From 5ee39a71fd89ab7240c5339d04161c44a8e03269 Mon Sep 17 00:00:00 2001 From: Michael Weiser Date: Thu, 1 Feb 2018 23:13:38 +0100 Subject: arm64: Disable unhandled signal log messages by default aarch64 unhandled signal kernel messages are very verbose, suggesting them to be more of a debugging aid: sigsegv[33]: unhandled level 2 translation fault (11) at 0x00000000, esr 0x92000046, in sigsegv[400000+71000] CPU: 1 PID: 33 Comm: sigsegv Tainted: G W 4.15.0-rc3+ #3 Hardware name: linux,dummy-virt (DT) pstate: 60000000 (nZCv daif -PAN -UAO) pc : 0x4003f4 lr : 0x4006bc sp : 0000fffffe94a060 x29: 0000fffffe94a070 x28: 0000000000000000 x27: 0000000000000000 x26: 0000000000000000 x25: 0000000000000000 x24: 00000000004001b0 x23: 0000000000486ac8 x22: 00000000004001c8 x21: 0000000000000000 x20: 0000000000400be8 x19: 0000000000400b30 x18: 0000000000484728 x17: 000000000865ffc8 x16: 000000000000270f x15: 00000000000000b0 x14: 0000000000000002 x13: 0000000000000001 x12: 0000000000000000 x11: 0000000000000000 x10: 0008000020008008 x9 : 000000000000000f x8 : ffffffffffffffff x7 : 0004000000000000 x6 : ffffffffffffffff x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000004003e4 x2 : 0000fffffe94a1e8 x1 : 000000000000000a x0 : 0000000000000000 Disable them by default, so they can be enabled using /proc/sys/debug/exception-trace. Cc: Signed-off-by: Michael Weiser Signed-off-by: Will Deacon --- arch/arm64/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm64/kernel/traps.c') diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index bbb0fde2780e..c8639f95e59a 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -57,7 +57,7 @@ static const char *handler[]= { "Error" }; -int show_unhandled_signals = 1; +int show_unhandled_signals = 0; static void dump_backtrace_entry(unsigned long where) { -- cgit From 1962682d2b2fbe6cfa995a85c53c069fadda473e Mon Sep 17 00:00:00 2001 From: Michael Weiser Date: Thu, 1 Feb 2018 23:13:36 +0100 Subject: arm64: Remove unimplemented syscall log message 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: Acked-by: Will Deacon Signed-off-by: Michael Weiser Signed-off-by: Will Deacon --- arch/arm64/kernel/traps.c | 8 -------- 1 file changed, 8 deletions(-) (limited to 'arch/arm64/kernel/traps.c') diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index c8639f95e59a..eb2d15147e8d 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -526,14 +526,6 @@ asmlinkage long do_ni_syscall(struct pt_regs *regs) } #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(); } -- cgit