[PATCH 1/2] man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH

[PATCH 1/2] man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH

[funsafemath]

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Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH flag, which allows to
use SECCOMP_FILTER_FLAG_TSYNC and SECCOMP_FILTER_FLAG_NEW_LISTENER
flags together by returning ESRCH on synchronization error instead
of the thread ID.

<https://lore.kernel.org/r/20200304180517.23867-1-tycho@tycho.ws>
---
 man/man2/seccomp.2 | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/man/man2/seccomp.2 b/man/man2/seccomp.2
index 75c7b2d58..0729a653c 100644
--- a/man/man2/seccomp.2
+++ b/man/man2/seccomp.2
@@ -241,6 +241,21 @@ .SH DESCRIPTION
 .B SECCOMP_MODE_STRICT
 or if it has attached new seccomp filters to itself,
 diverging from the calling thread's filter tree.
+.TP
+.BR SECCOMP_FILTER_FLAG_TSYNC_ESRCH " (since Linux 5.7)"
+.\" commit 51891498f2da78ee64dfad88fa53c9e85fb50abf
+Return
+.B ESRCH
+instead of the thread ID on synchronization failure if
+.B  SECCOMP_FILTER_FLAG_TSYNC
+was specified.
+.IP
+If this flag is not set, using
+.B SECCOMP_FILTER_FLAG_NEW_LISTENER
+and
+.B SECCOMP_FILTER_FLAG_TSYNC
+flags together results in
+.BR EINVAL .
 .RE
 .TP
 .BR SECCOMP_GET_ACTION_AVAIL " (since Linux 4.14)"
-- 
2.52.0


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Re: [PATCH 1/2] man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH

[Alejandro Colomar]

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Hi,

On 2026-05-16T21:53:17+0100, funsafemath wrote:
> Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH flag, which allows to
> use SECCOMP_FILTER_FLAG_TSYNC and SECCOMP_FILTER_FLAG_NEW_LISTENER
> flags together by returning ESRCH on synchronization error instead
> of the thread ID.
> 
> <https://lore.kernel.org/r/20200304180517.23867-1-tycho@tycho.ws>
> ---

Would you mind signing the patch?

>  man/man2/seccomp.2 | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/man/man2/seccomp.2 b/man/man2/seccomp.2
> index 75c7b2d58..0729a653c 100644
> --- a/man/man2/seccomp.2
> +++ b/man/man2/seccomp.2
> @@ -241,6 +241,21 @@ .SH DESCRIPTION
>  .B SECCOMP_MODE_STRICT
>  or if it has attached new seccomp filters to itself,
>  diverging from the calling thread's filter tree.
> +.TP
> +.BR SECCOMP_FILTER_FLAG_TSYNC_ESRCH " (since Linux 5.7)"
> +.\" commit 51891498f2da78ee64dfad88fa53c9e85fb50abf
> +Return
> +.B ESRCH

I expect that in user space, we'll see -1 in the return value, and ESRCH
in errno, right?  If so, we should say "Fail with ESRCH ...".

> +instead of the thread ID on synchronization failure if
> +.B  SECCOMP_FILTER_FLAG_TSYNC

Spurious double space.  s/  / /


Have a lovely day!
Alex

> +was specified.
> +.IP
> +If this flag is not set, using
> +.B SECCOMP_FILTER_FLAG_NEW_LISTENER
> +and
> +.B SECCOMP_FILTER_FLAG_TSYNC
> +flags together results in
> +.BR EINVAL .
>  .RE
>  .TP
>  .BR SECCOMP_GET_ACTION_AVAIL " (since Linux 4.14)"
> -- 
> 2.52.0
> 



-- 
<https://www.alejandro-colomar.es>

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[PATCH v2 0/2] Document seccomp flags

[funsafemath]

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Hello,

Yes, a libc wrapper would return -1, I've changed the wording and applied other suggestions.

funsafemath (2):
  man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH
  man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV

 man/man2/seccomp.2 | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

Range-diff against v1:
1:  c3c3b728b ! 1:  fec59f483 man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH
    @@ Commit message
     
         <https://lore.kernel.org/r/20200304180517.23867-1-tycho@tycho.ws>
     
    +    Signed-off-by: funsafemath <funsafemath@proton.me>
    +
      ## man/man2/seccomp.2 ##
     @@ man/man2/seccomp.2: .SH DESCRIPTION
      .B SECCOMP_MODE_STRICT
    @@ man/man2/seccomp.2: .SH DESCRIPTION
     +.TP
     +.BR SECCOMP_FILTER_FLAG_TSYNC_ESRCH " (since Linux 5.7)"
     +.\" commit 51891498f2da78ee64dfad88fa53c9e85fb50abf
    -+Return
    ++Fail with
     +.B ESRCH
    -+instead of the thread ID on synchronization failure if
    -+.B  SECCOMP_FILTER_FLAG_TSYNC
    ++instead of returning the thread ID on synchronization failure if
    ++.B SECCOMP_FILTER_FLAG_TSYNC
     +was specified.
     +.IP
     +If this flag is not set, using
2:  423b0141b ! 2:  8ead033b8 man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV
    @@ Commit message
     
         Relevant kernel documentation: <Documentation/userspace-api/seccomp_filter.rst>
     
    +    Signed-off-by: funsafemath <funsafemath@proton.me>
    +
      ## man/man2/seccomp.2 ##
     @@ man/man2/seccomp.2: .SH DESCRIPTION
      .B SECCOMP_FILTER_FLAG_TSYNC
    @@ man/man2/seccomp.2: .SH DESCRIPTION
     +.\" commit c2aa2dfef243efe213a480a1ee8566507a5152f4
     +Ignore non-fatal signals until the supervisor sends a response.
     +.IP
    ++The
     +.B SECCOMP_FILTER_FLAG_NEW_LISTENER
     +flag must be set.
      .RE
-- 
2.52.0


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[PATCH v2 1/2] man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH

[funsafemath]

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Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH flag, which allows to
use SECCOMP_FILTER_FLAG_TSYNC and SECCOMP_FILTER_FLAG_NEW_LISTENER
flags together by returning ESRCH on synchronization error instead
of the thread ID.

<https://lore.kernel.org/r/20200304180517.23867-1-tycho@tycho.ws>

Signed-off-by: funsafemath <funsafemath@proton.me>
---
 man/man2/seccomp.2 | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/man/man2/seccomp.2 b/man/man2/seccomp.2
index 75c7b2d58..a2776aab7 100644
--- a/man/man2/seccomp.2
+++ b/man/man2/seccomp.2
@@ -241,6 +241,21 @@ .SH DESCRIPTION
 .B SECCOMP_MODE_STRICT
 or if it has attached new seccomp filters to itself,
 diverging from the calling thread's filter tree.
+.TP
+.BR SECCOMP_FILTER_FLAG_TSYNC_ESRCH " (since Linux 5.7)"
+.\" commit 51891498f2da78ee64dfad88fa53c9e85fb50abf
+Fail with
+.B ESRCH
+instead of returning the thread ID on synchronization failure if
+.B SECCOMP_FILTER_FLAG_TSYNC
+was specified.
+.IP
+If this flag is not set, using
+.B SECCOMP_FILTER_FLAG_NEW_LISTENER
+and
+.B SECCOMP_FILTER_FLAG_TSYNC
+flags together results in
+.BR EINVAL .
 .RE
 .TP
 .BR SECCOMP_GET_ACTION_AVAIL " (since Linux 4.14)"
-- 
2.52.0


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[PATCH v2 2/2] man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV

[funsafemath]

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Document the SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV flag,
which makes the process ignore non-fatal signals until the supervisor sends a response

Relevant kernel documentation: <Documentation/userspace-api/seccomp_filter.rst>

Signed-off-by: funsafemath <funsafemath@proton.me>
---
 man/man2/seccomp.2 | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/man/man2/seccomp.2 b/man/man2/seccomp.2
index a2776aab7..d01a9eeaa 100644
--- a/man/man2/seccomp.2
+++ b/man/man2/seccomp.2
@@ -256,6 +256,14 @@ .SH DESCRIPTION
 .B SECCOMP_FILTER_FLAG_TSYNC
 flags together results in
 .BR EINVAL .
+.TP
+.BR SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV " (since Linux 5.19)"
+.\" commit c2aa2dfef243efe213a480a1ee8566507a5152f4
+Ignore non-fatal signals until the supervisor sends a response.
+.IP
+The
+.B SECCOMP_FILTER_FLAG_NEW_LISTENER
+flag must be set.
 .RE
 .TP
 .BR SECCOMP_GET_ACTION_AVAIL " (since Linux 4.14)"
-- 
2.52.0


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Re: [PATCH 1/2] man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH

[Tycho Andersen]

On Sat, May 16, 2026 at 11:38:48PM +0200, Alejandro Colomar wrote:
> Hi,
> 
> On 2026-05-16T21:53:17+0100, funsafemath wrote:
> > Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH flag, which allows to
> > use SECCOMP_FILTER_FLAG_TSYNC and SECCOMP_FILTER_FLAG_NEW_LISTENER
> > flags together by returning ESRCH on synchronization error instead
> > of the thread ID.
> > 
> > <https://lore.kernel.org/r/20200304180517.23867-1-tycho@tycho.ws>
> > ---
> 
> Would you mind signing the patch?
> 
> >  man/man2/seccomp.2 | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> > 
> > diff --git a/man/man2/seccomp.2 b/man/man2/seccomp.2
> > index 75c7b2d58..0729a653c 100644
> > --- a/man/man2/seccomp.2
> > +++ b/man/man2/seccomp.2
> > @@ -241,6 +241,21 @@ .SH DESCRIPTION
> >  .B SECCOMP_MODE_STRICT
> >  or if it has attached new seccomp filters to itself,
> >  diverging from the calling thread's filter tree.
> > +.TP
> > +.BR SECCOMP_FILTER_FLAG_TSYNC_ESRCH " (since Linux 5.7)"
> > +.\" commit 51891498f2da78ee64dfad88fa53c9e85fb50abf
> > +Return
> > +.B ESRCH
> 
> I expect that in user space, we'll see -1 in the return value, and ESRCH
> in errno, right?  If so, we should say "Fail with ESRCH ...".

Yes, exactly. Probably worth changing the wording in the commit
message as well.

Tycho

Re: [PATCH v2 0/2] Document seccomp flags

[Alejandro Colomar]

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Hi,

On 2026-05-18T04:13:08+0100, funsafemath wrote:
> Hello,
> 
> Yes, a libc wrapper would return -1, I've changed the wording and applied other suggestions.
> 
> funsafemath (2):
>   man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH
>   man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV

Thanks!  I've applied both patches.


Have a lovely night!
Alex

> 
>  man/man2/seccomp.2 | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> Range-diff against v1:
> 1:  c3c3b728b ! 1:  fec59f483 man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH
>     @@ Commit message
>      
>          <https://lore.kernel.org/r/20200304180517.23867-1-tycho@tycho.ws>
>      
>     +    Signed-off-by: funsafemath <funsafemath@proton.me>
>     +
>       ## man/man2/seccomp.2 ##
>      @@ man/man2/seccomp.2: .SH DESCRIPTION
>       .B SECCOMP_MODE_STRICT
>     @@ man/man2/seccomp.2: .SH DESCRIPTION
>      +.TP
>      +.BR SECCOMP_FILTER_FLAG_TSYNC_ESRCH " (since Linux 5.7)"
>      +.\" commit 51891498f2da78ee64dfad88fa53c9e85fb50abf
>     -+Return
>     ++Fail with
>      +.B ESRCH
>     -+instead of the thread ID on synchronization failure if
>     -+.B  SECCOMP_FILTER_FLAG_TSYNC
>     ++instead of returning the thread ID on synchronization failure if
>     ++.B SECCOMP_FILTER_FLAG_TSYNC
>      +was specified.
>      +.IP
>      +If this flag is not set, using
> 2:  423b0141b ! 2:  8ead033b8 man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV
>     @@ Commit message
>      
>          Relevant kernel documentation: <Documentation/userspace-api/seccomp_filter.rst>
>      
>     +    Signed-off-by: funsafemath <funsafemath@proton.me>
>     +
>       ## man/man2/seccomp.2 ##
>      @@ man/man2/seccomp.2: .SH DESCRIPTION
>       .B SECCOMP_FILTER_FLAG_TSYNC
>     @@ man/man2/seccomp.2: .SH DESCRIPTION
>      +.\" commit c2aa2dfef243efe213a480a1ee8566507a5152f4
>      +Ignore non-fatal signals until the supervisor sends a response.
>      +.IP
>     ++The
>      +.B SECCOMP_FILTER_FLAG_NEW_LISTENER
>      +flag must be set.
>       .RE
> -- 
> 2.52.0
> 



-- 
<https://www.alejandro-colomar.es>

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Re: [PATCH 1/2] man/man2/seccomp.2: Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH

[Alejandro Colomar]

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Hi Tycho,

On 2026-05-18T08:04:40-0600, Tycho Andersen wrote:
> On Sat, May 16, 2026 at 11:38:48PM +0200, Alejandro Colomar wrote:
> > Hi,
> > 
> > On 2026-05-16T21:53:17+0100, funsafemath wrote:
> > > Document SECCOMP_FILTER_FLAG_TSYNC_ESRCH flag, which allows to
> > > use SECCOMP_FILTER_FLAG_TSYNC and SECCOMP_FILTER_FLAG_NEW_LISTENER
> > > flags together by returning ESRCH on synchronization error instead
> > > of the thread ID.
> > > 
> > > <https://lore.kernel.org/r/20200304180517.23867-1-tycho@tycho.ws>
> > > ---
> > 
> > Would you mind signing the patch?
> > 
> > >  man/man2/seccomp.2 | 15 +++++++++++++++
> > >  1 file changed, 15 insertions(+)
> > > 
> > > diff --git a/man/man2/seccomp.2 b/man/man2/seccomp.2
> > > index 75c7b2d58..0729a653c 100644
> > > --- a/man/man2/seccomp.2
> > > +++ b/man/man2/seccomp.2
> > > @@ -241,6 +241,21 @@ .SH DESCRIPTION
> > >  .B SECCOMP_MODE_STRICT
> > >  or if it has attached new seccomp filters to itself,
> > >  diverging from the calling thread's filter tree.
> > > +.TP
> > > +.BR SECCOMP_FILTER_FLAG_TSYNC_ESRCH " (since Linux 5.7)"
> > > +.\" commit 51891498f2da78ee64dfad88fa53c9e85fb50abf
> > > +Return
> > > +.B ESRCH
> > 
> > I expect that in user space, we'll see -1 in the return value, and ESRCH
> > in errno, right?  If so, we should say "Fail with ESRCH ...".
> 
> Yes, exactly. Probably worth changing the wording in the commit
> message as well.

Thanks!  I've amended the commit message while applying v2.


Have a lovely night!
Alex

> 
> Tycho

-- 
<https://www.alejandro-colomar.es>

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