4.15-stable review patch. If anyone has any objections, please let me know.
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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(); }