diff mbox series

[bpf-next] bpf, docs: Add signed comparison example

Message ID 20230310233814.4641-1-dthaler1968@googlemail.com (mailing list archive)
State Accepted
Commit b9fe8e8d03d0df28b2431e3aaf8e115cf7bf2f65
Delegated to: BPF
Headers show
Series [bpf-next] bpf, docs: Add signed comparison example | expand

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netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 20 this patch: 20
netdev/cc_maintainers warning 14 maintainers not CCed: void@manifault.com andrii@kernel.org song@kernel.org sdf@google.com corbet@lwn.net haoluo@google.com yhs@fb.com linux-doc@vger.kernel.org daniel@iogearbox.net john.fastabend@gmail.com kpsingh@kernel.org jolsa@kernel.org martin.lau@linux.dev ast@kernel.org
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Commit Message

Dave Thaler March 10, 2023, 11:38 p.m. UTC 
From: Dave Thaler <dthaler@microsoft.com>

Improve clarity by adding an example of a signed comparison instruction

Signed-off-by: Dave Thaler <dthaler@microsoft.com>
---
 Documentation/bpf/instruction-set.rst | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Comments

David Vernet March 11, 2023, 7:27 p.m. UTC | #1 
On Fri, Mar 10, 2023 at 11:38:14PM +0000, Dave Thaler wrote:
> From: Dave Thaler <dthaler@microsoft.com>
> 
> Improve clarity by adding an example of a signed comparison instruction
> 
> Signed-off-by: Dave Thaler <dthaler@microsoft.com>

Acked-by: David Vernet <void@manifault.com>

> ---
>  Documentation/bpf/instruction-set.rst | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst
> index 5e43e14abe8..b4464058905 100644
> --- a/Documentation/bpf/instruction-set.rst
> +++ b/Documentation/bpf/instruction-set.rst
> @@ -11,7 +11,8 @@ Documentation conventions
>  =========================
>  
>  For brevity, this document uses the type notion "u64", "u32", etc.
> -to mean an unsigned integer whose width is the specified number of bits.
> +to mean an unsigned integer whose width is the specified number of bits,
> +and "s32", etc. to mean a signed integer of the specified number of bits.
>  
>  Registers and calling convention
>  ================================
> @@ -264,6 +265,14 @@ BPF_JSLE  0xd0   PC += off if dst <= src    signed
>  The eBPF program needs to store the return value into register R0 before doing a
>  BPF_EXIT.
>  
> +Example:
> +
> +``BPF_JSGE | BPF_X | BPF_JMP32`` (0x7e) means::
> +
> +  if (s32)dst s>= (s32)src goto +offset
> +
> +where 's>=' indicates a signed '>=' comparison.
> +
>  Helper functions
>  ~~~~~~~~~~~~~~~~
>  
> -- 
> 2.33.4
> 
> -- 
> Bpf mailing list
> Bpf@ietf.org
> https://www.ietf.org/mailman/listinfo/bpf
John Fastabend March 14, 2023, 5 a.m. UTC | #2 
Dave Thaler wrote:
> From: Dave Thaler <dthaler@microsoft.com>
> 
> Improve clarity by adding an example of a signed comparison instruction
> 
> Signed-off-by: Dave Thaler <dthaler@microsoft.com>
> ---
>  Documentation/bpf/instruction-set.rst | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst
> index 5e43e14abe8..b4464058905 100644
> --- a/Documentation/bpf/instruction-set.rst
> +++ b/Documentation/bpf/instruction-set.rst
> @@ -11,7 +11,8 @@ Documentation conventions
>  =========================
>  
>  For brevity, this document uses the type notion "u64", "u32", etc.
> -to mean an unsigned integer whose width is the specified number of bits.
> +to mean an unsigned integer whose width is the specified number of bits,
> +and "s32", etc. to mean a signed integer of the specified number of bits.
>  
>  Registers and calling convention
>  ================================
> @@ -264,6 +265,14 @@ BPF_JSLE  0xd0   PC += off if dst <= src    signed
>  The eBPF program needs to store the return value into register R0 before doing a
>  BPF_EXIT.
>  
> +Example:
> +
> +``BPF_JSGE | BPF_X | BPF_JMP32`` (0x7e) means::
> +
> +  if (s32)dst s>= (s32)src goto +offset
> +
> +where 's>=' indicates a signed '>=' comparison.
> +
>  Helper functions
>  ~~~~~~~~~~~~~~~~
>  
 

Acked-by: John Fastabend <john.fastabend@gmail.com>
patchwork-bot+netdevbpf@kernel.org March 14, 2023, 5:20 a.m. UTC | #3 
Hello:

This patch was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:

On Fri, 10 Mar 2023 23:38:14 +0000 you wrote:
> From: Dave Thaler <dthaler@microsoft.com>
> 
> Improve clarity by adding an example of a signed comparison instruction
> 
> Signed-off-by: Dave Thaler <dthaler@microsoft.com>
> ---
>  Documentation/bpf/instruction-set.rst | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)

Here is the summary with links:
  - [bpf-next] bpf, docs: Add signed comparison example
    https://git.kernel.org/bpf/bpf-next/c/b9fe8e8d03d0

You are awesome, thank you!
diff mbox series

Patch

diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst
index 5e43e14abe8..b4464058905 100644
--- a/Documentation/bpf/instruction-set.rst
+++ b/Documentation/bpf/instruction-set.rst
@@ -11,7 +11,8 @@  Documentation conventions
 =========================
 
 For brevity, this document uses the type notion "u64", "u32", etc.
-to mean an unsigned integer whose width is the specified number of bits.
+to mean an unsigned integer whose width is the specified number of bits,
+and "s32", etc. to mean a signed integer of the specified number of bits.
 
 Registers and calling convention
 ================================
@@ -264,6 +265,14 @@  BPF_JSLE  0xd0   PC += off if dst <= src    signed
 The eBPF program needs to store the return value into register R0 before doing a
 BPF_EXIT.
 
+Example:
+
+``BPF_JSGE | BPF_X | BPF_JMP32`` (0x7e) means::
+
+  if (s32)dst s>= (s32)src goto +offset
+
+where 's>=' indicates a signed '>=' comparison.
+
 Helper functions
 ~~~~~~~~~~~~~~~~