+ x86-mm-disable-instrumentations-of-mm-pgprotc.patch added to mm-hotfixes-unstable branch

+ x86-mm-disable-instrumentations-of-mm-pgprotc.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: x86/mm: disable instrumentations of mm/pgprot.c
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     x86-mm-disable-instrumentations-of-mm-pgprotc.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/x86-mm-disable-instrumentations-of-mm-pgprotc.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Naohiro Aota <naohiro.aota@wdc.com>
Subject: x86/mm: disable instrumentations of mm/pgprot.c
Date: Wed, 24 Aug 2022 17:47:26 +0900

Commit 4867fbbdd6b3 ("x86/mm: move protection_map[] inside the platform")
moved accesses to protection_map[] from mem_encrypt_amd.c to pgprot.c.  As
a result, the accesses are now targets of KASAN (and other
instrumentations), leading to the crash during the boot process.

Disable the instrumentations for pgprot.c like commit 67bb8e999e0a
("x86/mm: Disable various instrumentations of mm/mem_encrypt.c and
mm/tlb.c").

Before this patch, my AMD machine cannot boot since v6.0-rc1 with KASAN
enabled, without anything printed.  After the change, it successfully
boots up.

Fixes: 4867fbbdd6b3 ("x86/mm: move protection_map[] inside the platform")
Link: https://lkml.kernel.org/r/20220824084726.2174758-1-naohiro.aota@wdc.com
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/mm/Makefile |    3 +++
 1 file changed, 3 insertions(+)

--- a/arch/x86/mm/Makefile~x86-mm-disable-instrumentations-of-mm-pgprotc
+++ a/arch/x86/mm/Makefile
@@ -4,10 +4,12 @@ KCOV_INSTRUMENT_tlb.o			:= n
 KCOV_INSTRUMENT_mem_encrypt.o		:= n
 KCOV_INSTRUMENT_mem_encrypt_amd.o	:= n
 KCOV_INSTRUMENT_mem_encrypt_identity.o	:= n
+KCOV_INSTRUMENT_pgprot.o		:= n
 
 KASAN_SANITIZE_mem_encrypt.o		:= n
 KASAN_SANITIZE_mem_encrypt_amd.o	:= n
 KASAN_SANITIZE_mem_encrypt_identity.o	:= n
+KASAN_SANITIZE_pgprot.o		:= n
 
 # Disable KCSAN entirely, because otherwise we get warnings that some functions
 # reference __initdata sections.
@@ -17,6 +19,7 @@ ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_mem_encrypt.o		= -pg
 CFLAGS_REMOVE_mem_encrypt_amd.o		= -pg
 CFLAGS_REMOVE_mem_encrypt_identity.o	= -pg
+CFLAGS_REMOVE_pgprot.o			= -pg
 endif
 
 obj-y				:=  init.o init_$(BITS).o fault.o ioremap.o extable.o mmap.o \
_

Patches currently in -mm which might be from naohiro.aota@wdc.com are

x86-mm-disable-instrumentations-of-mm-pgprotc.patch