fix(execute): make sure Type=exec and PAMName= work together - #417
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fix(execute): make sure Type=exec and PAMName= work together#417deepin-ci-robot wants to merge 1 commit into
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If PAMName= is used we'll spawn a PAM session for the service, and leave a process around that closes the PAM session eventually. That process must close the "exec_fd" that we use to implement Type=exec. After all the logic relies on the fact that execve() will implicitly close the exec_fd, and the EOF seen on it is hence indication for the service manager that execve() has worked. But if we keep an fd open in the PAM service process, then this is not going to work. Hence close the fd explicitly so that it definitely doesn't stay pinned in the child. Changes: - Add debian/patches/fix-execute-type-exec-pamname-work-together.patch - Modify debian/patches/series - Modify debian/changelog Upstream: systemd/systemd@5863f1d Generated-By: glm-5.3-flash Co-Authored-By: deepin-ci-robot <packages@deepin.org>
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Problem Before the Change
When a service unit combined
Type=execwithPAMName=, systemd spawned a separate PAM child process (sd-pam) to handle the PAM session cleanup. That child inherited the service'sexec_fd, which is used to implementType=exec. The manager relies on seeing EOF onexec_fd— induced byexecve()implicitly closing it — to detect that the service successfully started. Because the PAM child kept the fd open, EOF never arrived and the manager waited forever, deadlocking service startup.What This PR Changes
Backport of upstream systemd commit 5863f1da:
setup_pam()now receives theexec_fdas a parameter and explicitly closes it (safe_close()) in the PAM child process, so the fd is no longer pinned in the child and the manager's EOF detection works as intended.Problem Solved After the Change
Services with both
Type=execandPAMName=start reliably: once the main process callsexecve(), the manager observes EOF onexec_fdand transitions the service out of the "starting" state instead of hanging indefinitely.Changes
Upstream
systemd/systemd@5863f1d (upstream PR: #30733)
Generated-By: glm-5.3-flash
Co-Authored-By: deepin-ci-robot packages@deepin.org