From ebb856730cc80a9c1fd383d39284b17bdd08f61f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C3=A1draig=20Brady?= Date: Sat, 24 Jan 2026 18:04:46 +0000 Subject: [PATCH] tail: fix EINTR handling on older systems tail(1) could fail with an "Interrupted system call" diagnostic, on some systems like Centos 5 (Linux 2.6.18). This was seen with tests/tail/overlay-headers.sh which sends SIGCONT, which should not induce a failure. * src/tail.c (tail_forever_inotify): Retry the poll() upon receiving a non terminating signal, and the syscall is not automatically restarted by the system. * NEWS: Mention the bug fix. Reported by Bruno Haible. --- NEWS | 4 ++++ src/tail.c | 2 +- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/NEWS b/NEWS index c3c985bb3..a19744ddd 100644 --- a/NEWS +++ b/NEWS @@ -31,6 +31,10 @@ GNU coreutils NEWS -*- outline -*- 'numfmt' no longer drops custom suffixes from numbers it cannot fully parse. [bug introduced with numfmt in coreutils-8.21] + 'tail -f --pid' can no longer exit upon receiving a non terminating signal. + On older Linux systems it may have failed with "Interrupted system call". + [bug introduced in coreutils-7.5] + 'timeout' will now propagate all terminating signals to the monitored command. Previously 'timeout' could have exited and left the monitored command running. [bug introduced with timeout in coreutils-7.0] diff --git a/src/tail.c b/src/tail.c index e549f5df0..c0d4e0329 100644 --- a/src/tail.c +++ b/src/tail.c @@ -1684,7 +1684,7 @@ tail_forever_inotify (int wd, struct File_spec *f, int n_files, pfd[1].events = pfd[1].revents = 0; file_change = poll (pfd, monitor_output + 1, delay); } - while (file_change == 0); + while (file_change == 0 || (file_change < 0 && errno == EINTR)); if (file_change < 0) error (EXIT_FAILURE, errno,