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

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

[Dave Thaler]

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
 ~~~~~~~~~~~~~~~~
 
-- 
2.33.4

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

[David Vernet]

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

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

[John Fastabend]

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>

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

[patchwork-bot+netdevbpf]

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!
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