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%3Ba=su...

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