diff mbox series

[v4.4] arm64: Remove unimplemented syscall log message

Message ID 20210602114651.423605-1-arnd@kernel.org
State New
Headers show
Series [v4.4] arm64: Remove unimplemented syscall log message | expand

Commit Message

Arnd Bergmann June 2, 2021, 11:46 a.m. UTC
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>
Cc: Martin Vajnar <martin.vajnar@gmail.com>
Cc: musl@lists.openwall.com
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>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This was backported to v4.14 and later, but is missing in v4.4 and
before, apparently because of a trivial merge conflict. This is
a manual backport I did after I saw a report about the issue
by Martin Vajnar on the musl mailing list.
---
 arch/arm64/kernel/traps.c | 8 --------
 1 file changed, 8 deletions(-)

Comments

Greg Kroah-Hartman June 8, 2021, 5:06 p.m. UTC | #1
On Wed, Jun 02, 2021 at 01:46:51PM +0200, Arnd Bergmann wrote:
> 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>

> Cc: Martin Vajnar <martin.vajnar@gmail.com>

> Cc: musl@lists.openwall.com

> 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>

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

> This was backported to v4.14 and later, but is missing in v4.4 and

> before, apparently because of a trivial merge conflict. This is

> a manual backport I did after I saw a report about the issue

> by Martin Vajnar on the musl mailing list.

> ---

>  arch/arm64/kernel/traps.c | 8 --------

>  1 file changed, 8 deletions(-)


Now queued up, thanks.

greg k-h
diff mbox series

Patch

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 02710f99c137..a8c0fd0574fa 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -381,14 +381,6 @@  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), (int)regs->syscallno);
-		dump_instr("", regs);
-		if (user_mode(regs))
-			__show_regs(regs);
-	}
-
 	return sys_ni_syscall();
 }