linux-kernel - [PATCH v2 08/10] x86/entry: Only allocate space for SYSENTER

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: <caff55262e5b42f4842bb9caea664e46543f724f.1457243356.git.luto@kernel.org>
Date:	Sat,  5 Mar 2016 21:52:21 -0800
From:	Andy Lutomirski <luto@...nel.org>
To:	x86@...nel.org
Cc:	linux-kernel@...r.kernel.org, Borislav Petkov <bp@...en8.de>,
	Oleg Nesterov <oleg@...hat.com>,
	Andrew Cooper <andrew.cooper3@...rix.com>,
	Brian Gerst <brgerst@...il.com>,
	Andy Lutomirski <luto@...nel.org>
Subject: [PATCH v2 08/10] x86/entry: Only allocate space for SYSENTER_stack if needed

The SYSENTER stack is only used on 32-bit kernels.  Remove it in
64-bit kernels.

(We may end up using it down the road on 64-bit kernels.  If so,
 we'll re-enable it for CONFIG_IA32_EMULATION.)

Signed-off-by: Andy Lutomirski <luto@...nel.org>
---
 arch/x86/include/asm/processor.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index ecb410310e70..7cd01b71b5bd 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -297,10 +297,12 @@ struct tss_struct {
 	 */
 	unsigned long		io_bitmap[IO_BITMAP_LONGS + 1];
 
+#ifdef CONFIG_X86_32
 	/*
 	 * Space for the temporary SYSENTER stack:
 	 */
 	unsigned long		SYSENTER_stack[64];
+#endif
 
 } ____cacheline_aligned;
 
-- 
2.5.0