linux-kernel - [PATCH v2 1/4] x86/mm: surround level4_kernel_pgt with #ifdef CONFIG_X86

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <20181019124921.13780-2-changbin.du@gmail.com>
Date:   Fri, 19 Oct 2018 12:49:18 +0000
From:   Du Changbin <changbin.du@...il.com>
To:     yamada.masahiro@...ionext.com, michal.lkml@...kovi.net,
        tglx@...utronix.de, mingo@...hat.com, linux@...linux.org.uk,
        akpm@...ux-foundation.org
Cc:     rostedt@...dmis.org, x86@...nel.org, linux-kbuild@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-sparse@...r.kernel.org, robin.murphy@....com,
        Du Changbin <changbin.du@...il.com>
Subject: [PATCH v2 1/4] x86/mm: surround level4_kernel_pgt with #ifdef CONFIG_X86_5LEVEL...#endif

The level4_kernel_pgt is only defined when X86_5LEVEL is enabled. So
surround level4_kernel_pgt with #ifdef CONFIG_X86_5LEVEL...#endif to
make code correct.

Signed-off-by: Du Changbin <changbin.du@...il.com>
Acked-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
---
 arch/x86/include/asm/pgtable_64.h |  2 ++
 arch/x86/kernel/head64.c          | 13 ++++++-------
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 9c85b54bf03c..9333f7fa5bdb 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -16,7 +16,9 @@
 #include <linux/threads.h>
 #include <asm/fixmap.h>
 
+#ifdef CONFIG_X86_5LEVEL
 extern p4d_t level4_kernel_pgt[512];
+#endif
 extern p4d_t level4_ident_pgt[512];
 extern pud_t level3_kernel_pgt[512];
 extern pud_t level3_ident_pgt[512];
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index ddee1f0870c4..4a59ef93c258 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -151,16 +151,15 @@ unsigned long __head __startup_64(unsigned long physaddr,
 
 	pgd = fixup_pointer(&early_top_pgt, physaddr);
 	p = pgd + pgd_index(__START_KERNEL_map);
-	if (la57)
-		*p = (unsigned long)level4_kernel_pgt;
-	else
-		*p = (unsigned long)level3_kernel_pgt;
-	*p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
-
+#ifdef CONFIG_X86_5LEVEL
 	if (la57) {
+		*p = (unsigned long)level4_kernel_pgt;
 		p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
 		p4d[511] += load_delta;
-	}
+	} else
+#endif
+		*p = (unsigned long)level3_kernel_pgt;
+	*p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
 
 	pud = fixup_pointer(&level3_kernel_pgt, physaddr);
 	pud[510] += load_delta;
-- 
2.17.1