] ebpf-docs: Use standard type convention in standard doc

[dthaler1968@googlemail.com]

From: Dave Thaler <dthaler@microsoft.com>

Signed-off-by: Dave Thaler <dthaler@microsoft.com>
---
 Documentation/bpf/instruction-set.rst | 14 ++++++++++----
 Documentation/bpf/linux-notes.rst     |  6 ++++++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst
index 4997d2088..a24bc5d53 100644
--- a/Documentation/bpf/instruction-set.rst
+++ b/Documentation/bpf/instruction-set.rst
@@ -7,6 +7,10 @@ eBPF Instruction Set Specification, v1.0
 
 This document specifies version 1.0 of the eBPF instruction set.
 
+Documentation conventions
+=========================
+
+This specification uses the standard C types (uint32_t, etc.) in documentation.
 
 Registers and calling convention
 ================================
@@ -114,7 +118,9 @@ BPF_END   0xd0   byte swap operations (see `Byte swap instructions`_ below)
 
 ``BPF_ADD | BPF_X | BPF_ALU`` means::
 
-  dst_reg = (u32) dst_reg + (u32) src_reg;
+  dst_reg = (uint32_t) dst_reg + (uint32_t) src_reg;
+
+where '(uint32_t)' indicates truncation to 32 bits.
 
 ``BPF_ADD | BPF_X | BPF_ALU64`` means::
 
@@ -122,7 +128,7 @@ BPF_END   0xd0   byte swap operations (see `Byte swap instructions`_ below)
 
 ``BPF_XOR | BPF_K | BPF_ALU`` means::
 
-  src_reg = (u32) src_reg ^ (u32) imm32
+  src_reg = (uint32_t) src_reg ^ (uint32_t) imm32
 
 ``BPF_XOR | BPF_K | BPF_ALU64`` means::
 
@@ -276,11 +282,11 @@ BPF_XOR   0xa0   atomic xor
 
 ``BPF_ATOMIC | BPF_W  | BPF_STX`` with 'imm' = BPF_ADD means::
 
-  *(u32 *)(dst_reg + off16) += src_reg
+  *(uint32_t *)(dst_reg + off16) += src_reg
 
 ``BPF_ATOMIC | BPF_DW | BPF_STX`` with 'imm' = BPF ADD means::
 
-  *(u64 *)(dst_reg + off16) += src_reg
+  *(uint32_t *)(dst_reg + off16) += src_reg
 
 In addition to the simple atomic operations, there also is a modifier and
 two complex atomic operations:
diff --git a/Documentation/bpf/linux-notes.rst b/Documentation/bpf/linux-notes.rst
index 1c31379b4..522ebe27d 100644
--- a/Documentation/bpf/linux-notes.rst
+++ b/Documentation/bpf/linux-notes.rst
@@ -7,6 +7,12 @@ Linux implementation notes
 
 This document provides more details specific to the Linux kernel implementation of the eBPF instruction set.
 
+Arithmetic instructions
+=======================
+
+While the eBPF instruction set document uses the standard C terminology as the cross-platform specification,
+in the Linux kernel, uint32_t is expressed as u32, uint64_t is expressed as u64, etc.
+
 Byte swap instructions
 ======================
 
-- 
2.33.4