From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Richard Weinberger Subject: Re: [PATCH] um: Fix kcov crash before kernel is started. Date: Sat, 14 Oct 2017 10:05:41 +0200 Message-ID: <3011782.xhPzxOy8Zy@blindfold> In-Reply-To: <20171013220025.3619-1-thomas@m3y3r.de> References: <20171013220025.3619-1-thomas@m3y3r.de> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org To: Thomas Meyer Cc: syzkaller@googlegroups.com, user-mode-linux-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org List-ID: Am Samstag, 14. Oktober 2017, 00:00:25 CEST schrieb Thomas Meyer: > UMLs current_thread_info() unconditionally assumes that the top of the stack > contains the thread_info structure. > Prevent kcov from using invalid curent_thread_info() data by disable > instrumentation of early startup code. > > Signed-off-by: Thomas Meyer > --- > arch/um/kernel/skas/Makefile | 2 ++ > lib/Makefile | 4 ++++ > 2 files changed, 6 insertions(+) > > diff --git a/arch/um/kernel/skas/Makefile b/arch/um/kernel/skas/Makefile > index 0b76d8869c94..df3aedb974a2 100644 > --- a/arch/um/kernel/skas/Makefile > +++ b/arch/um/kernel/skas/Makefile > @@ -3,6 +3,8 @@ > # Licensed under the GPL > # > > +KCOV_INSTRUMENT := n So, you disable kconv for the whole SKAS code? That's a bit broad. ;-\ > obj-y := clone.o mmu.o process.o syscall.o uaccess.o > > # clone.o is in the stub, so it can't be built with profiling > diff --git a/lib/Makefile b/lib/Makefile > index dafa79613fb4..18319ad5daab 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -16,6 +16,10 @@ KCOV_INSTRUMENT_list_debug.o := n > KCOV_INSTRUMENT_debugobjects.o := n > KCOV_INSTRUMENT_dynamic_debug.o := n > > +ifdef CONFIG_UML > +KCOV_INSTRUMENT_cmdline.o := n > +endif > + huh? Why do we need an exception for UML here? Thanks, //richard