From: dthaler1968@googlemail.com
To: bpf@vger.kernel.org
Cc: Dave Thaler <dthaler@microsoft.com>
Subject: [PATCH 14/15] ebpf-docs: Add extended call instructions
Date: Tue, 27 Sep 2022 18:59:57 +0000 [thread overview]
Message-ID: <20220927185958.14995-14-dthaler1968@googlemail.com> (raw)
In-Reply-To: <20220927185958.14995-1-dthaler1968@googlemail.com>
From: Dave Thaler <dthaler@microsoft.com>
Signed-off-by: Dave Thaler <dthaler@microsoft.com>
---
Documentation/bpf/instruction-set.rst | 52 +++++++++++++++++----------
1 file changed, 34 insertions(+), 18 deletions(-)
diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst
index 667d97715..2ac8f0dae 100644
--- a/Documentation/bpf/instruction-set.rst
+++ b/Documentation/bpf/instruction-set.rst
@@ -265,24 +265,26 @@ otherwise identical operations.
The 4-bit 'code' field encodes the operation as below, where PC is the program counter:
-======== ===== ========================= ============
-code value description notes
-======== ===== ========================= ============
-BPF_JA 0x00 PC += off BPF_JMP only
-BPF_JEQ 0x10 PC += off if dst == src
-BPF_JGT 0x20 PC += off if dst > src unsigned
-BPF_JGE 0x30 PC += off if dst >= src unsigned
-BPF_JSET 0x40 PC += off if dst & src
-BPF_JNE 0x50 PC += off if dst != src
-BPF_JSGT 0x60 PC += off if dst > src signed
-BPF_JSGE 0x70 PC += off if dst >= src signed
-BPF_CALL 0x80 function call see `Helper functions`_
-BPF_EXIT 0x90 function / program return BPF_JMP only
-BPF_JLT 0xa0 PC += off if dst < src unsigned
-BPF_JLE 0xb0 PC += off if dst <= src unsigned
-BPF_JSLT 0xc0 PC += off if dst < src signed
-BPF_JSLE 0xd0 PC += off if dst <= src signed
-======== ===== ========================= ============
+======== ===== === ========================== ========================
+code value src description notes
+======== ===== === ========================== ========================
+BPF_JA 0x0 0x0 PC += offset BPF_JMP only
+BPF_JEQ 0x1 any PC += offset if dst == src
+BPF_JGT 0x2 any PC += offset if dst > src unsigned
+BPF_JGE 0x3 any PC += offset if dst >= src unsigned
+BPF_JSET 0x4 any PC += offset if dst & src
+BPF_JNE 0x5 any PC += offset if dst != src
+BPF_JSGT 0x6 any PC += offset if dst > src signed
+BPF_JSGE 0x7 any PC += offset if dst >= src signed
+BPF_CALL 0x8 0x0 call helper function imm see `Helper functions`_
+BPF_CALL 0x8 0x1 call PC += offset see `eBPF functions`_
+BPF_CALL 0x8 0x2 call runtime function imm see `Runtime functions`_
+BPF_EXIT 0x9 0x0 return BPF_JMP only
+BPF_JLT 0xa any PC += offset if dst < src unsigned
+BPF_JLE 0xb any PC += offset if dst <= src unsigned
+BPF_JSLT 0xc any PC += offset if dst < src signed
+BPF_JSLE 0xd any PC += offset if dst <= src signed
+======== ===== === ========================== ========================
Helper functions
~~~~~~~~~~~~~~~~
@@ -301,6 +303,18 @@ with the remaining registers being ignored. The definition of a helper function
is responsible for specifying the type (e.g., integer, pointer, etc.) of the value returned,
the number of arguments, and the type of each argument.
+Runtime functions
+~~~~~~~~~~~~~~~~~
+Runtime functions are like helper functions except that they are not specific
+to eBPF programs. They use a different numbering space from helper functions,
+but otherwise the same considerations apply.
+
+eBPF functions
+~~~~~~~~~~~~~~
+eBPF functions are functions exposed by the same eBPF program as the caller,
+and are referenced by offset from the call instruction, similar to ``BPF_JA``.
+A ``BPF_EXIT`` within the eBPF function will return to the caller.
+
Load and store instructions
===========================
@@ -585,6 +599,8 @@ opcode src imm description referenc
0x7f any 0x00 dst >>= src `Arithmetic instructions`_
0x84 0x0 0x00 dst = (uint32_t)-dst `Arithmetic instructions`_
0x85 0x0 any call helper function imm `Helper functions`_
+0x85 0x1 any call PC += offset `eBPF functions`_
+0x85 0x2 any call runtime function imm `Runtime functions`_
0x87 0x0 0x00 dst = -dst `Arithmetic instructions`_
0x94 0x0 any dst = (uint32_t)((imm != 0) ? (dst % imm) : dst) `Arithmetic instructions`_
0x95 0x0 0x00 return `Jump instructions`_
--
2.33.4
next prev parent reply other threads:[~2022-09-27 19:00 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-27 18:59 [PATCH 01/15] ebpf-docs: Move legacy packet instructions to a separate file dthaler1968
2022-09-27 18:59 ` [PATCH 02/15] ebpf-docs: Linux byteswap note dthaler1968
2022-09-27 18:59 ` [PATCH 03/15] ebpf-docs: Move Clang notes to a separate file dthaler1968
2022-09-27 18:59 ` [PATCH 04/15] ebpf-docs: Add Clang note about BPF_ALU dthaler1968
2022-09-27 18:59 ` [PATCH 05/15] ebpf-docs: Add TOC and fix formatting dthaler1968
2022-09-27 18:59 ` [PATCH 06/15] ebpf-docs: Use standard type convention in standard doc dthaler1968
2022-09-30 20:49 ` Alexei Starovoitov
2022-09-27 18:59 ` [PATCH 07/15] ebpf-docs: Fix modulo zero, division by zero, overflow, and underflow dthaler1968
2022-09-30 20:52 ` Alexei Starovoitov
2022-09-30 21:54 ` Dave Thaler
2022-09-30 21:59 ` Alexei Starovoitov
2022-09-30 22:41 ` Dave Thaler
2022-09-30 23:41 ` Alexei Starovoitov
2022-10-04 16:36 ` Dave Thaler
2022-10-04 17:24 ` div_k. Was: " Alexei Starovoitov
2022-10-04 18:23 ` Dave Thaler
2022-10-04 18:34 ` Alexei Starovoitov
2023-09-29 21:03 ` Signed modulo operations Dave Thaler
2023-09-29 21:03 ` [Bpf] " Dave Thaler
2023-09-30 6:07 ` Carsten Bormann
2023-09-30 6:07 ` Carsten Bormann
2023-09-30 14:48 ` Alexei Starovoitov
2023-09-30 14:48 ` Alexei Starovoitov
2023-10-02 13:19 ` Eduard Zingerman
2022-09-27 18:59 ` [PATCH 08/15] ebpf-docs: Use consistent names for the same field dthaler1968
2022-09-30 20:57 ` Alexei Starovoitov
2022-10-04 14:44 ` Dave Thaler
2022-09-27 18:59 ` [PATCH 09/15] ebpf-docs: Explain helper functions dthaler1968
2022-09-30 22:01 ` Alexei Starovoitov
2022-09-30 23:01 ` Dave Thaler
2022-09-27 18:59 ` [PATCH 10/15] ebpf-docs: Add appendix of all opcodes in order dthaler1968
2022-09-30 22:02 ` Alexei Starovoitov
2022-09-30 22:43 ` Dave Thaler
2022-09-27 18:59 ` [PATCH 11/15] ebpf-docs: Improve English readability dthaler1968
2022-09-30 22:16 ` Alexei Starovoitov
2022-10-04 14:32 ` Dave Thaler
2022-10-04 15:38 ` Alexei Starovoitov
2022-10-04 15:55 ` Dave Thaler
2022-10-04 15:56 ` Dave Thaler
2022-10-04 16:19 ` Alexei Starovoitov
2022-10-04 16:41 ` Dave Thaler
2022-10-04 16:54 ` Dave Thaler
2022-10-06 20:44 ` Jim Harris
2022-09-27 18:59 ` [PATCH 12/15] ebpf-docs: Add Linux note about register calling convention dthaler1968
2022-09-30 22:17 ` Alexei Starovoitov
2022-09-27 18:59 ` [PATCH 13/15] ebpf-docs: Add extended 64-bit immediate instructions dthaler1968
2022-09-27 18:59 ` dthaler1968 [this message]
2022-09-27 18:59 ` [PATCH 15/15] ebpf-docs: Add note about invalid instruction dthaler1968
2022-09-30 22:21 ` Alexei Starovoitov
2022-09-30 20:50 ` [PATCH 01/15] ebpf-docs: Move legacy packet instructions to a separate file patchwork-bot+netdevbpf
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