From: Dave Thaler <dthaler1968@googlemail.com>
To: bpf@vger.kernel.org
Cc: bpf@ietf.org, Dave Thaler <dthaler1968@gmail.com>
Subject: [PATCH bpf-next] bpf, docs: Clarify helper ID and pointer terms in instruction-set.rst
Date: Fri, 19 Apr 2024 13:36:17 -0700 [thread overview]
Message-ID: <20240419203617.6850-1-dthaler1968@gmail.com> (raw)
Per IETF 119 meeting discussion and mailing list discussion at
https://mailarchive.ietf.org/arch/msg/bpf/2JwWQwFdOeMGv0VTbD0CKWwAOEA/
the following changes are made.
First, say call by "static ID" rather than call by "address"
Second, change "pointer" to "address"
Signed-off-by: Dave Thaler <dthaler1968@gmail.com>
---
.../bpf/standardization/instruction-set.rst | 48 +++++++++----------
1 file changed, 24 insertions(+), 24 deletions(-)
diff --git a/Documentation/bpf/standardization/instruction-set.rst b/Documentation/bpf/standardization/instruction-set.rst
index 8d0781f0b..1f92551a3 100644
--- a/Documentation/bpf/standardization/instruction-set.rst
+++ b/Documentation/bpf/standardization/instruction-set.rst
@@ -443,27 +443,27 @@ otherwise identical operations, and indicates the base64 conformance
group unless otherwise specified.
The 'code' field encodes the operation as below:
-======== ===== ======= =============================== ===================================================
-code value src_reg description notes
-======== ===== ======= =============================== ===================================================
-JA 0x0 0x0 PC += offset {JA, K, JMP} only
-JA 0x0 0x0 PC += imm {JA, K, JMP32} only
+======== ===== ======= ================================= ===================================================
+code value src_reg description notes
+======== ===== ======= ================================= ===================================================
+JA 0x0 0x0 PC += offset {JA, K, JMP} only
+JA 0x0 0x0 PC += imm {JA, K, JMP32} only
JEQ 0x1 any PC += offset if dst == src
-JGT 0x2 any PC += offset if dst > src unsigned
-JGE 0x3 any PC += offset if dst >= src unsigned
+JGT 0x2 any PC += offset if dst > src unsigned
+JGE 0x3 any PC += offset if dst >= src unsigned
JSET 0x4 any PC += offset if dst & src
JNE 0x5 any PC += offset if dst != src
-JSGT 0x6 any PC += offset if dst > src signed
-JSGE 0x7 any PC += offset if dst >= src signed
-CALL 0x8 0x0 call helper function by address {CALL, K, JMP} only, see `Helper functions`_
-CALL 0x8 0x1 call PC += imm {CALL, K, JMP} only, see `Program-local functions`_
-CALL 0x8 0x2 call helper function by BTF ID {CALL, K, JMP} only, see `Helper functions`_
-EXIT 0x9 0x0 return {CALL, K, JMP} only
-JLT 0xa any PC += offset if dst < src unsigned
-JLE 0xb any PC += offset if dst <= src unsigned
-JSLT 0xc any PC += offset if dst < src signed
-JSLE 0xd any PC += offset if dst <= src signed
-======== ===== ======= =============================== ===================================================
+JSGT 0x6 any PC += offset if dst > src signed
+JSGE 0x7 any PC += offset if dst >= src signed
+CALL 0x8 0x0 call helper function by static ID {CALL, K, JMP} only, see `Helper functions`_
+CALL 0x8 0x1 call PC += imm {CALL, K, JMP} only, see `Program-local functions`_
+CALL 0x8 0x2 call helper function by BTF ID {CALL, K, JMP} only, see `Helper functions`_
+EXIT 0x9 0x0 return {CALL, K, JMP} only
+JLT 0xa any PC += offset if dst < src unsigned
+JLE 0xb any PC += offset if dst <= src unsigned
+JSLT 0xc any PC += offset if dst < src signed
+JSLE 0xd any PC += offset if dst <= src signed
+======== ===== ======= ================================= ===================================================
The BPF program needs to store the return value into register R0 before doing an
``EXIT``.
@@ -498,9 +498,9 @@ Helper functions
Helper functions are a concept whereby BPF programs can call into a
set of function calls exposed by the underlying platform.
-Historically, each helper function was identified by an address
+Historically, each helper function was identified by a static ID
encoded in the 'imm' field. The available helper functions may differ
-for each program type, but address values are unique across all program types.
+for each program type, but static IDs are unique across all program types.
Platforms that support the BPF Type Format (BTF) support identifying
a helper function by a BTF ID encoded in the 'imm' field, where the BTF ID
@@ -667,11 +667,11 @@ src_reg pseudocode imm type dst type
======= ========================================= =========== ==============
0x0 dst = (next_imm << 32) | imm integer integer
0x1 dst = map_by_fd(imm) map fd map
-0x2 dst = map_val(map_by_fd(imm)) + next_imm map fd data pointer
-0x3 dst = var_addr(imm) variable id data pointer
-0x4 dst = code_addr(imm) integer code pointer
+0x2 dst = map_val(map_by_fd(imm)) + next_imm map fd data address
+0x3 dst = var_addr(imm) variable id data address
+0x4 dst = code_addr(imm) integer code address
0x5 dst = map_by_idx(imm) map index map
-0x6 dst = map_val(map_by_idx(imm)) + next_imm map index data pointer
+0x6 dst = map_val(map_by_idx(imm)) + next_imm map index data address
======= ========================================= =========== ==============
where
--
2.40.1
WARNING: multiple messages have this Message-ID (diff)
From: Dave Thaler <dthaler1968=40googlemail.com@dmarc.ietf.org>
To: bpf@vger.kernel.org
Cc: bpf@ietf.org, Dave Thaler <dthaler1968@gmail.com>
Subject: [Bpf] [PATCH bpf-next] bpf, docs: Clarify helper ID and pointer terms in instruction-set.rst
Date: Fri, 19 Apr 2024 13:36:17 -0700 [thread overview]
Message-ID: <20240419203617.6850-1-dthaler1968@gmail.com> (raw)
Message-ID: <20240419203617.cjMr0f0teTbxyyj3G_IAO3snqxL1oyEaomPINpOmYNc@z> (raw)
Per IETF 119 meeting discussion and mailing list discussion at
https://mailarchive.ietf.org/arch/msg/bpf/2JwWQwFdOeMGv0VTbD0CKWwAOEA/
the following changes are made.
First, say call by "static ID" rather than call by "address"
Second, change "pointer" to "address"
Signed-off-by: Dave Thaler <dthaler1968@gmail.com>
---
.../bpf/standardization/instruction-set.rst | 48 +++++++++----------
1 file changed, 24 insertions(+), 24 deletions(-)
diff --git a/Documentation/bpf/standardization/instruction-set.rst b/Documentation/bpf/standardization/instruction-set.rst
index 8d0781f0b..1f92551a3 100644
--- a/Documentation/bpf/standardization/instruction-set.rst
+++ b/Documentation/bpf/standardization/instruction-set.rst
@@ -443,27 +443,27 @@ otherwise identical operations, and indicates the base64 conformance
group unless otherwise specified.
The 'code' field encodes the operation as below:
-======== ===== ======= =============================== ===================================================
-code value src_reg description notes
-======== ===== ======= =============================== ===================================================
-JA 0x0 0x0 PC += offset {JA, K, JMP} only
-JA 0x0 0x0 PC += imm {JA, K, JMP32} only
+======== ===== ======= ================================= ===================================================
+code value src_reg description notes
+======== ===== ======= ================================= ===================================================
+JA 0x0 0x0 PC += offset {JA, K, JMP} only
+JA 0x0 0x0 PC += imm {JA, K, JMP32} only
JEQ 0x1 any PC += offset if dst == src
-JGT 0x2 any PC += offset if dst > src unsigned
-JGE 0x3 any PC += offset if dst >= src unsigned
+JGT 0x2 any PC += offset if dst > src unsigned
+JGE 0x3 any PC += offset if dst >= src unsigned
JSET 0x4 any PC += offset if dst & src
JNE 0x5 any PC += offset if dst != src
-JSGT 0x6 any PC += offset if dst > src signed
-JSGE 0x7 any PC += offset if dst >= src signed
-CALL 0x8 0x0 call helper function by address {CALL, K, JMP} only, see `Helper functions`_
-CALL 0x8 0x1 call PC += imm {CALL, K, JMP} only, see `Program-local functions`_
-CALL 0x8 0x2 call helper function by BTF ID {CALL, K, JMP} only, see `Helper functions`_
-EXIT 0x9 0x0 return {CALL, K, JMP} only
-JLT 0xa any PC += offset if dst < src unsigned
-JLE 0xb any PC += offset if dst <= src unsigned
-JSLT 0xc any PC += offset if dst < src signed
-JSLE 0xd any PC += offset if dst <= src signed
-======== ===== ======= =============================== ===================================================
+JSGT 0x6 any PC += offset if dst > src signed
+JSGE 0x7 any PC += offset if dst >= src signed
+CALL 0x8 0x0 call helper function by static ID {CALL, K, JMP} only, see `Helper functions`_
+CALL 0x8 0x1 call PC += imm {CALL, K, JMP} only, see `Program-local functions`_
+CALL 0x8 0x2 call helper function by BTF ID {CALL, K, JMP} only, see `Helper functions`_
+EXIT 0x9 0x0 return {CALL, K, JMP} only
+JLT 0xa any PC += offset if dst < src unsigned
+JLE 0xb any PC += offset if dst <= src unsigned
+JSLT 0xc any PC += offset if dst < src signed
+JSLE 0xd any PC += offset if dst <= src signed
+======== ===== ======= ================================= ===================================================
The BPF program needs to store the return value into register R0 before doing an
``EXIT``.
@@ -498,9 +498,9 @@ Helper functions
Helper functions are a concept whereby BPF programs can call into a
set of function calls exposed by the underlying platform.
-Historically, each helper function was identified by an address
+Historically, each helper function was identified by a static ID
encoded in the 'imm' field. The available helper functions may differ
-for each program type, but address values are unique across all program types.
+for each program type, but static IDs are unique across all program types.
Platforms that support the BPF Type Format (BTF) support identifying
a helper function by a BTF ID encoded in the 'imm' field, where the BTF ID
@@ -667,11 +667,11 @@ src_reg pseudocode imm type dst type
======= ========================================= =========== ==============
0x0 dst = (next_imm << 32) | imm integer integer
0x1 dst = map_by_fd(imm) map fd map
-0x2 dst = map_val(map_by_fd(imm)) + next_imm map fd data pointer
-0x3 dst = var_addr(imm) variable id data pointer
-0x4 dst = code_addr(imm) integer code pointer
+0x2 dst = map_val(map_by_fd(imm)) + next_imm map fd data address
+0x3 dst = var_addr(imm) variable id data address
+0x4 dst = code_addr(imm) integer code address
0x5 dst = map_by_idx(imm) map index map
-0x6 dst = map_val(map_by_idx(imm)) + next_imm map index data pointer
+0x6 dst = map_val(map_by_idx(imm)) + next_imm map index data address
======= ========================================= =========== ==============
where
--
2.40.1
--
Bpf mailing list
Bpf@ietf.org
https://www.ietf.org/mailman/listinfo/bpf
next reply other threads:[~2024-04-19 20:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-19 20:36 Dave Thaler [this message]
2024-04-19 20:36 ` [Bpf] [PATCH bpf-next] bpf, docs: Clarify helper ID and pointer terms in instruction-set.rst Dave Thaler
2024-04-21 16:43 ` David Vernet
2024-04-21 16:43 ` David Vernet
2024-04-21 17:10 ` patchwork-bot+netdevbpf
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