Patch "arm64: Remove unimplemented syscall log message" has been added to the 4.15-stable tree

Patch "arm64: Remove unimplemented syscall log message" has been added to the 4.15-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    arm64: Remove unimplemented syscall log message

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     arm64-remove-unimplemented-syscall-log-message.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 1962682d2b2fbe6cfa995a85c53c069fadda473e Mon Sep 17 00:00:00 2001
From: Michael Weiser <michael.weiser@gmx.de>
Date: Thu, 1 Feb 2018 23:13:36 +0100
Subject: arm64: Remove unimplemented syscall log message

From: Michael Weiser <michael.weiser@gmx.de>

commit 1962682d2b2fbe6cfa995a85c53c069fadda473e upstream.

Stop printing a (ratelimited) kernel message for each instance of an
unimplemented syscall being called. Userland making an unimplemented
syscall is not necessarily misbehaviour and to be expected with a
current userland running on an older kernel. Also, the current message
looks scary to users but does not actually indicate a real problem nor
help them narrow down the cause. Just rely on sys_ni_syscall() to return
-ENOSYS.

Cc: <stable@vger.kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm64/kernel/traps.c |    8 --------
 1 file changed, 8 deletions(-)

--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -526,14 +526,6 @@ asmlinkage long do_ni_syscall(struct pt_
 	}
 #endif
 
-	if (show_unhandled_signals_ratelimited()) {
-		pr_info("%s[%d]: syscall %d\n", current->comm,
-			task_pid_nr(current), regs->syscallno);
-		dump_instr("", regs);
-		if (user_mode(regs))
-			__show_regs(regs);
-	}
-
 	return sys_ni_syscall();
 }
 


Patches currently in stable-queue which might be from michael.weiser@gmx.de are

queue-4.15/arm64-remove-unimplemented-syscall-log-message.patch
queue-4.15/arm64-disable-unhandled-signal-log-messages-by-default.patch