diff options
Diffstat (limited to 'Documentation/bpf')
| -rw-r--r-- | Documentation/bpf/standardization/instruction-set.rst | 45 |
1 files changed, 24 insertions, 21 deletions
diff --git a/Documentation/bpf/standardization/instruction-set.rst b/Documentation/bpf/standardization/instruction-set.rst index fb8154cedd84..655494ac7af6 100644 --- a/Documentation/bpf/standardization/instruction-set.rst +++ b/Documentation/bpf/standardization/instruction-set.rst @@ -154,27 +154,27 @@ 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 -BPF_DIV 0x30 0 dst = (src != 0) ? (dst / src) : 0 -BPF_SDIV 0x30 1 dst = (src != 0) ? (dst s/ src) : 0 -BPF_OR 0x40 0 dst \|= src -BPF_AND 0x50 0 dst &= src -BPF_LSH 0x60 0 dst <<= (src & mask) -BPF_RSH 0x70 0 dst >>= (src & mask) -BPF_NEG 0x80 0 dst = -dst -BPF_MOD 0x90 0 dst = (src != 0) ? (dst % src) : dst -BPF_SMOD 0x90 1 dst = (src != 0) ? (dst s% src) : dst -BPF_XOR 0xa0 0 dst ^= src -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) -======== ===== ======= ========================================================== +========= ===== ======= ========================================================== +code value offset description +========= ===== ======= ========================================================== +BPF_ADD 0x00 0 dst += src +BPF_SUB 0x10 0 dst -= src +BPF_MUL 0x20 0 dst \*= src +BPF_DIV 0x30 0 dst = (src != 0) ? (dst / src) : 0 +BPF_SDIV 0x30 1 dst = (src != 0) ? (dst s/ src) : 0 +BPF_OR 0x40 0 dst \|= src +BPF_AND 0x50 0 dst &= src +BPF_LSH 0x60 0 dst <<= (src & mask) +BPF_RSH 0x70 0 dst >>= (src & mask) +BPF_NEG 0x80 0 dst = -dst +BPF_MOD 0x90 0 dst = (src != 0) ? (dst % src) : dst +BPF_SMOD 0x90 1 dst = (src != 0) ? (dst s% src) : dst +BPF_XOR 0xa0 0 dst ^= src +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. |