[PATCH pmg-api 1/3] pmgpolicy: fix failing run_command in children

[PATCH pmg-api 1/3] pmgpolicy: fix failing run_command in children

[Dominik Csapak]

Net::Server::PreForkSimple installs a handler for that in the parent
which reaps all children automatically with `waitpid(-1, ...)` and this
gets copied over on fork. Normally, the default `run_child` method sets
this back to the default, but in pmgpolicy that is overwritten and not
all signal handlers are set correctly.

This handler with its waitpid will be called before the one in
`run_command` which results in an error there.

To fix this, simply do what the default `run_child` does and set SIGCHLD
to 'DEFAULT'.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
 src/bin/pmgpolicy | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/bin/pmgpolicy b/src/bin/pmgpolicy
index d7d440c..31bffe7 100755
--- a/src/bin/pmgpolicy
+++ b/src/bin/pmgpolicy
@@ -1002,6 +1002,8 @@ sub run_child {
         exit;
     };
 
+    $SIG{'CHLD'} = 'DEFAULT';
+
     delete $prop->{children};
 
     $self->child_init_hook;
-- 
2.47.3

[RFC PATCH pmg-api 2/3] pmgpolicy: mimic Net::Server::PreForkSimple's signal handlers in child

[Dominik Csapak]

In PreForkSimple's `run_child` method, some signal handlers are reset
that were copied over from the parent process. In pmgpolicy this method
gets overwritten and some handlers are overwritten like the default,
except SIGPIPE.

This shouldn't introduce any changes currently since it's set to IGNORE
in the parent already, but by mimicking the run_child behavior, we
protect against future changes when it might get set to something else
in the parent.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
sending as RFC because i'm currently not sure if it makes a difference
at all, but it seems like the correct approach, considering it's what
PreForkSimple also does.

 src/bin/pmgpolicy | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/bin/pmgpolicy b/src/bin/pmgpolicy
index 31bffe7..e491d89 100755
--- a/src/bin/pmgpolicy
+++ b/src/bin/pmgpolicy
@@ -1003,6 +1003,7 @@ sub run_child {
     };
 
     $SIG{'CHLD'} = 'DEFAULT';
+    $SIG{'PIPE'} = 'IGNORE';
 
     delete $prop->{children};
 
-- 
2.47.3

[PATCH pmg-api 3/3] Revert "d/control: depend on proxmox-enterprise-support-keyring"

[Dominik Csapak]

This reverts commit 84ecdc14a35fba4ba1bd512c56b28184f50cb511.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
 debian/control | 1 -
 1 file changed, 1 deletion(-)

diff --git a/debian/control b/debian/control
index 9fdeccf..0d2567b 100644
--- a/debian/control
+++ b/debian/control
@@ -92,7 +92,6 @@ Depends: apt (>= 2~),
          postfix (>= 3.7.10),
          postgresql-17,
          proxmox-backup-client (>= 2.2.0),
-         proxmox-enterprise-support-keyring,
          proxmox-mini-journalreader (>= 1.3-1),
          proxmox-spamassassin (>= 4.0.0-2),
          proxmox-termproxy (>= 2.1.0),
-- 
2.47.3

Re: [PATCH pmg-api 3/3] Revert "d/control: depend on proxmox-enterprise-support-keyring"

[Dominik Csapak]

sorry, please disregard this 3/3 patch, i had this only to test the 
installation where that package was not yet available and forgot
to remove the commit before using git send-email...

applied: [PATCH pmg-api 1/3] pmgpolicy: fix failing run_command in children

[Stoiko Ivanov]

Thanks for the analysis and digging into this so quickly!

I gave it a spin on a reproducer of the issue (first only with your 1/3
and then additionally with your 2/3 applied) and it fixes the issue.

decided to apply both patches after looking through the commit-history of
pmgpolicy, and checking Net::Servers changes from a git-repository on
github [0] - it seems that the handling of SIGPIPE and SIGCHLD was added
at some point 2005 286cd15 ("fix signal handling"), while our
copy of run_child might have been copied off before that.
In any case it does not look like it was a deliberate decision to
keep the SIGCHLD handler from the parent.

I dropped the 3/3 that got sent by mistake.

[0]  https://github.com/rhandom/perl-net-server.git

On Wed, 10 Jun 2026 13:35:44 +0200, Dominik Csapak wrote:
> Net::Server::PreForkSimple installs a handler for that in the parent
> which reaps all children automatically with `waitpid(-1, ...)` and this
> gets copied over on fork. Normally, the default `run_child` method sets
> this back to the default, but in pmgpolicy that is overwritten and not
> all signal handlers are set correctly.
> 
> This handler with its waitpid will be called before the one in
> `run_command` which results in an error there.
> 
> [...]

Applied, thanks!

[1/3] pmgpolicy: fix failing run_command in children
      commit: 66d7976b9c73aacd94d0f66d5a28302a985cc5e5
[2/3] pmgpolicy: mimic Net::Server::PreForkSimple's signal handlers in child
      commit: c3b01e45d841e66779698fb03866fe5d397b56f3