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From: Borislav Petkov <>
To: Tom Lendacky <>
Cc:, Peter Zijlstra <>,, Ingo Molnar <>,
	"H. Peter Anvin" <>,
	Thomas Gleixner <>
Subject: Re: [PATCH] x86/mm: Disable various instrumentations of mem_encrypt.c
Date: Wed, 11 Oct 2017 11:57:26 +0200
Message-ID: <20171011095726.fzilylt32rpmkson@pd.tnic> (raw)
In-Reply-To: <>

On Tue, Oct 10, 2017 at 02:45:04PM -0500, Tom Lendacky wrote:
> Some routines in mem_encrypt.c are called very early in the boot process,
> e.g. sme_enable().  When CONFIG_KCOV is defined the resulting code added
> to sme_enable() (and others) for KCOV instrumentation results in a kernel
> crash.  Disable the KCOV instrumentation for mem_encrypt.c by adding
> KCOV_INSTRUMENT_mem_encrypt.o := n to arch/x86/mm/Makefile.
> In order to avoid other possible early boot issues, model mem_encrypt.c
> after head64.c in regards to tools. In addition to disabling KCOV as
> stated above and a previous patch that disables branch profiling, also
> remove the "-pg" CFLAG if CONFIG_FUNCTION_TRACER is enabled and set
> KASAN_SANITIZE to "n", each of which are done on a file basis.
> Reported-by: kernel test robot <>
> Signed-off-by: Tom Lendacky <>
> ---
>  arch/x86/mm/Makefile |   11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)

Reviewed-by: Borislav Petkov <>


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Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-10 19:45 Tom Lendacky
2017-10-11  9:57 ` Borislav Petkov [this message]
2017-10-11 18:15 ` [tip:x86/urgent] x86/mm: Disable various instrumentations of mm/mem_encrypt.c and mm/tlb.c tip-bot for Tom Lendacky

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