Commit fb213ecb authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

docs/bpf: Fix malformed documentation 



Two issues are fixed:
  1. Malformed table due to newly-introduced BPF_MOVSX
  2. Missing reference link for ``Sign-extension load operations``

Fixes: 245d4c40 ("docs/bpf: Add documentation for new instructions")
Cc: bpf@ietf.org
Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307291840.Cqhj7uox-lkp@intel.com/


Signed-off-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230730004251.381307-1-yonghong.song@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent eb03993a

Documentation/bpf/standardization/instruction-set.rst

+24 −21
Original line number Diff line number Diff line
@@ -154,9 +154,9 @@ otherwise identical operations. 
The 'code' field encodes the operation as below, where 'src' and 'dst' refer

to the values of the source and destination registers, respectively.



========  =====  =======  ==========================================================

=========  =====  =======  ==========================================================

code       value  offset   description

========  =====  =======  ==========================================================

=========  =====  =======  ==========================================================

BPF_ADD    0x00   0        dst += src

BPF_SUB    0x10   0        dst -= src

BPF_MUL    0x20   0        dst \*= src
@@ -174,7 +174,7 @@ BPF_MOV 0xb0 0 dst = src 
BPF_MOVSX  0xb0   8/16/32  dst = (s8,s16,s32)src

BPF_ARSH   0xc0   0        sign extending dst >>= (src & mask)

BPF_END    0xd0   0        byte swap operations (see `Byte swap instructions`_ below)

========  =====  =======  ==========================================================

=========  =====  =======  ==========================================================



Underflow and overflow are allowed during arithmetic operations, meaning

the 64-bit or 32-bit value will wrap. If eBPF program execution would
@@ -397,6 +397,9 @@ instructions that transfer data between a register and memory. 
Where size is one of: ``BPF_B``, ``BPF_H``, ``BPF_W``, or ``BPF_DW`` and

'unsigned size' is one of u8, u16, u32 or u64.



Sign-extension load operations

------------------------------



The ``BPF_MEMSX`` mode modifier is used to encode sign-extension load

instructions that transfer data between a register and memory.