[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20200430064301.1099452-5-ar@cs.msu.ru>
Date: Thu, 30 Apr 2020 09:42:58 +0300
From: Arseny Maslennikov <ar@...msu.ru>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Jiri Slaby <jslaby@...e.com>, linux-serial@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: Arseny Maslennikov <ar@...msu.ru>, Rob Landley <rob@...dley.net>,
"Eric W. Biederman" <ebiederm@...ssion.com>,
Pavel Machek <pavel@....cz>, linux-api@...r.kernel.org,
"Vladimir D. Seleznev" <vseleznv@...linux.org>
Subject: [PATCH v3 4/7] linux/signal.h: Ignore SIGINFO by default in new tasks
This matches the behaviour of other Unix-like systems that have SIGINFO
and causes less harm to processes that do not install handlers for this
signal, making the keyboard status character non-fatal for them.
This is implemented with the assumption that SIGINFO is defined
to be equivalent to SIGPWR; still, there is no reason for PWR to
result in termination of the signal recipient anyway — it does not
indicate there is a fatal problem with the recipient's execution
context (like e.g. FPE/ILL do), and we have TERM/KILL for explicit
termination requests.
To put it another way:
The only scenario where system behaviour actually changes is when the
signal recipient has default disposition for SIGPWR. If a process
chose to interpret a SIGPWR as an incentive to cleanly terminate, it
would supply its own handler — and this commit does not affect processes
with non-default handlers.
Signed-off-by: Arseny Maslennikov <ar@...msu.ru>
---
include/linux/signal.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/signal.h b/include/linux/signal.h
index 05bacd2ab..dc31da8fc 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -369,7 +369,7 @@ extern bool unhandled_signal(struct task_struct *tsk, int sig);
* | SIGSYS/SIGUNUSED | coredump |
* | SIGSTKFLT | terminate |
* | SIGWINCH | ignore |
- * | SIGPWR | terminate |
+ * | SIGPWR | ignore |
* | SIGRTMIN-SIGRTMAX | terminate |
* +--------------------+------------------+
* | non-POSIX signal | default action |
@@ -420,7 +420,8 @@ extern bool unhandled_signal(struct task_struct *tsk, int sig);
#define SIG_KERNEL_IGNORE_MASK (\
rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
- rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
+ rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) | \
+ rt_sigmask(SIGINFO) )
#define SIG_SPECIFIC_SICODES_MASK (\
rt_sigmask(SIGILL) | rt_sigmask(SIGFPE) | \
--
2.26.2
Powered by blists - more mailing lists