From e21ed1cebed09df11b4bf7809fd6d69b25457127 Mon Sep 17 00:00:00 2001 From: Jonathan Nieder Date: Mon, 8 Aug 2011 06:22:43 +0200 Subject: [PATCH] cap_syslog: don't use WARN_ONCE for CAP_SYS_ADMIN deprecation warning MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit f2c0d0266cc5eb36a4aa44944b4096ec121490aa upstream. syslog-ng versions before 3.3.0beta1 (2011-05-12) assume that CAP_SYS_ADMIN is sufficient to access syslog, so ever since CAP_SYSLOG was introduced (2010-11-25) they have triggered a warning. Commit ee24aebffb75 ("cap_syslog: accept CAP_SYS_ADMIN for now") improved matters a little by making syslog-ng work again, just keeping the WARN_ONCE(). But still, this is a warning that writes a stack trace we don't care about to syslog, sets a taint flag, and alarms sysadmins when nothing worse has happened than use of an old userspace with a recent kernel. Convert the WARN_ONCE to a printk_once to avoid that while continuing to give userspace developers a hint that this is an unwanted backward-compatibility feature and won't be around forever. Reported-by: Ralf Hildebrandt Reported-by: Niels Reported-by: Paweł Sikora Signed-off-by: Jonathan Nieder Liked-by: Gergely Nagy Acked-by: Serge Hallyn Acked-by: James Morris Signed-off-by: Linus Torvalds Cc: Christoph Biedl Signed-off-by: Greg Kroah-Hartman --- kernel/printk.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/printk.c b/kernel/printk.c index 084982f61dee..3fc470872a64 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -318,8 +318,10 @@ static int check_syslog_permissions(int type, bool from_file) return 0; /* For historical reasons, accept CAP_SYS_ADMIN too, with a warning */ if (capable(CAP_SYS_ADMIN)) { - WARN_ONCE(1, "Attempt to access syslog with CAP_SYS_ADMIN " - "but no CAP_SYSLOG (deprecated).\n"); + printk_once(KERN_WARNING "%s (%d): " + "Attempt to access syslog with CAP_SYS_ADMIN " + "but no CAP_SYSLOG (deprecated).\n", + current->comm, task_pid_nr(current)); return 0; } return -EPERM; -- 2.39.5