[bpf-next] docs/bpf: Fix an incorrect statement in verifier.rst

Commit Message

Yonghong Song Jan. 11, 2024, 5:21 a.m. UTC

In verifier.rst, I found an incorrect statement (maybe a typo) in section
'Liveness marks tracking'. Basically, the wrong register is attributed
to have a read mark. This may confuse the user.

Signed-off-by: Yonghong Song <[e-mail]>
---
 Documentation/bpf/verifier.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Alexei Starovoitov Jan. 13, 2024, 10:39 p.m. UTC | #1

On Wed, Jan 10, 2024 at 9:21 PM Yonghong Song <[e-mail]> wrote:
>
> In verifier.rst, I found an incorrect statement (maybe a typo) in section
> 'Liveness marks tracking'. Basically, the wrong register is attributed
> to have a read mark. This may confuse the user.
>
> Signed-off-by: Yonghong Song <[e-mail]>
> ---
>  Documentation/bpf/verifier.rst | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Documentation/bpf/verifier.rst b/Documentation/bpf/verifier.rst
> index f0ec19db301c..356894399fbf 100644
> --- a/Documentation/bpf/verifier.rst
> +++ b/Documentation/bpf/verifier.rst
> @@ -562,7 +562,7 @@ works::
>    * ``checkpoint[0].r1`` is marked as read;
>
>  * At instruction #5 exit is reached and ``checkpoint[0]`` can now be processed
> -  by ``clean_live_states()``. After this processing ``checkpoint[0].r0`` has a
> +  by ``clean_live_states()``. After this processing ``checkpoint[0].r1`` has a
>    read mark and all other registers and stack slots are marked as ``NOT_INIT``
>    or ``STACK_INVALID``

The typo fix looks correct to me.

Eduard,
since you're the author of this line. Pls double check.

Eduard Zingerman Jan. 13, 2024, 10:59 p.m. UTC | #2

On Sat, 2024-01-13 at 14:39 -0800, Alexei Starovoitov wrote:
[...]
> > diff --git a/Documentation/bpf/verifier.rst b/Documentation/bpf/verifier.rst
> > index f0ec19db301c..356894399fbf 100644
> > --- a/Documentation/bpf/verifier.rst
> > +++ b/Documentation/bpf/verifier.rst
> > @@ -562,7 +562,7 @@ works::
> >    * ``checkpoint[0].r1`` is marked as read;
> > 
> >  * At instruction #5 exit is reached and ``checkpoint[0]`` can now be processed
> > -  by ``clean_live_states()``. After this processing ``checkpoint[0].r0`` has a
> > +  by ``clean_live_states()``. After this processing ``checkpoint[0].r1`` has a
> >    read mark and all other registers and stack slots are marked as ``NOT_INIT``
> >    or ``STACK_INVALID``
> 
> The typo fix looks correct to me.
> 
> Eduard,
> since you're the author of this line. Pls double check.

Right, it should be r1, my mistake.

Acked-by: Eduard Zingerman <[e-mail]>

[e-mail] Jan. 13, 2024, 11:10 p.m. UTC | #3

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <[e-mail]>:

On Wed, 10 Jan 2024 21:21:36 -0800 you wrote:
> In verifier.rst, I found an incorrect statement (maybe a typo) in section
> 'Liveness marks tracking'. Basically, the wrong register is attributed
> to have a read mark. This may confuse the user.
> 
> Signed-off-by: Yonghong Song <[e-mail]>
> ---
>  Documentation/bpf/verifier.rst | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Here is the summary with links:
  - [bpf-next] docs/bpf: Fix an incorrect statement in verifier.rst
    https://git.kernel.org/bpf/bpf-next/c/90bde89658fb

You are awesome, thank you!

Patch

diff --git a/Documentation/bpf/verifier.rst b/Documentation/bpf/verifier.rst
index f0ec19db301c..356894399fbf 100644
--- a/Documentation/bpf/verifier.rst
+++ b/Documentation/bpf/verifier.rst
@@ -562,7 +562,7 @@  works::
   * ``checkpoint[0].r1`` is marked as read;
 
 * At instruction #5 exit is reached and ``checkpoint[0]`` can now be processed
-  by ``clean_live_states()``. After this processing ``checkpoint[0].r0`` has a
+  by ``clean_live_states()``. After this processing ``checkpoint[0].r1`` has a
   read mark and all other registers and stack slots are marked as ``NOT_INIT``
   or ``STACK_INVALID``