linux-kernel - Re: [PATCH v2 0/4] Enable measuring the kernel's Source-based Code Coverage and MC/DC with Clang

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20241009031738.2851980-1-wentaoz5@illinois.edu>
Date: Tue,  8 Oct 2024 22:17:38 -0500
From: Wentao Zhang <wentaoz5@...inois.edu>
To: nathan@...nel.org
Cc: Matt.Kelly2@...ing.com,
	akpm@...ux-foundation.org,
	andrew.j.oppelt@...ing.com,
	anton.ivanov@...bridgegreys.com,
	ardb@...nel.org,
	arnd@...db.de,
	bhelgaas@...gle.com,
	bp@...en8.de,
	chuck.wolber@...ing.com,
	dave.hansen@...ux.intel.com,
	dvyukov@...gle.com,
	hpa@...or.com,
	jinghao7@...inois.edu,
	johannes@...solutions.net,
	jpoimboe@...nel.org,
	justinstitt@...gle.com,
	kees@...nel.org,
	kent.overstreet@...ux.dev,
	linux-arch@...r.kernel.org,
	linux-efi@...r.kernel.org,
	linux-kbuild@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-trace-kernel@...r.kernel.org,
	linux-um@...ts.infradead.org,
	llvm@...ts.linux.dev,
	luto@...nel.org,
	marinov@...inois.edu,
	masahiroy@...nel.org,
	maskray@...gle.com,
	mathieu.desnoyers@...icios.com,
	matthew.l.weber3@...ing.com,
	mhiramat@...nel.org,
	mingo@...hat.com,
	morbo@...gle.com,
	ndesaulniers@...gle.com,
	oberpar@...ux.ibm.com,
	paulmck@...nel.org,
	peterz@...radead.org,
	richard@....at,
	rostedt@...dmis.org,
	samitolvanen@...gle.com,
	samuel.sarkisian@...ing.com,
	steven.h.vanderleest@...ing.com,
	tglx@...utronix.de,
	tingxur@...inois.edu,
	tyxu@...inois.edu,
	wentaoz5@...inois.edu,
	x86@...nel.org,
	chuckwolber@...il.com
Subject: Re: [PATCH v2 0/4] Enable measuring the kernel's Source-based Code Coverage and MC/DC with Clang

On 2024-10-03 18:29, Nathan Chancellor wrote:
> ...
>>> I was able to successfully build that same configuration and setup with
>>> my primary workstation, which is much beefier. Unfortunately, the
>>> resulting kernel did not boot with my usual VM testing setup. I will see
>>> if I can narrow down a particular configuration option that causes this
>>> tomorrow because I did a test with defconfig +
>>> CONFIG_LLVM_COV_PROFILE_ALL and it booted fine. Perhaps some other
>>> option that is not compatible with this? I'll follow up with more
>>> information as I have it.
>>
>> Good to hear that you've run it and thanks for reporting the booting issue.
>> You may send me the config if appropriate and I'll also take a look.
> 
> I seem to have narrowed down it to a few different configurations on top
> of x86_64_defconfig but I will include the full bad configuration as an
> attachment just in case anything else is relevant.
> 
> $ echo 'CONFIG_LLVM_COV_KERNEL=y
> CONFIG_LLVM_COV_PROFILE_ALL=y' >kernel/configs/llvm_cov.config
> 
> $ echo CONFIG_FORTIFY_SOURCE=y >kernel/configs/fortify_source.config
> 
> $ echo CONFIG_AMD_MEM_ENCRYPT=y >arch/x86/configs/amd_mem_encrypt.config
> 

Chuck and I can confirm the issue is reproducible these options, and we
are still looking into it. Thanks for catching this!

> ...
> 
> Another thing I noticed with this series is there is no entries added to
> MAINTAINERS. Who is going to be responsible for maintaining this code?
> 

We are going to add the following as the fifth patch in v3:

diff --git a/MAINTAINERS b/MAINTAINERS
index a097afd76..55438cb90 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13262,6 +13262,12 @@ F:	include/net/llc*
 F:	include/uapi/linux/llc.h
 F:	net/llc/

+LLVM-COV BASED KERNEL PROFILING
+M:	Wentao Zhang <wentaoz5@...inois.edu>
+M:	Chuck Wolber <chuck.wolber@...ing.com>
+S:	Maintained
+F:	kernel/llvm-cov/
+
 LM73 HARDWARE MONITOR DRIVER
 M:	Guillaume Ligneul <guillaume.ligneul@...il.com>
 L:	linux-hwmon@...r.kernel.org

Other than the booting issue, v3 is ready and being tested locally.

Thanks,
Wentao

> Cheers,
> Nathan